| Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/C/Linux/drivers/spi/ (Linux Kernel Version 6.17.9©) Datei vom 24.10.2025 mit Größe 133 kB |
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Quellcode-Bibliothek spi.c Sprache: C |
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// SPDX-License-Identifier: GPL-2.0-or-later // SPI init/core code // // Copyright (C) 2005 David Brownell // Copyright (C) 2008 Secret Lab Technologies Ltd. #include <linux/acpi.h> #include <linux/cache.h> #include <linux/clk/clk-conf.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/export.h> #include <linux/gpio/consumer.h> #include <linux/highmem.h> #include <linux/idr.h> #include <linux/init.h> #include <linux/ioport.h> #include <linux/kernel.h> #include <linux/kthread.h> #include <linux/mod_devicetable.h> #include <linux/mutex.h> #include <linux/of_device.h> #include <linux/of_irq.h> #include <linux/percpu.h> #include <linux/platform_data/x86/apple.h> #include <linux/pm_domain.h> #include <linux/pm_runtime.h> #include <linux/property.h> #include <linux/ptp_clock_kernel.h> #include <linux/sched/rt.h> #include <linux/slab.h> #include <linux/spi/offload/types.h> #include <linux/spi/spi.h> #include <linux/spi/spi-mem.h> #include <uapi/linux/sched/types.h> #define CREATE_TRACE_POINTS #include <trace/events/spi.h> EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); #include "internals.h" static DEFINE_IDR(spi_controller_idr); static void spidev_release(struct device *dev) { struct spi_device *spi = to_spi_device(dev); spi_controller_put(spi->controller); kfree(spi->driver_override); free_percpu(spi->pcpu_statistics); kfree(spi); } static ssize_t modalias_show(struct device *dev, struct device_attribute *a, char *buf) { const struct spi_device *spi = to_spi_device(dev); int len; len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); if (len != -ENODEV) return len; return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); } static DEVICE_ATTR_RO(modalias); static ssize_t driver_override_store(struct device *dev, struct device_attribute *a, const char *buf, size_t count) { struct spi_device *spi = to_spi_device(dev); int ret; ret = driver_set_override(dev, &spi->driver_override, buf, count); if (ret) return ret; return count; } static ssize_t driver_override_show(struct device *dev, struct device_attribute *a, char *buf) { const struct spi_device *spi = to_spi_device(dev); ssize_t len; device_lock(dev); len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); device_unlock(dev); return len; } static DEVICE_ATTR_RW(driver_override); static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev) { struct spi_statistics __percpu *pcpu_stats; if (dev) pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics); else pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL); if (pcpu_stats) { int cpu; for_each_possible_cpu(cpu) { struct spi_statistics *stat; stat = per_cpu_ptr(pcpu_stats, cpu); u64_stats_init(&stat->syncp); } } return pcpu_stats; } static ssize_t spi_emit_pcpu_stats(struct spi_statistics __percpu *stat, char *buf, size_t offset) { u64 val = 0; int i; for_each_possible_cpu(i) { const struct spi_statistics *pcpu_stats; u64_stats_t *field; unsigned int start; u64 inc; pcpu_stats = per_cpu_ptr(stat, i); field = (void *)pcpu_stats + offset; do { start = u64_stats_fetch_begin(&pcpu_stats->syncp); inc = u64_stats_read(field); } while (u64_stats_fetch_retry(&pcpu_stats->syncp, start)); val += inc; } return sysfs_emit(buf, "%llu\n", val); } #define SPI_STATISTICS_ATTRS(field, file) \ static ssize_t spi_controller_##field##_show(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct spi_controller *ctlr = container_of(dev, \ struct spi_controller, dev); \ return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \ } \ static struct device_attribute dev_attr_spi_controller_##field = { \ .attr = { .name = file, .mode = 0444 }, \ .show = spi_controller_##field##_show, \ }; \ static ssize_t spi_device_##field##_show(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct spi_device *spi = to_spi_device(dev); \ return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \ } \ static struct device_attribute dev_attr_spi_device_##field = { \ .attr = { .name = file, .mode = 0444 }, \ .show = spi_device_##field##_show, \ } #define SPI_STATISTICS_SHOW_NAME(name, file, field) \ static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \ char *buf) \ { \ return spi_emit_pcpu_stats(stat, buf, \ offsetof(struct spi_statistics, field)); \ } \ SPI_STATISTICS_ATTRS(name, file) #define SPI_STATISTICS_SHOW(field) \ SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ field) SPI_STATISTICS_SHOW(messages); SPI_STATISTICS_SHOW(transfers); SPI_STATISTICS_SHOW(errors); SPI_STATISTICS_SHOW(timedout); SPI_STATISTICS_SHOW(spi_sync); SPI_STATISTICS_SHOW(spi_sync_immediate); SPI_STATISTICS_SHOW(spi_async); SPI_STATISTICS_SHOW(bytes); SPI_STATISTICS_SHOW(bytes_rx); SPI_STATISTICS_SHOW(bytes_tx); #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ "transfer_bytes_histo_" number, \ transfer_bytes_histo[index]) SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); SPI_STATISTICS_SHOW(transfers_split_maxsize); static struct attribute *spi_dev_attrs[] = { &dev_attr_modalias.attr, &dev_attr_driver_override.attr, NULL, }; static const struct attribute_group spi_dev_group = { .attrs = spi_dev_attrs, }; static struct attribute *spi_device_statistics_attrs[] = { &dev_attr_spi_device_messages.attr, &dev_attr_spi_device_transfers.attr, &dev_attr_spi_device_errors.attr, &dev_attr_spi_device_timedout.attr, &dev_attr_spi_device_spi_sync.attr, &dev_attr_spi_device_spi_sync_immediate.attr, &dev_attr_spi_device_spi_async.attr, &dev_attr_spi_device_bytes.attr, &dev_attr_spi_device_bytes_rx.attr, &dev_attr_spi_device_bytes_tx.attr, &dev_attr_spi_device_transfer_bytes_histo0.attr, &dev_attr_spi_device_transfer_bytes_histo1.attr, &dev_attr_spi_device_transfer_bytes_histo2.attr, &dev_attr_spi_device_transfer_bytes_histo3.attr, &dev_attr_spi_device_transfer_bytes_histo4.attr, &dev_attr_spi_device_transfer_bytes_histo5.attr, &dev_attr_spi_device_transfer_bytes_histo6.attr, &dev_attr_spi_device_transfer_bytes_histo7.attr, &dev_attr_spi_device_transfer_bytes_histo8.attr, &dev_attr_spi_device_transfer_bytes_histo9.attr, &dev_attr_spi_device_transfer_bytes_histo10.attr, &dev_attr_spi_device_transfer_bytes_histo11.attr, &dev_attr_spi_device_transfer_bytes_histo12.attr, &dev_attr_spi_device_transfer_bytes_histo13.attr, &dev_attr_spi_device_transfer_bytes_histo14.attr, &dev_attr_spi_device_transfer_bytes_histo15.attr, &dev_attr_spi_device_transfer_bytes_histo16.attr, &dev_attr_spi_device_transfers_split_maxsize.attr, NULL, }; static const struct attribute_group spi_device_statistics_group = { .name = "statistics", .attrs = spi_device_statistics_attrs, }; static const struct attribute_group *spi_dev_groups[] = { &spi_dev_group, &spi_device_statistics_group, NULL, }; static struct attribute *spi_controller_statistics_attrs[] = { &dev_attr_spi_controller_messages.attr, &dev_attr_spi_controller_transfers.attr, &dev_attr_spi_controller_errors.attr, &dev_attr_spi_controller_timedout.attr, &dev_attr_spi_controller_spi_sync.attr, &dev_attr_spi_controller_spi_sync_immediate.attr, &dev_attr_spi_controller_spi_async.attr, &dev_attr_spi_controller_bytes.attr, &dev_attr_spi_controller_bytes_rx.attr, &dev_attr_spi_controller_bytes_tx.attr, &dev_attr_spi_controller_transfer_bytes_histo0.attr, &dev_attr_spi_controller_transfer_bytes_histo1.attr, &dev_attr_spi_controller_transfer_bytes_histo2.attr, &dev_attr_spi_controller_transfer_bytes_histo3.attr, &dev_attr_spi_controller_transfer_bytes_histo4.attr, &dev_attr_spi_controller_transfer_bytes_histo5.attr, &dev_attr_spi_controller_transfer_bytes_histo6.attr, &dev_attr_spi_controller_transfer_bytes_histo7.attr, &dev_attr_spi_controller_transfer_bytes_histo8.attr, &dev_attr_spi_controller_transfer_bytes_histo9.attr, &dev_attr_spi_controller_transfer_bytes_histo10.attr, &dev_attr_spi_controller_transfer_bytes_histo11.attr, &dev_attr_spi_controller_transfer_bytes_histo12.attr, &dev_attr_spi_controller_transfer_bytes_histo13.attr, &dev_attr_spi_controller_transfer_bytes_histo14.attr, &dev_attr_spi_controller_transfer_bytes_histo15.attr, &dev_attr_spi_controller_transfer_bytes_histo16.attr, &dev_attr_spi_controller_transfers_split_maxsize.attr, NULL, }; static const struct attribute_group spi_controller_statistics_group = { .name = "statistics", .attrs = spi_controller_statistics_attrs, }; static const struct attribute_group *spi_controller_groups[] = { &spi_controller_statistics_group, NULL, }; static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_st struct spi_transfer *xfer, struct spi_message *msg) { int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; struct spi_statistics *stats; if (l2len < 0) l2len = 0; get_cpu(); stats = this_cpu_ptr(pcpu_stats); u64_stats_update_begin(&stats->syncp); u64_stats_inc(&stats->transfers); u64_stats_inc(&stats->transfer_bytes_histo[l2len]); u64_stats_add(&stats->bytes, xfer->len); if (spi_valid_txbuf(msg, xfer)) u64_stats_add(&stats->bytes_tx, xfer->len); if (spi_valid_rxbuf(msg, xfer)) u64_stats_add(&stats->bytes_rx, xfer->len); u64_stats_update_end(&stats->syncp); put_cpu(); } /* * modalias support makes "modprobe $MODALIAS" new-style hotplug work, * and the sysfs version makes coldplug work too. */ static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const cha { while (id->name[0]) { if (!strcmp(name, id->name)) return id; id++; } return NULL; } const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) { const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); return spi_match_id(sdrv->id_table, sdev->modalias); } EXPORT_SYMBOL_GPL(spi_get_device_id); const void *spi_get_device_match_data(const struct spi_device *sdev) { const void *match; match = device_get_match_data(&sdev->dev); if (match) return match; return (const void *)spi_get_device_id(sdev)->driver_data; } EXPORT_SYMBOL_GPL(spi_get_device_match_data); static int spi_match_device(struct device *dev, const struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); const struct spi_driver *sdrv = to_spi_driver(drv); /* Check override first, and if set, only use the named driver */ if (spi->driver_override) return strcmp(spi->driver_override, drv->name) == 0; /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) return 1; /* Then try ACPI */ if (acpi_driver_match_device(dev, drv)) return 1; if (sdrv->id_table) return !!spi_match_id(sdrv->id_table, spi->modalias); return strcmp(spi->modalias, drv->name) == 0; } static int spi_uevent(const struct device *dev, struct kobj_uevent_env *env) { const struct spi_device *spi = to_spi_device(dev); int rc; rc = acpi_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); } static int spi_probe(struct device *dev) { const struct spi_driver *sdrv = to_spi_driver(dev->driver); struct spi_device *spi = to_spi_device(dev); struct fwnode_handle *fwnode = dev_fwnode(dev); int ret; ret = of_clk_set_defaults(dev->of_node, false); if (ret) return ret; if (is_of_node(fwnode)) spi->irq = of_irq_get(dev->of_node, 0); else if (is_acpi_device_node(fwnode) && spi->irq < 0) spi->irq = acpi_dev_gpio_irq_get(to_acpi_device_node(fwnode), 0); if (spi->irq == -EPROBE_DEFER) return dev_err_probe(dev, spi->irq, "Failed to get irq\n"); if (spi->irq < 0) spi->irq = 0; ret = dev_pm_domain_attach(dev, PD_FLAG_ATTACH_POWER_ON); if (ret) return ret; if (sdrv->probe) { ret = sdrv->probe(spi); if (ret) dev_pm_domain_detach(dev, true); } return ret; } static void spi_remove(struct device *dev) { const struct spi_driver *sdrv = to_spi_driver(dev->driver); if (sdrv->remove) sdrv->remove(to_spi_device(dev)); dev_pm_domain_detach(dev, true); } static void spi_shutdown(struct device *dev) { if (dev->driver) { const struct spi_driver *sdrv = to_spi_driver(dev->driver); if (sdrv->shutdown) sdrv->shutdown(to_spi_device(dev)); } } const struct bus_type spi_bus_type = { .name = "spi", .dev_groups = spi_dev_groups, .match = spi_match_device, .uevent = spi_uevent, .probe = spi_probe, .remove = spi_remove, .shutdown = spi_shutdown, }; EXPORT_SYMBOL_GPL(spi_bus_type); /** * __spi_register_driver - register a SPI driver * @owner: owner module of the driver to register * @sdrv: the driver to register * Context: can sleep * * Return: zero on success, else a negative error code. */ int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) { sdrv->driver.owner = owner; sdrv->driver.bus = &spi_bus_type; /* * For Really Good Reasons we use spi: modaliases not of: * modaliases for DT so module autoloading won't work if we * don't have a spi_device_id as well as a compatible string. */ if (sdrv->driver.of_match_table) { const struct of_device_id *of_id; for (of_id = sdrv->driver.of_match_table; of_id->compatible[0]; of_id++) { const char *of_name; /* Strip off any vendor prefix */ of_name = strnchr(of_id->compatible, sizeof(of_id->compatible), ','); if (of_name) of_name++; else of_name = of_id->compatible; if (sdrv->id_table) { const struct spi_device_id *spi_id; spi_id = spi_match_id(sdrv->id_table, of_name); if (spi_id) continue; } else { if (strcmp(sdrv->driver.name, of_name) == 0) continue; } pr_warn("SPI driver %s has no spi_device_id for %s\n", sdrv->driver.name, of_id->compatible); } } return driver_register(&sdrv->driver); } EXPORT_SYMBOL_GPL(__spi_register_driver); /*-------------------------------------------------------------------------*/ /* * SPI devices should normally not be created by SPI device drivers; that * would make them board-specific. Similarly with SPI controller drivers. * Device registration normally goes into like arch/.../mach.../board-YYY.c * with other readonly (flashable) information about mainboard devices. */ struct boardinfo { struct list_head list; struct spi_board_info board_info; }; static LIST_HEAD(board_list); static LIST_HEAD(spi_controller_list); /* * Used to protect add/del operation for board_info list and * spi_controller list, and their matching process also used * to protect object of type struct idr. */ static DEFINE_MUTEX(board_lock); /** * spi_alloc_device - Allocate a new SPI device * @ctlr: Controller to which device is connected * Context: can sleep * * Allows a driver to allocate and initialize a spi_device without * registering it immediately. This allows a driver to directly * fill the spi_device with device parameters before calling * spi_add_device() on it. * * Caller is responsible to call spi_add_device() on the returned * spi_device structure to add it to the SPI controller. If the caller * needs to discard the spi_device without adding it, then it should * call spi_dev_put() on it. * * Return: a pointer to the new device, or NULL. */ struct spi_device *spi_alloc_device(struct spi_controller *ctlr) { struct spi_device *spi; if (!spi_controller_get(ctlr)) return NULL; spi = kzalloc(sizeof(*spi), GFP_KERNEL); if (!spi) { spi_controller_put(ctlr); return NULL; } spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL); if (!spi->pcpu_statistics) { kfree(spi); spi_controller_put(ctlr); return NULL; } spi->controller = ctlr; spi->dev.parent = &ctlr->dev; spi->dev.bus = &spi_bus_type; spi->dev.release = spidev_release; spi->mode = ctlr->buswidth_override_bits; device_initialize(&spi->dev); return spi; } EXPORT_SYMBOL_GPL(spi_alloc_device); static void spi_dev_set_name(struct spi_device *spi) { struct device *dev = &spi->dev; struct fwnode_handle *fwnode = dev_fwnode(dev); if (is_acpi_device_node(fwnode)) { dev_set_name(dev, "spi-%s", acpi_dev_name(to_acpi_device_node(fwnode))); return; } if (is_software_node(fwnode)) { dev_set_name(dev, "spi-%pfwP", fwnode); return; } dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), spi_get_chipselect(spi, 