xref: /linux/drivers/hid/hid-vivaldi.c (revision e7c22eeaff8565d9a8374f320238c251ca31480b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * HID support for Vivaldi Keyboard
4  *
5  * Copyright 2020 Google LLC.
6  * Author: Sean O'Brien <seobrien@chromium.org>
7  */
8 
9 #include <linux/hid.h>
10 #include <linux/module.h>
11 
12 #define MIN_FN_ROW_KEY	1
13 #define MAX_FN_ROW_KEY	24
14 #define HID_VD_FN_ROW_PHYSMAP 0x00000001
15 #define HID_USAGE_FN_ROW_PHYSMAP (HID_UP_GOOGLEVENDOR | HID_VD_FN_ROW_PHYSMAP)
16 
17 static struct hid_driver hid_vivaldi;
18 
19 struct vivaldi_data {
20 	u32 function_row_physmap[MAX_FN_ROW_KEY - MIN_FN_ROW_KEY + 1];
21 	int max_function_row_key;
22 };
23 
24 static ssize_t function_row_physmap_show(struct device *dev,
25 					 struct device_attribute *attr,
26 					 char *buf)
27 {
28 	struct hid_device *hdev = to_hid_device(dev);
29 	struct vivaldi_data *drvdata = hid_get_drvdata(hdev);
30 	ssize_t size = 0;
31 	int i;
32 
33 	if (!drvdata->max_function_row_key)
34 		return 0;
35 
36 	for (i = 0; i < drvdata->max_function_row_key; i++)
37 		size += sprintf(buf + size, "%02X ",
38 				drvdata->function_row_physmap[i]);
39 	size += sprintf(buf + size, "\n");
40 	return size;
41 }
42 
43 DEVICE_ATTR_RO(function_row_physmap);
44 static struct attribute *sysfs_attrs[] = {
45 	&dev_attr_function_row_physmap.attr,
46 	NULL
47 };
48 
49 static const struct attribute_group input_attribute_group = {
50 	.attrs = sysfs_attrs
51 };
52 
53 static int vivaldi_probe(struct hid_device *hdev,
54 			 const struct hid_device_id *id)
55 {
56 	struct vivaldi_data *drvdata;
57 	int ret;
58 
59 	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
60 	hid_set_drvdata(hdev, drvdata);
61 
62 	ret = hid_parse(hdev);
63 	if (ret)
64 		return ret;
65 
66 	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
67 }
68 
69 static void vivaldi_feature_mapping(struct hid_device *hdev,
70 				    struct hid_field *field,
71 				    struct hid_usage *usage)
72 {
73 	struct vivaldi_data *drvdata = hid_get_drvdata(hdev);
74 	int fn_key;
75 	int ret;
76 	u32 report_len;
77 	u8 *buf;
78 
79 	if (field->logical != HID_USAGE_FN_ROW_PHYSMAP ||
80 	    (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL)
81 		return;
82 
83 	fn_key = (usage->hid & HID_USAGE);
84 	if (fn_key < MIN_FN_ROW_KEY || fn_key > MAX_FN_ROW_KEY)
85 		return;
86 	if (fn_key > drvdata->max_function_row_key)
87 		drvdata->max_function_row_key = fn_key;
88 
89 	buf = hid_alloc_report_buf(field->report, GFP_KERNEL);
90 	if (!buf)
91 		return;
92 
93 	report_len = hid_report_len(field->report);
94 	ret = hid_hw_raw_request(hdev, field->report->id, buf,
95 				 report_len, HID_FEATURE_REPORT,
96 				 HID_REQ_GET_REPORT);
97 	if (ret < 0) {
98 		dev_warn(&hdev->dev, "failed to fetch feature %d\n",
99 			 field->report->id);
100 		goto out;
101 	}
102 
103 	ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
104 				   report_len, 0);
105 	if (ret) {
106 		dev_warn(&hdev->dev, "failed to report feature %d\n",
107 			 field->report->id);
108 		goto out;
109 	}
110 
111 	drvdata->function_row_physmap[fn_key - MIN_FN_ROW_KEY] =
112 	    field->value[usage->usage_index];
113 
114 out:
115 	kfree(buf);
116 }
117 
118 static int vivaldi_input_configured(struct hid_device *hdev,
119 				    struct hid_input *hidinput)
120 {
121 	return sysfs_create_group(&hdev->dev.kobj, &input_attribute_group);
122 }
123 
124 static const struct hid_device_id vivaldi_table[] = {
125 	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_VIVALDI, HID_ANY_ID,
126 		     HID_ANY_ID) },
127 	{ }
128 };
129 
130 MODULE_DEVICE_TABLE(hid, vivaldi_table);
131 
132 static struct hid_driver hid_vivaldi = {
133 	.name = "hid-vivaldi",
134 	.id_table = vivaldi_table,
135 	.probe = vivaldi_probe,
136 	.feature_mapping = vivaldi_feature_mapping,
137 	.input_configured = vivaldi_input_configured,
138 };
139 
140 module_hid_driver(hid_vivaldi);
141 
142 MODULE_AUTHOR("Sean O'Brien");
143 MODULE_DESCRIPTION("HID vivaldi driver");
144 MODULE_LICENSE("GPL");
145