gscps2.c

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/*
 * drivers/input/serio/gscps2.c
 *
 * Copyright (c) 2004-2006 Helge Deller <[email protected]>
 * Copyright (c) 2002 Laurent Canet <[email protected]>
 * Copyright (c) 2002 Thibaut Varene <[email protected]>
 *
 * Pieces of code based on linux-2.4's hp_mouse.c & hp_keyb.c
 *  Copyright (c) 1999 Alex deVries <[email protected]>
 *  Copyright (c) 1999-2000 Philipp Rumpf <[email protected]>
 *  Copyright (c) 2000 Xavier Debacker <[email protected]>
 *  Copyright (c) 2000-2001 Thomas Marteau <[email protected]>
 *
 * HP GSC PS/2 port driver, found in PA/RISC Workstations
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * TODO:
 * - Dino testing (did HP ever shipped a machine on which this port
 *                 was usable/enabled ?)
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/serio.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/pci_ids.h>

#include <asm/irq.h>
#include <asm/io.h>
#include <asm/parisc-device.h>

MODULE_AUTHOR("Laurent Canet <[email protected]>, Thibaut Varene <[email protected]>, Helge Deller <[email protected]>");
MODULE_DESCRIPTION("HP GSC PS2 port driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);

#define PFX "gscps2.c: "

/*
 * Driver constants
 */

/* various constants */
#define ENABLE          1
#define DISABLE         0

#define GSC_DINO_OFFSET     0x0800  /* offset for DINO controller versus LASI one */

/* PS/2 IO port offsets */
#define GSC_ID          0x00    /* device ID offset (see: GSC_ID_XXX) */
#define GSC_RESET       0x00    /* reset port offset */
#define GSC_RCVDATA     0x04    /* receive port offset */
#define GSC_XMTDATA     0x04    /* transmit port offset */
#define GSC_CONTROL     0x08    /* see: Control register bits */
#define GSC_STATUS      0x0C    /* see: Status register bits */

/* Control register bits */
#define GSC_CTRL_ENBL       0x01    /* enable interface */
#define GSC_CTRL_LPBXR      0x02    /* loopback operation */
#define GSC_CTRL_DIAG       0x20    /* directly control clock/data line */
#define GSC_CTRL_DATDIR     0x40    /* data line direct control */
#define GSC_CTRL_CLKDIR     0x80    /* clock line direct control */

/* Status register bits */
#define GSC_STAT_RBNE       0x01    /* Receive Buffer Not Empty */
#define GSC_STAT_TBNE       0x02    /* Transmit Buffer Not Empty */
#define GSC_STAT_TERR       0x04    /* Timeout Error */
#define GSC_STAT_PERR       0x08    /* Parity Error */
#define GSC_STAT_CMPINTR    0x10    /* Composite Interrupt = irq on any port */
#define GSC_STAT_DATSHD     0x40    /* Data Line Shadow */
#define GSC_STAT_CLKSHD     0x80    /* Clock Line Shadow */

/* IDs returned by GSC_ID port register */
#define GSC_ID_KEYBOARD     0   /* device ID values */
#define GSC_ID_MOUSE        1


static irqreturn_t gscps2_interrupt(int irq, void *dev);

#define BUFFER_SIZE 0x0f

/* GSC PS/2 port device struct */
struct gscps2port {
    struct list_head node;
    struct parisc_device *padev;
    struct serio *port;
    spinlock_t lock;
    char *addr;
    u8 act, append; /* position in buffer[] */
    struct {
        u8 data;
        u8 str;
    } buffer[BUFFER_SIZE+1];
    int id;
};

/*
 * Various HW level routines
 */

#define gscps2_readb_input(x)       readb((x)+GSC_RCVDATA)
#define gscps2_readb_control(x)     readb((x)+GSC_CONTROL)
#define gscps2_readb_status(x)      readb((x)+GSC_STATUS)
#define gscps2_writeb_control(x, y) writeb((x), (y)+GSC_CONTROL)


/*
 * wait_TBE() - wait for Transmit Buffer Empty
 */

static int wait_TBE(char *addr)
{
    int timeout = 25000; /* device is expected to react within 250 msec */
    while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
        if (!--timeout)
            return 0;   /* This should not happen */
        udelay(10);
    }
    return 1;
}


/*
 * gscps2_flush() - flush the receive buffer
 */

static void gscps2_flush(struct gscps2port *ps2port)
{
    while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
        gscps2_readb_input(ps2port->addr);
    ps2port->act = ps2port->append = 0;
}