0)); } /* * Zero(0) is a valid physical CS value and can be located at any * logical CS in the spi->chip_select[]. If all the physical CS * are initialized to 0 then It would be difficult to differentiate * between a valid physical CS 0 & an unused logical CS whose physical * CS can be 0. As a solution to this issue initialize all the CS to -1. * Now all the unused logical CS will have -1 physical CS value & can be * ignored while performing physical CS validity checks. */ #define SPI_INVALID_CS ((s8)-1) static inline bool is_valid_cs(s8 chip_select) { return chip_select != SPI_INVALID_CS; } static inline int spi_dev_check_cs(struct device *dev, struct spi_device *spi, u8 idx, struct spi_device *new_spi, u8 new_idx) { u8 cs, cs_new; u8 idx_new; cs = spi_get_chipselect(spi, idx); for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) { cs_new = spi_get_chipselect(new_spi, idx_new); if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) { dev_err(dev, "chipselect %u already in use\n", cs_new); return -EBUSY; } } return 0; } static int spi_dev_check(struct device *dev, void *data) { struct spi_device *spi = to_spi_device(dev); struct spi_device *new_spi = data; int status, idx; if (spi->controller == new_spi->controller) { for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { status = spi_dev_check_cs(dev, spi, idx, new_spi, 0); if (status) return status; } } return 0; } static void spi_cleanup(struct spi_device *spi) { if (spi->controller->cleanup) spi->controller->cleanup(spi); } static int __spi_add_device(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; struct device *dev = ctlr->dev.parent; int status, idx; u8 cs; for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { /* Chipselects are numbered 0..max; validate. */ cs = spi_get_chipselect(spi, idx); if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) { dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx), ctlr->num_chipselect); return -EINVAL; } } /* * Make sure that multiple logical CS doesn't map to the same physical CS. * For example, spi->chip_select[0] != spi->chip_select[1] and so on. */ if (!spi_controller_is_target(ctlr)) { for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1); if (status) return status; } } /* Set the bus ID string */ spi_dev_set_name(spi); /* * We need to make sure there's no other device with this * chipselect **BEFORE** we call setup(), else we'll trash * its configuration. */ status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); if (status) return status; /* Controller may unregister concurrently */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && !device_is_registered(&ctlr->dev)) { return -ENODEV; } if (ctlr->cs_gpiods) { u8 cs; for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { cs = spi_get_chipselect(spi, idx); if (is_valid_cs(cs)) spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]); } } /* * Drivers may modify this initial i/o setup, but will * normally rely on the device being setup. Devices * using SPI_CS_HIGH can't coexist well otherwise... */ status = spi_setup(spi); if (status < 0) { dev_err(dev, "can't setup %s, status %d\n", dev_name(&spi->dev), status); return status; } /* Device may be bound to an active driver when this returns */ status = device_add(&spi->dev); if (status < 0) { dev_err(dev, "can't add %s, status %d\n", dev_name(&spi->dev), status); spi_cleanup(spi); } else { dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); } return status; } /** * spi_add_device - Add spi_device allocated with spi_alloc_device * @spi: spi_device to register * * Companion function to spi_alloc_device. Devices allocated with * spi_alloc_device can be added onto the SPI bus with this function. * * Return: 0 on success; negative errno on failure */ int spi_add_device(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; int status; /* Set the bus ID string */ spi_dev_set_name(spi); mutex_lock(&ctlr->add_lock); status = __spi_add_device(spi); mutex_unlock(&ctlr->add_lock); return status; } EXPORT_SYMBOL_GPL(spi_add_device); static void spi_set_all_cs_unused(struct spi_device *spi) { u8 idx; for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) spi_set_chipselect(spi, idx, SPI_INVALID_CS); } /** * spi_new_device - instantiate one new SPI device * @ctlr: Controller to which device is connected * @chip: Describes the SPI device * Context: can sleep * * On typical mainboards, this is purely internal; and it's not needed * after board init creates the hard-wired devices. Some development * platforms may not be able to use spi_register_board_info though, and * this is exported so that for example a USB or parport based adapter * driver could add devices (which it would learn about out-of-band). * * Return: the new device, or NULL. */ struct spi_device *spi_new_device(struct spi_controller *ctlr, struct spi_board_info *chip) { struct spi_device *proxy; int status; /* * NOTE: caller did any chip->bus_num checks necessary. * * Also, unless we change the return value convention to use * error-or-pointer (not NULL-or-pointer), troubleshootability * suggests syslogged diagnostics are best here (ugh). */ proxy = spi_alloc_device(ctlr); if (!proxy) return NULL; WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); /* Use provided chip-select for proxy device */ spi_set_all_cs_unused(proxy); spi_set_chipselect(proxy, 0, chip->chip_select); proxy->max_speed_hz = chip->max_speed_hz; proxy->mode = chip->mode; proxy->irq = chip->irq; strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); proxy->dev.platform_data = (void *) chip->platform_data; proxy->controller_data = chip->controller_data; proxy->controller_state = NULL; /* * By default spi->chip_select[0] will hold the physical CS number, * so set bit 0 in spi->cs_index_mask. */ proxy->cs_index_mask = BIT(0); if (chip->swnode) { status = device_add_software_node(&proxy->dev, chip->swnode); if (status) { dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n", chip->modalias, status); goto err_dev_put; } } status = spi_add_device(proxy); if (status < 0) goto err_dev_put; return proxy; err_dev_put: device_remove_software_node(&proxy->dev); spi_dev_put(proxy); return NULL; } EXPORT_SYMBOL_GPL(spi_new_device); /** * spi_unregister_device - unregister a single SPI device * @spi: spi_device to unregister * * Start making the passed SPI device vanish. Normally this would be handled * by spi_unregister_controller(). */ void spi_unregister_device(struct spi_device *spi) { struct fwnode_handle *fwnode; if (!spi) return; fwnode = dev_fwnode(&spi->dev); if (is_of_node(fwnode)) { of_node_clear_flag(to_of_node(fwnode), OF_POPULATED); of_node_put(to_of_node(fwnode)); } else if (is_acpi_device_node(fwnode)) { acpi_device_clear_enumerated(to_acpi_device_node(fwnode)); } device_remove_software_node(&spi->dev); device_del(&spi->dev); spi_cleanup(spi); put_device(&spi->dev); } EXPORT_SYMBOL_GPL(spi_unregister_device); static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, struct spi_board_info *bi) { struct spi_device *dev; if (ctlr->bus_num != bi->bus_num) return; dev = spi_new_device(ctlr, bi); if (!dev) dev_err(ctlr->dev.parent, "can't create new device for %s\n", bi->modalias); } /** * spi_register_board_info - register SPI devices for a given board * @info: array of chip descriptors * @n: how many descriptors are provided * Context: can sleep * * Board-specific early init code calls this (probably during arch_initcall) * with segments of the SPI device table. Any device nodes are created later, * after the relevant parent SPI controller (bus_num) is defined. We keep * this table of devices forever, so that reloading a controller driver will * not make Linux forget about these hard-wired devices. * * Other code can also call this, e.g. a particular add-on board might provide * SPI devices through its expansion connector, so code initializing that board * would naturally declare its SPI devices. * * The board info passed can safely be __initdata ... but be careful of * any embedded pointers (platform_data, etc), they're copied as-is. * * Return: zero on success, else a negative error code. */ int spi_register_board_info(struct spi_board_info const *info, unsigned n) { struct boardinfo *bi; int i; if (!n) return 0; bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); if (!bi) return -ENOMEM; for (i = 0; i < n; i++, bi++, info++) { struct spi_controller *ctlr; memcpy(&bi->board_info, info, sizeof(*info)); mutex_lock(&board_lock); list_add_tail(&bi->list, &board_list); list_for_each_entry(ctlr, &spi_controller_list, list) spi_match_controller_to_boardinfo(ctlr, &bi->board_info); mutex_unlock(&board_lock); } return 0; } /*-------------------------------------------------------------------------*/ /* Core methods for SPI resource management */ /** * spi_res_alloc - allocate a spi resource that is life-cycle managed * during the processing of a spi_message while using * spi_transfer_one * @spi: the SPI device for which we allocate memory * @release: the release code to execute for this resource * @size: size to alloc and return * @gfp: GFP allocation flags * * Return: the pointer to the allocated data * * This may get enhanced in the future to allocate from a memory pool * of the @spi_device or @spi_controller to avoid repeated allocations. */ static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release, size_t size, gfp_t gfp) { struct spi_res *sres; sres = kzalloc(sizeof(*sres) + size, gfp); if (!sres) return NULL; INIT_LIST_HEAD(&sres->entry); sres->release = release; return sres->data; } /** * spi_res_free - free an SPI resource * @res: pointer to the custom data of a resource */ static void spi_res_free(void *res) { struct spi_res *sres = container_of(res, struct spi_res, data); WARN_ON(!list_empty(&sres->entry)); kfree(sres); } /** * spi_res_add - add a spi_res to the spi_message * @message: the SPI message * @res: the spi_resource */ static void spi_res_add(struct spi_message *message, void *res) { struct spi_res *sres = container_of(res, struct spi_res, data); WARN_ON(!list_empty(&sres->entry)); list_add_tail(&sres->entry, &message->resources); } /** * spi_res_release - release all SPI resources for this message * @ctlr: the @spi_controller * @message: the @spi_message */ static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) { struct spi_res *res, *tmp; list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { if (res->release) res->release(ctlr, message, res->data); list_del(&res->entry); kfree(res); } } /*-------------------------------------------------------------------------*/ #define spi_for_each_valid_cs(spi, idx) \ for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) \ if (!(spi->cs_index_mask & BIT(idx))) {} else static inline bool spi_is_last_cs(struct spi_device *spi) { u8 idx; bool last = false; spi_for_each_valid_cs(spi, idx) { if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx)) last = true; } return last; } static void spi_toggle_csgpiod(struct spi_device *spi, u8 idx, bool enable, bool activate) { /* * Historically ACPI has no means of the GPIO polarity and * thus the SPISerialBus() resource defines it on the per-chip * basis. In order to avoid a chain of negations, the GPIO * polarity is considered being Active High. Even for the cases * when _DSD() is involved (in the updated versions of ACPI) * the GPIO CS polarity must be defined Active High to avoid * ambiguity. That's why we use enable, that takes SPI_CS_HIGH * into account. */ if (is_acpi_device_node(dev_fwnode(&spi->dev))) gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), !enable); else /* Polarity handled by GPIO library */ gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), activate); if (activate) spi_delay_exec(&spi->cs_setup, NULL); else spi_delay_exec(&spi->cs_inactive, NULL); } static void spi_set_cs(struct spi_device *spi, bool enable, bool force) { bool activate = enable; u8 idx; /* * Avoid calling into the driver (or doing delays) if the chip select * isn't actually changing from the last time this was called. */ if (!force && (enable == spi_is_last_cs(spi)) && (spi->controller->last_cs_index_mask == spi->cs_index_mask) && (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) return; trace_spi_set_cs(spi, activate); spi->controller->last_cs_index_mask = spi->cs_index_mask; for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS; spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; if (spi->controller->last_cs_mode_high) enable = !enable; /* * Handle chip select delays for GPIO based CS or controllers without * programmable chip select timing. */ if ((spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) && !activate) spi_delay_exec(&spi->cs_hold, NULL); if (spi_is_csgpiod(spi)) { if (!(spi->mode & SPI_NO_CS)) { spi_for_each_valid_cs(spi, idx) { if (spi_get_csgpiod(spi, idx)) spi_toggle_csgpiod(spi, idx, enable, activate); } } /* Some SPI controllers need both GPIO CS & ->set_cs() */ if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) && spi->controller->set_cs) spi->controller->set_cs(spi, !enable); } else if (spi->controller->set_cs) { spi->controller->set_cs(spi, !enable); } if (spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) { if (activate) spi_delay_exec(&spi->cs_setup, NULL); else spi_delay_exec(&spi->cs_inactive, NULL); } } #ifdef CONFIG_HAS_DMA static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev, struct sg_table *sgt, void *buf, size_t len, enum dma_data_direction dir, unsigned long attrs) { const bool vmalloced_buf = is_vmalloc_addr(buf); unsigned int max_seg_size = dma_get_max_seg_size(dev); #ifdef CONFIG_HIGHMEM const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && (unsigned long)buf < (PKMAP_BASE + (LAST_PKMAP * PAGE_SIZE))); #else const bool kmap_buf = false; #endif int desc_len; int sgs; struct page *vm_page; struct scatterlist *sg; void *sg_buf; size_t min; int i, ret; if (vmalloced_buf || kmap_buf) { desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE); sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); } else if (virt_addr_valid(buf)) { desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len); sgs = DIV_ROUND_UP(len, desc_len); } else { return -EINVAL; } ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); if (ret != 0) return ret; sg = &sgt->sgl[0]; for (i = 0; i < sgs; i++) { if (vmalloced_buf || kmap_buf) { /* * Next scatterlist entry size is the minimum between * the desc_len and the remaining buffer length that * fits in a page. */ min = min_t(size_t, desc_len, min_t(size_t, len, PAGE_SIZE - offset_in_page(buf))); if (vmalloced_buf) vm_page = vmalloc_to_page(buf); else vm_page = kmap_to_page(buf); if (!vm_page) { sg_free_table(sgt); return -ENOMEM; } sg_set_page(sg, vm_page, min, offset_in_page(buf)); } else { min = min_t(size_t, len, desc_len); sg_buf = buf; sg_set_buf(sg, sg_buf, min); } buf += min; len -= min; sg = sg_next(sg); } ret = dma_map_sgtable(dev, sgt, dir, attrs); if (ret < 0) { sg_free_table(sgt); return ret; } return 0; } int spi_map_buf(struct spi_controller *ctlr, struct device *dev, struct sg_table *sgt, void *buf, size_t len, enum dma_data_direction dir) { return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0); } static void spi_unmap_buf_attrs(struct spi_controller *ctlr, struct device *dev, struct sg_table *sgt, enum dma_data_direction dir, unsigned long attrs) { dma_unmap_sgtable(dev, sgt, dir, attrs); sg_free_table(sgt); sgt->orig_nents = 0; sgt->nents = 0; } void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, struct sg_table *sgt, enum dma_data_direction dir) { spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0); } static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) { struct