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-rw-r--r--arch/arm/plat-samsung/dev-backlight.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c
new file mode 100644
index 000000000000..3cedd4c407af
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+++ b/arch/arm/plat-samsung/dev-backlight.c
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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/io.h>
16#include <linux/pwm_backlight.h>
17
18#include <plat/devs.h>
19#include <plat/gpio-cfg.h>
20#include <plat/backlight.h>
21
22static int samsung_bl_init(struct device *dev)
23{
24 int ret = 0;
25 struct platform_device *timer_dev =
26 container_of(dev->parent, struct platform_device, dev);
27 struct samsung_bl_gpio_info *bl_gpio_info =
28 timer_dev->dev.platform_data;
29
30 ret = gpio_request(bl_gpio_info->no, "Backlight");
31 if (ret) {
32 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
33 return ret;
34 }
35
36 /* Configure GPIO pin with specific GPIO function for PWM timer */
37 s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
38
39 return 0;
40}
41
42static void samsung_bl_exit(struct device *dev)
43{
44 struct platform_device *timer_dev =
45 container_of(dev->parent, struct platform_device, dev);
46 struct samsung_bl_gpio_info *bl_gpio_info =
47 timer_dev->dev.platform_data;
48
49 s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
50 gpio_free(bl_gpio_info->no);
51}
52
53/* Initialize few important fields of platform_pwm_backlight_data
54 * structure with default values. These fields can be overridden by
55 * board-specific values sent from machine file.
56 * For ease of operation, these fields are initialized with values
57 * used by most samsung boards.
58 * Users has the option of sending info about other parameters
59 * for their specific boards
60 */
61
62static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
63 .max_brightness = 255,
64 .dft_brightness = 255,
65 .pwm_period_ns = 78770,
66 .init = samsung_bl_init,
67 .exit = samsung_bl_exit,
68};
69
70static struct platform_device samsung_dfl_bl_device __initdata = {
71 .name = "pwm-backlight",
72};
73
74/* samsung_bl_set - Set board specific data (if any) provided by user for
75 * PWM Backlight control and register specific PWM and backlight device.
76 * @gpio_info: structure containing GPIO info for PWM timer
77 * @bl_data: structure containing Backlight control data
78 */
79void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
80 struct platform_pwm_backlight_data *bl_data)
81{
82 int ret = 0;
83 struct platform_device *samsung_bl_device;
84 struct platform_pwm_backlight_data *samsung_bl_data;
85
86 samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
87 sizeof(struct platform_device), GFP_KERNEL);
88 if (!samsung_bl_device) {
89 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
90 return;
91 }
92
93 samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
94 sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
95 if (!samsung_bl_data) {
96 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
97 goto err_data;
98 }
99
100 /* Copy board specific data provided by user */
101 samsung_bl_data->pwm_id = bl_data->pwm_id;
102 samsung_bl_device->dev.parent =
103 &s3c_device_timer[samsung_bl_data->pwm_id].dev;
104
105 if (bl_data->max_brightness)
106 samsung_bl_data->max_brightness = bl_data->max_brightness;
107 if (bl_data->dft_brightness)
108 samsung_bl_data->dft_brightness = bl_data->dft_brightness;
109 if (bl_data->lth_brightness)
110 samsung_bl_data->lth_brightness = bl_data->lth_brightness;
111 if (bl_data->pwm_period_ns)
112 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
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->exit)
118 samsung_bl_data->exit = bl_data->exit;
119 if (bl_data->check_fb)
120 samsung_bl_data->check_fb = bl_data->check_fb;
121
122 /* Keep the GPIO info for future use */
123 s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
124
125 /* Register the specific PWM timer dev for Backlight control */
126 ret = platform_device_register(
127 &s3c_device_timer[samsung_bl_data->pwm_id]);
128 if (ret) {
129 printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
130 goto err_plat_reg1;
131 }
132
133 /* Register the Backlight dev */
134 ret = platform_device_register(samsung_bl_device);
135 if (ret) {
136 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
137 goto err_plat_reg2;
138 }
139
140 return;
141
142err_plat_reg2:
143 platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
144err_plat_reg1:
145 kfree(samsung_bl_data);
146err_data:
147 kfree(samsung_bl_device);
148 return;
149}