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
  23struct samsung_bl_drvdata {
  24        struct platform_pwm_backlight_data plat_data;
  25        struct samsung_bl_gpio_info *gpio_info;
  26};
  27
  28static int samsung_bl_init(struct device *dev)
  29{
  30        int ret = 0;
  31        struct platform_pwm_backlight_data *pdata = dev->platform_data;
  32        struct samsung_bl_drvdata *drvdata = container_of(pdata,
  33                                        struct samsung_bl_drvdata, plat_data);
  34        struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
  35
  36        ret = gpio_request(bl_gpio_info->no, "Backlight");
  37        if (ret) {
  38                printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
  39                return ret;
  40        }
  41
  42        /* Configure GPIO pin with specific GPIO function for PWM timer */
  43        s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
  44
  45        return 0;
  46}
  47
  48static void samsung_bl_exit(struct device *dev)
  49{
  50        struct platform_pwm_backlight_data *pdata = dev->platform_data;
  51        struct samsung_bl_drvdata *drvdata = container_of(pdata,
  52                                        struct samsung_bl_drvdata, plat_data);
  53        struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
  54
  55        s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
  56        gpio_free(bl_gpio_info->no);
  57}
  58
  59/* Initialize few important fields of platform_pwm_backlight_data
  60 * structure with default values. These fields can be overridden by
  61 * board-specific values sent from machine file.
  62 * For ease of operation, these fields are initialized with values
  63 * used by most samsung boards.
  64 * Users has the option of sending info about other parameters
  65 * for their specific boards
  66 */
  67
  68static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
  69        .plat_data = {
  70                .max_brightness = 255,
  71                .dft_brightness = 255,
  72                .pwm_period_ns  = 78770,
  73                .enable_gpio    = -1,
  74                .init           = samsung_bl_init,
  75                .exit           = samsung_bl_exit,
  76        },
  77};
  78
  79static struct platform_device samsung_dfl_bl_device __initdata = {
  80        .name           = "pwm-backlight",
  81};
  82
  83/* samsung_bl_set - Set board specific data (if any) provided by user for
  84 * PWM Backlight control and register specific PWM and backlight device.
  85 * @gpio_info:  structure containing GPIO info for PWM timer
  86 * @bl_data:    structure containing Backlight control data
  87 */
  88void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  89        struct platform_pwm_backlight_data *bl_data)
  90{
  91        int ret = 0;
  92        struct platform_device *samsung_bl_device;
  93        struct samsung_bl_drvdata *samsung_bl_drvdata;
  94        struct platform_pwm_backlight_data *samsung_bl_data;
  95
  96        samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  97                        sizeof(struct platform_device), GFP_KERNEL);
  98        if (!samsung_bl_device) {
  99                printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
 100                return;
 101        }
 102
 103        samsung_bl_drvdata = kmemdup(&samsung_dfl_bl_data,
 104                                sizeof(samsung_dfl_bl_data), GFP_KERNEL);
 105        if (!samsung_bl_drvdata) {
 106                printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
 107                goto err_data;
 108        }
 109        samsung_bl_device->dev.platform_data = &samsung_bl_drvdata->plat_data;
 110        samsung_bl_drvdata->gpio_info = gpio_info;
 111        samsung_bl_data = &samsung_bl_drvdata->plat_data;
 112
 113        /* Copy board specific data provided by user */
 114        samsung_bl_data->pwm_id = bl_data->pwm_id;
 115        samsung_bl_device->dev.parent = &samsung_device_pwm.dev;
 116
 117        if (bl_data->max_brightness)
 118                samsung_bl_data->max_brightness = bl_data->max_brightness;
 119        if (bl_data->dft_brightness)
 120                samsung_bl_data->dft_brightness = bl_data->dft_brightness;
 121        if (bl_data->lth_brightness)
 122                samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 123        if (bl_data->pwm_period_ns)
 124                samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
 125        if (bl_data->enable_gpio >= 0)
 126                samsung_bl_data->enable_gpio = bl_data->enable_gpio;
 127        if (bl_data->init)
 128                samsung_bl_data->init = bl_data->init;
 129        if (bl_data->notify)
 130                samsung_bl_data->notify = bl_data->notify;
 131        if (bl_data->notify_after)
 132                samsung_bl_data->notify_after = bl_data->notify_after;
 133        if (bl_data->exit)
 134                samsung_bl_data->exit = bl_data->exit;
 135        if (bl_data->check_fb)
 136                samsung_bl_data->check_fb = bl_data->check_fb;
 137
 138        /* Register the Backlight dev */
 139        ret = platform_device_register(samsung_bl_device);
 140        if (ret) {
 141                printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 142                goto err_plat_reg2;
 143        }
 144
 145        return;
 146
 147err_plat_reg2:
 148        kfree(samsung_bl_data);
 149err_data:
 150        kfree(samsung_bl_device);
 151        return;
 152}
 153