1 /*
2 * Backlight Driver for HP Jornada 680
3 *
4 * Copyright (c) 2005 Andriy Skulysh
5 *
6 * Based on Sharp's Corgi Backlight Driver
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <linux/fb.h>
19 #include <linux/backlight.h>
20
21 #include <cpu/dac.h>
22 #include <mach/hp6xx.h>
23 #include <asm/hd64461.h>
24
25 #define HP680_MAX_INTENSITY 255
26 #define HP680_DEFAULT_INTENSITY 10
27
28 static int hp680bl_suspended;
29 static int current_intensity;
30 static DEFINE_SPINLOCK(bl_lock);
31
hp680bl_send_intensity(struct backlight_device * bd)32 static void hp680bl_send_intensity(struct backlight_device *bd)
33 {
34 unsigned long flags;
35 u16 v;
36 int intensity = backlight_get_brightness(bd);
37
38 if (hp680bl_suspended)
39 intensity = 0;
40
41 spin_lock_irqsave(&bl_lock, flags);
42 if (intensity && current_intensity == 0) {
43 sh_dac_enable(DAC_LCD_BRIGHTNESS);
44 v = inw(HD64461_GPBDR);
45 v &= ~HD64461_GPBDR_LCDOFF;
46 outw(v, HD64461_GPBDR);
47 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
48 } else if (intensity == 0 && current_intensity != 0) {
49 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
50 sh_dac_disable(DAC_LCD_BRIGHTNESS);
51 v = inw(HD64461_GPBDR);
52 v |= HD64461_GPBDR_LCDOFF;
53 outw(v, HD64461_GPBDR);
54 } else if (intensity) {
55 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
56 }
57 spin_unlock_irqrestore(&bl_lock, flags);
58
59 current_intensity = intensity;
60 }
61
62
63 #ifdef CONFIG_PM_SLEEP
hp680bl_suspend(struct device * dev)64 static int hp680bl_suspend(struct device *dev)
65 {
66 struct backlight_device *bd = dev_get_drvdata(dev);
67
68 hp680bl_suspended = 1;
69 hp680bl_send_intensity(bd);
70 return 0;
71 }
72
hp680bl_resume(struct device * dev)73 static int hp680bl_resume(struct device *dev)
74 {
75 struct backlight_device *bd = dev_get_drvdata(dev);
76
77 hp680bl_suspended = 0;
78 hp680bl_send_intensity(bd);
79 return 0;
80 }
81 #endif
82
83 static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
84
hp680bl_set_intensity(struct backlight_device * bd)85 static int hp680bl_set_intensity(struct backlight_device *bd)
86 {
87 hp680bl_send_intensity(bd);
88 return 0;
89 }
90
hp680bl_get_intensity(struct backlight_device * bd)91 static int hp680bl_get_intensity(struct backlight_device *bd)
92 {
93 return current_intensity;
94 }
95
96 static const struct backlight_ops hp680bl_ops = {
97 .get_brightness = hp680bl_get_intensity,
98 .update_status = hp680bl_set_intensity,
99 };
100
hp680bl_probe(struct platform_device * pdev)101 static int hp680bl_probe(struct platform_device *pdev)
102 {
103 struct backlight_properties props;
104 struct backlight_device *bd;
105
106 memset(&props, 0, sizeof(struct backlight_properties));
107 props.type = BACKLIGHT_RAW;
108 props.max_brightness = HP680_MAX_INTENSITY;
109 bd = devm_backlight_device_register(&pdev->dev, "hp680-bl", &pdev->dev,
110 NULL, &hp680bl_ops, &props);
111 if (IS_ERR(bd))
112 return PTR_ERR(bd);
113
114 platform_set_drvdata(pdev, bd);
115
116 bd->props.brightness = HP680_DEFAULT_INTENSITY;
117 hp680bl_send_intensity(bd);
118
119 return 0;
120 }
121
hp680bl_remove(struct platform_device * pdev)122 static void hp680bl_remove(struct platform_device *pdev)
123 {
124 struct backlight_device *bd = platform_get_drvdata(pdev);
125
126 bd->props.brightness = 0;
127 bd->props.power = 0;
128 hp680bl_send_intensity(bd);
129 }
130
131 static struct platform_driver hp680bl_driver = {
132 .probe = hp680bl_probe,
133 .remove = hp680bl_remove,
134 .driver = {
135 .name = "hp680-bl",
136 .pm = &hp680bl_pm_ops,
137 },
138 };
139
140 static struct platform_device *hp680bl_device;
141
hp680bl_init(void)142 static int __init hp680bl_init(void)
143 {
144 int ret;
145
146 ret = platform_driver_register(&hp680bl_driver);
147 if (ret)
148 return ret;
149 hp680bl_device = platform_device_register_simple("hp680-bl", -1,
150 NULL, 0);
151 if (IS_ERR(hp680bl_device)) {
152 platform_driver_unregister(&hp680bl_driver);
153 return PTR_ERR(hp680bl_device);
154 }
155 return 0;
156 }
157
hp680bl_exit(void)158 static void __exit hp680bl_exit(void)
159 {
160 platform_device_unregister(hp680bl_device);
161 platform_driver_unregister(&hp680bl_driver);
162 }
163
164 module_init(hp680bl_init);
165 module_exit(hp680bl_exit);
166
167 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
168 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
169 MODULE_LICENSE("GPL");
170