LXR linux/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
  19#include <plat/devs.h>
  20#include <plat/gpio-cfg.h>
  21#include <plat/backlight.h>
  22
  23static int samsung_bl_init(struct device *dev)
  24{
  25        int ret = 0;
  26        struct platform_device *timer_dev =
  27                        container_of(dev->parent, struct platform_device, dev);
  28        struct samsung_bl_gpio_info *bl_gpio_info =
  29                        timer_dev->dev.platform_data;
  30
  31        ret = gpio_request(bl_gpio_info->no, "Backlight");
  32        if (ret) {
  33                printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
  34                return ret;
  35        }
  36
  37        /* Configure GPIO pin with specific GPIO function for PWM timer */
  38        s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
  39
  40        return 0;
  41}
  42
  43static void samsung_bl_exit(struct device *dev)
  44{
  45        struct platform_device *timer_dev =
  46                        container_of(dev->parent, struct platform_device, dev);
  47        struct samsung_bl_gpio_info *bl_gpio_info =
  48                        timer_dev->dev.platform_data;
  49
  50        s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
  51        gpio_free(bl_gpio_info->no);
  52}
  53
  54/* Initialize few important fields of platform_pwm_backlight_data
  55 * structure with default values. These fields can be overridden by
  56 * board-specific values sent from machine file.
  57 * For ease of operation, these fields are initialized with values
  58 * used by most samsung boards.
  59 * Users has the option of sending info about other parameters
  60 * for their specific boards
  61 */
  62
  63static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
  64        .max_brightness = 255,
  65        .dft_brightness = 255,
  66        .pwm_period_ns  = 78770,
  67        .init           = samsung_bl_init,
  68        .exit           = samsung_bl_exit,
  69};
  70
  71static struct platform_device samsung_dfl_bl_device __initdata = {
  72        .name           = "pwm-backlight",
  73};
  74
  75/* samsung_bl_set - Set board specific data (if any) provided by user for
  76 * PWM Backlight control and register specific PWM and backlight device.
  77 * @gpio_info:  structure containing GPIO info for PWM timer
  78 * @bl_data:    structure containing Backlight control data
  79 */
  80void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  81        struct platform_pwm_backlight_data *bl_data)
  82{
  83        int ret = 0;
  84        struct platform_device *samsung_bl_device;
  85        struct platform_pwm_backlight_data *samsung_bl_data;
  86
  87        samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  88                        sizeof(struct platform_device), GFP_KERNEL);
  89        if (!samsung_bl_device) {
  90                printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  91                return;
  92        }
  93
  94        samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
  95                sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
  96        if (!samsung_bl_data) {
  97                printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
  98                goto err_data;
  99        }
 100
 101        /* Copy board specific data provided by user */
 102        samsung_bl_data->pwm_id = bl_data->pwm_id;
 103        samsung_bl_device->dev.parent =
 104                        &s3c_device_timer[samsung_bl_data->pwm_id].dev;
 105
 106        if (bl_data->max_brightness)
 107                samsung_bl_data->max_brightness = bl_data->max_brightness;
 108        if (bl_data->dft_brightness)
 109                samsung_bl_data->dft_brightness = bl_data->dft_brightness;
 110        if (bl_data->lth_brightness)
 111                samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 112        if (bl_data->pwm_period_ns)
 113                samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
 114        if (bl_data->init)
 115                samsung_bl_data->init = bl_data->init;
 116        if (bl_data->notify)
 117                samsung_bl_data->notify = bl_data->notify;
 118        if (bl_data->notify_after)
 119                samsung_bl_data->notify_after = bl_data->notify_after;
 120        if (bl_data->exit)
 121                samsung_bl_data->exit = bl_data->exit;
 122        if (bl_data->check_fb)
 123                samsung_bl_data->check_fb = bl_data->check_fb;
 124
 125        /* Keep the GPIO info for future use */
 126        s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
 127
 128        /* Register the specific PWM timer dev for Backlight control */
 129        ret = platform_device_register(
 130                        &s3c_device_timer[samsung_bl_data->pwm_id]);
 131        if (ret) {
 132                printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
 133                goto err_plat_reg1;
 134        }
 135
 136        /* Register the Backlight dev */
 137        ret = platform_device_register(samsung_bl_device);
 138        if (ret) {
 139                printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 140                goto err_plat_reg2;
 141        }
 142
 143        return;
 144
 145err_plat_reg2:
 146        platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
 147err_plat_reg1:
 148        kfree(samsung_bl_data);
 149err_data:
 150        kfree(samsung_bl_device);
 151        return;
 152}
 153