1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /*************************************************************************** |
3 | * Copyright (C) 2010-2012 by Bruno Prémont <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 | |
17 | static int picolcd_get_brightness(struct backlight_device *bdev) |
18 | { |
19 | struct picolcd_data *data = bl_get_data(bl_dev: bdev); |
20 | return data->lcd_brightness; |
21 | } |
22 | |
23 | static int picolcd_set_brightness(struct backlight_device *bdev) |
24 | { |
25 | struct picolcd_data *data = bl_get_data(bl_dev: 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(lock: &data->lock, flags); |
39 | return 0; |
40 | } |
41 | |
42 | static 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 | |
47 | static 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 | |
53 | int 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(name: dev_name(dev), dev, devdata: data, |
70 | ops: &picolcd_blops, props: &props); |
71 | if (IS_ERR(ptr: bdev)) { |
72 | dev_err(dev, "failed to register backlight\n" ); |
73 | return PTR_ERR(ptr: 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 | |
82 | void picolcd_exit_backlight(struct picolcd_data *data) |
83 | { |
84 | struct backlight_device *bdev = data->backlight; |
85 | |
86 | data->backlight = NULL; |
87 | backlight_device_unregister(bd: bdev); |
88 | } |
89 | |
90 | int picolcd_resume_backlight(struct picolcd_data *data) |
91 | { |
92 | if (!data->backlight) |
93 | return 0; |
94 | return picolcd_set_brightness(bdev: data->backlight); |
95 | } |
96 | |
97 | #ifdef CONFIG_PM |
98 | void 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(bdev: data->backlight); |
106 | data->lcd_power = data->backlight->props.power = bl_power; |
107 | } |
108 | #endif /* CONFIG_PM */ |
109 | |
110 | |