hid-google-hammer.c
3.69 KB
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
// SPDX-License-Identifier: GPL-2.0+
/*
* HID driver for Google Hammer device.
*
* Copyright (c) 2017 Google Inc.
* Author: Wei-Ning Huang <wnhuang@google.com>
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#include <linux/hid.h>
#include <linux/leds.h>
#include <linux/module.h>
#include "hid-ids.h"
#define MAX_BRIGHTNESS 100
/* HID usage for keyboard backlight (Alphanumeric display brightness) */
#define HID_AD_BRIGHTNESS 0x00140046
struct hammer_kbd_leds {
struct led_classdev cdev;
struct hid_device *hdev;
u8 buf[2] ____cacheline_aligned;
};
static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
enum led_brightness br)
{
struct hammer_kbd_leds *led = container_of(cdev,
struct hammer_kbd_leds,
cdev);
int ret;
led->buf[0] = 0;
led->buf[1] = br;
/*
* Request USB HID device to be in Full On mode, so that sending
* hardware output report and hardware raw request won't fail.
*/
ret = hid_hw_power(led->hdev, PM_HINT_FULLON);
if (ret < 0) {
hid_err(led->hdev, "failed: device not resumed %d\n", ret);
return ret;
}
ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf));
if (ret == -ENOSYS)
ret = hid_hw_raw_request(led->hdev, 0, led->buf,
sizeof(led->buf),
HID_OUTPUT_REPORT,
HID_REQ_SET_REPORT);
if (ret < 0)
hid_err(led->hdev, "failed to set keyboard backlight: %d\n",
ret);
/* Request USB HID device back to Normal Mode. */
hid_hw_power(led->hdev, PM_HINT_NORMAL);
return ret;
}
static int hammer_register_leds(struct hid_device *hdev)
{
struct hammer_kbd_leds *kbd_backlight;
kbd_backlight = devm_kzalloc(&hdev->dev,
sizeof(*kbd_backlight),
GFP_KERNEL);
if (!kbd_backlight)
return -ENOMEM;
kbd_backlight->hdev = hdev;
kbd_backlight->cdev.name = "hammer::kbd_backlight";
kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS;
kbd_backlight->cdev.brightness_set_blocking =
hammer_kbd_brightness_set_blocking;
kbd_backlight->cdev.flags = LED_HW_PLUGGABLE;
/* Set backlight to 0% initially. */
hammer_kbd_brightness_set_blocking(&kbd_backlight->cdev, 0);
return devm_led_classdev_register(&hdev->dev, &kbd_backlight->cdev);
}
static int hammer_input_configured(struct hid_device *hdev,
struct hid_input *hi)
{
struct list_head *report_list =
&hdev->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report;
if (list_empty(report_list))
return 0;
report = list_first_entry(report_list, struct hid_report, list);
if (report->maxfield == 1 &&
report->field[0]->application == HID_GD_KEYBOARD &&
report->field[0]->maxusage == 1 &&
report->field[0]->usage[0].hid == HID_AD_BRIGHTNESS) {
int err = hammer_register_leds(hdev);
if (err)
hid_warn(hdev,
"Failed to register keyboard backlight: %d\n",
err);
}
return 0;
}
static const struct hid_device_id hammer_devices[] = {
{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) },
{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) },
{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) },
{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WHISKERS) },
{ }
};
MODULE_DEVICE_TABLE(hid, hammer_devices);
static struct hid_driver hammer_driver = {
.name = "hammer",
.id_table = hammer_devices,
.input_configured = hammer_input_configured,
};
module_hid_driver(hammer_driver);
MODULE_LICENSE("GPL");