device *tx_dev, *rx_dev; struct spi_transfer *xfer; int ret; if (!ctlr->can_dma) return 0; if (ctlr->dma_tx) tx_dev = ctlr->dma_tx->device->dev; else if (ctlr->dma_map_dev) tx_dev = ctlr->dma_map_dev; else tx_dev = ctlr->dev.parent; if (ctlr->dma_rx) rx_dev = ctlr->dma_rx->device->dev; else if (ctlr->dma_map_dev) rx_dev = ctlr->dma_map_dev; else rx_dev = ctlr->dev.parent; ret = -ENOMSG; list_for_each_entry(xfer, &msg->transfers, transfer_list) { /* The sync is done before each transfer. */ unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; if (!ctlr->can_dma(ctlr, msg->spi, xfer)) continue; if (xfer->tx_buf != NULL) { ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, (void *)xfer->tx_buf, xfer->len, DMA_TO_DEVICE, attrs); if (ret != 0) return ret; xfer->tx_sg_mapped = true; } if (xfer->rx_buf != NULL) { ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, xfer->rx_buf, xfer->len, DMA_FROM_DEVICE, attrs); if (ret != 0) { spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE, attrs); return ret; } xfer->rx_sg_mapped = true; } } /* No transfer has been mapped, bail out with success */ if (ret) return 0; ctlr->cur_rx_dma_dev = rx_dev; ctlr->cur_tx_dma_dev = tx_dev; return 0; } static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) { struct device *rx_dev = ctlr->cur_rx_dma_dev; struct device *tx_dev = ctlr->cur_tx_dma_dev; struct spi_transfer *xfer; list_for_each_entry(xfer, &msg->transfers, transfer_list) { /* The sync has already been done after each transfer. */ unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; if (xfer->rx_sg_mapped) spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE, attrs); xfer->rx_sg_mapped = false; if (xfer->tx_sg_mapped) spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE, attrs); xfer->tx_sg_mapped = false; } return 0; } static void spi_dma_sync_for_device(struct spi_controller *ctlr, struct spi_transfer *xfer) { struct device *rx_dev = ctlr->cur_rx_dma_dev; struct device *tx_dev = ctlr->cur_tx_dma_dev; if (xfer->tx_sg_mapped) dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); if (xfer->rx_sg_mapped) dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); } static void spi_dma_sync_for_cpu(struct spi_controller *ctlr, struct spi_transfer *xfer) { struct device *rx_dev = ctlr->cur_rx_dma_dev; struct device *tx_dev = ctlr->cur_tx_dma_dev; if (xfer->rx_sg_mapped) dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); if (xfer->tx_sg_mapped) dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); } #else /* !CONFIG_HAS_DMA */ static inline int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) { return 0; } static inline int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) { return 0; } static void spi_dma_sync_for_device(struct spi_controller *ctrl, struct spi_transfer *xfer) { } static void spi_dma_sync_for_cpu(struct spi_controller *ctrl, struct spi_transfer *xfer) { } #endif /* !CONFIG_HAS_DMA */ static inline int spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) { struct spi_transfer *xfer; list_for_each_entry(xfer, &msg->transfers, transfer_list) { /* * Restore the original value of tx_buf or rx_buf if they are * NULL. */ if (xfer->tx_buf == ctlr->dummy_tx) xfer->tx_buf = NULL; if (xfer->rx_buf == ctlr->dummy_rx) xfer->rx_buf = NULL; } return __spi_unmap_msg(ctlr, msg); } static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) { struct spi_transfer *xfer; void *tmp; unsigned int max_tx, max_rx; if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) && !(msg->spi->mode & SPI_3WIRE)) { max_tx = 0; max_rx = 0; list_for_each_entry(xfer, &msg->transfers, transfer_list) { if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && !xfer->tx_buf) max_tx = max(xfer->len, max_tx); if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && !xfer->rx_buf) max_rx = max(xfer->len, max_rx); } if (max_tx) { tmp = krealloc(ctlr->dummy_tx, max_tx, GFP_KERNEL | GFP_DMA | __GFP_ZERO); if (!tmp) return -ENOMEM; ctlr->dummy_tx = tmp; } if (max_rx) { tmp = krealloc(ctlr->dummy_rx, max_rx, GFP_KERNEL | GFP_DMA); if (!tmp) return -ENOMEM; ctlr->dummy_rx = tmp; } if (max_tx || max_rx) { list_for_each_entry(xfer, &msg->transfers, transfer_list) { if (!xfer->len) continue; if (!xfer->tx_buf) xfer->tx_buf = ctlr->dummy_tx; if (!xfer->rx_buf) xfer->rx_buf = ctlr->dummy_rx; } } } return __spi_map_msg(ctlr, msg); } static int spi_transfer_wait(struct spi_controller *ctlr, struct spi_message *msg, struct spi_transfer *xfer) { struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; u32 speed_hz = xfer->speed_hz; unsigned long long ms; if (spi_controller_is_target(ctlr)) { if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); return -EINTR; } } else { if (!speed_hz) speed_hz = 100000; /* * For each byte we wait for 8 cycles of the SPI clock. * Since speed is defined in Hz and we want milliseconds, * use respective multiplier, but before the division, * otherwise we may get 0 for short transfers. */ ms = 8LL * MSEC_PER_SEC * xfer->len; do_div(ms, speed_hz); /* * Increase it twice and add 200 ms tolerance, use * predefined maximum in case of overflow. */ ms += ms + 200; if (ms > UINT_MAX) ms = UINT_MAX; ms = wait_for_completion_timeout(&ctlr->xfer_completion, msecs_to_jiffies(ms)); if (ms == 0) { SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); dev_err(&msg->spi->dev, "SPI transfer timed out\n"); return -ETIMEDOUT; } if (xfer->error & SPI_TRANS_FAIL_IO) return -EIO; } return 0; } static void _spi_transfer_delay_ns(u32 ns) { if (!ns) return; if (ns <= NSEC_PER_USEC) { ndelay(ns); } else { u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC); fsleep(us); } } int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) { u32 delay = _delay->value; u32 unit = _delay->unit; u32 hz; if (!delay) return 0; switch (unit) { case SPI_DELAY_UNIT_USECS: delay *= NSEC_PER_USEC; break; case SPI_DELAY_UNIT_NSECS: /* Nothing to do here */ break; case SPI_DELAY_UNIT_SCK: /* Clock cycles need to be obtained from spi_transfer */ if (!xfer) return -EINVAL; /* * If there is unknown effective speed, approximate it * by underestimating with half of the requested Hz. */ hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; if (!hz) return -EINVAL; /* Convert delay to nanoseconds */ delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz); break; default: return -EINVAL; } return delay; } EXPORT_SYMBOL_GPL(spi_delay_to_ns); int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) { int delay; might_sleep(); if (!_delay) return -EINVAL; delay = spi_delay_to_ns(_delay, xfer); if (delay < 0) return delay; _spi_transfer_delay_ns(delay); return 0; } EXPORT_SYMBOL_GPL(spi_delay_exec); static void _spi_transfer_cs_change_delay(struct spi_message *msg, struct spi_transfer *xfer) { u32 default_delay_ns = 10 * NSEC_PER_USEC; u32 delay = xfer->cs_change_delay.value; u32 unit = xfer->cs_change_delay.unit; int ret; /* Return early on "fast" mode - for everything but USECS */ if (!delay) { if (unit == SPI_DELAY_UNIT_USECS) _spi_transfer_delay_ns(default_delay_ns); return; } ret = spi_delay_exec(&xfer->cs_change_delay, xfer); if (ret) { dev_err_once(&msg->spi->dev, "Use of unsupported delay unit %i, using default of %luus\n", unit, default_delay_ns / NSEC_PER_USEC); _spi_transfer_delay_ns(default_delay_ns); } } void spi_transfer_cs_change_delay_exec(struct spi_message *msg, struct spi_transfer *xfer) { _spi_transfer_cs_change_delay(msg, xfer); } EXPORT_SYMBOL_GPL(spi_transfer_cs_change_delay_exec); /* * spi_transfer_one_message - Default implementation of transfer_one_message() * * This is a standard implementation of transfer_one_message() for * drivers which implement a transfer_one() operation. It provides * standard handling of delays and chip select management. */ static int spi_transfer_one_message(struct spi_controller *ctlr, struct spi_message *msg) { struct spi_transfer *xfer; bool keep_cs = false; int ret = 0; struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list); spi_set_cs(msg->spi, !xfer->cs_off, false); SPI_STATISTICS_INCREMENT_FIELD(statm, messages); SPI_STATISTICS_INCREMENT_FIELD(stats, messages); list_for_each_entry(xfer, &msg->transfers, transfer_list) { trace_spi_transfer_start(msg, xfer); spi_statistics_add_transfer_stats(statm, xfer, msg); spi_statistics_add_transfer_stats(stats, xfer, msg); if (!ctlr->ptp_sts_supported) { xfer->ptp_sts_word_pre = 0; ptp_read_system_prets(xfer->ptp_sts); } if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { reinit_completion(&ctlr->xfer_completion); fallback_pio: spi_dma_sync_for_device(ctlr, xfer); ret = ctlr->transfer_one(ctlr, msg->spi, xfer); if (ret < 0) { spi_dma_sync_for_cpu(ctlr, xfer); if ((xfer->tx_sg_mapped || xfer->rx_sg_mapped) && (xfer->error & SPI_TRANS_FAIL_NO_START)) { __spi_unmap_msg(ctlr, msg); ctlr->fallback = true; xfer->error &= ~SPI_TRANS_FAIL_NO_START; goto fallback_pio; } SPI_STATISTICS_INCREMENT_FIELD(statm, errors); SPI_STATISTICS_INCREMENT_FIELD(stats, errors); dev_err(&msg->spi->dev, "SPI transfer failed: %d\n", ret); goto out; } if (ret > 0) { ret = spi_transfer_wait(ctlr, msg, xfer); if (ret < 0) msg->status = ret; } spi_dma_sync_for_cpu(ctlr, xfer); } else { if (xfer->len) dev_err(&msg->spi->dev, "Bufferless transfer has length %u\n", xfer->len); } if (!ctlr->ptp_sts_supported) { ptp_read_system_postts(xfer->ptp_sts); xfer->ptp_sts_word_post = xfer->len; } trace_spi_transfer_stop(msg, xfer); if (msg->status != -EINPROGRESS) goto out; spi_transfer_delay_exec(xfer); if (xfer->cs_change) { if (list_is_last(&xfer->transfer_list, &msg->transfers)) { keep_cs = true; } else { if (!xfer->cs_off) spi_set_cs(msg->spi, false, false); _spi_transfer_cs_change_delay(msg, xfer); if (!list_next_entry(xfer, transfer_list)->cs_off) spi_set_cs(msg->spi, true, false); } } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) && xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) { spi_set_cs(msg->spi, xfer->cs_off, false); } msg->actual_length += xfer->len; } out: if (ret != 0 || !keep_cs) spi_set_cs(msg->spi, false, false); if (msg->status == -EINPROGRESS) msg->status = ret; if (msg->status && ctlr->handle_err) ctlr->handle_err(ctlr, msg); spi_finalize_current_message(ctlr); return ret; } /** * spi_finalize_current_transfer - report completion of a transfer * @ctlr: the controller reporting completion * * Called by SPI drivers using the core transfer_one_message() * implementation to notify it that the current interrupt driven * transfer has finished and the next one may be scheduled. */ void spi_finalize_current_transfer(struct spi_controller *ctlr) { complete(&ctlr->xfer_completion); } EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); static void spi_idle_runtime_pm(struct spi_controller *ctlr) { if (ctlr->auto_runtime_pm) { pm_runtime_put_autosuspend(ctlr->dev.parent); } } static int __spi_pump_transfer_message(struct spi_controller *ctlr, struct spi_message *msg, bool was_busy) { struct spi_transfer *xfer; int ret; if (!was_busy && ctlr->auto_runtime_pm) { ret = pm_runtime_get_sync(ctlr->dev.parent); if (ret < 0) { pm_runtime_put_noidle(ctlr->dev.parent); dev_err(&ctlr->dev, "Failed to power device: %d\n", ret); msg->status = ret; spi_finalize_current_message(ctlr); return ret; } } if (!was_busy) trace_spi_controller_busy(ctlr); if (!was_busy && ctlr->prepare_transfer_hardware) { ret = ctlr->prepare_transfer_hardware(ctlr); if (ret) { dev_err(&ctlr->dev, "failed to prepare transfer hardware: %d\n", ret); if (ctlr->auto_runtime_pm) pm_runtime_put(ctlr->dev.parent); msg->status = ret; spi_finalize_current_message(ctlr); return ret; } } trace_spi_message_start(msg); if (ctlr->prepare_message) { ret = ctlr->prepare_message(ctlr, msg); if (ret) { dev_err(&ctlr->dev, "failed to prepare message: %d\n", ret); msg->status = ret; spi_finalize_current_message(ctlr); return ret; } msg->prepared = true; } ret = spi_map_msg(ctlr, msg); if (ret) { msg->status = ret; spi_finalize_current_message(ctlr); return ret; } if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { list_for_each_entry(xfer, &msg->transfers, transfer_list) { xfer->ptp_sts_word_pre = 0; ptp_read_system_prets(xfer->ptp_sts); } } /* * Drivers implementation of transfer_one_message() must arrange for * spi_finalize_current_message() to get called. Most drivers will do * this in the calling context, but some don't. For those cases, a * completion is used to guarantee that this function does not return * until spi_finalize_current_message() is done accessing * ctlr->cur_msg. * Use of the following two flags enable to opportunistically skip the * use of the completion since its use involves expensive spin locks. * In case of a race with the context that calls * spi_finalize_current_message() the completion will always be used, * due to strict ordering of these flags using barriers. */ WRITE_ONCE(ctlr->cur_msg_incomplete, true); WRITE_ONCE(ctlr->cur_msg_need_completion, false); reinit_completion(&ctlr->cur_msg_completion); smp_wmb(); /* Make these available to spi_finalize_current_message() */ ret = ctlr->transfer_one_message(ctlr, msg); if (ret) { dev_err(&ctlr->dev, "failed to transfer one message from queue\n"); return ret; } WRITE_ONCE(ctlr->cur_msg_need_completion, true); smp_mb(); /* See spi_finalize_current_message()... */ if (READ_ONCE(ctlr->cur_msg_incomplete)) wait_for_completion(&ctlr->cur_msg_completion); return 0; } /** * __spi_pump_messages - function which processes SPI message queue * @ctlr: controller to process queue for * @in_kthread: true if we are in the context of the message pump thread * * This function checks if there is any SPI message in the queue that * needs processing and if so call out to the driver to initialize hardware * and transfer each message. * * Note that it is called both from the kthread itself and also from * inside spi_sync(); the queue extraction handling at the top of the * function should deal with this safely. */ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) { struct spi_message *msg; bool was_busy = false; unsigned long flags; int ret; /* Take the I/O mutex */ mutex_lock(&ctlr->io_mutex); /* Lock queue */ spin_lock_irqsave(&ctlr->queue_lock, flags); /* Make sure we are not already running a message */ if (ctlr->cur_msg) goto out_unlock; /* Check if the queue is idle */ if (list_empty(&ctlr->queue) || !ctlr->running) { if (!ctlr->busy) goto out_unlock; /* Defer any non-atomic teardown to the thread */ if (!in_kthread) { if (!ctlr->dummy_rx && !ctlr->dummy_tx && !ctlr->unprepare_transfer_hardware) { spi_idle_runtime_pm(ctlr); ctlr->busy = false; ctlr->queue_empty = true; trace_spi_controller_idle(ctlr); } else { kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); } goto out_unlock; } ctlr->busy = false; spin_unlock_irqrestore(&ctlr->queue_lock, flags); kfree(ctlr->dummy_rx); ctlr->dummy_rx = NULL; kfree(ctlr->dummy_tx); ctlr->dummy_tx = NULL; if (ctlr->unprepare_transfer_hardware && ctlr->unprepare_transfer_hardware(ctlr)) dev_err(&ctlr->dev, "failed to unprepare transfer hardware\n"); spi_idle_runtime_pm(ctlr); trace_spi_controller_idle(ctlr); spin_lock_irqsave(&ctlr->queue_lock, flags); ctlr->queue_empty = true; goto out_unlock; } /* Extract head of queue */ msg = list_first_entry(&ctlr->queue, struct spi_message, queue); ctlr->cur_msg = msg; list_del_init(&msg->queue); if (ctlr->busy) was_busy = true; else ctlr->busy = true; spin_unlock_irqrestore(&ctlr->queue_lock, flags); ret = __spi_pump_transfer_message(ctlr, msg, was_busy); kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); ctlr->cur_msg = NULL; ctlr->fallback = false; mutex_unlock(&ctlr->io_mutex); /* Prod the scheduler in case transfer_one() was busy waiting */ if (!ret) cond_resched(); return; out_unlock: