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 
32 static void hp680bl_send_intensity(struct backlight_device *bd)
33 {
34 	unsigned long flags;
35 	u16 v;
36 	int intensity = bd->props.brightness;
37 
38 	if (bd->props.power != FB_BLANK_UNBLANK)
39 		intensity = 0;
40 	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
41 		intensity = 0;
42 	if (hp680bl_suspended)
43 		intensity = 0;
44 
45 	spin_lock_irqsave(&bl_lock, flags);
46 	if (intensity && current_intensity == 0) {
47 		sh_dac_enable(DAC_LCD_BRIGHTNESS);
48 		v = inw(HD64461_GPBDR);
49 		v &= ~HD64461_GPBDR_LCDOFF;
50 		outw(v, HD64461_GPBDR);
51 		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
52 	} else if (intensity == 0 && current_intensity != 0) {
53 		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
54 		sh_dac_disable(DAC_LCD_BRIGHTNESS);
55 		v = inw(HD64461_GPBDR);
56 		v |= HD64461_GPBDR_LCDOFF;
57 		outw(v, HD64461_GPBDR);
58 	} else if (intensity) {
59 		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
60 	}
61 	spin_unlock_irqrestore(&bl_lock, flags);
62 
63 	current_intensity = intensity;
64 }
65 
66 
67 #ifdef CONFIG_PM_SLEEP
68 static int hp680bl_suspend(struct device *dev)
69 {
70 	struct backlight_device *bd = dev_get_drvdata(dev);
71 
72 	hp680bl_suspended = 1;
73 	hp680bl_send_intensity(bd);
74 	return 0;
75 }
76 
77 static int hp680bl_resume(struct device *dev)
78 {
79 	struct backlight_device *bd = dev_get_drvdata(dev);
80 
81 	hp680bl_suspended = 0;
82 	hp680bl_send_intensity(bd);
83 	return 0;
84 }
85 #endif
86 
87 static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
88 
89 static int hp680bl_set_intensity(struct backlight_device *bd)
90 {
91 	hp680bl_send_intensity(bd);
92 	return 0;
93 }
94 
95 static int hp680bl_get_intensity(struct backlight_device *bd)
96 {
97 	return current_intensity;
98 }
99 
100 static const struct backlight_ops hp680bl_ops = {
101 	.get_brightness = hp680bl_get_intensity,
102 	.update_status  = hp680bl_set_intensity,
103 };
104 
105 static int hp680bl_probe(struct platform_device *pdev)
106 {
107 	struct backlight_properties props;
108 	struct backlight_device *bd;
109 
110 	memset(&props, 0, sizeof(struct backlight_properties));
111 	props.type = BACKLIGHT_RAW;
112 	props.max_brightness = HP680_MAX_INTENSITY;
113 	bd = devm_backlight_device_register(&pdev->dev, "hp680-bl", &pdev->dev,
114 					NULL, &hp680bl_ops, &props);
115 	if (IS_ERR(bd))
116 		return PTR_ERR(bd);
117 
118 	platform_set_drvdata(pdev, bd);
119 
120 	bd->props.brightness = HP680_DEFAULT_INTENSITY;
121 	hp680bl_send_intensity(bd);
122 
123 	return 0;
124 }
125 
126 static int hp680bl_remove(struct platform_device *pdev)
127 {
128 	struct backlight_device *bd = platform_get_drvdata(pdev);
129 
130 	bd->props.brightness = 0;
131 	bd->props.power = 0;
132 	hp680bl_send_intensity(bd);
133 
134 	return 0;
135 }
136 
137 static struct platform_driver hp680bl_driver = {
138 	.probe		= hp680bl_probe,
139 	.remove		= hp680bl_remove,
140 	.driver		= {
141 		.name	= "hp680-bl",
142 		.pm	= &hp680bl_pm_ops,
143 	},
144 };
145 
146 static struct platform_device *hp680bl_device;
147 
148 static int __init hp680bl_init(void)
149 {
150 	int ret;
151 
152 	ret = platform_driver_register(&hp680bl_driver);
153 	if (ret)
154 		return ret;
155 	hp680bl_device = platform_device_register_simple("hp680-bl", -1,
156 							NULL, 0);
157 	if (IS_ERR(hp680bl_device)) {
158 		platform_driver_unregister(&hp680bl_driver);
159 		return PTR_ERR(hp680bl_device);
160 	}
161 	return 0;
162 }
163 
164 static void __exit hp680bl_exit(void)
165 {
166 	platform_device_unregister(hp680bl_device);
167 	platform_driver_unregister(&hp680bl_driver);
168 }
169 
170 module_init(hp680bl_init);
171 module_exit(hp680bl_exit);
172 
173 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
174 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
175 MODULE_LICENSE("GPL");
176