cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hid-primax.c (1822B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * HID driver for primax and similar keyboards with in-band modifiers
      4 *
      5 * Copyright 2011 Google Inc. All Rights Reserved
      6 *
      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 band
     26		 * 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 level
     38		 * drivers don't particularly care if there are in-band
     39		 * 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_LICENSE("GPL");