tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * LCD / Backlight control code for Sharp SL-6000x (tosa)
3 *
4 * Copyright (c) 2005 Dirk Opfer
5 * Copyright (c) 2007,2008 Dmitry Baryshkov
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
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/device.h>
16#include <linux/spi/spi.h>
17#include <linux/i2c.h>
18#include <linux/gpio.h>
19#include <linux/fb.h>
20#include <linux/backlight.h>
21#include <linux/slab.h>
22
23#include <asm/mach/sharpsl_param.h>
24
25#include <mach/tosa.h>
26
27#define COMADJ_DEFAULT 97
28
29#define DAC_CH1 0
30#define DAC_CH2 1
31
32struct tosa_bl_data {
33 struct i2c_client *i2c;
34 struct backlight_device *bl;
35
36 int comadj;
37};
38
39static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
40{
41 struct spi_device *spi = data->i2c->dev.platform_data;
42
43 i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
44
45 /* SetBacklightDuty */
46 i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
47
48 /* SetBacklightVR */
49 gpio_set_value(TOSA_GPIO_BL_C20MA, brightness & 0x100);
50
51 tosa_bl_enable(spi, brightness);
52}
53
54static int tosa_bl_update_status(struct backlight_device *dev)
55{
56 struct backlight_properties *props = &dev->props;
57 struct tosa_bl_data *data = dev_get_drvdata(&dev->dev);
58 int power = max(props->power, props->fb_blank);
59 int brightness = props->brightness;
60
61 if (power)
62 brightness = 0;
63
64 tosa_bl_set_backlight(data, brightness);
65
66 return 0;
67}
68
69static int tosa_bl_get_brightness(struct backlight_device *dev)
70{
71 struct backlight_properties *props = &dev->props;
72
73 return props->brightness;
74}
75
76static const struct backlight_ops bl_ops = {
77 .get_brightness = tosa_bl_get_brightness,
78 .update_status = tosa_bl_update_status,
79};
80
81static int tosa_bl_probe(struct i2c_client *client,
82 const struct i2c_device_id *id)
83{
84 struct backlight_properties props;
85 struct tosa_bl_data *data;
86 int ret = 0;
87
88 data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
89 GFP_KERNEL);
90 if (!data)
91 return -ENOMEM;
92
93 data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
94
95 ret = devm_gpio_request_one(&client->dev, TOSA_GPIO_BL_C20MA,
96 GPIOF_OUT_INIT_LOW, "backlight");
97 if (ret) {
98 dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
99 return ret;
100 }
101
102 i2c_set_clientdata(client, data);
103 data->i2c = client;
104
105 memset(&props, 0, sizeof(struct backlight_properties));
106 props.type = BACKLIGHT_RAW;
107 props.max_brightness = 512 - 1;
108 data->bl = backlight_device_register("tosa-bl", &client->dev, data,
109 &bl_ops, &props);
110 if (IS_ERR(data->bl)) {
111 ret = PTR_ERR(data->bl);
112 goto err_reg;
113 }
114
115 data->bl->props.brightness = 69;
116 data->bl->props.power = FB_BLANK_UNBLANK;
117
118 backlight_update_status(data->bl);
119
120 return 0;
121
122err_reg:
123 data->bl = NULL;
124 return ret;
125}
126
127static int tosa_bl_remove(struct i2c_client *client)
128{
129 struct tosa_bl_data *data = i2c_get_clientdata(client);
130
131 backlight_device_unregister(data->bl);
132 data->bl = NULL;
133
134 return 0;
135}
136
137#ifdef CONFIG_PM
138static int tosa_bl_suspend(struct i2c_client *client, pm_message_t pm)
139{
140 struct tosa_bl_data *data = i2c_get_clientdata(client);
141
142 tosa_bl_set_backlight(data, 0);
143
144 return 0;
145}
146
147static int tosa_bl_resume(struct i2c_client *client)
148{
149 struct tosa_bl_data *data = i2c_get_clientdata(client);
150
151 backlight_update_status(data->bl);
152 return 0;
153}
154#else
155#define tosa_bl_suspend NULL
156#define tosa_bl_resume NULL
157#endif
158
159static const struct i2c_device_id tosa_bl_id[] = {
160 { "tosa-bl", 0 },
161 { },
162};
163
164static struct i2c_driver tosa_bl_driver = {
165 .driver = {
166 .name = "tosa-bl",
167 .owner = THIS_MODULE,
168 },
169 .probe = tosa_bl_probe,
170 .remove = tosa_bl_remove,
171 .suspend = tosa_bl_suspend,
172 .resume = tosa_bl_resume,
173 .id_table = tosa_bl_id,
174};
175
176module_i2c_driver(tosa_bl_driver);
177
178MODULE_AUTHOR("Dmitry Baryshkov");
179MODULE_LICENSE("GPL v2");
180MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
181