Quelle  oaktrail.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 * Intel OakTrail Platform support
 *
 * Copyright (C) 2010-2011 Intel Corporation
 * Author: Yin Kangkai (kangkai.yin@intel.com)
 *
 * based on Compal driver, Copyright (C) 2008 Cezary Jackiewicz
 * <cezary.jackiewicz (at) gmail.com>, based on MSI driver
 * Copyright (C) 2006 Lennart Poettering <mzxreary (at) 0pointer (dot) de>
 *
 * This driver does below things:
 * 1. registers itself in the Linux backlight control in
 *    /sys/class/backlight/intel_oaktrail/
 *
 * 2. registers in the rfkill subsystem here: /sys/class/rfkill/rfkillX/
 *    for these components: wifi, bluetooth, wwan (3g), gps
 *
 * This driver might work on other products based on Oaktrail. If you
 * want to try it you can pass force=1 as argument to the module which
 * will force it to load even when the DMI data doesn't identify the
 * product as compatible.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/acpi.h>
#include <linux/backlight.h>
#include <linux/dmi.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/rfkill.h>

#include <acpi/video.h>

#define DRIVER_NAME "intel_oaktrail"
#define DRIVER_VERSION "0.4ac1"

/*
 * This is the devices status address in EC space, and the control bits
 * definition:
 *
 * (1 << 0): Camera enable/disable, RW.
 * (1 << 1): Bluetooth enable/disable, RW.
 * (1 << 2): GPS enable/disable, RW.
 * (1 << 3): WiFi enable/disable, RW.
 * (1 << 4): WWAN (3G) enable/disable, RW.
 * (1 << 5): Touchscreen enable/disable, Read Only.
 */
#define OT_EC_DEVICE_STATE_ADDRESS 0xD6

#define OT_EC_CAMERA_MASK (1 << 0)
#define OT_EC_BT_MASK  (1 << 1)
#define OT_EC_GPS_MASK  (1 << 2)
#define OT_EC_WIFI_MASK  (1 << 3)
#define OT_EC_WWAN_MASK  (1 << 4)
#define OT_EC_TS_MASK  (1 << 5)

/*
 * This is the address in EC space and commands used to control LCD backlight:
 *
 * Two steps needed to change the LCD backlight:
 *   1. write the backlight percentage into OT_EC_BL_BRIGHTNESS_ADDRESS;
 *   2. write OT_EC_BL_CONTROL_ON_DATA into OT_EC_BL_CONTROL_ADDRESS.
 *
 * To read the LCD back light, just read out the value from
 * OT_EC_BL_BRIGHTNESS_ADDRESS.
 *
 * LCD backlight brightness range: 0 - 100 (OT_EC_BL_BRIGHTNESS_MAX)
 */
#define OT_EC_BL_BRIGHTNESS_ADDRESS 0x44
#define OT_EC_BL_BRIGHTNESS_MAX  100
#define OT_EC_BL_CONTROL_ADDRESS 0x3A
#define OT_EC_BL_CONTROL_ON_DATA 0x1A


static bool force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");

static struct platform_device *oaktrail_device;
static struct backlight_device *oaktrail_bl_device;
static struct rfkill *bt_rfkill;
static struct rfkill *gps_rfkill;
static struct rfkill *wifi_rfkill;
static struct rfkill *wwan_rfkill;


/* rfkill */
static int oaktrail_rfkill_set(void *data, bool blocked)
{
 u8 value;
 u8 result;
 unsigned long radio = (unsigned long) data;

 ec_read(OT_EC_DEVICE_STATE_ADDRESS, &result);

 if (!blocked)
  value = (u8) (result | radio);
 else
  value = (u8) (result & ~radio);

 ec_write(OT_EC_DEVICE_STATE_ADDRESS, value);

 return 0;
}

static const struct rfkill_ops oaktrail_rfkill_ops = {
 .set_block = oaktrail_rfkill_set,
};

static struct rfkill *oaktrail_rfkill_new(char *name, enum rfkill_type type,
       unsigned long mask)
{
 struct rfkill *rfkill_dev;
 u8 value;
 int err;

 rfkill_dev = rfkill_alloc(name, &oaktrail_device->dev, type,
      &oaktrail_rfkill_ops, (void *)mask);
 if (!rfkill_dev)
  return ERR_PTR(-ENOMEM);

 ec_read(OT_EC_DEVICE_STATE_ADDRESS, &value);
 rfkill_init_sw_state(rfkill_dev, (value & mask) != 1);

 err = rfkill_register(rfkill_dev);
 if (err) {
  rfkill_destroy(rfkill_dev);
  return ERR_PTR(err);
 }

 return rfkill_dev;
}

static inline void __oaktrail_rfkill_cleanup(struct rfkill *rf)
{
 if (rf) {
  rfkill_unregister(rf);
  rfkill_destroy(rf);
 }
}

static void oaktrail_rfkill_cleanup(void)
{
 __oaktrail_rfkill_cleanup(wifi_rfkill);
 __oaktrail_rfkill_cleanup(bt_rfkill);
 __oaktrail_rfkill_cleanup(gps_rfkill);
 __oaktrail_rfkill_cleanup(wwan_rfkill);
}

static int oaktrail_rfkill_init(void)
{
 int ret;

 wifi_rfkill = oaktrail_rfkill_new("oaktrail-wifi",
       RFKILL_TYPE_WLAN,
       OT_EC_WIFI_MASK);
 if (IS_ERR(wifi_rfkill)) {
  ret = PTR_ERR(wifi_rfkill);
  wifi_rfkill = NULL;
  goto cleanup;
 }

