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
23struct samsung_bl_drvdata {
24	struct platform_pwm_backlight_data plat_data;
25	struct samsung_bl_gpio_info *gpio_info;
26};
27
28static 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
48static 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
68static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
69	.plat_data = {
70		.max_brightness = 255,
71		.dft_brightness = 255,
72		.pwm_period_ns  = 78770,
73		.enable_gpio    = -1,
74		.init           = samsung_bl_init,
75		.exit           = samsung_bl_exit,
76	},
77};
78
79static struct platform_device samsung_dfl_bl_device __initdata = {
80	.name		= "pwm-backlight",
81};
82
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
87 */
88void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
89	struct platform_pwm_backlight_data *bl_data)
90{
91	int ret = 0;
92	struct platform_device *samsung_bl_device;
93	struct samsung_bl_drvdata *samsung_bl_drvdata;
94	struct platform_pwm_backlight_data *samsung_bl_data;
95
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__);
100		return;
101	}
102
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__);
107		goto err_data;
108	}
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;
112
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;
116
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;
127	if (bl_data->init)
128		samsung_bl_data->init = bl_data->init;
129	if (bl_data->notify)
130		samsung_bl_data->notify = bl_data->notify;
131	if (bl_data->notify_after)
132		samsung_bl_data->notify_after = bl_data->notify_after;
133	if (bl_data->exit)
134		samsung_bl_data->exit = bl_data->exit;
135	if (bl_data->check_fb)
136		samsung_bl_data->check_fb = bl_data->check_fb;
137
138	/* Register the Backlight dev */
139	ret = platform_device_register(samsung_bl_device);
140	if (ret) {
141		printk(KERN_ERR "failed to register backlight device: %d\n", ret);
142		goto err_plat_reg2;
143	}
144
145	return;
146
147err_plat_reg2:
148	kfree(samsung_bl_data);
149err_data:
150	kfree(samsung_bl_device);
151	return;
152}
153