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/slab.h>
16 #include <linux/io.h>
17 #include <linux/pwm_backlight.h>
18
19 #include <plat/devs.h>
20 #include <plat/gpio-cfg.h>
21 #include <plat/backlight.h>
22
samsung_bl_init(struct device * dev)23 static int samsung_bl_init(struct device *dev)
24 {
25 int ret = 0;
26 struct platform_device *timer_dev =
27 container_of(dev->parent, struct platform_device, dev);
28 struct samsung_bl_gpio_info *bl_gpio_info =
29 timer_dev->dev.platform_data;
30
31 ret = gpio_request(bl_gpio_info->no, "Backlight");
32 if (ret) {
33 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
34 return ret;
35 }
36
37 /* Configure GPIO pin with specific GPIO function for PWM timer */
38 s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
39
40 return 0;
41 }
42
samsung_bl_exit(struct device * dev)43 static void samsung_bl_exit(struct device *dev)
44 {
45 struct platform_device *timer_dev =
46 container_of(dev->parent, struct platform_device, dev);
47 struct samsung_bl_gpio_info *bl_gpio_info =
48 timer_dev->dev.platform_data;
49
50 s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
51 gpio_free(bl_gpio_info->no);
52 }
53
54 /* Initialize few important fields of platform_pwm_backlight_data
55 * structure with default values. These fields can be overridden by
56 * board-specific values sent from machine file.
57 * For ease of operation, these fields are initialized with values
58 * used by most samsung boards.
59 * Users has the option of sending info about other parameters
60 * for their specific boards
61 */
62
63 static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
64 .max_brightness = 255,
65 .dft_brightness = 255,
66 .pwm_period_ns = 78770,
67 .init = samsung_bl_init,
68 .exit = samsung_bl_exit,
69 };
70
71 static struct platform_device samsung_dfl_bl_device __initdata = {
72 .name = "pwm-backlight",
73 };
74
75 /* samsung_bl_set - Set board specific data (if any) provided by user for
76 * PWM Backlight control and register specific PWM and backlight device.
77 * @gpio_info: structure containing GPIO info for PWM timer
78 * @bl_data: structure containing Backlight control data
79 */
samsung_bl_set(struct samsung_bl_gpio_info * gpio_info,struct platform_pwm_backlight_data * bl_data)80 void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
81 struct platform_pwm_backlight_data *bl_data)
82 {
83 int ret = 0;
84 struct platform_device *samsung_bl_device;
85 struct platform_pwm_backlight_data *samsung_bl_data;
86
87 samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
88 sizeof(struct platform_device), GFP_KERNEL);
89 if (!samsung_bl_device) {
90 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
91 return;
92 }
93
94 samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
95 sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
96 if (!samsung_bl_data) {
97 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
98 goto err_data;
99 }
100
101 /* Copy board specific data provided by user */
102 samsung_bl_data->pwm_id = bl_data->pwm_id;
103 samsung_bl_device->dev.parent =
104 &s3c_device_timer[samsung_bl_data->pwm_id].dev;
105
106 if (bl_data->max_brightness)
107 samsung_bl_data->max_brightness = bl_data->max_brightness;
108 if (bl_data->dft_brightness)
109 samsung_bl_data->dft_brightness = bl_data->dft_brightness;
110 if (bl_data->lth_brightness)
111 samsung_bl_data->lth_brightness = bl_data->lth_brightness;
112 if (bl_data->pwm_period_ns)
113 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
114 if (bl_data->init)
115 samsung_bl_data->init = bl_data->init;
116 if (bl_data->notify)
117 samsung_bl_data->notify = bl_data->notify;
118 if (bl_data->exit)
119 samsung_bl_data->exit = bl_data->exit;
120 if (bl_data->check_fb)
121 samsung_bl_data->check_fb = bl_data->check_fb;
122
123 /* Keep the GPIO info for future use */
124 s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
125
126 /* Register the specific PWM timer dev for Backlight control */
127 ret = platform_device_register(
128 &s3c_device_timer[samsung_bl_data->pwm_id]);
129 if (ret) {
130 printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
131 goto err_plat_reg1;
132 }
133
134 /* Register the Backlight dev */
135 ret = platform_device_register(samsung_bl_device);
136 if (ret) {
137 printk(KERN_ERR "failed to register backlight device: %d\n", ret);
138 goto err_plat_reg2;
139 }
140
141 return;
142
143 err_plat_reg2:
144 platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
145 err_plat_reg1:
146 kfree(samsung_bl_data);
147 err_data:
148 kfree(samsung_bl_device);
149 return;
150 }
151