spin_unlock_irqrestore(&ctlr->queue_lock, flags); mutex_unlock(&ctlr->io_mutex); } /** * spi_pump_messages - kthread work function which processes spi message queue * @work: pointer to kthread work struct contained in the controller struct */ static void spi_pump_messages(struct kthread_work *work) { struct spi_controller *ctlr = container_of(work, struct spi_controller, pump_messages); __spi_pump_messages(ctlr, true); } /** * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp * @ctlr: Pointer to the spi_controller structure of the driver * @xfer: Pointer to the transfer being timestamped * @progress: How many words (not bytes) have been transferred so far * @irqs_off: If true, will disable IRQs and preemption for the duration of the * transfer, for less jitter in time measurement. Only compatible * with PIO drivers. If true, must follow up with * spi_take_timestamp_post or otherwise system will crash. * WARNING: for fully predictable results, the CPU frequency must * also be under control (governor). * * This is a helper for drivers to collect the beginning of the TX timestamp * for the requested byte from the SPI transfer. The frequency with which this * function must be called (once per word, once for the whole transfer, once * per batch of words etc) is arbitrary as long as the @tx buffer offset is * greater than or equal to the requested byte at the time of the call. The * timestamp is only taken once, at the first such call. It is assumed that * the driver advances its @tx buffer pointer monotonically. */ void spi_take_timestamp_pre(struct spi_controller *ctlr, struct spi_transfer *xfer, size_t progress, bool irqs_off) { if (!xfer->ptp_sts) return; if (xfer->timestamped) return; if (progress > xfer->ptp_sts_word_pre) return; /* Capture the resolution of the timestamp */ xfer->ptp_sts_word_pre = progress; if (irqs_off) { local_irq_save(ctlr->irq_flags); preempt_disable(); } ptp_read_system_prets(xfer->ptp_sts); } EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); /** * spi_take_timestamp_post - helper to collect the end of the TX timestamp * @ctlr: Pointer to the spi_controller structure of the driver * @xfer: Pointer to the transfer being timestamped * @progress: How many words (not bytes) have been transferred so far * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. * * This is a helper for drivers to collect the end of the TX timestamp for * the requested byte from the SPI transfer. Can be called with an arbitrary * frequency: only the first call where @tx exceeds or is equal to the * requested word will be timestamped. */ void spi_take_timestamp_post(struct spi_controller *ctlr, struct spi_transfer *xfer, size_t progress, bool irqs_off) { if (!xfer->ptp_sts) return; if (xfer->timestamped) return; if (progress < xfer->ptp_sts_word_post) return; ptp_read_system_postts(xfer->ptp_sts); if (irqs_off) { local_irq_restore(ctlr->irq_flags); preempt_enable(); } /* Capture the resolution of the timestamp */ xfer->ptp_sts_word_post = progress; xfer->timestamped = 1; } EXPORT_SYMBOL_GPL(spi_take_timestamp_post); /** * spi_set_thread_rt - set the controller to pump at realtime priority * @ctlr: controller to boost priority of * * This can be called because the controller requested realtime priority * (by setting the ->rt value before calling spi_register_controller()) or * because a device on the bus said that its transfers needed realtime * priority. * * NOTE: at the moment if any device on a bus says it needs realtime then * the thread will be at realtime priority for all transfers on that * controller. If this eventually becomes a problem we may see if we can * find a way to boost the priority only temporarily during relevant * transfers. */ static void spi_set_thread_rt(struct spi_controller *ctlr) { dev_info(&ctlr->dev, "will run message pump with realtime priority\n"); sched_set_fifo(ctlr->kworker->task); } static int spi_init_queue(struct spi_controller *ctlr) { ctlr->running = false; ctlr->busy = false; ctlr->queue_empty = true; ctlr->kworker = kthread_run_worker(0, dev_name(&ctlr->dev)); if (IS_ERR(ctlr->kworker)) { dev_err(&ctlr->dev, "failed to create message pump kworker\n"); return PTR_ERR(ctlr->kworker); } kthread_init_work(&ctlr->pump_messages, spi_pump_messages); /* * Controller config will indicate if this controller should run the * message pump with high (realtime) priority to reduce the transfer * latency on the bus by minimising the delay between a transfer * request and the scheduling of the message pump thread. Without this * setting the message pump thread will remain at default priority. */ if (ctlr->rt) spi_set_thread_rt(ctlr); return 0; } /** * spi_get_next_queued_message() - called by driver to check for queued * messages * @ctlr: the controller to check for queued messages * * If there are more messages in the queue, the next message is returned from * this call. * * Return: the next message in the queue, else NULL if the queue is empty. */ struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) { struct spi_message *next; unsigned long flags; /* Get a pointer to the next message, if any */ spin_lock_irqsave(&ctlr->queue_lock, flags); next = list_first_entry_or_null(&ctlr->queue, struct spi_message, queue); spin_unlock_irqrestore(&ctlr->queue_lock, flags); return next; } EXPORT_SYMBOL_GPL(spi_get_next_queued_message); /* * __spi_unoptimize_message - shared implementation of spi_unoptimize_message() * and spi_maybe_unoptimize_message() * @msg: the message to unoptimize * * Peripheral drivers should use spi_unoptimize_message() and callers inside * core should use spi_maybe_unoptimize_message() rather than calling this * function directly. * * It is not valid to call this on a message that is not currently optimized. */ static void __spi_unoptimize_message(struct spi_message *msg) { struct spi_controller *ctlr = msg->spi->controller; if (ctlr->unoptimize_message) ctlr->unoptimize_message(msg); spi_res_release(ctlr, msg); msg->optimized = false; msg->opt_state = NULL; } /* * spi_maybe_unoptimize_message - unoptimize msg not managed by a peripheral * @msg: the message to unoptimize * * This function is used to unoptimize a message if and only if it was * optimized by the core (via spi_maybe_optimize_message()). */ static void spi_maybe_unoptimize_message(struct spi_message *msg) { if (!msg->pre_optimized && msg->optimized && !msg->spi->controller->defer_optimize_message) __spi_unoptimize_message(msg); } /** * spi_finalize_current_message() - the current message is complete * @ctlr: the controller to return the message to * * Called by the driver to notify the core that the message in the front of the * queue is complete and can be removed from the queue. */ void spi_finalize_current_message(struct spi_controller *ctlr) { struct spi_transfer *xfer; struct spi_message *mesg; int ret; mesg = ctlr->cur_msg; if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { list_for_each_entry(xfer, &mesg->transfers, transfer_list) { ptp_read_system_postts(xfer->ptp_sts); xfer->ptp_sts_word_post = xfer->len; } } if (unlikely(ctlr->ptp_sts_supported)) list_for_each_entry(xfer, &mesg->transfers, transfer_list) WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); spi_unmap_msg(ctlr, mesg); if (mesg->prepared && ctlr->unprepare_message) { ret = ctlr->unprepare_message(ctlr, mesg); if (ret) { dev_err(&ctlr->dev, "failed to unprepare message: %d\n", ret); } } mesg->prepared = false; spi_maybe_unoptimize_message(mesg); WRITE_ONCE(ctlr->cur_msg_incomplete, false); smp_mb(); /* See __spi_pump_transfer_message()... */ if (READ_ONCE(ctlr->cur_msg_need_completion)) complete(&ctlr->cur_msg_completion); trace_spi_message_done(mesg); mesg->state = NULL; if (mesg->complete) mesg->complete(mesg->context); } EXPORT_SYMBOL_GPL(spi_finalize_current_message); static int spi_start_queue(struct spi_controller *ctlr) { unsigned long flags; spin_lock_irqsave(&ctlr->queue_lock, flags); if (ctlr->running || ctlr->busy) { spin_unlock_irqrestore(&ctlr->queue_lock, flags); return -EBUSY; } ctlr->running = true; ctlr->cur_msg = NULL; spin_unlock_irqrestore(&ctlr->queue_lock, flags); kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); return 0; } static int spi_stop_queue(struct spi_controller *ctlr) { unsigned int limit = 500; unsigned long flags; /* * This is a bit lame, but is optimized for the common execution path. * A wait_queue on the ctlr->busy could be used, but then the common * execution path (pump_messages) would be required to call wake_up or * friends on every SPI message. Do this instead. */ do { spin_lock_irqsave(&ctlr->queue_lock, flags); if (list_empty(&ctlr->queue) && !ctlr->busy) { ctlr->running = false; spin_unlock_irqrestore(&ctlr->queue_lock, flags); return 0; } spin_unlock_irqrestore(&ctlr->queue_lock, flags); usleep_range(10000, 11000); } while (--limit); return -EBUSY; } static int spi_destroy_queue(struct spi_controller *ctlr) { int ret; ret = spi_stop_queue(ctlr); /* * kthread_flush_worker will block until all work is done. * If the reason that stop_queue timed out is that the work will never * finish, then it does no good to call flush/stop thread, so * return anyway. */ if (ret) { dev_err(&ctlr->dev, "problem destroying queue\n"); return ret; } kthread_destroy_worker(ctlr->kworker); return 0; } static int __spi_queued_transfer(struct spi_device *spi, struct spi_message *msg, bool need_pump) { struct spi_controller *ctlr = spi->controller; unsigned long flags; spin_lock_irqsave(&ctlr->queue_lock, flags); if (!ctlr->running) { spin_unlock_irqrestore(&ctlr->queue_lock, flags); return -ESHUTDOWN; } msg->actual_length = 0; msg->status = -EINPROGRESS; list_add_tail(&msg->queue, &ctlr->queue); ctlr->queue_empty = false; if (!ctlr->busy && need_pump) kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); spin_unlock_irqrestore(&ctlr->queue_lock, flags); return 0; } /** * spi_queued_transfer - transfer function for queued transfers * @spi: SPI device which is requesting transfer * @msg: SPI message which is to handled is queued to driver queue * * Return: zero on success, else a negative error code. */ static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) { return __spi_queued_transfer(spi, msg, true); } static int spi_controller_initialize_queue(struct spi_controller *ctlr) { int ret; ctlr->transfer = spi_queued_transfer; if (!ctlr->transfer_one_message) ctlr->transfer_one_message = spi_transfer_one_message; /* Initialize and start queue */ ret = spi_init_queue(ctlr); if (ret) { dev_err(&ctlr->dev, "problem initializing queue\n"); goto err_init_queue; } ctlr->queued = true; ret = spi_start_queue(ctlr); if (ret) { dev_err(&ctlr->dev, "problem starting queue\n"); goto err_start_queue; } return 0; err_start_queue: spi_destroy_queue(ctlr); err_init_queue: return ret; } /** * spi_flush_queue - Send all pending messages in the queue from the callers' * context * @ctlr: controller to process queue for * * This should be used when one wants to ensure all pending messages have been * sent before doing something. Is used by the spi-mem code to make sure SPI * memory operations do not preempt regular SPI transfers that have been queued * before the spi-mem operation. */ void spi_flush_queue(struct spi_controller *ctlr) { if (ctlr->transfer == spi_queued_transfer) __spi_pump_messages(ctlr, false); } /*-------------------------------------------------------------------------*/ #if defined(CONFIG_OF) static void of_spi_parse_dt_cs_delay(struct device_node *nc, struct spi_delay *delay, const char *prop) { u32 value; if (!of_property_read_u32(nc, prop, &value)) { if (value > U16_MAX) { delay->value = DIV_ROUND_UP(value, 1000); delay->unit = SPI_DELAY_UNIT_USECS; } else { delay->value = value; delay->unit = SPI_DELAY_UNIT_NSECS; } } } static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, struct device_node *nc) { u32 value, cs[SPI_CS_CNT_MAX]; int rc, idx; /* Mode (clock phase/polarity/etc.) */ if (of_property_read_bool(nc, "spi-cpha")) spi->mode |= SPI_CPHA; if (of_property_read_bool(nc, "spi-cpol")) spi->mode |= SPI_CPOL; if (of_property_read_bool(nc, "spi-3wire")) spi->mode |= SPI_3WIRE; if (of_property_read_bool(nc, "spi-lsb-first")) spi->mode |= SPI_LSB_FIRST; if (of_property_read_bool(nc, "spi-cs-high")) spi->mode |= SPI_CS_HIGH; /* Device DUAL/QUAD mode */ if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { switch (value) { case 0: spi->mode |= SPI_NO_TX; break; case 1: break; case 2: spi->mode |= SPI_TX_DUAL; break; case 4: spi->mode |= SPI_TX_QUAD; break; case 8: spi->mode |= SPI_TX_OCTAL; break; default: dev_warn(&ctlr->dev, "spi-tx-bus-width %d not supported\n", value); break; } } if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { switch (value) { case 0: spi->mode |= SPI_NO_RX; break; case 1: break; case 2: spi->mode |= SPI_RX_DUAL; break; case 4: spi->mode |= SPI_RX_QUAD; break; case 8: spi->mode |= SPI_RX_OCTAL; break; default: dev_warn(&ctlr->dev, "spi-rx-bus-width %d not supported\n", value); break; } } if (spi_controller_is_target(ctlr)) { if (!of_node_name_eq(nc, "slave")) { dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", nc); return -EINVAL; } return 0; } if (ctlr->num_chipselect > SPI_CS_CNT_MAX) { dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n"); return -EINVAL; } spi_set_all_cs_unused(spi); /* Device address */ rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1, SPI_CS_CNT_MAX); if (rc < 0) { dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", nc, rc); return rc; } if (rc > ctlr->num_chipselect) { dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n", nc, rc); return -EINVAL; } if ((of_property_present(nc, "parallel-memories")) && (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) { dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n"); return -EINVAL; } for (idx = 0; idx < rc; idx++) spi_set_chipselect(spi, idx, cs[idx]); /* * By default spi->chip_select[0] will hold the physical CS number, * so set bit 0 in spi->cs_index_mask. */ spi->cs_index_mask = BIT(0); /* Device speed */ if (!of_property_read_u32(nc, "spi-max-frequency", &value)) spi->max_speed_hz = value; /* Device CS delays */ of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns"); of_spi_parse_dt_cs_delay(nc, &spi->cs_hold, "spi-cs-hold-delay-ns"); of_spi_parse_dt_cs_delay(nc, &spi->cs_inactive, "spi-cs-inactive-delay-ns"); return 0; } static struct spi_device * of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) { struct spi_device *spi; int rc; /* Alloc an spi_device */ spi = spi_alloc_device(ctlr); if (!spi) { dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); rc = -ENOMEM; goto err_out; } /* Select device driver */ rc = of_alias_from_compatible(nc, spi->modalias, sizeof(spi->modalias)); if (rc < 0) { dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); goto err_out; } rc = of_spi_parse_dt(ctlr, spi, nc); if (rc) goto err_out; /* Store a pointer to the node in the device structure */ of_node_get(nc); device_set_node(&spi->dev, of_fwnode_handle(nc)); /* Register the new device */ rc = spi_add_device(spi); if (rc) { dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); goto err_of_node_put; } return spi; err_of_node_put: of_node_put(nc); err_out: spi_dev_put(spi); return ERR_PTR(rc); } /** * of_register_spi_devices() - Register child devices onto the SPI bus * @ctlr: Pointer to spi_controller device * * Registers an spi_device for each child node of controller node which * represents a valid SPI target device. */ static void of_register_spi_devices(struct spi_controller *ctlr) { struct spi_device *spi; struct device_node *nc; for_each_available_child_of_node(ctlr->dev.of_node, nc) { if (of_node_test_and_set_flag(nc, OF_POPULATED)) continue; spi = of_register_spi_device(ctlr, nc); if (IS_ERR(spi)) { dev_warn(&ctlr->dev, "Failed to create SPI device for %pOF\n", nc); of_node_clear_flag(nc, OF_POPULATED); } } } #else static void of_register_spi_devices(struct spi_controller *ctlr) { } #endif /** * spi_new_ancillary_device() - Register ancillary SPI device * @spi: Pointer to the main SPI device registering the ancillary device * @chip_select: Chip Select of the ancillary device * * Register an ancillary SPI device; for example some chips have a chip-select * for normal device usage and another one for setup/firmware upload. * * This may only be called from main SPI device's probe routine. * * Return: 0 on success; negative errno on failure */ struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select) { struct spi_controller *ctlr = spi->controller; struct spi_device *ancillary; int rc; /* Alloc an spi_device */ ancillary = spi_alloc_device(ctlr); if (!ancillary) { rc = -ENOMEM; goto err_out; } strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); /* Use provided chip-select for ancillary device */ spi_set_all_cs_unused(ancillary); spi_set_chipselect(ancillary, 0, chip_select); /* Take over SPI mode/speed from SPI main device */ ancillary->max_speed_hz = spi->max_speed_hz; ancillary->mode = spi->mode; /* * By default spi->chip_select[0] will hold the physical CS number, * so set bit 0 in spi->cs_index_mask. */ ancillary->cs_index_mask = BIT(0); WARN_ON(!mutex_is_locked(&ctlr->add_lock)); /* Register the new device */ rc = __spi_add_device(ancillary); if (rc) { dev_err(&spi->dev, "failed to register ancillary device\n"); goto err_out; } return ancillary; err_out: spi_dev_put(ancillary); return ERR_PTR(rc); } EXPORT_SYMBOL_GPL(spi_new_ancillary_device); #ifdef CONFIG_ACPI struct acpi_spi_lookup { struct spi_controller *ctlr; u32 max_speed_hz; u32 mode; int irq; u8 bits_per_word; u8 chip_select; int n; int index; }; static int acpi_spi_count(struct acpi_resource *ares, void *data) { struct acpi_resource_spi_serialbus *sb; int *count = data; if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) return 1; sb = &ares->data.spi_serial_bus; if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI) return 1; *count = *count + 1; return 1; } /** * acpi_spi_count_resources - Count the number of SpiSerialBus resources * @adev: ACPI device * * Return: the number of SpiSerialBus resources in the ACPI-device's * resource-list; or a negative error code. */ int acpi_spi_count_resources(struct acpi_device *adev) { LIST_HEAD(r); int count = 0; int ret; ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count); if (ret < 0) return ret; acpi_dev_free_resource_list(&r); return count; } EXPORT_SYMBOL_GPL(acpi_spi_count_resources); static void acpi_spi_parse_apple_properties(struct acpi_device *dev, struct acpi_spi_lookup *lookup) { const union acpi_object *obj; if (!x86_apple_machine) return; if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) && obj->buffer.length >= 4) lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) && obj->buffer.length == 8) lookup->bits_per_word = *(u64 *)obj->buffer.pointer; if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) lookup->mode |= SPI_LSB_FIRST; if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) lookup->mode |= SPI_CPOL; if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) lookup->mode |= SPI_CPHA; } static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) { struct acpi_spi_lookup *lookup = data; struct spi_controller *ctlr = lookup->ctlr; if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { struct acpi_resource_spi_serialbus *sb; acpi_handle parent_handle; acpi_status status; sb = &ares->data.spi_serial_bus; if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { if (lookup->index != -1 && lookup->n++ != lookup->index) return 1; status = acpi_get_handle(NULL, sb->resource_source.string_ptr, &parent_handle); if (ACPI_FAILURE(status)) return -ENODEV; if (ctlr) { if (!device_match_acpi_handle(ctlr->dev.parent, parent_handle)) return -ENODEV; } else { struct acpi_device *adev; adev = acpi_fetch_acpi_dev(parent_handle); if (!adev) return -ENODEV; ctlr = acpi_spi_find_controller_by_adev(adev); if (!ctlr) return -EPROBE_DEFER; lookup->ctlr = ctlr; } /* * ACPI DeviceSelection numbering is handled by the * host controller driver in Windows and can vary * from driver to driver. In Linux we always expect * 0 .. max - 1 so we need to ask the driver to * translate between the two schemes. */ if (ctlr->fw_translate_cs) { int cs = ctlr->fw_translate_cs(ctlr, sb->device_selection); if (cs < 0) return cs; lookup->chip_select = cs; } else { lookup->chip_select = sb->device_selection; } lookup->max_speed_hz = sb->connection_speed; lookup->bits_per_word = sb->data_bit_length; if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) lookup->mode |= SPI_CPHA; if (sb->clock_polarity == ACPI_SPI_START_HIGH) lookup->mode |= SPI_CPOL; if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) lookup->mode |= SPI_CS_HIGH; } } else if (lookup->irq < 0) { struct resource r; if (acpi_dev_resource_interrupt(ares, 0, &r)) lookup->irq = r.start; } /* Always tell the ACPI core to skip this resource */ return 1; } /** * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information * @ctlr: controller to which the spi device belongs * @adev: ACPI Device for the spi device * @index: Index of the spi resource inside the ACPI Node * * This should be used to allocate a new SPI device from and ACPI Device node. * The caller is responsible for calling spi_add_device to register the SPI device. * * If ctlr is set to NULL, the Controller for the SPI device will be looked up * using the resource. * If index is set to -1, index is not used. * Note: If index is -1, ctlr must be set. * * Return: a pointer to the new device, or ERR_PTR on error. */ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, struct acpi_device *adev, int index) { acpi_handle parent_handle = NULL; struct list_head resource_list; struct acpi_spi_lookup lookup = {}; struct spi_device *spi; int ret; if (!ctlr && index == -1) return ERR_PTR(-EINVAL); lookup.ctlr = ctlr; lookup.irq = -1; lookup.index = index; lookup.n = 0; INIT_LIST_HEAD(&resource_list); ret = acpi_dev_get_resources(adev, &resource_list, acpi_spi_add_resource, &lookup); acpi_dev_free_resource_list(&resource_list); if (ret < 0) /* Found SPI in _CRS but it points to another controller */ return ERR_PTR(ret); if (!lookup.max_speed_hz && ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && device_match_acpi_handle(lookup.ctlr->dev.parent, parent_handle)) { /* Apple does not use _CRS but nested devices for SPI target devices */ acpi_spi_parse_apple_properties(adev, &lookup); } if (!lookup.max_speed_hz) return ERR_PTR(-ENODEV); spi = spi_alloc_device(lookup.ctlr); if (!spi) { dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n", dev_name(&adev->dev)); return ERR_PTR(-ENOMEM); } spi_set_all_cs_unused(spi); spi_set_chipselect(spi, 0, lookup.chip_select); ACPI_COMPANION_SET(&spi->dev, adev); spi->max_speed_hz = lookup.max_speed_hz; spi->mode |= lookup.mode; spi->irq = lookup.irq; spi->bits_per_word = lookup.bits_per_word; /* * By default spi->chip_select[0] will hold the physical CS number, * so set bit 0 in spi->cs_index_mask. */ spi->cs_index_mask = BIT(0); return spi; } EXPORT_SYMBOL_GPL(acpi_spi_device_alloc); static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, struct acpi_device *adev) { struct spi_device *spi; if (acpi_bus_get_status(adev) || !adev->status.present || acpi_device_enumerated(adev)) return AE_OK; spi = acpi_spi_device_alloc(ctlr, adev, -1); if (IS_ERR(spi)) { if (PTR_ERR(spi) == -ENOMEM) return AE_NO_MEMORY; else return AE_OK; } acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, sizeof(spi->modalias)); /* * This gets re-tried in spi_probe() for -EPROBE_DEFER handling in case * the GPIO controller does not have a driver yet. This needs to be done * here too, because this call sets the GPIO direction and/or bias. * Setting these needs to be done even if there is no driver, in which * case spi_probe() will never get called. */ if (spi->irq < 0) spi->irq = acpi_dev_gpio_irq_get(adev, 0); acpi_device_set_enumerated(adev); adev->power.flags.ignore_parent = true; if (spi_add_device(spi)) { adev->power.flags.ignore_parent = false; dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", dev_name(&adev->dev)); spi_dev_put(spi); } return AE_OK; } static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, void *data, void **return_value) { struct acpi_device *adev = acpi_fetch_acpi_dev(handle); struct spi_controller *ctlr = data; if (!adev) return AE_OK; return acpi_register_spi_device(ctlr, adev); } #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 static void acpi_register_spi_devices(struct spi_controller *ctlr) { acpi_status status; acpi_handle handle; handle = ACPI_HANDLE(ctlr->dev.parent); if (!handle) return; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, SPI_ACPI_ENUMERATE_MAX_DEPTH, acpi_spi_add_device, NULL, ctlr, NULL); if (ACPI_FAILURE(status)) dev_warn(&ctlr->dev, "failed to enumerate SPI target devices\n"); } #else static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} #endif /* CONFIG_ACPI */ static void spi_controller_release(struct device *dev) { struct spi_controller *ctlr; ctlr = container_of(dev, struct spi_controller, dev); kfree(ctlr); } static const struct class spi_controller_class = { .name = "spi_master", .dev_release = spi_controller_release, .dev_groups = spi_controller_groups, }; #ifdef CONFIG_SPI_SLAVE /** * spi_target_abort - abort the ongoing transfer request on an SPI target controller * @spi: device used for the current transfer */ int spi_target_abort(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; if (spi_controller_is_target(ctlr) && ctlr->target_abort) return ctlr->target_abort(ctlr); return -ENOTSUPP; } EXPORT_SYMBOL_GPL(spi_target_abort); static ssize_t slave_show(struct device *dev, struct device_attribute *attr, char *buf) { struct spi_controller *ctlr = container_of(dev, struct spi_controller, dev); struct device *child; int ret; child = device_find_any_child(&ctlr->dev); ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); put_device(child); return ret; } static ssize_t slave_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct spi_controller *ctlr = container_of(dev, struct spi_controller, dev); struct spi_device *spi; struct device *child; char name[32]; int rc; rc = sscanf(buf, "%31s", name); if (rc != 1 || !name[0]) return -EINVAL; child = device_find_any_child(&ctlr->dev); if (child) { /* Remove registered target device */ device_unregister(child); put_device(child); } if (strcmp(name, "(null)")) { /* Register new target device */ spi = spi_alloc_device(ctlr); if (!spi) return -ENOMEM; strscpy(spi->modalias, name, sizeof(spi->modalias)); rc = spi_add_device(spi); if (rc) { spi_dev_put(spi); return rc; } } return count; } static DEVICE_ATTR_RW(slave); static struct attribute *spi_target_attrs[] = { &dev_attr_slave.attr, NULL, }; static const struct attribute_group spi_target_group = { .attrs = spi_target_attrs, }; static const struct attribute_group *spi_target_groups[] = { &spi_controller_statistics_group, &spi_target_group, NULL, }; static const struct class spi_target_class = { .name = "spi_slave", .dev_release = spi_controller_release, .dev_groups = spi_target_groups, }; #else extern struct class spi_target_class; /* dummy */ #endif /** * __spi_alloc_controller - allocate an SPI host or target controller * @dev: the controller, possibly using the platform_bus * @size: how much zeroed driver-private data to allocate; the pointer to this * memory is in the driver_data field of the returned device, accessible * with spi_controller_get_devdata(); the memory is cacheline aligned; * drivers granting DMA access to portions of their private data need to * round up @size using ALIGN(size, dma_get_cache_alignment()). * @target: flag indicating whether to allocate an SPI host (false) or SPI target (true) * controller * Context: can sleep * * This call is used only by SPI controller drivers, which are the * only ones directly touching chip registers. It's how they allocate * an spi_controller structure, prior to calling spi_register_controller(). * * This must be called from context that can sleep. * * The caller is responsible for assigning the bus number and initializing the * controller's methods before calling spi_register_controller(); and (after * errors adding the device) calling spi_controller_put() to prevent a memory * leak. * * Return: the SPI controller structure on success, else NULL. */ struct spi_controller *__spi_alloc_controller(struct device *dev, unsigned int size, bool target) { struct spi_controller *ctlr; size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); if (!dev) return NULL; ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); if (!ctlr) return NULL; device_initialize(&ctlr->dev); INIT_LIST_HEAD(&ctlr->queue); spin_lock_init(&ctlr->queue_lock); spin_lock_init(&ctlr->bus_lock_spinlock); mutex_init(&ctlr->bus_lock_mutex); mutex_init(&ctlr->io_mutex); mutex_init(&ctlr->add_lock); ctlr->bus_num = -1; ctlr->num_chipselect = 1; ctlr->target = target; if (IS_ENABLED(CONFIG_SPI_SLAVE) && target) ctlr->dev.class = &spi_target_class; else ctlr->dev.class = &spi_controller_class; ctlr->dev.parent = dev; pm_suspend_ignore_children(&ctlr->dev, true); spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); return ctlr; } EXPORT_SYMBOL_GPL(__spi_alloc_controller); static void devm_spi_release_controller(struct device *dev, void *ctlr) { spi_controller_put(*(struct spi_controller **)ctlr); } /** * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() * @dev: physical device of SPI controller * @size: how much zeroed driver-private data to allocate * @target: whether to allocate an SPI host (false) or SPI target (true) controller * Context: can sleep * * Allocate an SPI controller and automatically release a reference on it * when @dev is unbound from its driver. Drivers are thus relieved from * having to call spi_controller_put(). * * The arguments to this function are identical to __spi_alloc_controller(). * * Return: the SPI controller structure on success, else NULL. */ struct spi_controller *__devm_spi_alloc_controller(struct device *dev, unsigned int size, bool target) { struct spi_controller **ptr, *ctlr; ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), GFP_KERNEL); if (!ptr) return NULL; ctlr = __spi_alloc_controller(dev, size, target); if (ctlr) { ctlr->devm_allocated = true; *ptr = ctlr; devres_add(dev, ptr); } else { devres_free(ptr); } return ctlr; } EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); /** * spi_get_gpio_descs() - grab chip select GPIOs for the controller * @ctlr: The SPI controller to grab GPIO descriptors for */ static int spi_get_gpio_descs(struct spi_controller *ctlr) { int nb, i; struct gpio_desc **cs; struct device *dev = &ctlr->dev; unsigned long native_cs_mask = 0; unsigned int num_cs_gpios = 0; nb = gpiod_count(dev, "cs"); if (nb < 0) { /* No GPIOs at all is fine, else return the error */ if (nb == -ENOENT) return 0; return nb; } ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), GFP_KERNEL); if (!cs) return -ENOMEM; ctlr->cs_gpiods = cs; for (i = 0; i < nb; i++) { /* * Most chipselects are active low, the inverted * semantics are handled by special quirks in gpiolib, * so initializing them GPIOD_OUT_LOW here means * "unasserted", in most cases this will drive the physical * line high. */ cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, GPIOD_OUT_LOW); if (IS_ERR(cs[i])) return PTR_ERR(cs[i]); if (cs[i]) { /* * If we find a CS GPIO, name it after the device and * chip select line. */ char *gpioname; gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", dev_name(dev), i); if (!gpioname) return -ENOMEM; gpiod_set_consumer_name(cs[i], gpioname); num_cs_gpios++; continue; } if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { dev_err(dev, "Invalid native chip select %d\n", i); return -EINVAL; } native_cs_mask |= BIT(i); } ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; if ((ctlr->flags & SPI_CONTROLLER_GPIO_SS) && num_cs_gpios && ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) { dev_err(dev, "No unused native chip select available\n"); return -EINVAL; } return 0; } static int spi_controller_check_ops(struct spi_controller *ctlr) { /* * The controller may implement only the high-level SPI-memory like * operations if it does not support regular SPI transfers, and this is * valid use case. * If ->mem_ops or ->mem_ops->exec_op is NULL, we request that at least * one of the ->transfer_xxx() method be implemented. */ if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) { if (!ctlr->transfer && !ctlr->transfer_one && !ctlr->transfer_one_message) { return -EINVAL; } } return 0; } /* Allocate dynamic bus number using Linux idr */ static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end) { int id; mutex_lock(&board_lock); id = idr_alloc(&spi_controller_idr, ctlr, start, end, GFP_KERNEL); mutex_unlock(&board_lock); if (WARN(id < 0, "couldn't get idr")) return id == -ENOSPC ? -EBUSY : id; ctlr->bus_num = id; return 0; } /** * spi_register_controller - register SPI host or target controller * @ctlr: initialized controller, originally from spi_alloc_host() or * spi_alloc_target() * Context: can sleep * * SPI controllers connect to their drivers using some non-SPI bus, * such as the platform bus. The final stage of probe() in that code * includes calling spi_register_controller() to hook up to this SPI bus glue. * * SPI controllers use board specific (often SOC specific) bus numbers, * and board-specific addressing for SPI devices combines those numbers * with chip select numbers. Since SPI does not directly support dynamic * device identification, boards need configuration tables telling which * chip is at which address. * * This must be called from context that can sleep. It returns zero on * success, else a negative error code (dropping the controller's refcount). * After a successful return, the caller is responsible for calling * spi_unregister_controller(). * * Return: zero on success, else a negative error code. */ int spi_register_controller(struct spi_controller *ctlr) { struct device *dev = ctlr->dev.parent; struct boardinfo *bi; int first_dynamic; int status; int idx; if (!dev) return -ENODEV; /* * Make sure all necessary hooks are implemented before registering * the SPI controller. */ status = spi_controller_check_ops(ctlr); if (status) return status; if (ctlr->bus_num < 0) ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi"); if (ctlr->bus_num >= 0) { /* Devices with a fixed bus num must check-in with the num */ status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1); if (status) return status; } if (ctlr->bus_num < 0) { first_dynamic = of_alias_get_highest_id("spi"); if (first_dynamic < 0) first_dynamic = 0; else first_dynamic++; status = spi_controller_id_alloc(ctlr, first_dynamic, 0); if (status) return status; } ctlr->bus_lock_flag = 0; init_completion(&ctlr->xfer_completion); init_completion(&ctlr->cur_msg_completion); if (!ctlr->max_dma_len) ctlr->max_dma_len = INT_MAX; /* * Register the device, then userspace will see it. * Registration fails if the bus ID is in use. */ dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); if (!spi_controller_is_target(ctlr) && ctlr->use_gpio_descriptors) { status = spi_get_gpio_descs(ctlr); if (status) goto free_bus_id; /* * A controller using GPIO descriptors always * supports SPI_CS_HIGH if need be. */ ctlr->mode_bits |= SPI_CS_HIGH; } /* * Even if it's just one always-selected device, there must * be at least one chipselect. */ if (!ctlr->num_chipselect) { status = -EINVAL; goto free_bus_id; } /* Setting last_cs to SPI_INVALID_CS means no chip selected */ for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) ctlr->last_cs[idx] = SPI_INVALID_CS; status = device_add(&ctlr->dev); if (status < 0) goto free_bus_id; dev_dbg(dev, "registered %s %s\n", spi_controller_is_target(ctlr) ? "target" : "host", dev_name(&ctlr->dev)); /* * If we're using a queued driver, start the queue. Note that we don't * need the queueing logic if the driver is only supporting high-level * memory operations. */ if (ctlr->transfer) { dev_info(dev, "controller is unqueued, this is deprecated\n"); } else if (ctlr->transfer_one || ctlr->transfer_one_message) { status = spi_controller_initialize_queue(ctlr); if (status) { device_del(&ctlr->dev); goto free_bus_id; } } /* Add statistics */ ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev); if (!ctlr->pcpu_statistics) { dev_err(dev, "Error allocating per-cpu statistics\n"); status = -ENOMEM; goto destroy_queue; } mutex_lock(&board_lock); list_add_tail(&ctlr->list, &spi_controller_list); list_for_each_entry(bi, &board_list, list) spi_match_controller_to_boardinfo(ctlr, &bi->board_info); mutex_unlock(&board_lock); /* Register devices from the device tree and ACPI */ of_register_spi_devices(ctlr); acpi_register_spi_devices(ctlr); return status; destroy_queue: spi_destroy_queue(ctlr); free_bus_id: mutex_lock(&board_lock); idr_remove(&spi_controller_idr, ctlr->bus_num); mutex_unlock(&board_lock); return status; } EXPORT_SYMBOL_GPL(spi_register_controller); static void devm_spi_unregister(struct device *dev, void *res) { spi_unregister_controller(*(struct spi_controller **)res); } /** * devm_spi_register_controller - register managed SPI host or target controller * @dev: device managing SPI controller * @ctlr: initialized controller, originally from spi_alloc_host() or * spi_alloc_target() * Context: can sleep * * Register a SPI device as with spi_register_controller() which will * automatically be unregistered and freed. * * Return: zero on success, else a negative error code. */ int devm_spi_register_controller(struct device *dev, struct spi_controller *ctlr) { struct spi_controller **ptr; int ret; ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); if (!ptr) return -ENOMEM; ret = spi_register_controller(ctlr); if (!ret) { *ptr = ctlr; devres_add(dev, ptr); } else { devres_free(ptr); } return ret; } EXPORT_SYMBOL_GPL(devm_spi_register_controller); static int __unregister(struct device *dev, void *null) { spi_unregister_device(to_spi_device(dev)); return 0; } /** * spi_unregister_controller - unregister SPI host or target controller * @ctlr: the controller being unregistered * Context: can sleep * * This call is used only by SPI controller drivers, which are the * only ones directly touching chip registers. * * This must be called from context that can sleep. * * Note that this function also drops a reference to the controller. */ void spi_unregister_controller(struct spi_controller *ctlr) { struct spi_controller *found; int id = ctlr->bus_num; /* Prevent addition of new devices, unregister existing ones */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) mutex_lock(&ctlr->add_lock); device_for_each_child(&ctlr->dev, NULL, __unregister); /* First make sure that this controller was ever added */ mutex_lock(&board_lock); found = idr_find(&spi_controller_idr, id); mutex_unlock(&board_lock); if (ctlr->queued) { if (spi_destroy_queue(ctlr)) dev_err(&ctlr->dev, "queue remove failed\n"); } mutex_lock(&board_lock); list_del(&ctlr->list); mutex_unlock(&board_lock); device_del(&ctlr->dev); /* Free bus id */ mutex_lock(&board_lock); if (found == ctlr) idr_remove(&spi_controller_idr, id); mutex_unlock(&board_lock); if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) mutex_unlock(&ctlr->add_lock); /* * Release the last reference on the controller if its driver * has not yet been converted to devm_spi_alloc_host/target(). */ if (!ctlr->devm_allocated) put_device(&ctlr->dev); } EXPORT_SYMBOL_GPL(spi_unregister_controller); static inline int __spi_check_suspended(const struct spi_controller *ctlr) { return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0; } static inline void __spi_mark_suspended(struct spi_controller *ctlr) { mutex_lock(&ctlr->bus_lock_mutex); ctlr->flags |= SPI_CONTROLLER_SUSPENDED; mutex_unlock(&ctlr->bus_lock_mutex); } static inline void __spi_mark_resumed(struct spi_controller *ctlr) { mutex_lock(&ctlr->bus_lock_mutex); ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED; mutex_unlock(&ctlr->bus_lock_mutex); } int spi_controller_suspend(struct spi_controller *ctlr) { int ret = 0; /* Basically no-ops for non-queued controllers */ if (ctlr->queued) { ret = spi_stop_queue(ctlr); if (ret) dev_err(&ctlr->dev, "queue stop failed\n"); } __spi_mark_suspended(ctlr); return ret; } EXPORT_SYMBOL_GPL(spi_controller_suspend); int spi_controller_resume(struct spi_controller *ctlr) { int ret = 0; __spi_mark_resumed(ctlr); if (ctlr->queued) { ret = spi_start_queue(ctlr); if (ret) dev_err(&ctlr->dev, "queue restart failed\n"); } return ret; } EXPORT_SYMBOL_GPL(spi_controller_resume); /*-------------------------------------------------------------------------*/ /* Core methods for spi_message alterations */ static void __spi_replace_transfers_release(struct spi_controller *ctlr, struct spi_message *msg, void *res) { struct spi_replaced_transfers *rxfer = res; size_t i; /* Call extra callback if requested */ if (rxfer->release) rxfer->release(ctlr, msg, res); /* Insert replaced transfers back into the message */ list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); /* Remove the formerly inserted entries */ for (i = 0; i < rxfer->inserted; i++) list_del(&rxfer->inserted_transfers[i].transfer_list); } /** * spi_replace_transfers - replace transfers with several transfers * and register change with spi_message.resources * @msg: the spi_message we work upon * @xfer_first: the first spi_transfer we want to replace * @remove: number of transfers to remove * @insert: the number of transfers we want to insert instead * @release: extra release code necessary in some circumstances * @extradatasize: extra data to allocate (with alignment guarantees * of struct @spi_transfer) * @gfp: gfp flags * * Returns: pointer to @spi_replaced_transfers, * PTR_ERR(...) in case of errors. */ static struct spi_replaced_transfers *spi_replace_transfers( struct spi_message *msg, struct spi_transfer *xfer_first, size_t remove, size_t insert, spi_replaced_release_t release, size_t extradatasize, gfp_t gfp) { struct spi_replaced_transfers *rxfer; struct spi_transfer *xfer; size_t i; /* Allocate the structure using spi_res */ rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, struct_size(rxfer, inserted_transfers, insert) + extradatasize, gfp); if (!rxfer) return ERR_PTR(-ENOMEM); /* The release code to invoke before running the generic release */ rxfer->release = release; /* Assign extradata */ if (extradatasize) rxfer->extradata = &rxfer->inserted_transfers[insert]; /* Init the replaced_transfers list */ INIT_LIST_HEAD(&rxfer->replaced_transfers); /* * Assign the list_entry after which we should reinsert * the @replaced_transfers - it may be spi_message.messages! */ rxfer->replaced_after = xfer_first->transfer_list.prev; /* Remove the requested number of transfers */ for (i = 0; i < remove; i++) { /* * If the entry after replaced_after it is msg->transfers * then we have been requested to remove more transfers * than are in the list. */ if (rxfer->replaced_after->next == &msg->transfers) { dev_err(&msg->spi->dev, "requested to remove more spi_transfers than are available\n"); /* Insert replaced transfers back into the message */ list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); /* Free the spi_replace_transfer structure... */ spi_res_free(rxfer); /* ...and return with an error */ return ERR_PTR(-EINVAL); } /* * Remove the entry after replaced_after from list of * transfers and add it to list of replaced_transfers. */ list_move_tail(rxfer->replaced_after->next, &rxfer->replaced_transfers); } /* * Create copy of the given xfer with identical settings * based on the first transfer to get removed. */ for (i = 0; i < insert; i++) { /* We need to run in reverse order */ xfer = &rxfer->inserted_transfers[insert - 1 - i]; /* Copy all spi_transfer data */ memcpy(xfer, xfer_first, sizeof(*xfer)); /* Add to list */ list_add(&xfer->transfer_list, rxfer->replaced_after); /* Clear cs_change and delay for all but the last */ if (i) { xfer->cs_change = false; xfer->delay.value = 0; } } /* Set up inserted... */ rxfer->inserted = insert; /* ...and register it with spi_res/spi_message */ spi_res_add(msg, rxfer); return rxfer; } static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, struct spi_message *msg, struct spi_transfer **xferp, size_t maxsize) { struct spi_transfer *xfer = *xferp, *xfers; struct spi_replaced_transfers *srt; size_t offset; size_t count, i; /* Calculate how many we have to replace */ count = DIV_ROUND_UP(xfer->len, maxsize); /* Create replacement */ srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, GFP_KERNEL); if (IS_ERR(srt)) return PTR_ERR(srt); xfers = srt->inserted_transfers; /* * Now handle each of those newly inserted spi_transfers. * Note that the replacements spi_transfers all are preset * to the same values as *xferp, so tx_buf, rx_buf and len * are all identical (as well as most others) * so we just have to fix up len and the pointers. */ /* * The first transfer just needs the length modified, so we * run it outside the loop. */ xfers[0].len = min_t(size_t, maxsize, xfer[0].len); /* All the others need rx_buf/tx_buf also set */ for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { /* Update rx_buf, tx_buf and DMA */ if (xfers[i].rx_buf) xfers[i].rx_buf += offset; if (xfers[i].tx_buf) xfers[i].tx_buf += offset; /* Update length */ xfers[i].len = min(maxsize, xfers[i].len - offset); } /* * We set up xferp to the last entry we have inserted, * so that we skip those already split transfers. */ *xferp = &xfers[count - 1]; /* Increment statistics counters */ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, transfers_split_maxsize); SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics, transfers_split_maxsize); return 0; } /** * spi_split_transfers_maxsize - split spi transfers into multiple transfers * when an individual transfer exceeds a * certain size * @ctlr: the @spi_controller for this transfer * @msg: the @spi_message to transform * @maxsize: the maximum when to apply this * * This function allocates resources that are automatically freed during the * spi message unoptimize phase so this function should only be called from * optimize_message callbacks. * * Return: status of transformation */ int spi_split_transfers_maxsize(struct spi_controller *ctlr, struct spi_message *msg, size_t maxsize) { struct spi_transfer *xfer; int ret; /* * Iterate over the transfer_list, * but note that xfer is advanced to the last transfer inserted * to avoid checking sizes again unnecessarily (also xfer does * potentially belong to a different list by the time the * replacement has happened). */ list_for_each_entry(xfer, &msg->transfers, transfer_list) { if (xfer->len > maxsize) { ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, maxsize); if (ret) return ret; } } return 0; } EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); /** * spi_split_transfers_maxwords - split SPI transfers into multiple transfers * when an individual transfer exceeds a * certain number of SPI words * @ctlr: the @spi_controller for this transfer * @msg: the @spi_message to transform * @maxwords: the number of