summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/da903x.c
blob: 93bb4340cc64e66470841868c1d52535ef595d2e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
 * Backlight driver for Dialog Semiconductor DA9030/DA9034
 *
 * Copyright (C) 2008 Compulab, Ltd.
 * 	Mike Rapoport <mike@compulab.co.il>
 *
 * Copyright (C) 2006-2008 Marvell International Ltd.
 * 	Eric Miao <eric.miao@marvell.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/mfd/da903x.h>

#define DA9030_WLED_CONTROL	0x25
#define DA9030_WLED_CP_EN	(1 << 6)
#define DA9030_WLED_TRIM(x)	((x) & 0x7)

#define DA9034_WLED_CONTROL1	0x3C
#define DA9034_WLED_CONTROL2	0x3D

#define DA9034_WLED_BOOST_EN	(1 << 5)

#define DA9030_MAX_BRIGHTNESS	7
#define DA9034_MAX_BRIGHTNESS	0x7f

struct da903x_backlight_data {
	struct device *da903x_dev;
	int id;
	int current_brightness;
};

static int da903x_backlight_set(struct backlight_device *bl, int brightness)
{
	struct da903x_backlight_data *data = bl_get_data(bl);
	struct device *dev = data->da903x_dev;
	uint8_t val;
	int ret = 0;

	switch (data->id) {
	case DA9034_ID_WLED:
		ret = da903x_update(dev, DA9034_WLED_CONTROL1,
				brightness, 0x7f);
		if (ret)
			return ret;

		if (data->current_brightness && brightness == 0)
			ret = da903x_clr_bits(dev,
					DA9034_WLED_CONTROL2,
					DA9034_WLED_BOOST_EN);

		if (data->current_brightness == 0 && brightness)
			ret = da903x_set_bits(dev,
					DA9034_WLED_CONTROL2,
					DA9034_WLED_BOOST_EN);
		break;
	case DA9030_ID_WLED:
		val = DA9030_WLED_TRIM(brightness);
		val |= brightness ? DA9030_WLED_CP_EN : 0;
		ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
		break;
	}

	if (ret)
		return ret;

	data->current_brightness = brightness;
	return 0;
}

static int da903x_backlight_update_status(struct backlight_device *bl)
{
	int brightness = bl->props.brightness;

	if (bl->props.power != FB_BLANK_UNBLANK)
		brightness = 0;

	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
		brightness = 0;

	return da903x_backlight_set(bl, brightness);
}

static int da903x_backlight_get_brightness(struct backlight_device *bl)
{
	struct da903x_backlight_data *data = bl_get_data(bl);
	return data->current_brightness;
}

static struct backlight_ops da903x_backlight_ops = {
	.update_status	= da903x_backlight_update_status,
	.get_brightness	= da903x_backlight_get_brightness,
};

static int da903x_backlight_probe(struct platform_device *pdev)
{
	struct da903x_backlight_data *data;
	struct backlight_device *bl;
	int max_brightness;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;

	switch (pdev->id) {
	case DA9030_ID_WLED:
		max_brightness = DA9030_MAX_BRIGHTNESS;
		break;
	case DA9034_ID_WLED:
		max_brightness = DA9034_MAX_BRIGHTNESS;
		break;
	default:
		dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
				pdev->id);
		kfree(data);
		return -EINVAL;
	}

	data->id = pdev->id;
	data->da903x_dev = pdev->dev.parent;
	data->current_brightness = 0;

	bl = backlight_device_register(pdev->name, data->da903x_dev,
			data, &da903x_backlight_ops);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		kfree(data);
		return PTR_ERR(bl);
	}

	bl->props.max_brightness = max_brightness;
	bl->props.brightness = max_brightness;

	platform_set_drvdata(pdev, bl);
	backlight_update_status(bl);
	return 0;
}

static int da903x_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);
	struct da903x_backlight_data *data = bl_get_data(bl);

	backlight_device_unregister(bl);
	kfree(data);
	return 0;
}

#ifdef CONFIG_PM
static int da903x_backlight_suspend(struct platform_device *pdev,
				 pm_message_t state)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);
	return da903x_backlight_set(bl, 0);
}

static int da903x_backlight_resume(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);

	backlight_update_status(bl);
	return 0;
}
#else
#define da903x_backlight_suspend	NULL
#define da903x_backlight_resume		NULL
#endif

static struct platform_driver da903x_backlight_driver = {
	.driver		= {
		.name	= "da903x-backlight",
		.owner	= THIS_MODULE,
	},
	.probe		= da903x_backlight_probe,
	.remove		= da903x_backlight_remove,
	.suspend	= da903x_backlight_suspend,
	.resume		= da903x_backlight_resume,
};

static int __init da903x_backlight_init(void)
{
	return platform_driver_register(&da903x_backlight_driver);
}
module_init(da903x_backlight_init);

static void __exit da903x_backlight_exit(void)
{
	platform_driver_unregister(&da903x_backlight_driver);
}
module_exit(da903x_backlight_exit);

MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
	      "Mike Rapoport <mike@compulab.co.il>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da903x-backlight");