1/*
2 *  Backlight Driver for the KB3886 Backlight
3 *
4 *  Copyright (c) 2007-2008 Claudio Nieder
5 *
6 *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
7 *
8 *  This program is free software; you can redistribute it and/or modify
9 *  it under the terms of the GNU General Public License version 2 as
10 *  published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/platform_device.h>
18#include <linux/mutex.h>
19#include <linux/fb.h>
20#include <linux/backlight.h>
21#include <linux/delay.h>
22#include <linux/dmi.h>
23
24#define KB3886_PARENT 0x64
25#define KB3886_IO 0x60
26#define KB3886_ADC_DAC_PWM 0xC4
27#define KB3886_PWM0_WRITE 0x81
28#define KB3886_PWM0_READ 0x41
29
30static DEFINE_MUTEX(bl_mutex);
31
32static void kb3886_bl_set_intensity(int intensity)
33{
34	mutex_lock(&bl_mutex);
35	intensity = intensity&0xff;
36	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
37	usleep_range(10000, 11000);
38	outb(KB3886_PWM0_WRITE, KB3886_IO);
39	usleep_range(10000, 11000);
40	outb(intensity, KB3886_IO);
41	mutex_unlock(&bl_mutex);
42}
43
44struct kb3886bl_machinfo {
45	int max_intensity;
46	int default_intensity;
47	int limit_mask;
48	void (*set_bl_intensity)(int intensity);
49};
50
51static struct kb3886bl_machinfo kb3886_bl_machinfo = {
52	.max_intensity = 0xff,
53	.default_intensity = 0xa0,
54	.limit_mask = 0x7f,
55	.set_bl_intensity = kb3886_bl_set_intensity,
56};
57
58static struct platform_device kb3886bl_device = {
59	.name		= "kb3886-bl",
60	.dev		= {
61		.platform_data	= &kb3886_bl_machinfo,
62	},
63	.id		= -1,
64};
65
66static struct platform_device *devices[] __initdata = {
67	&kb3886bl_device,
68};
69
70/*
71 * Back to driver
72 */
73
74static int kb3886bl_intensity;
75static struct backlight_device *kb3886_backlight_device;
76static struct kb3886bl_machinfo *bl_machinfo;
77
78static unsigned long kb3886bl_flags;
79#define KB3886BL_SUSPENDED     0x01
80
81static struct dmi_system_id kb3886bl_device_table[] __initdata = {
82	{
83		.ident = "Sahara Touch-iT",
84		.matches = {
85			DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
86			DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
87		},
88	},
89	{ }
90};
91
92static int kb3886bl_send_intensity(struct backlight_device *bd)
93{
94	int intensity = bd->props.brightness;
95
96	if (bd->props.power != FB_BLANK_UNBLANK)
97		intensity = 0;
98	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
99		intensity = 0;
100	if (kb3886bl_flags & KB3886BL_SUSPENDED)
101		intensity = 0;
102
103	bl_machinfo->set_bl_intensity(intensity);
104
105	kb3886bl_intensity = intensity;
106	return 0;
107}
108
109#ifdef CONFIG_PM_SLEEP
110static int kb3886bl_suspend(struct device *dev)
111{
112	struct backlight_device *bd = dev_get_drvdata(dev);
113
114	kb3886bl_flags |= KB3886BL_SUSPENDED;
115	backlight_update_status(bd);
116	return 0;
117}
118
119static int kb3886bl_resume(struct device *dev)
120{
121	struct backlight_device *bd = dev_get_drvdata(dev);
122
123	kb3886bl_flags &= ~KB3886BL_SUSPENDED;
124	backlight_update_status(bd);
125	return 0;
126}
127#endif
128
129static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
130
131static int kb3886bl_get_intensity(struct backlight_device *bd)
132{
133	return kb3886bl_intensity;
134}
135
136static const struct backlight_ops kb3886bl_ops = {
137	.get_brightness = kb3886bl_get_intensity,
138	.update_status  = kb3886bl_send_intensity,
139};
140
141static int kb3886bl_probe(struct platform_device *pdev)
142{
143	struct backlight_properties props;
144	struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev);
145
146	bl_machinfo = machinfo;
147	if (!machinfo->limit_mask)
148		machinfo->limit_mask = -1;
149
150	memset(&props, 0, sizeof(struct backlight_properties));
151	props.type = BACKLIGHT_RAW;
152	props.max_brightness = machinfo->max_intensity;
153	kb3886_backlight_device = devm_backlight_device_register(&pdev->dev,
154							"kb3886-bl", &pdev->dev,
155							NULL, &kb3886bl_ops,
156							&props);
157	if (IS_ERR(kb3886_backlight_device))
158		return PTR_ERR(kb3886_backlight_device);
159
160	platform_set_drvdata(pdev, kb3886_backlight_device);
161
162	kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
163	kb3886_backlight_device->props.brightness = machinfo->default_intensity;
164	backlight_update_status(kb3886_backlight_device);
165
166	return 0;
167}
168
169static struct platform_driver kb3886bl_driver = {
170	.probe		= kb3886bl_probe,
171	.driver		= {
172		.name	= "kb3886-bl",
173		.pm	= &kb3886bl_pm_ops,
174	},
175};
176
177static int __init kb3886_init(void)
178{
179	if (!dmi_check_system(kb3886bl_device_table))
180		return -ENODEV;
181
182	platform_add_devices(devices, ARRAY_SIZE(devices));
183	return platform_driver_register(&kb3886bl_driver);
184}
185
186static void __exit kb3886_exit(void)
187{
188	platform_driver_unregister(&kb3886bl_driver);
189}
190
191module_init(kb3886_init);
192module_exit(kb3886_exit);
193
194MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
195MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
196MODULE_LICENSE("GPL");
197MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");
198