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| 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 const struct attribute_group vivaldi_attribute_group = { |
| 120 | + .attrs = vivaldi_sysfs_attrs, |
| 121 | +}; |
| 122 | + |
| 123 | +/** |
| 124 | + * vivaldi_input_configured - Complete initialization of device using vivaldi map |
| 125 | + * @hdev: HID device to which vivaldi attributes should be attached |
| 126 | + * @hidinput: HID input device (unused) |
| 127 | + */ |
| 128 | +int vivaldi_input_configured(struct hid_device *hdev, |
| 129 | + struct hid_input *hidinput) |
| 130 | +{ |
| 131 | + struct vivaldi_data *data = hid_get_drvdata(hdev); |
| 132 | + |
| 133 | + if (!data->num_function_row_keys) |
| 134 | + return 0; |
| 135 | + |
| 136 | + return devm_device_add_group(&hdev->dev, &vivaldi_attribute_group); |
| 137 | +} |
| 138 | +EXPORT_SYMBOL_GPL(vivaldi_input_configured); |
| 139 | + |
| 140 | +MODULE_LICENSE("GPL"); |
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