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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q40kbd.c (3746B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  Copyright (c) 2000-2001 Vojtech Pavlik
      4 *
      5 *  Based on the work of:
      6 *	Richard Zidlicky <Richard.Zidlicky@stud.informatik.uni-erlangen.de>
      7 */
      8
      9/*
     10 * Q40 PS/2 keyboard controller driver for Linux/m68k
     11 */
     12
     13/*
     14 */
     15
     16#include <linux/module.h>
     17#include <linux/serio.h>
     18#include <linux/interrupt.h>
     19#include <linux/err.h>
     20#include <linux/bitops.h>
     21#include <linux/platform_device.h>
     22#include <linux/slab.h>
     23
     24#include <asm/io.h>
     25#include <linux/uaccess.h>
     26#include <asm/q40_master.h>
     27#include <asm/irq.h>
     28#include <asm/q40ints.h>
     29
     30#define DRV_NAME	"q40kbd"
     31
     32MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
     33MODULE_DESCRIPTION("Q40 PS/2 keyboard controller driver");
     34MODULE_LICENSE("GPL");
     35MODULE_ALIAS("platform:" DRV_NAME);
     36
     37struct q40kbd {
     38	struct serio *port;
     39	spinlock_t lock;
     40};
     41
     42static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
     43{
     44	struct q40kbd *q40kbd = dev_id;
     45	unsigned long flags;
     46
     47	spin_lock_irqsave(&q40kbd->lock, flags);
     48
     49	if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
     50		serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
     51
     52	master_outb(-1, KEYBOARD_UNLOCK_REG);
     53
     54	spin_unlock_irqrestore(&q40kbd->lock, flags);
     55
     56	return IRQ_HANDLED;
     57}
     58
     59/*
     60 * q40kbd_flush() flushes all data that may be in the keyboard buffers
     61 */
     62
     63static void q40kbd_flush(struct q40kbd *q40kbd)
     64{
     65	int maxread = 100;
     66	unsigned long flags;
     67
     68	spin_lock_irqsave(&q40kbd->lock, flags);
     69
     70	while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
     71		master_inb(KEYCODE_REG);
     72
     73	spin_unlock_irqrestore(&q40kbd->lock, flags);
     74}
     75
     76static void q40kbd_stop(void)
     77{
     78	master_outb(0, KEY_IRQ_ENABLE_REG);
     79	master_outb(-1, KEYBOARD_UNLOCK_REG);
     80}
     81
     82/*
     83 * q40kbd_open() is called when a port is open by the higher layer.
     84 * It allocates the interrupt and enables in in the chip.
     85 */
     86
     87static int q40kbd_open(struct serio *port)
     88{
     89	struct q40kbd *q40kbd = port->port_data;
     90
     91	q40kbd_flush(q40kbd);
     92
     93	/* off we go */
     94	master_outb(-1, KEYBOARD_UNLOCK_REG);
     95	master_outb(1, KEY_IRQ_ENABLE_REG);
     96
     97	return 0;
     98}
     99
    100static void q40kbd_close(struct serio *port)
    101{
    102	struct q40kbd *q40kbd = port->port_data;
    103
    104	q40kbd_stop();
    105	q40kbd_flush(q40kbd);
    106}
    107
    108static int q40kbd_probe(struct platform_device *pdev)
    109{
    110	struct q40kbd *q40kbd;
    111	struct serio *port;
    112	int error;
    113
    114	q40kbd = kzalloc(sizeof(struct q40kbd), GFP_KERNEL);
    115	port = kzalloc(sizeof(struct serio), GFP_KERNEL);
    116	if (!q40kbd || !port) {
    117		error = -ENOMEM;
    118		goto err_free_mem;
    119	}
    120
    121	q40kbd->port = port;
    122	spin_lock_init(&q40kbd->lock);
    123
    124	port->id.type = SERIO_8042;
    125	port->open = q40kbd_open;
    126	port->close = q40kbd_close;
    127	port->port_data = q40kbd;
    128	port->dev.parent = &pdev->dev;
    129	strlcpy(port->name, "Q40 Kbd Port", sizeof(port->name));
    130	strlcpy(port->phys, "Q40", sizeof(port->phys));
    131
    132	q40kbd_stop();
    133
    134	error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
    135			    DRV_NAME, q40kbd);
    136	if (error) {
    137		dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
    138		goto err_free_mem;
    139	}
    140
    141	serio_register_port(q40kbd->port);
    142
    143	platform_set_drvdata(pdev, q40kbd);
    144	printk(KERN_INFO "serio: Q40 kbd registered\n");
    145
    146	return 0;
    147
    148err_free_mem:
    149	kfree(port);
    150	kfree(q40kbd);
    151	return error;
    152}
    153
    154static int q40kbd_remove(struct platform_device *pdev)
    155{
    156	struct q40kbd *q40kbd = platform_get_drvdata(pdev);
    157
    158	/*
    159	 * q40kbd_close() will be called as part of unregistering
    160	 * and will ensure that IRQ is turned off, so it is safe
    161	 * to unregister port first and free IRQ later.
    162	 */
    163	serio_unregister_port(q40kbd->port);
    164	free_irq(Q40_IRQ_KEYBOARD, q40kbd);
    165	kfree(q40kbd);
    166
    167	return 0;
    168}
    169
    170static struct platform_driver q40kbd_driver = {
    171	.driver		= {
    172		.name	= "q40kbd",
    173	},
    174	.remove		= q40kbd_remove,
    175};
    176
    177module_platform_driver_probe(q40kbd_driver, q40kbd_probe);