 bt_rfkill = oaktrail_rfkill_new("oaktrail-bluetooth",
     RFKILL_TYPE_BLUETOOTH,
     OT_EC_BT_MASK);
 if (IS_ERR(bt_rfkill)) {
  ret = PTR_ERR(bt_rfkill);
  bt_rfkill = NULL;
  goto cleanup;
 }

 gps_rfkill = oaktrail_rfkill_new("oaktrail-gps",
      RFKILL_TYPE_GPS,
      OT_EC_GPS_MASK);
 if (IS_ERR(gps_rfkill)) {
  ret = PTR_ERR(gps_rfkill);
  gps_rfkill = NULL;
  goto cleanup;
 }

 wwan_rfkill = oaktrail_rfkill_new("oaktrail-wwan",
       RFKILL_TYPE_WWAN,
       OT_EC_WWAN_MASK);
 if (IS_ERR(wwan_rfkill)) {
  ret = PTR_ERR(wwan_rfkill);
  wwan_rfkill = NULL;
  goto cleanup;
 }

 return 0;

cleanup:
 oaktrail_rfkill_cleanup();
 return ret;
}


/* backlight */
static int get_backlight_brightness(struct backlight_device *b)
{
 u8 value;
 ec_read(OT_EC_BL_BRIGHTNESS_ADDRESS, &value);

 return value;
}

static int set_backlight_brightness(struct backlight_device *b)
{
 u8 percent = (u8) b->props.brightness;
 if (percent < 0 || percent > OT_EC_BL_BRIGHTNESS_MAX)
  return -EINVAL;

 ec_write(OT_EC_BL_BRIGHTNESS_ADDRESS, percent);
 ec_write(OT_EC_BL_CONTROL_ADDRESS, OT_EC_BL_CONTROL_ON_DATA);

 return 0;
}

static const struct backlight_ops oaktrail_bl_ops = {
 .get_brightness = get_backlight_brightness,
 .update_status = set_backlight_brightness,
};

static int oaktrail_backlight_init(void)
{
 struct backlight_device *bd;
 struct backlight_properties props;

 memset(&props, 0, sizeof(struct backlight_properties));
 props.type = BACKLIGHT_PLATFORM;
 props.max_brightness = OT_EC_BL_BRIGHTNESS_MAX;
 bd = backlight_device_register(DRIVER_NAME,
           &oaktrail_device->dev, NULL,
           &oaktrail_bl_ops,
           &props);

 if (IS_ERR(bd)) {
  oaktrail_bl_device = NULL;
  pr_warn("Unable to register backlight device\n");
  return PTR_ERR(bd);
 }

 oaktrail_bl_device = bd;

 bd->props.brightness = get_backlight_brightness(bd);
 bd->props.power = BACKLIGHT_POWER_ON;
 backlight_update_status(bd);

 return 0;
}

static void oaktrail_backlight_exit(void)
{
 backlight_device_unregister(oaktrail_bl_device);
}

static int oaktrail_probe(struct platform_device *pdev)
{
 return 0;
}

static struct platform_driver oaktrail_driver = {
 .driver = {
  .name = DRIVER_NAME,
 },
 .probe = oaktrail_probe,
};

static int dmi_check_cb(const struct dmi_system_id *id)
{
 pr_info("Identified model '%s'\n", id->ident);
 return 0;
}

static const struct dmi_system_id oaktrail_dmi_table[] __initconst = {
 {
  .ident = "OakTrail platform",
  .matches = {
   DMI_MATCH(DMI_PRODUCT_NAME, "OakTrail platform"),
  },
  .callback = dmi_check_cb
 },
 { }
};
MODULE_DEVICE_TABLE(dmi, oaktrail_dmi_table);

static int __init oaktrail_init(void)
{
 int ret;

 if (acpi_disabled) {
  pr_err("ACPI needs to be enabled for this driver to work!\n");
  return -ENODEV;
 }

 if (!force && !dmi_check_system(oaktrail_dmi_table)) {
  pr_err("Platform not recognized (You could try the module's force-parameter)");
  return -ENODEV;
 }

 ret = platform_driver_register(&oaktrail_driver);
 if (ret) {
  pr_warn("Unable to register platform driver\n");
  goto err_driver_reg;
 }

 oaktrail_device = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE);
 if (!oaktrail_device) {
  pr_warn("Unable to allocate platform device\n");
  ret = -ENOMEM;
  goto err_device_alloc;
 }

 ret = platform_device_add(oaktrail_device);
 if (ret) {
  pr_warn("Unable to add platform device\n");
  goto err_device_add;
 }

 if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
  ret = oaktrail_backlight_init();
  if (ret)
   goto err_backlight;
 }

 ret = oaktrail_rfkill_init();
 if (ret) {
  pr_warn("Setup rfkill failed\n");
  goto err_rfkill;
 }

 pr_info("Driver "DRIVER_VERSION" successfully loaded\n");
 return 0;

err_rfkill:
 oaktrail_backlight_exit();
err_backlight:
 platform_device_del(oaktrail_device);
err_device_add:
 platform_device_put(oaktrail_device);
err_device_alloc:
 platform_driver_unregister(&oaktrail_driver);
err_driver_reg:

 return ret;
}

static void __exit oaktrail_cleanup(void)
{
 oaktrail_backlight_exit();
 oaktrail_rfkill_cleanup();
 platform_device_unregister(oaktrail_device);
 platform_driver_unregister(&oaktrail_driver);

 pr_info("Driver unloaded\n");
}

module_init(oaktrail_init);
module_exit(oaktrail_cleanup);

MODULE_AUTHOR("Yin Kangkai ");
MODULE_DESCRIPTION("Intel Oaktrail Platform ACPI Extras");
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");