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 <asm/cpu/dac.h>
22#include <asm/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 = 0;
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
68static int hp680bl_suspend(struct platform_device *pdev, pm_message_t state)
69{
70	struct backlight_device *bd = platform_get_drvdata(pdev);
71
72	hp680bl_suspended = 1;
73	hp680bl_send_intensity(bd);
74	return 0;
75}
76
77static int hp680bl_resume(struct platform_device *pdev)
78{
79	struct backlight_device *bd = platform_get_drvdata(pdev);
80
81	hp680bl_suspended = 0;
82	hp680bl_send_intensity(bd);
83	return 0;
84}
85#else
86#define hp680bl_suspend	NULL
87#define hp680bl_resume	NULL
88#endif
89
90static int hp680bl_set_intensity(struct backlight_device *bd)
91{
92	hp680bl_send_intensity(bd);
93	return 0;
94}
95
96static int hp680bl_get_intensity(struct backlight_device *bd)
97{
98	return current_intensity;
99}
100
101static struct backlight_ops hp680bl_ops = {
102	.get_brightness = hp680bl_get_intensity,
103	.update_status  = hp680bl_set_intensity,
104};
105
106static int __init hp680bl_probe(struct platform_device *pdev)
107{
108	struct backlight_device *bd;
109
110	bd = backlight_device_register ("hp680-bl", &pdev->dev, NULL,
111		    &hp680bl_ops);
112	if (IS_ERR(bd))
113		return PTR_ERR(bd);
114
115	platform_set_drvdata(pdev, bd);
116
117	bd->props.max_brightness = HP680_MAX_INTENSITY;
118	bd->props.brightness = HP680_DEFAULT_INTENSITY;
119	hp680bl_send_intensity(bd);
120
121	return 0;
122}
123
124static int hp680bl_remove(struct platform_device *pdev)
125{
126	struct backlight_device *bd = platform_get_drvdata(pdev);
127
128	hp680bl_data.brightness = 0;
129	hp680bl_data.power = 0;
130	hp680bl_send_intensity(bd);
131
132	backlight_device_unregister(bd);
133
134	return 0;
135}
136
137static struct platform_driver hp680bl_driver = {
138	.probe		= hp680bl_probe,
139	.remove		= hp680bl_remove,
140	.suspend	= hp680bl_suspend,
141	.resume		= hp680bl_resume,
142	.driver		= {
143		.name	= "hp680-bl",
144	},
145};
146
147static struct platform_device *hp680bl_device;
148
149static int __init hp680bl_init(void)
150{
151	int ret;
152
153	ret = platform_driver_register(&hp680bl_driver);
154	if (!ret) {
155		hp680bl_device = platform_device_alloc("hp680-bl", -1);
156		if (!hp680bl_device)
157			return -ENOMEM;
158
159		ret = platform_device_add(hp680bl_device);
160
161		if (ret) {
162			platform_device_put(hp680bl_device);
163			platform_driver_unregister(&hp680bl_driver);
164		}
165	}
166	return ret;
167}
168
169static void __exit hp680bl_exit(void)
170{
171	platform_device_unregister(hp680bl_device);
172 	platform_driver_unregister(&hp680bl_driver);
173}
174
175module_init(hp680bl_init);
176module_exit(hp680bl_exit);
177
178MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
179MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
180MODULE_LICENSE("GPL");
181