words to limit each transfer to * * This function allocates resources that are automatically freed during the * spi message unoptimize phase so this function should only be called from * optimize_message callbacks. * * Return: status of transformation */ int spi_split_transfers_maxwords(struct spi_controller *ctlr, struct spi_message *msg, size_t maxwords) { struct spi_transfer *xfer; /* * Iterate over the transfer_list, * but note that xfer is advanced to the last transfer inserted * to avoid checking sizes again unnecessarily (also xfer does * potentially belong to a different list by the time the * replacement has happened). */ list_for_each_entry(xfer, &msg->transfers, transfer_list) { size_t maxsize; int ret; maxsize = maxwords * spi_bpw_to_bytes(xfer->bits_per_word); if (xfer->len > maxsize) { ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, maxsize); if (ret) return ret; } } return 0; } EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords); /*-------------------------------------------------------------------------*/ /* * Core methods for SPI controller protocol drivers. Some of the * other core methods are currently defined as inline functions. */ static int __spi_validate_bits_per_word(struct spi_controller *ctlr, u8 bits_per_word) { if (ctlr->bits_per_word_mask) { /* Only 32 bits fit in the mask */ if (bits_per_word > 32) return -EINVAL; if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) return -EINVAL; } return 0; } /** * spi_set_cs_timing - configure CS setup, hold, and inactive delays * @spi: the device that requires specific CS timing configuration * * Return: zero on success, else a negative error code. */ static int spi_set_cs_timing(struct spi_device *spi) { struct device *parent = spi->controller->dev.parent; int status = 0; if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) { if (spi->controller->auto_runtime_pm) { status = pm_runtime_get_sync(parent); if (status < 0) { pm_runtime_put_noidle(parent); dev_err(&spi->controller->dev, "Failed to power device: %d\n", status); return status; } status = spi->controller->set_cs_timing(spi); pm_runtime_put_autosuspend(parent); } else { status = spi->controller->set_cs_timing(spi); } } return status; } /** * spi_setup - setup SPI mode and clock rate * @spi: the device whose settings are being modified * Context: can sleep, and no requests are queued to the device * * SPI protocol drivers may need to update the transfer mode if the * device doesn't work with its default. They may likewise need * to update clock rates or word sizes from initial values. This function * changes those settings, and must be called from a context that can sleep. * Except for SPI_CS_HIGH, which takes effect immediately, the changes take * effect the next time the device is selected and data is transferred to * or from it. When this function returns, the SPI device is deselected. * * Note that this call will fail if the protocol driver specifies an option * that the underlying controller or its driver does not support. For * example, not all hardware supports wire transfers using nine bit words, * LSB-first wire encoding, or active-high chipselects. * * Return: zero on success, else a negative error code. */ int spi_setup(struct spi_device *spi) { unsigned bad_bits, ugly_bits; int status; /* * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO * are set at the same time. */ if ((hweight_long(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || (hweight_long(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { dev_err(&spi->dev, "setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); return -EINVAL; } /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */ if ((spi->mode & SPI_3WIRE) && (spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) return -EINVAL; /* Check against conflicting MOSI idle configuration */ if ((spi->mode & SPI_MOSI_IDLE_LOW) && (spi->mode & SPI_MOSI_IDLE_HIGH)) { dev_err(&spi->dev, "setup: MOSI configured to idle low and high at the same time.\n"); return -EINVAL; } /* * Help drivers fail *cleanly* when they need options * that aren't supported with their current controller. * SPI_CS_WORD has a fallback software implementation, * so it is ignored here. */ bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | SPI_NO_TX | SPI_NO_RX); ugly_bits = bad_bits & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); if (ugly_bits) { dev_warn(&spi->dev, "setup: ignoring unsupported mode bits %x\n", ugly_bits); spi->mode &= ~ugly_bits; bad_bits &= ~ugly_bits; } if (bad_bits) { dev_err(&spi->dev, "setup: unsupported mode bits %x\n", bad_bits); return -EINVAL; } if (!spi->bits_per_word) { spi->bits_per_word = 8; } else { /* * Some controllers may not support the default 8 bits-per-word * so only perform the check when this is explicitly provided. */ status = __spi_validate_bits_per_word(spi->controller, spi->bits_per_word); if (status) return status; } if (spi->controller->max_speed_hz && (!spi->max_speed_hz || spi->max_speed_hz > spi->controller->max_speed_hz)) spi->max_speed_hz = spi->controller->max_speed_hz; mutex_lock(&spi->controller->io_mutex); if (spi->controller->setup) { status = spi->controller->setup(spi); if (status) { mutex_unlock(&spi->controller->io_mutex); dev_err(&spi->controller->dev, "Failed to setup device: %d\n", status); return status; } } status = spi_set_cs_timing(spi); if (status) { mutex_unlock(&spi->controller->io_mutex); return status; } if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { status = pm_runtime_resume_and_get(spi->controller->dev.parent); if (status < 0) { mutex_unlock(&spi->controller->io_mutex); dev_err(&spi->controller->dev, "Failed to power device: %d\n", status); return status; } /* * We do not want to return positive value from pm_runtime_get, * there are many instances of devices calling spi_setup() and * checking for a non-zero return value instead of a negative * return value. */ status = 0; spi_set_cs(spi, false, true); pm_runtime_put_autosuspend(spi->controller->dev.parent); } else { spi_set_cs(spi, false, true); } mutex_unlock(&spi->controller->io_mutex); if (spi->rt && !spi->controller->rt) { spi->controller->rt = true; spi_set_thread_rt(spi->controller); } trace_spi_setup(spi, status); dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n", spi->mode & SPI_MODE_X_MASK, (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", (spi->mode & SPI_3WIRE) ? "3wire, " : "", (spi->mode & SPI_LOOP) ? "loopback, " : "", spi->bits_per_word, spi->max_speed_hz, status); return status; } EXPORT_SYMBOL_GPL(spi_setup); static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, struct spi_device *spi) { int delay1, delay2; delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); if (delay1 < 0) return delay1; delay2 = spi_delay_to_ns(&spi->word_delay, xfer); if (delay2 < 0) return delay2; if (delay1 < delay2) memcpy(&xfer->word_delay, &spi->word_delay, sizeof(xfer->word_delay)); return 0; } static int __spi_validate(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; struct spi_transfer *xfer; int w_size; if (list_empty(&message->transfers)) return -EINVAL; message->spi = spi; /* * Half-duplex links include original MicroWire, and ones with * only one data pin like SPI_3WIRE (switches direction) or where * either MOSI or MISO is missing. They can also be caused by * software limitations. */ if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || (spi->mode & SPI_3WIRE)) { unsigned flags = ctlr->flags; list_for_each_entry(xfer, &message->transfers, transfer_list) { if (xfer->rx_buf && xfer->tx_buf) return -EINVAL; if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) return -EINVAL; if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) return -EINVAL; } } /* * Set transfer bits_per_word and max speed as spi device default if * it is not set for this transfer. * Set transfer tx_nbits and rx_nbits as single transfer default * (SPI_NBITS_SINGLE) if it is not set for this transfer. * Ensure transfer word_delay is at least as long as that required by * device itself. */ message->frame_length = 0; list_for_each_entry(xfer, &message->transfers, transfer_list) { xfer->effective_speed_hz = 0; message->frame_length += xfer->len; if (!xfer->bits_per_word) xfer->bits_per_word = spi->bits_per_word; if (!xfer->speed_hz) xfer->speed_hz = spi->max_speed_hz; if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) xfer->speed_hz = ctlr->max_speed_hz; if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) return -EINVAL; /* DDR mode is supported only if controller has dtr_caps=true. * default considered as SDR mode for SPI and QSPI controller. * Note: This is applicable only to QSPI controller. */ if (xfer->dtr_mode && !ctlr->dtr_caps) return -EINVAL; /* * SPI transfer length should be multiple of SPI word size * where SPI word size should be power-of-two multiple. */ if (xfer->bits_per_word <= 8) w_size = 1; else if (xfer->bits_per_word <= 16) w_size = 2; else w_size = 4; /* No partial transfers accepted */ if (xfer->len % w_size) return -EINVAL; if (xfer->speed_hz && ctlr->min_speed_hz && xfer->speed_hz < ctlr->min_speed_hz) return -EINVAL; if (xfer->tx_buf && !xfer->tx_nbits) xfer->tx_nbits = SPI_NBITS_SINGLE; if (xfer->rx_buf && !xfer->rx_nbits) xfer->rx_nbits = SPI_NBITS_SINGLE; /* * Check transfer tx/rx_nbits: * 1. check the value matches one of single, dual and quad * 2. check tx/rx_nbits match the mode in spi_device */ if (xfer->tx_buf) { if (spi->mode & SPI_NO_TX) return -EINVAL; if (xfer->tx_nbits != SPI_NBITS_SINGLE && xfer->tx_nbits != SPI_NBITS_DUAL && xfer->tx_nbits != SPI_NBITS_QUAD && xfer->tx_nbits != SPI_NBITS_OCTAL) return -EINVAL; if ((xfer->tx_nbits == SPI_NBITS_DUAL) && !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) return -EINVAL; if ((xfer->tx_nbits == SPI_NBITS_QUAD) && !(spi->mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) return -EINVAL; if ((xfer->tx_nbits == SPI_NBITS_OCTAL) && !(spi->mode & SPI_TX_OCTAL)) return -EINVAL; } /* Check transfer rx_nbits */ if (xfer->rx_buf) { if (spi->mode & SPI_NO_RX) return -EINVAL; if (xfer->rx_nbits != SPI_NBITS_SINGLE && xfer->rx_nbits != SPI_NBITS_DUAL && xfer->rx_nbits != SPI_NBITS_QUAD && xfer->rx_nbits != SPI_NBITS_OCTAL) return -EINVAL; if ((xfer->rx_nbits == SPI_NBITS_DUAL) && !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) return -EINVAL; if ((xfer->rx_nbits == SPI_NBITS_QUAD) && !(spi->mode & (SPI_RX_QUAD | SPI_RX_OCTAL))) return -EINVAL; if ((xfer->rx_nbits == SPI_NBITS_OCTAL) && !(spi->mode & SPI_RX_OCTAL)) return -EINVAL; } if (_spi_xfer_word_delay_update(xfer, spi)) return -EINVAL; /* Make sure controller supports required offload features. */ if (xfer->offload_flags) { if (!message->offload) return -EINVAL; if (xfer->offload_flags & ~message->offload->xfer_flags) return -EINVAL; } } message->status = -EINPROGRESS; return 0; } /* * spi_split_transfers - generic handling of transfer splitting * @msg: the message to split * * Under certain conditions, a SPI controller may not support arbitrary * transfer sizes or other features required by a peripheral. This function * will split the transfers in the message into smaller transfers that are * supported by the controller. * * Controllers with special requirements not covered here can also split * transfers in the optimize_message() callback. * * Context: can sleep * Return: zero on success, else a negative error code */ static int spi_split_transfers(struct spi_message *msg) { struct spi_controller *ctlr = msg->spi->controller; struct spi_transfer *xfer; int ret; /* * If an SPI controller does not support toggling the CS line on each * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO * for the CS line, we can emulate the CS-per-word hardware function by * splitting transfers into one-word transfers and ensuring that * cs_change is set for each transfer. */ if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) { ret = spi_split_transfers_maxwords(ctlr, msg, 1); if (ret) return ret; list_for_each_entry(xfer, &msg->transfers, transfer_list) { /* Don't change cs_change on the last entry in the list */ if (list_is_last(&xfer->transfer_list, &msg->transfers)) break; xfer->cs_change = 1; } } else { ret = spi_split_transfers_maxsize(ctlr, msg, spi_max_transfer_size(msg->spi)); if (ret) return ret; } return 0; } /* * __spi_optimize_message - shared implementation for spi_optimize_message() * and spi_maybe_optimize_message() * @spi: the device that will be used for the message * @msg: the message to optimize * * Peripheral drivers will call spi_optimize_message() and the spi core will * call spi_maybe_optimize_message() instead of calling this directly. * * It is not valid to call this on a message that has already been optimized. * * Return: zero on success, else a negative error code */ static int __spi_optimize_message(struct spi_device *spi, struct spi_message *msg) { struct spi_controller *ctlr = spi->controller; int ret; ret = __spi_validate(spi, msg); if (ret) return ret; ret = spi_split_transfers(msg); if (ret) return ret; if (ctlr->optimize_message) { ret = ctlr->optimize_message(msg); if (ret) { spi_res_release(ctlr, msg); return ret; } } msg->optimized = true; return 0; } /* * spi_maybe_optimize_message - optimize message if it isn't already pre-optimized * @spi: the device that will be used for the message * @msg: the message to optimize * Return: zero on success, else a negative error code */ static int spi_maybe_optimize_message(struct spi_device *spi, struct spi_message *msg) { if (spi->controller->defer_optimize_message) { msg->spi = spi; return 0; } if (msg->pre_optimized) return 0; return __spi_optimize_message(spi, msg); } /** * spi_optimize_message - do any one-time validation and setup for a SPI message * @spi: the device that will be used for the message * @msg: the message to optimize * * Peripheral drivers that reuse the same message repeatedly may call this to * perform as much message prep as possible once, rather than repeating it each * time a message transfer is performed to improve throughput and reduce CPU * usage. * * Once a message has been optimized, it cannot be modified with the exception * of updating the contents of any xfer->tx_buf (the pointer can't be changed, * only the data in the memory it points to). * * Calls to this function must be balanced with calls to spi_unoptimize_message() * to avoid leaking resources. * * Context: can sleep * Return: zero on success, else a negative error code */ int spi_optimize_message(struct spi_device *spi, struct spi_message *msg) { int ret; /* * Pre-optimization is not supported and optimization is deferred e.g. * when using spi-mux. */ if (spi->controller->defer_optimize_message) return 0; ret = __spi_optimize_message(spi, msg); if (ret) return ret; /* * This flag indicates that the peripheral driver called spi_optimize_message() * and therefore we shouldn't unoptimize message automatically when finalizing * the message but rather wait until spi_unoptimize_message() is called * by the peripheral driver. */ msg->pre_optimized = true; return 0; } EXPORT_SYMBOL_GPL(spi_optimize_message); /** * spi_unoptimize_message - releases any resources allocated by spi_optimize_message() * @msg: the message to unoptimize * * Calls to this function must be balanced with calls to spi_optimize_message(). * * Context: can sleep */ void spi_unoptimize_message(struct spi_message *msg) { if (msg-spi-controller>) return; __spi_unoptimize_message(msg); msg->re_optimized = false } EXPORT_SYMBOL_GPL(spi_unoptimize_message); static int __{ 0x2000011, 0x007a { struct (UNC_NUM_JACK_CODEC , ,CH_R)0x00} struct { SDW_SDCA_CTL, RT711_SDCA_ENT_PLATFORM_FU44,RT711_SDCA_CTL_FU_CH_GAIN,) x00} /* * Some controllers do not support