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/slab.h>
20 
21 #include <video/platform_lcd.h>
22 
23 struct platform_lcd {
24 	struct device		*us;
25 	struct lcd_device	*lcd;
26 	struct plat_lcd_data	*pdata;
27 
28 	unsigned int		 power;
29 	unsigned int		 suspended : 1;
30 };
31 
32 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
33 {
34 	return lcd_get_data(lcd);
35 }
36 
37 static int platform_lcd_get_power(struct lcd_device *lcd)
38 {
39 	struct platform_lcd *plcd = to_our_lcd(lcd);
40 
41 	return plcd->power;
42 }
43 
44 static int platform_lcd_set_power(struct lcd_device *lcd, int power)
45 {
46 	struct platform_lcd *plcd = to_our_lcd(lcd);
47 	int lcd_power = 1;
48 
49 	if (power == FB_BLANK_POWERDOWN || plcd->suspended)
50 		lcd_power = 0;
51 
52 	plcd->pdata->set_power(plcd->pdata, lcd_power);
53 	plcd->power = power;
54 
55 	return 0;
56 }
57 
58 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
59 {
60 	struct platform_lcd *plcd = to_our_lcd(lcd);
61 	struct plat_lcd_data *pdata = plcd->pdata;
62 
63 	if (pdata->match_fb)
64 		return pdata->match_fb(pdata, info);
65 
66 	return plcd->us->parent == info->device;
67 }
68 
69 static struct lcd_ops platform_lcd_ops = {
70 	.get_power	= platform_lcd_get_power,
71 	.set_power	= platform_lcd_set_power,
72 	.check_fb	= platform_lcd_match,
73 };
74 
75 static int __devinit platform_lcd_probe(struct platform_device *pdev)
76 {
77 	struct plat_lcd_data *pdata;
78 	struct platform_lcd *plcd;
79 	struct device *dev = &pdev->dev;
80 	int err;
81 
82 	pdata = pdev->dev.platform_data;
83 	if (!pdata) {
84 		dev_err(dev, "no platform data supplied\n");
85 		return -EINVAL;
86 	}
87 
88 	plcd = kzalloc(sizeof(struct platform_lcd), GFP_KERNEL);
89 	if (!plcd) {
90 		dev_err(dev, "no memory for state\n");
91 		return -ENOMEM;
92 	}
93 
94 	plcd->us = dev;
95 	plcd->pdata = pdata;
96 	plcd->lcd = lcd_device_register(dev_name(dev), dev,
97 					plcd, &platform_lcd_ops);
98 	if (IS_ERR(plcd->lcd)) {
99 		dev_err(dev, "cannot register lcd device\n");
100 		err = PTR_ERR(plcd->lcd);
101 		goto err_mem;
102 	}
103 
104 	platform_set_drvdata(pdev, plcd);
105 	platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
106 
107 	return 0;
108 
109  err_mem:
110 	kfree(plcd);
111 	return err;
112 }
113 
114 static int __devexit platform_lcd_remove(struct platform_device *pdev)
115 {
116 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
117 
118 	lcd_device_unregister(plcd->lcd);
119 	kfree(plcd);
120 
121 	return 0;
122 }
123 
124 #ifdef CONFIG_PM
125 static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st)
126 {
127 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
128 
129 	plcd->suspended = 1;
130 	platform_lcd_set_power(plcd->lcd, plcd->power);
131 
132 	return 0;
133 }
134 
135 static int platform_lcd_resume(struct platform_device *pdev)
136 {
137 	struct platform_lcd *plcd = platform_get_drvdata(pdev);
138 
139 	plcd->suspended = 0;
140 	platform_lcd_set_power(plcd->lcd, plcd->power);
141 
142 	return 0;
143 }
144 #else
145 #define platform_lcd_suspend NULL
146 #define platform_lcd_resume NULL
147 #endif
148 
149 static struct platform_driver platform_lcd_driver = {
150 	.driver		= {
151 		.name	= "platform-lcd",
152 		.owner	= THIS_MODULE,
153 	},
154 	.probe		= platform_lcd_probe,
155 	.remove		= __devexit_p(platform_lcd_remove),
156 	.suspend        = platform_lcd_suspend,
157 	.resume         = platform_lcd_resume,
158 };
159 
160 static int __init platform_lcd_init(void)
161 {
162 	return platform_driver_register(&platform_lcd_driver);
163 }
164 
165 static void __exit platform_lcd_cleanup(void)
166 {
167 	platform_driver_unregister(&platform_lcd_driver);
168 }
169 
170 module_init(platform_lcd_init);
171 module_exit(platform_lcd_cleanup);
172 
173 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
174 MODULE_LICENSE("GPL v2");
175 MODULE_ALIAS("platform:platform-lcd");
176