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 = 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
68static 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
77static 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
87static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
88
89static int hp680bl_set_intensity(struct backlight_device *bd)
90{
91	hp680bl_send_intensity(bd);
92	return 0;
93}
94
95static int hp680bl_get_intensity(struct backlight_device *bd)
96{
97	return current_intensity;
98}
99
100static const struct backlight_ops hp680bl_ops = {
101	.get_brightness = hp680bl_get_intensity,
102	.update_status  = hp680bl_set_intensity,
103};
104
105static 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
126static 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
137static 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
146static struct platform_device *hp680bl_device;
147
148static 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
164static void __exit hp680bl_exit(void)
165{
166	platform_device_unregister(hp680bl_device);
167	platform_driver_unregister(&hp680bl_driver);
168}
169
170module_init(hp680bl_init);
171module_exit(hp680bl_exit);
172
173MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
174MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
175MODULE_LICENSE("GPL");
176