summaryrefslogtreecommitdiff
path: root/drivers/video/backlight/aat2870_bl.c
blob: f13a3f7e2e8fc251c8d598a4033f8439972ae031 (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
/*
 * linux/drivers/video/backlight/aat2870_bl.c
 *
 * Copyright (c) 2011, NVIDIA Corporation.
 * Author: Jin Park <jinyoungp@nvidia.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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/mfd/aat2870.h>

struct aat2870_bl_driver_data {
	struct platform_device *pdev;
	struct backlight_device *bd;

	int channels;
	int max_current;
	int brightness; /* current brightness */
};

static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,
				     int brightness)
{
	struct backlight_device *bd = aat2870_bl->bd;
	int val;

	val = brightness * aat2870_bl->max_current;
	val /= bd->props.max_brightness;

	return val;
}

static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)
{
	struct aat2870_data *aat2870
			= dev_get_drvdata(aat2870_bl->pdev->dev.parent);

	return aat2870->write(aat2870, AAT2870_BL_CH_EN,
			      (u8)aat2870_bl->channels);
}

static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)
{
	struct aat2870_data *aat2870
			= dev_get_drvdata(aat2870_bl->pdev->dev.parent);

	return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0);
}

static int aat2870_bl_get_brightness(struct backlight_device *bd)
{
	return bd->props.brightness;
}

static int aat2870_bl_update_status(struct backlight_device *bd)
{
	struct aat2870_bl_driver_data *aat2870_bl = dev_get_drvdata(&bd->dev);
	struct aat2870_data *aat2870 =
			dev_get_drvdata(aat2870_bl->pdev->dev.parent);
	int brightness = bd->props.brightness;
	int ret;

	if ((brightness < 0) || (bd->props.max_brightness < brightness)) {
		dev_err(&bd->dev, "invalid brightness, %d\n", brightness);
		return -EINVAL;
	}

	dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",
		 bd->props.brightness, bd->props.power, bd->props.state);

	if ((bd->props.power != FB_BLANK_UNBLANK) ||
			(bd->props.state & BL_CORE_FBBLANK) ||
			(bd->props.state & BL_CORE_SUSPENDED))
		brightness = 0;

	ret = aat2870->write(aat2870, AAT2870_BLM,
			     (u8)aat2870_brightness(aat2870_bl, brightness));
	if (ret < 0)
		return ret;

	if (brightness == 0) {
		ret = aat2870_bl_disable(aat2870_bl);
		if (ret < 0)
			return ret;
	} else if (aat2870_bl->brightness == 0) {
		ret = aat2870_bl_enable(aat2870_bl);
		if (ret < 0)
			return ret;
	}

	aat2870_bl->brightness = brightness;

	return 0;
}

static int aat2870_bl_check_fb(struct backlight_device *bd, struct fb_info *fi)
{
	return 1;
}

static const struct backlight_ops aat2870_bl_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.get_brightness = aat2870_bl_get_brightness,
	.update_status = aat2870_bl_update_status,
	.check_fb = aat2870_bl_check_fb,
};

static int aat2870_bl_probe(struct platform_device *pdev)
{
	struct aat2870_bl_platform_data *pdata = pdev->dev.platform_data;
	struct aat2870_bl_driver_data *aat2870_bl;
	struct backlight_device *bd;
	struct backlight_properties props;
	int ret = 0;

	if (!pdata) {
		dev_err(&pdev->dev, "No platform data\n");
		ret = -ENXIO;
		goto out;
	}

	if (pdev->id != AAT2870_ID_BL) {
		dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
		ret = -EINVAL;
		goto out;
	}

	aat2870_bl = kzalloc(sizeof(struct aat2870_bl_driver_data), GFP_KERNEL);
	if (!aat2870_bl) {
		dev_err(&pdev->dev,
			"Failed to allocate memory for aat2870 backlight\n");
		ret = -ENOMEM;
		goto out;
	}

	memset(&props, 0, sizeof(struct backlight_properties));

	props.type = BACKLIGHT_RAW;
	bd = backlight_device_register("aat2870-backlight", &pdev->dev,
				       aat2870_bl, &aat2870_bl_ops, &props);
	if (IS_ERR(bd)) {
		dev_err(&pdev->dev,
			"Failed allocate memory for backlight device\n");
		ret = PTR_ERR(bd);
		goto out_kfree;
	}

	aat2870_bl->pdev = pdev;
	platform_set_drvdata(pdev, aat2870_bl);

	aat2870_bl->bd = bd;

	if (pdata->channels > 0)
		aat2870_bl->channels = pdata->channels;
	else
		aat2870_bl->channels = AAT2870_BL_CH_ALL;

	if (pdata->max_brightness > 0)
		aat2870_bl->max_current = pdata->max_current;
	else
		aat2870_bl->max_current = AAT2870_CURRENT_27_9;

	if (pdata->max_brightness > 0)
		bd->props.max_brightness = pdata->max_brightness;
	else
		bd->props.max_brightness = 255;

	aat2870_bl->brightness = 0;
	bd->props.power = FB_BLANK_UNBLANK;
	bd->props.brightness = bd->props.max_brightness;

	ret = aat2870_bl_update_status(bd);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to initialize\n");
		goto out_bl_dev_unregister;
	}

	return 0;

out_bl_dev_unregister:
	backlight_device_unregister(bd);
out_kfree:
	kfree(aat2870_bl);
out:
	return ret;
}

static int aat2870_bl_remove(struct platform_device *pdev)
{
	struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev);
	struct backlight_device *bd = aat2870_bl->bd;

	bd->props.power = FB_BLANK_POWERDOWN;
	bd->props.brightness = 0;
	backlight_update_status(bd);

	backlight_device_unregister(bd);
	kfree(aat2870_bl);

	return 0;
}

static struct platform_driver aat2870_bl_driver = {
	.driver = {
		.name	= "aat2870-backlight",
		.owner	= THIS_MODULE,
	},
	.probe		= aat2870_bl_probe,
	.remove		= aat2870_bl_remove,
};

static int __init aat2870_bl_init(void)
{
	return platform_driver_register(&aat2870_bl_driver);
}
subsys_initcall(aat2870_bl_init);

static void __exit aat2870_bl_exit(void)
{
	platform_driver_unregister(&aat2870_bl_driver);
}
module_exit(aat2870_bl_exit);

MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");