aboutsummaryrefslogtreecommitdiff
path: root/drivers/video/backlight/88pm860x_bl.c
blob: a1376dc73d71cd79492c388afc340d7fba229545 (plain)
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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * Backlight driver for Marvell Semiconductor 88PM8606
 *
 * Copyright (C) 2009 Marvell International Ltd.
 *	Haojian Zhuang <haojian.zhuang@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/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/mfd/88pm860x.h>
#include <linux/module.h>

#define MAX_BRIGHTNESS		(0xFF)
#define MIN_BRIGHTNESS		(0)

#define CURRENT_BITMASK		(0x1F << 1)

struct pm860x_backlight_data {
	struct pm860x_chip *chip;
	struct i2c_client *i2c;
	int	current_brightness;
	int	port;
	int	pwm;
	int	iset;
};

static inline int wled_a(int port)
{
	int ret;

	ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
	return ret;
}

static inline int wled_b(int port)
{
	int ret;

	ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
	return ret;
}

/* WLED2 & WLED3 share the same IDC */
static inline int wled_idc(int port)
{
	int ret;

	switch (port) {
	case PM8606_BACKLIGHT1:
	case PM8606_BACKLIGHT2:
		ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
		break;
	case PM8606_BACKLIGHT3:
	default:
		ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
		break;
	}
	return ret;
}

static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
{
	struct pm860x_backlight_data *data = bl_get_data(bl);
	struct pm860x_chip *chip = data->chip;
	unsigned char value;
	int ret;

	if (brightness > MAX_BRIGHTNESS)
		value = MAX_BRIGHTNESS;
	else
		value = brightness;

	ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
	if (ret < 0)
		goto out;

	if ((data->current_brightness == 0) && brightness) {
		if (data->iset) {
			ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
					      CURRENT_BITMASK, data->iset);
			if (ret < 0)
				goto out;
		}
		if (data->pwm) {
			ret = pm860x_set_bits(data->i2c, PM8606_PWM,
					      PM8606_PWM_FREQ_MASK, data->pwm);
			if (ret < 0)
				goto out;
		}
		if (brightness == MAX_BRIGHTNESS) {
			/* set WLED_ON bit as 100% */
			ret = pm860x_set_bits(data->i2c, wled_b(data->port),
					      PM8606_WLED_ON, PM8606_WLED_ON);
		}
	} else {
		if (brightness == MAX_BRIGHTNESS) {
			/* set WLED_ON bit as 100% */
			ret = pm860x_set_bits(data->i2c, wled_b(data->port),
					      PM8606_WLED_ON, PM8606_WLED_ON);
		} else {
			/* clear WLED_ON bit since it's not 100% */
			ret = pm860x_set_bits(data->i2c, wled_b(data->port),
					      PM8606_WLED_ON, 0);
		}
	}
	if (ret < 0)
		goto out;

	dev_dbg(chip->dev, "set brightness %d\n", value);
	data->current_brightness = value;
	return 0;
out:
	dev_dbg(chip->dev, "set brightness %d failure with return "
		"value:%d\n", value, ret);
	return ret;
}

static int pm860x_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;

	if (bl->props.state & BL_CORE_SUSPENDED)
		brightness = 0;

	return pm860x_backlight_set(bl, brightness);
}

static int pm860x_backlight_get_brightness(struct backlight_device *bl)
{
	struct pm860x_backlight_data *data = bl_get_data(bl);
	struct pm860x_chip *chip = data->chip;
	int ret;

	ret = pm860x_reg_read(data->i2c, wled_a(data->port));
	if (ret < 0)
		goto out;
	data->current_brightness = ret;
	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
	return data->current_brightness;
out:
	return -EINVAL;
}

static const struct backlight_ops pm860x_backlight_ops = {
	.options	= BL_CORE_SUSPENDRESUME,
	.update_status	= pm860x_backlight_update_status,
	.get_brightness	= pm860x_backlight_get_brightness,
};

static int pm860x_backlight_probe(struct platform_device *pdev)
{
	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct pm860x_backlight_pdata *pdata = NULL;
	struct pm860x_backlight_data *data;
	struct backlight_device *bl;
	struct resource *res;
	struct backlight_properties props;
	unsigned char value;
	char name[MFD_NAME_SIZE];
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "No I/O resource!\n");
		return -EINVAL;
	}

	pdata = pdev->dev.platform_data;
	if (pdata == NULL) {
		dev_err(&pdev->dev, "platform data isn't assigned to "
			"backlight\n");
		return -EINVAL;
	}

	data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;
	strncpy(name, res->name, MFD_NAME_SIZE);
	data->chip = chip;
	data->i2c = (chip->id == CHIP_PM8606) ? chip->client	\
			: chip->companion;
	data->current_brightness = MAX_BRIGHTNESS;
	data->pwm = pdata->pwm;
	data->iset = pdata->iset;
	data->port = pdata->flags;
	if (data->port < 0) {
		dev_err(&pdev->dev, "wrong platform data is assigned");
		kfree(data);
		return -EINVAL;
	}

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = MAX_BRIGHTNESS;
	bl = backlight_device_register(name, &pdev->dev, data,
					&pm860x_backlight_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		kfree(data);
		return PTR_ERR(bl);
	}
	bl->props.brightness = MAX_BRIGHTNESS;

	platform_set_drvdata(pdev, bl);

	/* Enable reference VSYS */
	ret = pm860x_reg_read(data->i2c, PM8606_VSYS);
	if (ret < 0)
		goto out;
	if ((ret & PM8606_VSYS_EN) == 0) {
		value = ret | PM8606_VSYS_EN;
		ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);
		if (ret < 0)
			goto out;
	}
	/* Enable reference OSC */
	ret = pm860x_reg_read(data->i2c, PM8606_MISC);
	if (ret < 0)
		goto out;
	if ((ret & PM8606_MISC_OSC_EN) == 0) {
		value = ret | PM8606_MISC_OSC_EN;
		ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);
		if (ret < 0)
			goto out;
	}
	/* read current backlight */
	ret = pm860x_backlight_get_brightness(bl);
	if (ret < 0)
		goto out;

	backlight_update_status(bl);
	return 0;
out:
	backlight_device_unregister(bl);
	kfree(data);
	return ret;
}

static int pm860x_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);
	struct pm860x_backlight_data *data = bl_get_data(bl);

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

static struct platform_driver pm860x_backlight_driver = {
	.driver		= {
		.name	= "88pm860x-backlight",
		.owner	= THIS_MODULE,
	},
	.probe		= pm860x_backlight_probe,
	.remove		= pm860x_backlight_remove,
};

module_platform_driver(pm860x_backlight_driver);

MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:88pm860x-backlight");