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, report->id, report_data, 70 report_len, HID_FEATURE_REPORT, 71 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(hdev, HID_FEATURE_REPORT, report_data, 88 report_len, 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(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_DESCRIPTION("Helpers for ChromeOS HID Vivaldi keyboards"); 142 MODULE_LICENSE("GPL"); 143