tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* drivers/video/backlight/platform_lcd.c
2 *
3 * Copyright 2008 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * Generic platform-device LCD power control interface.
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
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/fb.h>
17#include <linux/backlight.h>
18#include <linux/lcd.h>
19#include <linux/of.h>
20#include <linux/slab.h>
21
22#include <video/platform_lcd.h>
23
24struct platform_lcd {
25 struct device *us;
26 struct lcd_device *lcd;
27 struct plat_lcd_data *pdata;
28
29 unsigned int power;
30 unsigned int suspended:1;
31};
32
33static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
34{
35 return lcd_get_data(lcd);
36}
37
38static int platform_lcd_get_power(struct lcd_device *lcd)
39{
40 struct platform_lcd *plcd = to_our_lcd(lcd);
41
42 return plcd->power;
43}
44
45static int platform_lcd_set_power(struct lcd_device *lcd, int power)
46{
47 struct platform_lcd *plcd = to_our_lcd(lcd);
48 int lcd_power = 1;
49
50 if (power == FB_BLANK_POWERDOWN || plcd->suspended)
51 lcd_power = 0;
52
53 plcd->pdata->set_power(plcd->pdata, lcd_power);
54 plcd->power = power;
55
56 return 0;
57}
58
59static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
60{
61 struct platform_lcd *plcd = to_our_lcd(lcd);
62 struct plat_lcd_data *pdata = plcd->pdata;
63
64 if (pdata->match_fb)
65 return pdata->match_fb(pdata, info);
66
67 return plcd->us->parent == info->device;
68}
69
70static struct lcd_ops platform_lcd_ops = {
71 .get_power = platform_lcd_get_power,
72 .set_power = platform_lcd_set_power,
73 .check_fb = platform_lcd_match,
74};
75
76static int platform_lcd_probe(struct platform_device *pdev)
77{
78 struct plat_lcd_data *pdata;
79 struct platform_lcd *plcd;
80 struct device *dev = &pdev->dev;
81 int err;
82
83 pdata = pdev->dev.platform_data;
84 if (!pdata) {
85 dev_err(dev, "no platform data supplied\n");
86 return -EINVAL;
87 }
88
89 if (pdata->probe) {
90 err = pdata->probe(pdata);
91 if (err)
92 return err;
93 }
94
95 plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
96 GFP_KERNEL);
97 if (!plcd) {
98 dev_err(dev, "no memory for state\n");
99 return -ENOMEM;
100 }
101
102 plcd->us = dev;
103 plcd->pdata = pdata;
104 plcd->lcd = lcd_device_register(dev_name(dev), dev,
105 plcd, &platform_lcd_ops);
106 if (IS_ERR(plcd->lcd)) {
107 dev_err(dev, "cannot register lcd device\n");
108 err = PTR_ERR(plcd->lcd);
109 goto err;
110 }
111
112 platform_set_drvdata(pdev, plcd);
113 platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
114
115 return 0;
116
117 err:
118 return err;
119}
120
121static int platform_lcd_remove(struct platform_device *pdev)
122{
123 struct platform_lcd *plcd = platform_get_drvdata(pdev);
124
125 lcd_device_unregister(plcd->lcd);
126
127 return 0;
128}
129
130#ifdef CONFIG_PM_SLEEP
131static int platform_lcd_suspend(struct device *dev)
132{
133 struct platform_lcd *plcd = dev_get_drvdata(dev);
134
135 plcd->suspended = 1;
136 platform_lcd_set_power(plcd->lcd, plcd->power);
137
138 return 0;
139}
140
141static int platform_lcd_resume(struct device *dev)
142{
143 struct platform_lcd *plcd = dev_get_drvdata(dev);
144
145 plcd->suspended = 0;
146 platform_lcd_set_power(plcd->lcd, plcd->power);
147
148 return 0;
149}
150#endif
151
152static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
153 platform_lcd_resume);
154
155#ifdef CONFIG_OF
156static const struct of_device_id platform_lcd_of_match[] = {
157 { .compatible = "platform-lcd" },
158 {},
159};
160MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
161#endif
162
163static struct platform_driver platform_lcd_driver = {
164 .driver = {
165 .name = "platform-lcd",
166 .owner = THIS_MODULE,
167 .pm = &platform_lcd_pm_ops,
168 .of_match_table = of_match_ptr(platform_lcd_of_match),
169 },
170 .probe = platform_lcd_probe,
171 .remove = platform_lcd_remove,
172};
173
174module_platform_driver(platform_lcd_driver);
175
176MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
177MODULE_LICENSE("GPL v2");
178MODULE_ALIAS("platform:platform-lcd");