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
  19 struct samsung_bl_drvdata {
  20         struct platform_pwm_backlight_data plat_data;
  21         struct samsung_bl_gpio_info *gpio_info;
  22 };
  23
  24 static 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
  44 static 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
  64 static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
  65         .plat_data = {
  66                 .max_brightness = 255,
  67                 .dft_brightness = 255,
  68                 .init           = samsung_bl_init,
  69                 .exit           = samsung_bl_exit,
  70         },
  71 };
  72
  73 static struct platform_device samsung_dfl_bl_device __initdata = {
  74         .name           = "pwm-backlight",
  75 };
  76
  77 /* samsung_bl_set - Set board specific data (if any) provided by user for
  78  * PWM Backlight control and register specific PWM and backlight device.
  79  * @gpio_info:  structure containing GPIO info for PWM timer
  80  * @bl_data:    structure containing Backlight control data
  81  */
  82 void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
  83         struct platform_pwm_backlight_data *bl_data)
  84 {
  85         int ret = 0;
  86         struct platform_device *samsung_bl_device;
  87         struct samsung_bl_drvdata *samsung_bl_drvdata;
  88         struct platform_pwm_backlight_data *samsung_bl_data;
  89
  90         samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
  91                         sizeof(struct platform_device), GFP_KERNEL);
  92         if (!samsung_bl_device)
  93                 return;
  94
  95         samsung_bl_drvdata = kmemdup(&samsung_dfl_bl_data,
  96                                 sizeof(samsung_dfl_bl_data), GFP_KERNEL);
  97         if (!samsung_bl_drvdata)
  98                 goto err_data;
  99
 100         samsung_bl_device->dev.platform_data = &samsung_bl_drvdata->plat_data;
 101         samsung_bl_drvdata->gpio_info = gpio_info;
 102         samsung_bl_data = &samsung_bl_drvdata->plat_data;
 103
 104         /* Copy board specific data provided by user */
 105         samsung_bl_device->dev.parent = &samsung_device_pwm.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->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->notify_after)
 118                 samsung_bl_data->notify_after = bl_data->notify_after;
 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         /* Register the Backlight dev */
 125         ret = platform_device_register(samsung_bl_device);
 126         if (ret) {
 127                 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
 128                 goto err_plat_reg2;
 129         }
 130
 131         return;
 132
 133 err_plat_reg2:
 134         kfree(samsung_bl_data);
 135 err_data:
 136         kfree(samsung_bl_device);
 137 }