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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pcsp_input.c (1984B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  PC Speaker beeper driver for Linux
      4 *
      5 *  Copyright (c) 2002 Vojtech Pavlik
      6 *  Copyright (c) 1992 Orest Zborowski
      7 */
      8
      9
     10#include <linux/init.h>
     11#include <linux/input.h>
     12#include <linux/io.h>
     13#include "pcsp.h"
     14#include "pcsp_input.h"
     15
     16static void pcspkr_do_sound(unsigned int count)
     17{
     18	unsigned long flags;
     19
     20	raw_spin_lock_irqsave(&i8253_lock, flags);
     21
     22	if (count) {
     23		/* set command for counter 2, 2 byte write */
     24		outb_p(0xB6, 0x43);
     25		/* select desired HZ */
     26		outb_p(count & 0xff, 0x42);
     27		outb((count >> 8) & 0xff, 0x42);
     28		/* enable counter 2 */
     29		outb_p(inb_p(0x61) | 3, 0x61);
     30	} else {
     31		/* disable counter 2 */
     32		outb(inb_p(0x61) & 0xFC, 0x61);
     33	}
     34
     35	raw_spin_unlock_irqrestore(&i8253_lock, flags);
     36}
     37
     38void pcspkr_stop_sound(void)
     39{
     40	pcspkr_do_sound(0);
     41}
     42
     43static int pcspkr_input_event(struct input_dev *dev, unsigned int type,
     44			      unsigned int code, int value)
     45{
     46	unsigned int count = 0;
     47
     48	if (atomic_read(&pcsp_chip.timer_active) || !pcsp_chip.pcspkr)
     49		return 0;
     50
     51	switch (type) {
     52	case EV_SND:
     53		switch (code) {
     54		case SND_BELL:
     55			if (value)
     56				value = 1000;
     57			break;
     58		case SND_TONE:
     59			break;
     60		default:
     61			return -1;
     62		}
     63		break;
     64
     65	default:
     66		return -1;
     67	}
     68
     69	if (value > 20 && value < 32767)
     70		count = PIT_TICK_RATE / value;
     71
     72	pcspkr_do_sound(count);
     73
     74	return 0;
     75}
     76
     77int pcspkr_input_init(struct input_dev **rdev, struct device *dev)
     78{
     79	int err;
     80
     81	struct input_dev *input_dev = devm_input_allocate_device(dev);
     82	if (!input_dev)
     83		return -ENOMEM;
     84
     85	input_dev->name = "PC Speaker";
     86	input_dev->phys = "isa0061/input0";
     87	input_dev->id.bustype = BUS_ISA;
     88	input_dev->id.vendor = 0x001f;
     89	input_dev->id.product = 0x0001;
     90	input_dev->id.version = 0x0100;
     91	input_dev->dev.parent = dev;
     92
     93	input_dev->evbit[0] = BIT(EV_SND);
     94	input_dev->sndbit[0] = BIT(SND_BELL) | BIT(SND_TONE);
     95	input_dev->event = pcspkr_input_event;
     96
     97	err = input_register_device(input_dev);
     98	if (err)
     99		return err;
    100
    101	*rdev = input_dev;
    102	return 0;
    103}