Quelle  loongson2_pm.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 * Loongson-2 PM Support
 *
 * Copyright (C) 2023 Loongson Technology Corporation Limited
 */

#include <linux/io.h>
#include <linux/of.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/suspend.h>
#include <linux/interrupt.h>
#include <linux/of_platform.h>
#include <linux/pm_wakeirq.h>
#include <linux/platform_device.h>
#include <asm/bootinfo.h>
#include <asm/suspend.h>

#define LOONGSON2_PM1_CNT_REG  0x14
#define LOONGSON2_PM1_STS_REG  0x0c
#define LOONGSON2_PM1_ENA_REG  0x10
#define LOONGSON2_GPE0_STS_REG  0x28
#define LOONGSON2_GPE0_ENA_REG  0x2c

#define LOONGSON2_PM1_PWRBTN_STS BIT(8)
#define LOONGSON2_PM1_PCIEXP_WAKE_STS BIT(14)
#define LOONGSON2_PM1_WAKE_STS  BIT(15)
#define LOONGSON2_PM1_CNT_INT_EN BIT(0)
#define LOONGSON2_PM1_PWRBTN_EN  LOONGSON2_PM1_PWRBTN_STS

static struct loongson2_pm {
 void __iomem   *base;
 struct input_dev  *dev;
 bool    suspended;
} loongson2_pm;

#define loongson2_pm_readw(reg)  readw(loongson2_pm.base + reg)
#define loongson2_pm_readl(reg)  readl(loongson2_pm.base + reg)
#define loongson2_pm_writew(val, reg) writew(val, loongson2_pm.base + reg)
#define loongson2_pm_writel(val, reg) writel(val, loongson2_pm.base + reg)

static void loongson2_pm_status_clear(void)
{
 u16 value;

 value = loongson2_pm_readw(LOONGSON2_PM1_STS_REG);
 value |= (LOONGSON2_PM1_PWRBTN_STS | LOONGSON2_PM1_PCIEXP_WAKE_STS |
    LOONGSON2_PM1_WAKE_STS);
 loongson2_pm_writew(value, LOONGSON2_PM1_STS_REG);
 loongson2_pm_writel(loongson2_pm_readl(LOONGSON2_GPE0_STS_REG), LOONGSON2_GPE0_STS_REG);
}

static void loongson2_pm_irq_enable(void)
{
 u16 value;

 value = loongson2_pm_readw(LOONGSON2_PM1_CNT_REG);
 value |= LOONGSON2_PM1_CNT_INT_EN;
 loongson2_pm_writew(value, LOONGSON2_PM1_CNT_REG);

 value = loongson2_pm_readw(LOONGSON2_PM1_ENA_REG);
 value |= LOONGSON2_PM1_PWRBTN_EN;
 loongson2_pm_writew(value, LOONGSON2_PM1_ENA_REG);
}

static int loongson2_suspend_enter(suspend_state_t state)
{
 loongson2_pm_status_clear();
 loongarch_common_suspend();
 loongarch_suspend_enter();
 loongarch_common_resume();
 loongson2_pm_irq_enable();
 pm_set_resume_via_firmware();

 return 0;
}

static int loongson2_suspend_begin(suspend_state_t state)
{
 pm_set_suspend_via_firmware();

 return 0;
}

static int loongson2_suspend_valid_state(suspend_state_t state)
{
 return (state == PM_SUSPEND_MEM);
}

static const struct platform_suspend_ops loongson2_suspend_ops = {
 .valid = loongson2_suspend_valid_state,
 .begin = loongson2_suspend_begin,
 .enter = loongson2_suspend_enter,
};

static int loongson2_power_button_init(struct device *dev, int irq)
{
 int ret;
 struct input_dev *button;

 button = input_allocate_device();
 if (!dev)
  return -ENOMEM;

 button->name = "Power Button";
 button->phys = "pm/button/input0";
 button->id.bustype = BUS_HOST;
 button->dev.parent = NULL;
 input_set_capability(button, EV_KEY, KEY_POWER);

 ret = input_register_device(button);
 if (ret)
  goto free_dev;

 dev_pm_set_wake_irq(&button->dev, irq);
 device_set_wakeup_capable(&button->dev, true);
 device_set_wakeup_enable(&button->dev, true);

 loongson2_pm.dev = button;
 dev_info(dev, "Power Button: Init successful!\n");

 return 0;

free_dev:
 input_free_device(button);

 return ret;
}

static irqreturn_t loongson2_pm_irq_handler(int irq, void *dev_id)
{
 u16 status = loongson2_pm_readw(LOONGSON2_PM1_STS_REG);

 if (!loongson2_pm.suspended && (status & LOONGSON2_PM1_PWRBTN_STS)) {
  pr_info("Power Button pressed...\n");
  input_report_key(loongson2_pm.dev, KEY_POWER, 1);
  input_sync(loongson2_pm.dev);
  input_report_key(loongson2_pm.dev, KEY_POWER, 0);
  input_sync(loongson2_pm.dev);
 }

 loongson2_pm_status_clear();

 return IRQ_HANDLED;
}

static int __maybe_unused loongson2_pm_suspend(struct device *dev)
{
 loongson2_pm.suspended = true;

 return 0;
}

static int __maybe_unused loongson2_pm_resume(struct device *dev)
{
 loongson2_pm.suspended = false;

 return 0;
}
static SIMPLE_DEV_PM_OPS(loongson2_pm_ops, loongson2_pm_suspend, loongson2_pm_resume);

static int loongson2_pm_probe(struct platform_device *pdev)
{
 int irq, retval;
 u64 suspend_addr;
 struct device *dev = &pdev->dev;

 loongson2_pm.base = devm_platform_ioremap_resource(pdev, 0);
 if (IS_ERR(loongson2_pm.base))
  return PTR_ERR(loongson2_pm.base);

 irq = platform_get_irq(pdev, 0);
 if (irq < 0)
  return irq;

 if (!device_property_read_u64(dev, "loongson,suspend-address", &suspend_addr))
  loongson_sysconf.suspend_addr = (u64)phys_to_virt(suspend_addr);
 else
  dev_err(dev, "No loongson,suspend-address, could not support S3!\n");

 if (loongson2_power_button_init(dev, irq))
  return -EINVAL;

 retval = devm_request_irq(&pdev->dev, irq, loongson2_pm_irq_handler,
      IRQF_SHARED, "pm_irq", &loongson2_pm);
 if (retval)
  return retval;

 loongson2_pm_irq_enable();
 loongson2_pm_status_clear();

 if (loongson_sysconf.suspend_addr)
  suspend_set_ops(&loongson2_suspend_ops);

 /* Populate children */
 retval = devm_of_platform_populate(dev);
 if (retval)
  dev_err(dev, "Error populating children, reboot and poweroff might not work properly\n");

 return 0;
}

static const struct of_device_id loongson2_pm_match[] = {
 { .compatible = "loongson,ls2k0500-pmc", },
 {},
};

static struct platform_driver loongson2_pm_driver = {
 .driver = {
  .name = "ls2k-pm",
  .pm = &loongson2_pm_ops,
  .of_match_table = loongson2_pm_match,
 },
 .probe = loongson2_pm_probe,
};
module_platform_driver(loongson2_pm_driver);

MODULE_DESCRIPTION("Loongson-2 PM driver");
MODULE_LICENSE("GPL");