1 /*
2 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com
4 *
5 * Common infrastructure for PWM Backlight for Samsung boards
6 *
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.
10 */
11
12 #include <linux/gpio.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.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
21 #include "backlight.h"
22
23 struct samsung_bl_drvdata {
24 struct platform_pwm_backlight_data plat_data;
25 struct samsung_bl_gpio_info *gpio_info;
26 };
27
samsung_bl_init(struct device * dev)28 static int samsung_bl_init(struct device *dev)
29 {
30 int ret = 0;
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;
35
36 ret = gpio_request(bl_gpio_info->no, "Backlight");
37 if (ret) {
38 printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
39 return ret;
40 }
41
42 /* Configure GPIO pin with specific GPIO function for PWM timer */
43 s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
44
45 return 0;
46 }
47
samsung_bl_exit(struct device * dev)48 static void samsung_bl_exit(struct device *dev)
49 {
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;
54
55 s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
56 gpio_free(bl_gpio_info->no);
57 }
58
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
66 */
67
68 static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
69 .plat_data = {
70 .max_brightness = 255,
71 .dft_brightness = 255,
72 .enable_gpio = -1,
73 .init = samsung_bl_init,
74 .exit = samsung_bl_exit,
75 },
76 };
77
78 static struct platform_device samsung_dfl_bl_device __initdata = {
79 .name = "pwm-backlight",
80 };
81
82 /* samsung_bl_set - Set board specific data (if any) provided by user for
83 * PWM Backlight control and register specific PWM and backlight device.
84 * @gpio_info: structure containing GPIO info for PWM timer
85 * @bl_data: structure containing Backlight control data
86 */
samsung_bl_set(struct samsung_bl_gpio_info * gpio_info,struct platform_pwm_backlight_data * bl_data)87 void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
88 struct platform_pwm_backlight_data *bl_data)
89 {
90 int ret = 0;
91 struct platform_device *samsung_bl_device;
92 struct samsung_bl_drvdata *samsung_bl_drvdata;
93 struct platform_pwm_backlight_data *samsung_bl_data;
94
95 samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
96 sizeof(struct platform_device), GFP_KERNEL);
97 if (!samsung_bl_device) {
98 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
99 return;
100 }
101
102 samsung_bl_drvdata = kmemdup(&samsung_dfl_bl_data,
103 sizeof(samsung_dfl_bl_data), GFP_KERNEL);
104 if (!samsung_bl_drvdata) {
105 printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
106 goto err_data;
107 }
108 samsung_bl_device->dev.platform_data = &samsung_bl_drvdata->plat_data;
109 samsung_bl_drvdata->gpio_info = gpio_info;
110 samsung_bl_data = &samsung_bl_drvdata->plat_data;
111
112 /* Copy board specific data provided by user */
113 samsung_bl_device->dev.parent = &samsung_device_pwm.dev;
114
115 if (bl_data->max_brightness)
116 samsung_bl_data->max_brightness = bl_data->max_brightness;
117 if (bl_data->dft_brightness)
118 samsung_bl_data->dft_brightness = bl_data->dft_brightness;
119 if (bl_data->lth_brightness)
120 samsung_bl_data->lth_brightness = bl_data->lth_brightness;
121 if (bl_data->enable_gpio >= 0)
122 samsung_bl_data->enable_gpio = bl_data->enable_gpio;
123 if (bl_data->init)
124 samsung_bl_data->init = bl_data->init;
125 if (bl_data->notify)
126 samsung_bl_data->notify = bl_data->notify;
127 if (bl_data->notify_after)
128 samsung_bl_data->notify_after = bl_data->notify_after;
129 if (bl_data->exit)
130 samsung_bl_data->exit = bl_data->exit;
131 if (bl_data->check_fb)
132 samsung_bl_data->check_fb = bl_data->check_fb;
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 kfree(samsung_bl_data);
145 err_data:
146 kfree(samsung_bl_device);
147 return;
148 }
149