ct82c710.c

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/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 */

/*
 *  82C710 C&T mouse port chip driver for Linux
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <[email protected]>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <asm/io.h>

MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
MODULE_DESCRIPTION("82C710 C&T mouse port chip driver");
MODULE_LICENSE("GPL");

/*
 * ct82c710 interface
 */

#define CT82C710_DEV_IDLE     0x01      /* Device Idle */
#define CT82C710_RX_FULL      0x02      /* Device Char received */
#define CT82C710_TX_IDLE      0x04      /* Device XMIT Idle */
#define CT82C710_RESET        0x08      /* Device Reset */
#define CT82C710_INTS_ON      0x10      /* Device Interrupt On */
#define CT82C710_ERROR_FLAG   0x20      /* Device Error */
#define CT82C710_CLEAR        0x40      /* Device Clear */
#define CT82C710_ENABLE       0x80      /* Device Enable */

#define CT82C710_IRQ          12

#define CT82C710_DATA         ct82c710_iores.start
#define CT82C710_STATUS       (ct82c710_iores.start + 1)

static struct serio *ct82c710_port;
static struct platform_device *ct82c710_device;
static struct resource ct82c710_iores;

/*
 * Interrupt handler for the 82C710 mouse port. A character
 * is waiting in the 82C710.
 */

static irqreturn_t ct82c710_interrupt(int cpl, void *dev_id)
{
    return serio_interrupt(ct82c710_port, inb(CT82C710_DATA), 0);
}

/*
 * Wait for device to send output char and flush any input char.
 */

static int ct82c170_wait(void)
{
    int timeout = 60000;

    while ((inb(CT82C710_STATUS) & (CT82C710_RX_FULL | CT82C710_TX_IDLE | CT82C710_DEV_IDLE))
               != (CT82C710_DEV_IDLE | CT82C710_TX_IDLE) && timeout) {

        if (inb_p(CT82C710_STATUS) & CT82C710_RX_FULL) inb_p(CT82C710_DATA);

        udelay(1);
        timeout--;
    }

    return !timeout;
}

static void ct82c710_close(struct serio *serio)
{
    if (ct82c170_wait())
        printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");

    outb_p(inb_p(CT82C710_STATUS) & ~(CT82C710_ENABLE | CT82C710_INTS_ON), CT82C710_STATUS);

    if (ct82c170_wait())
        printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");

    free_irq(CT82C710_IRQ, NULL);
}

static int ct82c710_open(struct serio *serio)
{
    unsigned char status;
    int err;

    err = request_irq(CT82C710_IRQ, ct82c710_interrupt, 0, "ct82c710", NULL);
    if (err)
        return err;

    status = inb_p(CT82C710_STATUS);

    status |= (CT82C710_ENABLE | CT82C710_RESET);
    outb_p(status, CT82C710_STATUS);

    status &= ~(CT82C710_RESET);
    outb_p(status, CT82C710_STATUS);

    status |= CT82C710_INTS_ON;
    outb_p(status, CT82C710_STATUS);    /* Enable interrupts */

    while (ct82c170_wait()) {
        printk(KERN_ERR "ct82c710: Device busy in open()\n");
        status &= ~(CT82C710_ENABLE | CT82C710_INTS_ON);
        outb_p(status, CT82C710_STATUS);
        free_irq(CT82C710_IRQ, NULL);
        return -EBUSY;
    }

    return 0;
}

/*
 * Write to the 82C710 mouse device.
 */

static int ct82c710_write(struct serio *port, unsigned char c)
{
    if (ct82c170_wait()) return -1;
    outb_p(c, CT82C710_DATA);
    return 0;
}

/*
 * See if we can find a 82C710 device. Read mouse address.
 */

static int __init ct82c710_detect(void)
{
    outb_p(0x55, 0x2fa);                /* Any value except 9, ff or 36 */
    outb_p(0xaa, 0x3fa);                /* Inverse of 55 */
    outb_p(0x36, 0x3fa);                /* Address the chip */
    outb_p(0xe4, 0x3fa);                /* 390/4; 390 = config address */
    outb_p(0x1b, 0x2fa);                /* Inverse of e4 */
    outb_p(0x0f, 0x390);                /* Write index */
    if (inb_p(0x391) != 0xe4)           /* Config address found? */
        return -ENODEV;             /* No: no 82C710 here */

    outb_p(0x0d, 0x390);                /* Write index */
    ct82c710_iores.start = inb_p(0x391) << 2;   /* Get mouse I/O address */
    ct82c710_iores.end = ct82c710_iores.start + 1;
    ct82c710_iores.flags = IORESOURCE_IO;
    outb_p(0x0f, 0x390);
    outb_p(0x0f, 0x391);                /* Close config mode */

    return 0;
}

static int __devinit ct82c710_probe(struct platform_device *dev)
{
    ct82c710_port = kzalloc(sizeof(struct serio), GFP_KERNEL);
    if (!ct82c710_port)
        return -ENOMEM;

    ct82c710_port->id.type = SERIO_8042;
    ct82c710_port->dev.parent = &dev->dev;
    ct82c710_port->open = ct82c710_open;
    ct82c710_port->close = ct82c710_close;
    ct82c710_port->write = ct82c710_write;
    strlcpy(ct82c710_port->name, "C&T 82c710 mouse port",
        sizeof(ct82c710_port->name));
    snprintf(ct82c710_port->phys, sizeof(ct82c710_port->phys),
         "isa%16llx/serio0", (unsigned long long)CT82C710_DATA);

    serio_register_port(ct82c710_port);

    printk(KERN_INFO "serio: C&T 82c710 mouse port at %#llx irq %d\n",
        (unsigned long long)CT82C710_DATA, CT82C710_IRQ);

    return 0;
}

static int __devexit ct82c710_remove(struct platform_device *dev)
{
    serio_unregister_port(ct82c710_port);

    return 0;
}

static struct platform_driver ct82c710_driver = {
    .driver     = {
        .name   = "ct82c710",
        .owner  = THIS_MODULE,
    },
    .probe      = ct82c710_probe,
    .remove     = __devexit_p(ct82c710_remove),
};


static int __init ct82c710_init(void)
{
    int error;

    error = ct82c710_detect();
    if (error)
        return error;

    error = platform_driver_register(&ct82c710_driver);
    if (error)
        return error;

    ct82c710_device = platform_device_alloc("ct82c710", -1);
    if (!ct82c710_device) {
        error = -ENOMEM;
        goto err_unregister_driver;
    }

    error = platform_device_add_resources(ct82c710_device, &ct82c710_iores, 1);
    if (error)
        goto err_free_device;

    error = platform_device_add(ct82c710_device);
    if (error)
        goto err_free_device;

    return 0;

 err_free_device:
    platform_device_put(ct82c710_device);
 err_unregister_driver:
    platform_driver_unregister(&ct82c710_driver);
    return error;
}

static void __exit ct82c710_exit(void)
{
    platform_device_unregister(ct82c710_device);
    platform_driver_unregister(&ct82c710_driver);
}

module_init(ct82c710_init);
module_exit(ct82c710_exit);