xref: /linux/drivers/video/backlight/jornada720_lcd.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  *
3  * LCD driver for HP Jornada 700 series (710/720/728)
4  * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version
8  * 2 or any later version as published by the Free Software Foundation.
9  *
10  */
11 
12 #include <linux/device.h>
13 #include <linux/fb.h>
14 #include <linux/kernel.h>
15 #include <linux/lcd.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/delay.h>
19 
20 #include <mach/jornada720.h>
21 #include <mach/hardware.h>
22 
23 #include <video/s1d13xxxfb.h>
24 
25 #define LCD_MAX_CONTRAST	0xff
26 #define LCD_DEF_CONTRAST	0x80
27 
28 static int jornada_lcd_get_power(struct lcd_device *ld)
29 {
30 	/* LDD2 in PPC = LCD POWER */
31 	if (PPSR & PPC_LDD2)
32 		return FB_BLANK_UNBLANK;	/* PW ON */
33 	else
34 		return FB_BLANK_POWERDOWN;	/* PW OFF */
35 }
36 
37 static int jornada_lcd_get_contrast(struct lcd_device *ld)
38 {
39 	int ret;
40 
41 	if (jornada_lcd_get_power(ld) != FB_BLANK_UNBLANK)
42 		return 0;
43 
44 	jornada_ssp_start();
45 
46 	if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY) {
47 		dev_err(&ld->dev, "get contrast failed\n");
48 		jornada_ssp_end();
49 		return -ETIMEDOUT;
50 	} else {
51 		ret = jornada_ssp_byte(TXDUMMY);
52 		jornada_ssp_end();
53 		return ret;
54 	}
55 }
56 
57 static int jornada_lcd_set_contrast(struct lcd_device *ld, int value)
58 {
59 	int ret;
60 
61 	jornada_ssp_start();
62 
63 	/* start by sending our set contrast cmd to mcu */
64 	ret = jornada_ssp_byte(SETCONTRAST);
65 
66 	/* push the new value */
67 	if (jornada_ssp_byte(value) != TXDUMMY) {
68 		dev_err(&ld->dev, "set contrast failed\n");
69 		jornada_ssp_end();
70 		return -ETIMEDOUT;
71 	}
72 
73 	/* if we get here we can assume everything went well */
74 	jornada_ssp_end();
75 
76 	return 0;
77 }
78 
79 static int jornada_lcd_set_power(struct lcd_device *ld, int power)
80 {
81 	if (power != FB_BLANK_UNBLANK) {
82 		PPSR &= ~PPC_LDD2;
83 		PPDR |= PPC_LDD2;
84 	} else {
85 		PPSR |= PPC_LDD2;
86 	}
87 
88 	return 0;
89 }
90 
91 static struct lcd_ops jornada_lcd_props = {
92 	.get_contrast = jornada_lcd_get_contrast,
93 	.set_contrast = jornada_lcd_set_contrast,
94 	.get_power = jornada_lcd_get_power,
95 	.set_power = jornada_lcd_set_power,
96 };
97 
98 static int jornada_lcd_probe(struct platform_device *pdev)
99 {
100 	struct lcd_device *lcd_device;
101 	int ret;
102 
103 	lcd_device = lcd_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_lcd_props);
104 
105 	if (IS_ERR(lcd_device)) {
106 		ret = PTR_ERR(lcd_device);
107 		dev_err(&pdev->dev, "failed to register device\n");
108 		return ret;
109 	}
110 
111 	platform_set_drvdata(pdev, lcd_device);
112 
113 	/* lets set our default values */
114 	jornada_lcd_set_contrast(lcd_device, LCD_DEF_CONTRAST);
115 	jornada_lcd_set_power(lcd_device, FB_BLANK_UNBLANK);
116 	/* give it some time to startup */
117 	msleep(100);
118 
119 	return 0;
120 }
121 
122 static int jornada_lcd_remove(struct platform_device *pdev)
123 {
124 	struct lcd_device *lcd_device = platform_get_drvdata(pdev);
125 
126 	lcd_device_unregister(lcd_device);
127 
128 	return 0;
129 }
130 
131 static struct platform_driver jornada_lcd_driver = {
132 	.probe	= jornada_lcd_probe,
133 	.remove	= jornada_lcd_remove,
134 	.driver	= {
135 		.name	= "jornada_lcd",
136 	},
137 };
138 
139 module_platform_driver(jornada_lcd_driver);
140 
141 MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
142 MODULE_DESCRIPTION("HP Jornada 710/720/728 LCD driver");
143 MODULE_LICENSE("GPL");
144