1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Helpers for ChromeOS HID Vivaldi keyboards |
4 | * |
5 | * Copyright (C) 2022 Google, Inc |
6 | */ |
7 | |
8 | #include <linux/export.h> |
9 | #include <linux/hid.h> |
10 | #include <linux/input/vivaldi-fmap.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <linux/types.h> |
14 | |
15 | #include "hid-vivaldi-common.h" |
16 | |
17 | #define MIN_FN_ROW_KEY 1 |
18 | #define MAX_FN_ROW_KEY VIVALDI_MAX_FUNCTION_ROW_KEYS |
19 | #define HID_VD_FN_ROW_PHYSMAP 0x00000001 |
20 | #define HID_USAGE_FN_ROW_PHYSMAP (HID_UP_GOOGLEVENDOR | HID_VD_FN_ROW_PHYSMAP) |
21 | |
22 | /** |
23 | * vivaldi_feature_mapping - Fill out vivaldi keymap data exposed via HID |
24 | * @hdev: HID device to parse |
25 | * @field: HID field to parse |
26 | * @usage: HID usage to parse |
27 | * |
28 | * Note: this function assumes that driver data attached to @hdev contains an |
29 | * instance of &struct vivaldi_data at the very beginning. |
30 | */ |
31 | void vivaldi_feature_mapping(struct hid_device *hdev, |
32 | struct hid_field *field, struct hid_usage *usage) |
33 | { |
34 | struct vivaldi_data *data = hid_get_drvdata(hdev); |
35 | struct hid_report *report = field->report; |
36 | u8 *report_data, *buf; |
37 | u32 report_len; |
38 | unsigned int fn_key; |
39 | int ret; |
40 | |
41 | if (field->logical != HID_USAGE_FN_ROW_PHYSMAP || |
42 | (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL) |
43 | return; |
44 | |
45 | fn_key = usage->hid & HID_USAGE; |
46 | if (fn_key < MIN_FN_ROW_KEY || fn_key > MAX_FN_ROW_KEY) |
47 | return; |
48 | |
49 | if (fn_key > data->num_function_row_keys) |
50 | data->num_function_row_keys = fn_key; |
51 | |
52 | report_data = buf = hid_alloc_report_buf(report, GFP_KERNEL); |
53 | if (!report_data) |
54 | return; |
55 | |
56 | report_len = hid_report_len(report); |
57 | if (!report->id) { |
58 | /* |
59 | * hid_hw_raw_request() will stuff report ID (which will be 0) |
60 | * into the first byte of the buffer even for unnumbered |
61 | * reports, so we need to account for this to avoid getting |
62 | * -EOVERFLOW in return. |
63 | * Note that hid_alloc_report_buf() adds 7 bytes to the size |
64 | * so we can safely say that we have space for an extra byte. |
65 | */ |
66 | report_len++; |
67 | } |
68 | |
69 | ret = hid_hw_raw_request(hdev, reportnum: report->id, buf: report_data, |
70 | len: report_len, rtype: HID_FEATURE_REPORT, |
71 | reqtype: HID_REQ_GET_REPORT); |
72 | if (ret < 0) { |
73 | dev_warn(&hdev->dev, "failed to fetch feature %d\n" , |
74 | field->report->id); |
75 | goto out; |
76 | } |
77 | |
78 | if (!report->id) { |
79 | /* |
80 | * Undo the damage from hid_hw_raw_request() for unnumbered |
81 | * reports. |
82 | */ |
83 | report_data++; |
84 | report_len--; |
85 | } |
86 | |
87 | ret = hid_report_raw_event(hid: hdev, type: HID_FEATURE_REPORT, data: report_data, |
88 | size: report_len, interrupt: 0); |
89 | if (ret) { |
90 | dev_warn(&hdev->dev, "failed to report feature %d\n" , |
91 | field->report->id); |
92 | goto out; |
93 | } |
94 | |
95 | data->function_row_physmap[fn_key - MIN_FN_ROW_KEY] = |
96 | field->value[usage->usage_index]; |
97 | |
98 | out: |
99 | kfree(objp: buf); |
100 | } |
101 | EXPORT_SYMBOL_GPL(vivaldi_feature_mapping); |
102 | |
103 | static ssize_t function_row_physmap_show(struct device *dev, |
104 | struct device_attribute *attr, |
105 | char *buf) |
106 | { |
107 | struct hid_device *hdev = to_hid_device(dev); |
108 | struct vivaldi_data *data = hid_get_drvdata(hdev); |
109 | |
110 | return vivaldi_function_row_physmap_show(data, buf); |
111 | } |
112 | |
113 | static DEVICE_ATTR_RO(function_row_physmap); |
114 | static struct attribute *vivaldi_sysfs_attrs[] = { |
115 | &dev_attr_function_row_physmap.attr, |
116 | NULL |
117 | }; |
118 | |
119 | static umode_t vivaldi_is_visible(struct kobject *kobj, struct attribute *attr, |
120 | int n) |
121 | { |
122 | struct hid_device *hdev = to_hid_device(kobj_to_dev(kobj)); |
123 | struct vivaldi_data *data = hid_get_drvdata(hdev); |
124 | |
125 | if (!data->num_function_row_keys) |
126 | return 0; |
127 | return attr->mode; |
128 | } |
129 | |
130 | static const struct attribute_group vivaldi_attribute_group = { |
131 | .attrs = vivaldi_sysfs_attrs, |
132 | .is_visible = vivaldi_is_visible, |
133 | }; |
134 | |
135 | const struct attribute_group *vivaldi_attribute_groups[] = { |
136 | &vivaldi_attribute_group, |
137 | NULL, |
138 | }; |
139 | EXPORT_SYMBOL_GPL(vivaldi_attribute_groups); |
140 | |
141 | MODULE_LICENSE("GPL" ); |
142 | |