doing regular SPI transfers. Return * ENOTSUPP when this is the case. */ if (!ctlr->transfer) return -ENOTSUPP; SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async); SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async); trace_spi_message_submit(message); if (!ctlr->ptp_sts_supported) { list_for_each_entry(xfer, &message->transfers, transfer_list) { xfer->ptp_sts_word_pre = 0; ptp_read_system_prets(xfer->ptp_sts); } } return ctlr->transfer(spi, message); } static void devm_spi_unoptimize_message(void *msg) { spi_unoptimize_message(msg); } /** * devm_spi_optimize_message - managed version of spi_optimize_message() * @dev: the device that manages @msg (usually @spi->dev) * @spi: the device that will be used for the message * @msg: the message to optimize * Return: zero on success, else a negative error code * * spi_unoptimize_message() will automatically be called when the device is * removed. */ int devm_spi_optimize_message(struct device *dev, struct spi_device *spi, struct spi_message *msg) { int ret; ret = spi_optimize_message(spi, msg); if (ret) return ret; return devm_add_action_or_reset(dev, devm_spi_unoptimize_message, msg); } EXPORT_SYMBOL_GPL(devm_spi_optimize_message); /** * spi_async - asynchronous SPI transfer * @spi: device with which data will be exchanged * @message: describes the data transfers, including completion callback * Context: any (IRQs may be blocked, etc) * * This call may be used in_irq and other contexts which can't sleep, * as well as from task contexts which can sleep. * * The completion callback is invoked in a context which can't sleep. * Before that invocation, the value of message->status is undefined. * When the callback is issued, message->status holds either zero (to * indicate complete success) or a negative error code. After that * callback returns, the driver which issued the transfer request may * deallocate the associated memory; it's no longer in use by any SPI * core or controller driver code. * * Note that although all messages to a spi_device are handled in * FIFO order, messages may go to different devices in other orders. * Some device might be higher priority, or have various "hard" access * time requirements, for example. * * On detection of any fault during the transfer, processing of * the entire message is aborted, and the device is deselected. * Until returning from the associated message completion callback, * no other spi_message queued to that device will be processed. * (This rule applies equally to all the synchronous transfer calls, * which are wrappers around this core asynchronous primitive.) * * Return: zero on success, else a negative error code. */ int spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; int ret; unsigned long flags; ret = spi_maybe_optimize_message(spi, message); if (ret) return ret; spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); if (ctlr->bus_lock_flag) ret = -EBUSY; else ret = __spi_async(spi, message); spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); return ret; } EXPORT_SYMBOL_GPL(spi_async); static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_mes { bool was_busy; int ret; mutex_lock(&ctlr->io_mutex); was_busy = ctlr->busy; ctlr->cur_msg = msg; ret = __spi_pump_transfer_message(ctlr, msg, was_busy); if (ret) dev_err(&ctlr->dev, "noqueue transfer failed\n"); ctlr->cur_msg = NULL; ctlr->fallback = false; if (!was_busy) { kfree(ctlr->dummy_rx); ctlr->dummy_rx = NULL; kfree(ctlr->dummy_tx); ctlr->dummy_tx = NULL; if (ctlr->unprepare_transfer_hardware && ctlr->unprepare_transfer_hardware(ctlr)) dev_err(&ctlr->dev, "failed to unprepare transfer hardware\n"); spi_idle_runtime_pm(ctlr); } mutex_unlock(&ctlr->io_mutex); } /*-------------------------------------------------------------------------*/ /* * Utility methods for SPI protocol drivers, layered on * top of the core. Some other utility methods are defined as * inline functions. */ static void spi_complete(void *arg) { complete(arg); } static int __spi_sync(struct spi_device *spi, struct spi_message *message) { DECLARE_COMPLETION_ONSTACK(done); unsigned long flags; int status; struct spi_controller *ctlr = spi->controller; if (__spi_check_suspended(ctlr)) { dev_warn_once(&spi->dev, "Attempted to sync while suspend\n"); return -ESHUTDOWN; } status = spi_maybe_optimize_message(spi, message); if (status) return status; SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync); /* * Checking queue_empty here only guarantees async/sync message * ordering when coming from the same context. It does not need to * guard against reentrancy from a different context. The io_mutex * will catch those cases. */ if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) { message->actual_length = 0; message->status = -EINPROGRESS; trace_spi_message_submit(message); SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate); SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate); __spi_transfer_message_noqueue(ctlr, message); return message->status; } /* * There are messages in the async queue that could have originated * from the same context, so we need to preserve ordering. * Therefor we send the message to the async queue and wait until they * are completed. */ message->complete = spi_complete; message->context = &done; spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); status = __spi_async(spi, message); spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); if (status == 0) { wait_for_completion(&done); status = message->status; } message->complete = NULL; message->context = NULL; return status; } /** * spi_sync - blocking/synchronous SPI data transfers * @spi: device with which data will be exchanged * @message: describes the data transfers * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. Low-overhead controller * drivers may DMA directly into and out of the message buffers. * * Note that the SPI device's chip select is active during the message, * and then is normally disabled between messages. Drivers for some * frequently-used devices may want to minimize costs of selecting a chip, * by leaving it selected in anticipation that the next message will go * to the same chip. (That may increase power usage.) * * Also, the caller is guaranteeing that the memory associated with the * message will not be freed before this call returns. * * Return: zero on success, else a negative error code. */ int spi_sync(struct spi_device *spi, struct spi_message *message) { int ret; mutex_lock(&spi->controller->bus_lock_mutex); ret = __spi_sync(spi, message); mutex_unlock(&spi->controller->bus_lock_mutex); return ret; } EXPORT_SYMBOL_GPL(spi_sync); /** * spi_sync_locked - version of spi_sync with exclusive bus usage * @spi: device with which data will be exchanged * @message: describes the data transfers * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. Low-overhead controller * drivers may DMA directly into and out of the message buffers. * * This call should be used by drivers that require exclusive access to the * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must * be released by a spi_bus_unlock call when the exclusive access is over. * * Return: zero on success, else a negative error code. */ int spi_sync_locked(struct spi_device *spi, struct spi_message *message) { return __spi_sync(spi, message); } EXPORT_SYMBOL_GPL(spi_sync_locked); /** * spi_bus_lock - obtain a lock for exclusive SPI bus usage * @ctlr: SPI bus controller that should be locked for exclusive bus access * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. * * This call should be used by drivers that require exclusive access to the * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the * exclusive access is over. Data transfer must be done by spi_sync_locked * and spi_async_locked calls when the SPI bus lock is held. * * Return: always zero. */ int spi_bus_lock(struct spi_controller *ctlr) { unsigned long flags; mutex_lock(&ctlr->bus_lock_mutex); spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); ctlr->bus_lock_flag = 1; spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); /* Mutex remains locked until spi_bus_unlock() is called */ return 0; } EXPORT_SYMBOL_GPL(spi_bus_lock); /** * spi_bus_unlock - release the lock for exclusive SPI bus usage * @ctlr: SPI bus controller that was locked for exclusive bus access * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. * * This call releases an SPI bus lock previously obtained by an spi_bus_lock * call. * * Return: always zero. */ int spi_bus_unlock(struct spi_controller *ctlr) { ctlr->bus_lock_flag = 0; mutex_unlock(&ctlr->bus_lock_mutex); return 0; } EXPORT_SYMBOL_GPL(spi_bus_unlock); /* Portable code must never pass more than 32 bytes */ #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) static u8 *buf; /** * spi_write_then_read - SPI synchronous write followed by read * @spi: device with which data will be exchanged * @txbuf: data to be written (need not be DMA-safe) * @n_tx: size of txbuf, in bytes * @rxbuf: buffer into which data will be read (need not be DMA-safe) * @n_rx: size of rxbuf, in bytes * Context: can sleep * * This performs a half duplex MicroWire style transaction with the * device, sending txbuf and then reading rxbuf. The return value * is zero for success, else a negative errno status code. * This call may only be used from a context that may sleep. * * Parameters to this routine are always copied using a small buffer. * Performance-sensitive or bulk transfer code should instead use * spi_{async,sync}() calls with DMA-safe buffers. * * Return: zero on success, else a negative error code. */ int spi_write_then_read(struct spi_device *spi, const void *txbuf, unsigned n_tx, void *rxbuf, unsigned n_rx) { static DEFINE_MUTEX(lock); int status; struct spi_message message; struct spi_transfer x[2]; u8 *local_buf; /* * Use preallocated DMA-safe buffer if we can. We can't avoid * copying here, (as a pure convenience thing), but we can * keep heap costs out of the hot path unless someone else is * using the pre-allocated buffer or the transfer is too large. */ if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), GFP_KERNEL | GFP_DMA); if (!local_buf) return -ENOMEM; } else { local_buf = buf; } spi_message_init(&message); memset(x, 0, sizeof(x)); if (n_tx) { x[0].len = n_tx; spi_message_add_tail(&x[0], &message); } if (n_rx) { x[1].len = n_rx; spi_message_add_tail(&x[1], &message); } memcpy(local_buf, txbuf, n_tx); x[0].tx_buf = local_buf; x[1].rx_buf = local_buf + n_tx; /* Do the I/O */ status = spi_sync(spi, &message); if (status == 0) memcpy(rxbuf, x[1].rx_buf, n_rx); if (x[0].tx_buf == buf) mutex_unlock(&lock); else kfree(local_buf); return status; } EXPORT_SYMBOL_GPL(spi_write_then_read); /*-------------------------------------------------------------------------*/ #if IS_ENABLED(CONFIG_OF_DYNAMIC) /* Must call put_device() when done with returned spi_device device */ static struct spi_device *of_find_spi_device_by_node(struct device_node *node) { struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); return dev ? to_spi_device(dev) : NULL; } /* The spi controllers are not using spi_bus, so we find it with another way */ static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node { struct device *dev; dev = class_find_device_by_of_node(&spi_controller_class, node); if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) dev = class_find_device_by_of_node(&spi_target_class, node); if (!dev) return NULL; /* Reference got in class_find_device */ return container_of(dev, struct spi_controller, dev); } static int of_spi_notify(struct notifier_block *nb, unsigned long action, void *arg) { struct of_reconfig_data *rd = arg; struct spi_controller *ctlr; struct spi_device *spi; switch (of_reconfig_get_state_change(action, arg)) { case OF_RECONFIG_CHANGE_ADD: ctlr = of_find_spi_controller_by_node(rd->dn->parent); if (ctlr == NULL) return NOTIFY_OK; /* Not for us */ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { put_device(&ctlr->dev); return NOTIFY_OK; } /* * Clear the flag before adding the device so that fw_devlink * doesn't skip adding consumers to this device. */ rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE; spi = of_register_spi_device(ctlr, rd->dn); put_device(&ctlr->dev); if (IS_ERR(spi)) { pr_err("%s: failed to create for '%pOF'\n", __func__, rd->dn); of_node_clear_flag(rd->dn, OF_POPULATED); return notifier_from_errno(PTR_ERR(spi)); } break; case OF_RECONFIG_CHANGE_REMOVE: /* Already depopulated? */ if (!of_node_check_flag(rd->dn, OF_POPULATED)) return NOTIFY_OK; /* Find our device by node */ spi = of_find_spi_device_by_node(rd->dn); if (spi == NULL) return NOTIFY_OK; /* No? not meant for us */ /* Unregister takes one ref away */ spi_unregister_device(spi); /* And put the reference of the find */ put_device(&spi->dev); break; } return NOTIFY_OK; } static struct notifier_block spi_of_notifier = { .notifier_call = of_spi_notify, }; #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ extern struct notifier_block spi_of_notifier; #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ #if IS_ENABLED(CONFIG_ACPI) static int spi_acpi_controller_match(struct device *dev, const void *data) { return device_match_acpi_dev(dev->parent, data); } struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) { struct device *dev; dev = class_find_device(&spi_controller_class, NULL, adev, spi_acpi_controller_match); if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) dev = class_find_device(&spi_target_class, NULL, adev, spi_acpi_controller_match); if (!dev) return NULL; return container_of(dev, struct spi_controller, dev); } EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev); static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) { struct device *dev; dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); return to_spi_device(dev); } static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, void *arg) { struct acpi_device *adev = arg; struct spi_controller *ctlr; struct spi_device *spi; switch (value) { case ACPI_RECONFIG_DEVICE_ADD: ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev)); if (!ctlr) break; acpi_register_spi_device(ctlr, adev); put_device(&ctlr->dev); break; case ACPI_RECONFIG_DEVICE_REMOVE: if (!acpi_device_enumerated(adev)) break; spi = acpi_spi_find_device_by_adev(adev); if (!spi) break; spi_unregister_device(spi); put_device(&spi->dev); break; } return NOTIFY_OK; } static struct notifier_block spi_acpi_notifier = { .notifier_call = acpi_spi_notify, }; #else extern struct notifier_block spi_acpi_notifier; #endif static int __init spi_init(void) { int status; buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); if (!buf) { status = -ENOMEM; goto err0; } status = bus_register(&spi_bus_type); if (status < 0) goto err1; status = class_register(&spi_controller_class); if (status < 0) goto err2; if (IS_ENABLED(CONFIG_SPI_SLAVE)) { status = class_register(&spi_target_class); if (status < 0) goto err3; } if (IS_ENABLED(CONFIG_OF_DYNAMIC)) WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); if (IS_ENABLED(CONFIG_ACPI)) WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); return 0; err3: class_unregister(&spi_controller_class); err2: bus_unregister(&spi_bus_type); err1: kfree(buf); buf = NULL; err0: return status; } /* * A board_info is normally registered in arch_initcall(), * but even essential drivers wait till later. * * REVISIT only boardinfo really needs static linking. The rest (device and * driver registration) _could_ be dynamically linked (modular) ... Costs * include needing to have boardinfo data structures be much more public. */ postcore_initcall(spi_init);
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2026-10-11