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                 .enable_gpio    = -1,
  69                 .init           = samsung_bl_init,
  70                 .exit           = samsung_bl_exit,
  71         },
  72 };
  73
  74 static 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  */
  83 void __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
 136 err_plat_reg2:
 137         kfree(samsung_bl_data);
 138 err_data:
 139         kfree(samsung_bl_device);
 140 }