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