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 
20 #include <video/platform_lcd.h>
21 
22 struct platform_lcd {
23 	struct device		*us;
24 	struct lcd_device	*lcd;
25 	struct plat_lcd_data	*pdata;
26 
27 	unsigned int		 power;
28 	unsigned int		 suspended : 1;
29 };
30 
31 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
32 {
33 	return lcd_get_data(lcd);
34 }
35 
36 static int platform_lcd_get_power(struct lcd_device *lcd)
37 {
38 	struct platform_lcd *plcd = to_our_lcd(lcd);
39 
40 	return plcd->power;
41 }
42 
43 static int platform_lcd_set_power(struct lcd_device *lcd, int power)
44 {
45 	struct platform_lcd *plcd = to_our_lcd(lcd);
46 	int lcd_power = 1;
47 
48 	if (power == FB_BLANK_POWERDOWN || plcd->suspended)
49 		lcd_power = 0;
50 
51 	plcd->pdata->set_power(plcd->pdata, lcd_power);
52 	plcd->power = power;
53 
54 	return 0;
55 }
56 
57 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
58 {
59 	struct platform_lcd *plcd = to_our_lcd(lcd);
60 	struct plat_lcd_data *pdata = plcd->pdata;
61 
62 	if (pdata->match_fb)
63 		return pdata->match_fb(pdata, info);
64 
65 	return plcd->us->parent == info->device;
66 }
67 
68 static struct lcd_ops platform_lcd_ops = {
69 	.get_power	= platform_lcd_get_power,
70 	.set_power	= platform_lcd_set_power,
71 	.check_fb	= platform_lcd_match,
72 };
73 
74 static int __devinit platform_lcd_probe(struct platform_device *pdev)
75 {
76 	struct plat_lcd_data *pdata;
77 	struct platform_lcd *plcd;
78 	struct device *dev = &pdev->dev;
79 	int err;
80 
81 	pdata = pdev->dev.platform_data;
82 	if (!pdata) {
83 		dev_err(dev, "no platform data supplied\n");
84 		return -EINVAL;
85 	}
86 
87 	plcd = kzalloc(sizeof(struct platform_lcd), GFP_KERNEL);
88 	if (!plcd) {
89 		dev_err(dev, "no memory for state\n");
90 		return -ENOMEM;
91 	}
92 
93 	plcd->us = dev;
94 	plcd->pdata = pdata;
95 	plcd->lcd = lcd_device_register("platform-lcd", dev,
96 					plcd, &platform_lcd_ops);
97 	if (IS_ERR(plcd->lcd)) {
98 		dev_err(dev, "cannot register lcd device\n");
99 		err = PTR_ERR(plcd->lcd);
100 		goto err_mem;
101 	}
102 
103 	platform_set_drvdata(pdev, plcd);
104 	return 0;
105 
106  err_mem:
107 	kfree(plcd);
108 	return err;
109 }
110 
111 static int __devexit platform_lcd_remove(struct platform_device *pdev)
112 {
113 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
114 
115 	lcd_device_unregister(plcd->lcd);
116 	kfree(plcd);
117 
118 	return 0;
119 }
120 
121 #ifdef CONFIG_PM
122 static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st)
123 {
124 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
125 
126 	plcd->suspended = 1;
127 	platform_lcd_set_power(plcd->lcd, plcd->power);
128 
129 	return 0;
130 }
131 
132 static int platform_lcd_resume(struct platform_device *pdev)
133 {
134 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
135 
136 	plcd->suspended = 0;
137 	platform_lcd_set_power(plcd->lcd, plcd->power);
138 
139 	return 0;
140 }
141 #else
142 #define platform_lcd_suspend NULL
143 #define platform_lcd_resume NULL
144 #endif
145 
146 static struct platform_driver platform_lcd_driver = {
147 	.driver		= {
148 		.name	= "platform-lcd",
149 		.owner	= THIS_MODULE,
150 	},
151 	.probe		= platform_lcd_probe,
152 	.remove		= __devexit_p(platform_lcd_remove),
153 	.suspend        = platform_lcd_suspend,
154 	.resume         = platform_lcd_resume,
155 };
156 
157 static int __init platform_lcd_init(void)
158 {
159 	return platform_driver_register(&platform_lcd_driver);
160 }
161 
162 static void __exit platform_lcd_cleanup(void)
163 {
164 	platform_driver_unregister(&platform_lcd_driver);
165 }
166 
167 module_init(platform_lcd_init);
168 module_exit(platform_lcd_cleanup);
169 
170 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
171 MODULE_LICENSE("GPL v2");
172 MODULE_ALIAS("platform:platform-lcd");
173