LXR linux/arch/arm/mach-s3c64xx/dev-backlight.c

   1// SPDX-License-Identifier: GPL-2.0
   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#include <linux/gpio.h>
   9#include <linux/platform_device.h>
  10#include <linux/slab.h>
  11#include <linux/io.h>
  12#include <linux/pwm_backlight.h>
  13
  14#include <plat/devs.h>
  15#include <plat/gpio-cfg.h>
  16
  17#include "backlight.h"
  18
  19struct samsung_bl_drvdata {
  20        struct platform_pwm_backlight_data plat_data;
  21        struct samsung_bl_gpio_info *gpio_info;
  22};
  23
  24static int samsung_bl_init(struct device *dev)
  25{
  26        int ret = 0;
  27        struct platform_pwm_backlight_data *pdata = dev->platform_data;
  28        struct samsung_bl_drvdata *drvdata = container_of(pdata,
  29                                        struct samsung_bl_drvdata, plat_data);
  30        struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
  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
  44static void samsung_bl_exit(struct device *dev)
  45{
  46        struct platform_pwm_backlight_data *pdata = dev->platform_data;
  47        struct samsung_bl_drvdata *drvdata = container_of(pdata,
  48                                        struct samsung_bl_drvdata, plat_data);
  49        struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
  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
  64static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
  65        .plat_data = {
  66                .max_brightness = 255,
  67                .dft_brightness = 255,
  68                .enable_gpio    = -1,
  69                .init           = samsung_bl_init,
  70                .exit           = samsung_bl_exit,
  71        },
  72};
  73
  74static struct platform_device samsung_dfl_bl_device __initdata = {
  75        .name           = "pwm-backlight",
  76};
  77
  78/* samsung_bl_set - Set board specific data (if any) provided by user for
  79 * PWM Backlight control and register specific PWM and backlight device.
  80 * @gpio_info:  structure containing GPIO info for PWM timer
  81 * @bl_data:    structure containing Backlight control data
  82 */
  83void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  84        struct platform_pwm_backlight_data *bl_data)
  85{
  86        int ret = 0;
  87        struct platform_device *samsung_bl_device;
  88        struct samsung_bl_drvdata *samsung_bl_drvdata;
  89        struct platform_pwm_backlight_data *samsung_bl_data;
  90
  91        samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  92                        sizeof(struct platform_device), GFP_KERNEL);
  93        if (!samsung_bl_device)
  94                return;
  95
  96        samsung_bl_drvdata = kmemdup(&samsung_dfl_bl_data,
  97                                sizeof(samsung_dfl_bl_data), GFP_KERNEL);
  98        if (!samsung_bl_drvdata)
  99                goto err_data;
 100
 101        samsung_bl_device->dev.platform_data = &samsung_bl_drvdata->plat_data;
 102        samsung_bl_drvdata->gpio_info = gpio_info;
 103        samsung_bl_data = &samsung_bl_drvdata->plat_data;
 104
 105        /* Copy board specific data provided by user */
 106        samsung_bl_device->dev.parent = &samsung_device_pwm.dev;
 107
 108        if (bl_data->max_brightness)
 109                samsung_bl_data->max_brightness = bl_data->max_brightness;
 110        if (bl_data->dft_brightness)
 111                samsung_bl_data->dft_brightness = bl_data->dft_brightness;
 112        if (bl_data->lth_brightness)
 113                samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 114        if (bl_data->enable_gpio >= 0)
 115                samsung_bl_data->enable_gpio = bl_data->enable_gpio;
 116        if (bl_data->init)
 117                samsung_bl_data->init = bl_data->init;
 118        if (bl_data->notify)
 119                samsung_bl_data->notify = bl_data->notify;
 120        if (bl_data->notify_after)
 121                samsung_bl_data->notify_after = bl_data->notify_after;
 122        if (bl_data->exit)
 123                samsung_bl_data->exit = bl_data->exit;
 124        if (bl_data->check_fb)
 125                samsung_bl_data->check_fb = bl_data->check_fb;
 126
 127        /* Register the Backlight dev */
 128        ret = platform_device_register(samsung_bl_device);
 129        if (ret) {
 130                printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 131                goto err_plat_reg2;
 132        }
 133
 134        return;
 135
 136err_plat_reg2:
 137        kfree(samsung_bl_data);
 138err_data:
 139        kfree(samsung_bl_device);
 140}
 141