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/slab.h>
  16 #include <linux/io.h>
  17 #include <linux/pwm_backlight.h>
  18 #include <linux/slab.h>
  19
  20 #include <plat/devs.h>
  21 #include <plat/gpio-cfg.h>
  22 #include <plat/backlight.h>
  23
  24 static int samsung_bl_init(struct device *dev)
  25 {
  26         int ret = 0;
  27         struct platform_device *timer_dev =
  28                         container_of(dev->parent, struct platform_device, dev);
  29         struct samsung_bl_gpio_info *bl_gpio_info =
  30                         timer_dev->dev.platform_data;
  31
  32         ret = gpio_request(bl_gpio_info->no, "Backlight");
  33         if (ret) {
  34                 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
  35                 return ret;
  36         }
  37
  38         /* Configure GPIO pin with specific GPIO function for PWM timer */
  39         s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
  40
  41         return 0;
  42 }
  43
  44 static void samsung_bl_exit(struct device *dev)
  45 {
  46         struct platform_device *timer_dev =
  47                         container_of(dev->parent, struct platform_device, dev);
  48         struct samsung_bl_gpio_info *bl_gpio_info =
  49                         timer_dev->dev.platform_data;
  50
  51         s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
  52         gpio_free(bl_gpio_info->no);
  53 }
  54
  55 /* Initialize few important fields of platform_pwm_backlight_data
  56  * structure with default values. These fields can be overridden by
  57  * board-specific values sent from machine file.
  58  * For ease of operation, these fields are initialized with values
  59  * used by most samsung boards.
  60  * Users has the option of sending info about other parameters
  61  * for their specific boards
  62  */
  63
  64 static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
  65         .max_brightness = 255,
  66         .dft_brightness = 255,
  67         .pwm_period_ns  = 78770,
  68         .init           = samsung_bl_init,
  69         .exit           = samsung_bl_exit,
  70 };
  71
  72 static struct platform_device samsung_dfl_bl_device __initdata = {
  73         .name           = "pwm-backlight",
  74 };
  75
  76 /* samsung_bl_set - Set board specific data (if any) provided by user for
  77  * PWM Backlight control and register specific PWM and backlight device.
  78  * @gpio_info:  structure containing GPIO info for PWM timer
  79  * @bl_data:    structure containing Backlight control data
  80  */
  81 void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  82         struct platform_pwm_backlight_data *bl_data)
  83 {
  84         int ret = 0;
  85         struct platform_device *samsung_bl_device;
  86         struct platform_pwm_backlight_data *samsung_bl_data;
  87
  88         samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  89                         sizeof(struct platform_device), GFP_KERNEL);
  90         if (!samsung_bl_device) {
  91                 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  92                 return;
  93         }
  94
  95         samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
  96                 sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
  97         if (!samsung_bl_data) {
  98                 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  99                 goto err_data;
 100         }
 101
 102         /* Copy board specific data provided by user */
 103         samsung_bl_data->pwm_id = bl_data->pwm_id;
 104         samsung_bl_device->dev.parent =
 105                         &s3c_device_timer[samsung_bl_data->pwm_id].dev;
 106
 107         if (bl_data->max_brightness)
 108                 samsung_bl_data->max_brightness = bl_data->max_brightness;
 109         if (bl_data->dft_brightness)
 110                 samsung_bl_data->dft_brightness = bl_data->dft_brightness;
 111         if (bl_data->lth_brightness)
 112                 samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 113         if (bl_data->pwm_period_ns)
 114                 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
 115         if (bl_data->init)
 116                 samsung_bl_data->init = bl_data->init;
 117         if (bl_data->notify)
 118                 samsung_bl_data->notify = bl_data->notify;
 119         if (bl_data->exit)
 120                 samsung_bl_data->exit = bl_data->exit;
 121         if (bl_data->check_fb)
 122                 samsung_bl_data->check_fb = bl_data->check_fb;
 123
 124         /* Keep the GPIO info for future use */
 125         s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
 126
 127         /* Register the specific PWM timer dev for Backlight control */
 128         ret = platform_device_register(
 129                         &s3c_device_timer[samsung_bl_data->pwm_id]);
 130         if (ret) {
 131                 printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
 132                 goto err_plat_reg1;
 133         }
 134
 135         /* Register the Backlight dev */
 136         ret = platform_device_register(samsung_bl_device);
 137         if (ret) {
 138                 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 139                 goto err_plat_reg2;
 140         }
 141
 142         return;
 143
 144 err_plat_reg2:
 145         platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
 146 err_plat_reg1:
 147         kfree(samsung_bl_data);
 148 err_data:
 149         kfree(samsung_bl_device);
 150         return;
 151 }