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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * HID driver for primax and similar keyboards with in-band modifiers4 *5 * Copyright 2011 Google Inc. All Rights Reserved6 *7 * Author:8 * Terry Lambert <tlambert@google.com>9 */10 11#include <linux/device.h>12#include <linux/hid.h>13#include <linux/module.h>14 15#include "hid-ids.h"16 17static int px_raw_event(struct hid_device *hid, struct hid_report *report,18 u8 *data, int size)19{20 int idx = size;21 22 switch (report->id) {23 case 0: /* keyboard input */24 /*25 * Convert in-band modifier key values into out of band26 * modifier bits and pull the key strokes from the report.27 * Thus a report data set which looked like:28 *29 * [00][00][E0][30][00][00][00][00]30 * (no modifier bits + "Left Shift" key + "1" key)31 *32 * Would be converted to:33 *34 * [01][00][00][30][00][00][00][00]35 * (Left Shift modifier bit + "1" key)36 *37 * As long as it's in the size range, the upper level38 * drivers don't particularly care if there are in-band39 * 0-valued keys, so they don't stop parsing.40 */41 while (--idx > 1) {42 if (data[idx] < 0xE0 || data[idx] > 0xE7)43 continue;44 data[0] |= (1 << (data[idx] - 0xE0));45 data[idx] = 0;46 }47 hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, 0);48 return 1;49 50 default: /* unknown report */51 /* Unknown report type; pass upstream */52 hid_info(hid, "unknown report type %d\n", report->id);53 break;54 }55 56 return 0;57}58 59static const struct hid_device_id px_devices[] = {60 { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },61 { }62};63MODULE_DEVICE_TABLE(hid, px_devices);64 65static struct hid_driver px_driver = {66 .name = "primax",67 .id_table = px_devices,68 .raw_event = px_raw_event,69};70module_hid_driver(px_driver);71 72MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");73MODULE_DESCRIPTION("HID driver for primax and similar keyboards with in-band modifiers");74MODULE_LICENSE("GPL");75