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