arch/arm/plat-samsung/dev-backlight.c

   1 /* linux/arch/arm/plat-samsung/dev-backlight.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Common infrastructure for PWM Backlight for Samsung boards
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/gpio.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/pwm_backlight.h>
  17
  18 #include <plat/devs.h>
  19 #include <plat/gpio-cfg.h>
  20 #include <plat/backlight.h>
  21
  22 static int samsung_bl_init(struct device *dev)
  23 {
  24         int ret = 0;
  25         struct platform_device *timer_dev =
  26                         container_of(dev->parent, struct platform_device, dev);
  27         struct samsung_bl_gpio_info *bl_gpio_info =
  28                         timer_dev->dev.platform_data;
  29
  30         ret = gpio_request(bl_gpio_info->no, "Backlight");
  31         if (ret) {
  32                 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
  33                 return ret;
  34         }
  35
  36         /* Configure GPIO pin with specific GPIO function for PWM timer */
  37         s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
  38
  39         return 0;
  40 }
  41
  42 static void samsung_bl_exit(struct device *dev)
  43 {
  44         struct platform_device *timer_dev =
  45                         container_of(dev->parent, struct platform_device, dev);
  46         struct samsung_bl_gpio_info *bl_gpio_info =
  47                         timer_dev->dev.platform_data;
  48
  49         s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
  50         gpio_free(bl_gpio_info->no);
  51 }
  52
  53 /* Initialize few important fields of platform_pwm_backlight_data
  54  * structure with default values. These fields can be overridden by
  55  * board-specific values sent from machine file.
  56  * For ease of operation, these fields are initialized with values
  57  * used by most samsung boards.
  58  * Users has the option of sending info about other parameters
  59  * for their specific boards
  60  */
  61
  62 static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
  63         .max_brightness = 255,
  64         .dft_brightness = 255,
  65         .pwm_period_ns  = 78770,
  66         .init           = samsung_bl_init,
  67         .exit           = samsung_bl_exit,
  68 };
  69
  70 static struct platform_device samsung_dfl_bl_device __initdata = {
  71         .name           = "pwm-backlight",
  72 };
  73
  74 /* samsung_bl_set - Set board specific data (if any) provided by user for
  75  * PWM Backlight control and register specific PWM and backlight device.
  76  * @gpio_info:  structure containing GPIO info for PWM timer
  77  * @bl_data:    structure containing Backlight control data
  78  */
  79 void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  80         struct platform_pwm_backlight_data *bl_data)
  81 {
  82         int ret = 0;
  83         struct platform_device *samsung_bl_device;
  84         struct platform_pwm_backlight_data *samsung_bl_data;
  85
  86         samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  87                         sizeof(struct platform_device), GFP_KERNEL);
  88         if (!samsung_bl_device) {
  89                 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  90                 return;
  91         }
  92
  93         samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
  94                 sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
  95         if (!samsung_bl_data) {
  96                 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  97                 goto err_data;
  98         }
  99
 100         /* Copy board specific data provided by user */
 101         samsung_bl_data->pwm_id = bl_data->pwm_id;
 102         samsung_bl_device->dev.parent =
 103                         &s3c_device_timer[samsung_bl_data->pwm_id].dev;
 104
 105         if (bl_data->max_brightness)
 106                 samsung_bl_data->max_brightness = bl_data->max_brightness;
 107         if (bl_data->dft_brightness)
 108                 samsung_bl_data->dft_brightness = bl_data->dft_brightness;
 109         if (bl_data->lth_brightness)
 110                 samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 111         if (bl_data->pwm_period_ns)
 112                 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
 113         if (bl_data->init)
 114                 samsung_bl_data->init = bl_data->init;
 115         if (bl_data->notify)
 116                 samsung_bl_data->notify = bl_data->notify;
 117         if (bl_data->exit)
 118                 samsung_bl_data->exit = bl_data->exit;
 119         if (bl_data->check_fb)
 120                 samsung_bl_data->check_fb = bl_data->check_fb;
 121
 122         /* Keep the GPIO info for future use */
 123         s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
 124
 125         /* Register the specific PWM timer dev for Backlight control */
 126         ret = platform_device_register(
 127                         &s3c_device_timer[samsung_bl_data->pwm_id]);
 128         if (ret) {
 129                 printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
 130                 goto err_plat_reg1;
 131         }
 132
 133         /* Register the Backlight dev */
 134         ret = platform_device_register(samsung_bl_device);
 135         if (ret) {
 136                 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 137                 goto err_plat_reg2;
 138         }
 139
 140         return;
 141
 142 err_plat_reg2:
 143         platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
 144 err_plat_reg1:
 145         kfree(samsung_bl_data);
 146 err_data:
 147         kfree(samsung_bl_device);
 148         return;
 149 }