Quelle  da9052_bl.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Backlight Driver for Dialog DA9052 PMICs
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: David Dajun Chen <dchen@diasemi.com>
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/reg.h>

#define DA9052_MAX_BRIGHTNESS  0xFF

enum {
 DA9052_WLEDS_OFF,
 DA9052_WLEDS_ON,
};

enum {
 DA9052_TYPE_WLED1,
 DA9052_TYPE_WLED2,
 DA9052_TYPE_WLED3,
};

static const unsigned char wled_bank[] = {
 DA9052_LED1_CONF_REG,
 DA9052_LED2_CONF_REG,
 DA9052_LED3_CONF_REG,
};

struct da9052_bl {
 struct da9052 *da9052;
 uint brightness;
 uint state;
 uint led_reg;
};

static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
{
 unsigned char boost_en;
 unsigned char i_sink;
 int ret;

 boost_en = 0x3F;
 i_sink = 0xFF;
 if (wleds->state == DA9052_WLEDS_OFF) {
  boost_en = 0x00;
  i_sink = 0x00;
 }

 ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
 if (ret < 0)
  return ret;

 ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
 if (ret < 0)
  return ret;

 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
 if (ret < 0)
  return ret;

 usleep_range(10000, 11000);

 if (wleds->brightness) {
  ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
           wleds->brightness);
  if (ret < 0)
   return ret;
 }

 return 0;
}

static int da9052_backlight_update_status(struct backlight_device *bl)
{
 int brightness = bl->props.brightness;
 struct da9052_bl *wleds = bl_get_data(bl);

 wleds->brightness = brightness;
 wleds->state = DA9052_WLEDS_ON;

 return da9052_adjust_wled_brightness(wleds);
}

static int da9052_backlight_get_brightness(struct backlight_device *bl)
{
 struct da9052_bl *wleds = bl_get_data(bl);

 return wleds->brightness;
}

static const struct backlight_ops da9052_backlight_ops = {
 .update_status = da9052_backlight_update_status,
 .get_brightness = da9052_backlight_get_brightness,
};

static int da9052_backlight_probe(struct platform_device *pdev)
{
 struct backlight_device *bl;
 struct backlight_properties props;
 struct da9052_bl *wleds;

 wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
 if (!wleds)
  return -ENOMEM;

 wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
 wleds->brightness = 0;
 wleds->led_reg = platform_get_device_id(pdev)->driver_data;
 wleds->state = DA9052_WLEDS_OFF;

 memset(&props, 0, sizeof(struct backlight_properties));
 props.type = BACKLIGHT_RAW;
 props.max_brightness = DA9052_MAX_BRIGHTNESS;

 bl = devm_backlight_device_register(&pdev->dev, pdev->name,
     wleds->da9052->dev, wleds,
     &da9052_backlight_ops, &props);
 if (IS_ERR(bl)) {
  dev_err(&pdev->dev, "Failed to register backlight\n");
  return PTR_ERR(bl);
 }

 bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
 bl->props.brightness = 0;
 platform_set_drvdata(pdev, bl);

 return da9052_adjust_wled_brightness(wleds);
}

static void da9052_backlight_remove(struct platform_device *pdev)
{
 struct backlight_device *bl = platform_get_drvdata(pdev);
 struct da9052_bl *wleds = bl_get_data(bl);

 wleds->brightness = 0;
 wleds->state = DA9052_WLEDS_OFF;
 da9052_adjust_wled_brightness(wleds);
}

static const struct platform_device_id da9052_wled_ids[] = {
 {
  .name  = "da9052-wled1",
  .driver_data = DA9052_TYPE_WLED1,
 },
 {
  .name  = "da9052-wled2",
  .driver_data = DA9052_TYPE_WLED2,
 },
 {
  .name  = "da9052-wled3",
  .driver_data = DA9052_TYPE_WLED3,
 },
 { },
};
MODULE_DEVICE_TABLE(platform, da9052_wled_ids);

static struct platform_driver da9052_wled_driver = {
 .probe  = da9052_backlight_probe,
 .remove  = da9052_backlight_remove,
 .id_table = da9052_wled_ids,
 .driver = {
  .name = "da9052-wled",
 },
};

module_platform_driver(da9052_wled_driver);

MODULE_AUTHOR("David Dajun Chen ");
MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
MODULE_LICENSE("GPL");