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1// SPDX-License-Identifier: GPL-2.02/*3 * Helpers for ChromeOS HID Vivaldi keyboards4 *5 * Copyright (C) 2022 Google, Inc6 */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 118#define MAX_FN_ROW_KEY VIVALDI_MAX_FUNCTION_ROW_KEYS19#define HID_VD_FN_ROW_PHYSMAP 0x0000000120#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 HID24 * @hdev: HID device to parse25 * @field: HID field to parse26 * @usage: HID usage to parse27 *28 * Note: this function assumes that driver data attached to @hdev contains an29 * instance of &struct vivaldi_data at the very beginning.30 */31void 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 unnumbered61 * reports, so we need to account for this to avoid getting62 * -EOVERFLOW in return.63 * Note that hid_alloc_report_buf() adds 7 bytes to the size64 * 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 unnumbered81 * 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 98out:99 kfree(buf);100}101EXPORT_SYMBOL_GPL(vivaldi_feature_mapping);102 103static 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 113static DEVICE_ATTR_RO(function_row_physmap);114static struct attribute *vivaldi_sysfs_attrs[] = {115 &dev_attr_function_row_physmap.attr,116 NULL117};118 119static 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 130static const struct attribute_group vivaldi_attribute_group = {131 .attrs = vivaldi_sysfs_attrs,132 .is_visible = vivaldi_is_visible,133};134 135const struct attribute_group *vivaldi_attribute_groups[] = {136 &vivaldi_attribute_group,137 NULL,138};139EXPORT_SYMBOL_GPL(vivaldi_attribute_groups);140 141MODULE_DESCRIPTION("Helpers for ChromeOS HID Vivaldi keyboards");142MODULE_LICENSE("GPL");143