1/***************************************************************************
2 *   Copyright (C) 2010-2012 by Bruno Pr��mont <bonbons@linux-vserver.org>  *
3 *                                                                         *
4 *   Based on Logitech G13 driver (v0.4)                                   *
5 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
6 *                                                                         *
7 *   This program is free software: you can redistribute it and/or modify  *
8 *   it under the terms of the GNU General Public License as published by  *
9 *   the Free Software Foundation, version 2 of the License.               *
10 *                                                                         *
11 *   This driver is distributed in the hope that it will be useful, but    *
12 *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
14 *   General Public License for more details.                              *
15 *                                                                         *
16 *   You should have received a copy of the GNU General Public License     *
17 *   along with this software. If not see <http://www.gnu.org/licenses/>.  *
18 ***************************************************************************/
19
20#include <linux/hid.h>
21
22#include <linux/fb.h>
23#include <linux/backlight.h>
24
25#include "hid-picolcd.h"
26
27static int picolcd_get_brightness(struct backlight_device *bdev)
28{
29	struct picolcd_data *data = bl_get_data(bdev);
30	return data->lcd_brightness;
31}
32
33static int picolcd_set_brightness(struct backlight_device *bdev)
34{
35	struct picolcd_data *data = bl_get_data(bdev);
36	struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);
37	unsigned long flags;
38
39	if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
40		return -ENODEV;
41
42	data->lcd_brightness = bdev->props.brightness & 0x0ff;
43	data->lcd_power      = bdev->props.power;
44	spin_lock_irqsave(&data->lock, flags);
45	hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0);
46	if (!(data->status & PICOLCD_FAILED))
47		hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
48	spin_unlock_irqrestore(&data->lock, flags);
49	return 0;
50}
51
52static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb)
53{
54	return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev));
55}
56
57static const struct backlight_ops picolcd_blops = {
58	.update_status  = picolcd_set_brightness,
59	.get_brightness = picolcd_get_brightness,
60	.check_fb       = picolcd_check_bl_fb,
61};
62
63int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)
64{
65	struct device *dev = &data->hdev->dev;
66	struct backlight_device *bdev;
67	struct backlight_properties props;
68	if (!report)
69		return -ENODEV;
70	if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
71			report->field[0]->report_size != 8) {
72		dev_err(dev, "unsupported BRIGHTNESS report");
73		return -EINVAL;
74	}
75
76	memset(&props, 0, sizeof(props));
77	props.type = BACKLIGHT_RAW;
78	props.max_brightness = 0xff;
79	bdev = backlight_device_register(dev_name(dev), dev, data,
80			&picolcd_blops, &props);
81	if (IS_ERR(bdev)) {
82		dev_err(dev, "failed to register backlight\n");
83		return PTR_ERR(bdev);
84	}
85	bdev->props.brightness     = 0xff;
86	data->lcd_brightness       = 0xff;
87	data->backlight            = bdev;
88	picolcd_set_brightness(bdev);
89	return 0;
90}
91
92void picolcd_exit_backlight(struct picolcd_data *data)
93{
94	struct backlight_device *bdev = data->backlight;
95
96	data->backlight = NULL;
97	backlight_device_unregister(bdev);
98}
99
100int picolcd_resume_backlight(struct picolcd_data *data)
101{
102	if (!data->backlight)
103		return 0;
104	return picolcd_set_brightness(data->backlight);
105}
106
107#ifdef CONFIG_PM
108void picolcd_suspend_backlight(struct picolcd_data *data)
109{
110	int bl_power = data->lcd_power;
111	if (!data->backlight)
112		return;
113
114	data->backlight->props.power = FB_BLANK_POWERDOWN;
115	picolcd_set_brightness(data->backlight);
116	data->lcd_power = data->backlight->props.power = bl_power;
117}
118#endif /* CONFIG_PM */
119
120