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
28static int hp680bl_suspended;
29static int current_intensity;
30static DEFINE_SPINLOCK(bl_lock);
31
32static 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
64static 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
73static 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
83static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
84
85static int hp680bl_set_intensity(struct backlight_device *bd)
86{
87	hp680bl_send_intensity(bd);
88	return 0;
89}
90
91static int hp680bl_get_intensity(struct backlight_device *bd)
92{
93	return current_intensity;
94}
95
96static const struct backlight_ops hp680bl_ops = {
97	.get_brightness = hp680bl_get_intensity,
98	.update_status  = hp680bl_set_intensity,
99};
100
101static 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
122static 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
131static struct platform_driver hp680bl_driver = {
132	.probe		= hp680bl_probe,
133	.remove_new	= hp680bl_remove,
134	.driver		= {
135		.name	= "hp680-bl",
136		.pm	= &hp680bl_pm_ops,
137	},
138};
139
140static struct platform_device *hp680bl_device;
141
142static 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
158static void __exit hp680bl_exit(void)
159{
160	platform_device_unregister(hp680bl_device);
161	platform_driver_unregister(&hp680bl_driver);
162}
163
164module_init(hp680bl_init);
165module_exit(hp680bl_exit);
166
167MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
168MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
169MODULE_LICENSE("GPL");
170