1// SPDX-License-Identifier: GPL-2.0-only
2/***************************************************************************
3 *   Copyright (C) 2010-2012 by Bruno Pr��mont <bonbons@linux-vserver.org>  *
4 *                                                                         *
5 *   Based on Logitech G13 driver (v0.4)                                   *
6 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
7 *                                                                         *
8 ***************************************************************************/
9
10#include <linux/hid.h>
11
12#include <linux/fb.h>
13#include <linux/backlight.h>
14
15#include "hid-picolcd.h"
16
17static int picolcd_get_brightness(struct backlight_device *bdev)
18{
19	struct picolcd_data *data = bl_get_data(bdev);
20	return data->lcd_brightness;
21}
22
23static int picolcd_set_brightness(struct backlight_device *bdev)
24{
25	struct picolcd_data *data = bl_get_data(bdev);
26	struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);
27	unsigned long flags;
28
29	if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
30		return -ENODEV;
31
32	data->lcd_brightness = bdev->props.brightness & 0x0ff;
33	data->lcd_power      = bdev->props.power;
34	spin_lock_irqsave(&data->lock, flags);
35	hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0);
36	if (!(data->status & PICOLCD_FAILED))
37		hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
38	spin_unlock_irqrestore(&data->lock, flags);
39	return 0;
40}
41
42static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb)
43{
44	return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev));
45}
46
47static const struct backlight_ops picolcd_blops = {
48	.update_status  = picolcd_set_brightness,
49	.get_brightness = picolcd_get_brightness,
50	.check_fb       = picolcd_check_bl_fb,
51};
52
53int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)
54{
55	struct device *dev = &data->hdev->dev;
56	struct backlight_device *bdev;
57	struct backlight_properties props;
58	if (!report)
59		return -ENODEV;
60	if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
61			report->field[0]->report_size != 8) {
62		dev_err(dev, "unsupported BRIGHTNESS report");
63		return -EINVAL;
64	}
65
66	memset(&props, 0, sizeof(props));
67	props.type = BACKLIGHT_RAW;
68	props.max_brightness = 0xff;
69	bdev = backlight_device_register(dev_name(dev), dev, data,
70			&picolcd_blops, &props);
71	if (IS_ERR(bdev)) {
72		dev_err(dev, "failed to register backlight\n");
73		return PTR_ERR(bdev);
74	}
75	bdev->props.brightness     = 0xff;
76	data->lcd_brightness       = 0xff;
77	data->backlight            = bdev;
78	picolcd_set_brightness(bdev);
79	return 0;
80}
81
82void picolcd_exit_backlight(struct picolcd_data *data)
83{
84	struct backlight_device *bdev = data->backlight;
85
86	data->backlight = NULL;
87	backlight_device_unregister(bdev);
88}
89
90int picolcd_resume_backlight(struct picolcd_data *data)
91{
92	if (!data->backlight)
93		return 0;
94	return picolcd_set_brightness(data->backlight);
95}
96
97#ifdef CONFIG_PM
98void picolcd_suspend_backlight(struct picolcd_data *data)
99{
100	int bl_power = data->lcd_power;
101	if (!data->backlight)
102		return;
103
104	data->backlight->props.power = FB_BLANK_POWERDOWN;
105	picolcd_set_brightness(data->backlight);
106	data->lcd_power = data->backlight->props.power = bl_power;
107}
108#endif /* CONFIG_PM */
109
110