2 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com
5 * Common infrastructure for PWM Backlight for Samsung boards
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/gpio.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
16 #include <linux/pwm_backlight.h>
18 #include <plat/devs.h>
19 #include <plat/gpio-cfg.h>
21 #include "backlight.h"
23 struct samsung_bl_drvdata {
24 struct platform_pwm_backlight_data plat_data;
25 struct samsung_bl_gpio_info *gpio_info;
28 static int samsung_bl_init(struct device *dev)
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;
36 ret = gpio_request(bl_gpio_info->no, "Backlight");
38 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
42 /* Configure GPIO pin with specific GPIO function for PWM timer */
43 s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
48 static void samsung_bl_exit(struct device *dev)
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;
55 s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
56 gpio_free(bl_gpio_info->no);
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
68 static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
70 .max_brightness = 255,
71 .dft_brightness = 255,
72 .pwm_period_ns = 78770,
74 .init = samsung_bl_init,
75 .exit = samsung_bl_exit,
79 static struct platform_device samsung_dfl_bl_device __initdata = {
80 .name = "pwm-backlight",
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
88 void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
89 struct platform_pwm_backlight_data *bl_data)
92 struct platform_device *samsung_bl_device;
93 struct samsung_bl_drvdata *samsung_bl_drvdata;
94 struct platform_pwm_backlight_data *samsung_bl_data;
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__);
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__);
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;
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;
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;
128 samsung_bl_data->init = bl_data->init;
130 samsung_bl_data->notify = bl_data->notify;
131 if (bl_data->notify_after)
132 samsung_bl_data->notify_after = bl_data->notify_after;
134 samsung_bl_data->exit = bl_data->exit;
135 if (bl_data->check_fb)
136 samsung_bl_data->check_fb = bl_data->check_fb;
138 /* Register the Backlight dev */
139 ret = platform_device_register(samsung_bl_device);
141 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
148 kfree(samsung_bl_data);
150 kfree(samsung_bl_device);