/*
 * gscps2_writeb_output() - write a byte to the port
 *
 * returns 1 on success, 0 on error
 */

static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
{
    unsigned long flags;
    char *addr = ps2port->addr;

    if (!wait_TBE(addr)) {
        printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
        return 0;
    }

    while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
        /* wait */;

    spin_lock_irqsave(&ps2port->lock, flags);
    writeb(data, addr+GSC_XMTDATA);
    spin_unlock_irqrestore(&ps2port->lock, flags);

    /* this is ugly, but due to timing of the port it seems to be necessary. */
    mdelay(6);

    /* make sure any received data is returned as fast as possible */
    /* this is important e.g. when we set the LEDs on the keyboard */
    gscps2_interrupt(0, NULL);

    return 1;
}


/*
 * gscps2_enable() - enables or disables the port
 */

static void gscps2_enable(struct gscps2port *ps2port, int enable)
{
    unsigned long flags;
    u8 data;

    /* now enable/disable the port */
    spin_lock_irqsave(&ps2port->lock, flags);
    gscps2_flush(ps2port);
    data = gscps2_readb_control(ps2port->addr);
    if (enable)
        data |= GSC_CTRL_ENBL;
    else
        data &= ~GSC_CTRL_ENBL;
    gscps2_writeb_control(data, ps2port->addr);
    spin_unlock_irqrestore(&ps2port->lock, flags);
    wait_TBE(ps2port->addr);
    gscps2_flush(ps2port);
}

/*
 * gscps2_reset() - resets the PS/2 port
 */

static void gscps2_reset(struct gscps2port *ps2port)
{
    char *addr = ps2port->addr;
    unsigned long flags;

    /* reset the interface */
    spin_lock_irqsave(&ps2port->lock, flags);
    gscps2_flush(ps2port);
    writeb(0xff, addr+GSC_RESET);
    gscps2_flush(ps2port);
    spin_unlock_irqrestore(&ps2port->lock, flags);
}

static LIST_HEAD(ps2port_list);

static irqreturn_t gscps2_interrupt(int irq, void *dev)
{
    struct gscps2port *ps2port;

    list_for_each_entry(ps2port, &ps2port_list, node) {

      unsigned long flags;
      spin_lock_irqsave(&ps2port->lock, flags);

      while ( (ps2port->buffer[ps2port->append].str =
           gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
        ps2port->buffer[ps2port->append].data =
                gscps2_readb_input(ps2port->addr);
        ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
      }

      spin_unlock_irqrestore(&ps2port->lock, flags);

    } /* list_for_each_entry */

    /* all data was read from the ports - now report the data to upper layer */

    list_for_each_entry(ps2port, &ps2port_list, node) {

      while (ps2port->act != ps2port->append) {

        unsigned int rxflags;
        u8 data, status;

        /* Did new data arrived while we read existing data ?
           If yes, exit now and let the new irq handler start over again */
        if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
        return IRQ_HANDLED;

        status = ps2port->buffer[ps2port->act].str;
        data   = ps2port->buffer[ps2port->act].data;

        ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
        rxflags =   ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
            ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );

        serio_interrupt(ps2port->port, data, rxflags);

      } /* while() */

    } /* list_for_each_entry */

    return IRQ_HANDLED;
}


/*
 * gscps2_write() - send a byte out through the aux interface.
 */

static int gscps2_write(struct serio *port, unsigned char data)
{
    struct gscps2port *ps2port = port->port_data;

    if (!gscps2_writeb_output(ps2port, data)) {
        printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
        return -1;
    }
    return 0;
}

/*
 * gscps2_open() is called when a port is opened by the higher layer.
 * It resets and enables the port.
 */

static int gscps2_open(struct serio *port)
{
    struct gscps2port *ps2port = port->port_data;

    gscps2_reset(ps2port);

    /* enable it */
    gscps2_enable(ps2port, ENABLE);

    gscps2_interrupt(0, NULL);

    return 0;
}

/*
 * gscps2_close() disables the port
 */

static void gscps2_close(struct serio *port)
{
    struct gscps2port *ps2port = port->port_data;
    gscps2_enable(ps2port, DISABLE);
}

static int __devinit gscps2_probe(struct parisc_device *dev)
{
    struct gscps2port *ps2port;
    struct serio *serio;
    unsigned long hpa = dev->hpa.start;
    int ret;

    if (!dev->irq)
        return -ENODEV;

    /* Offset for DINO PS/2. Works with LASI even */
    if (dev->id.sversion == 0x96)
        hpa += GSC_DINO_OFFSET;

    ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
    serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
    if (!ps2port || !serio) {
        ret = -ENOMEM;
        goto fail_nomem;
    }

    dev_set_drvdata(&dev->dev, ps2port);

    ps2port->port = serio;
    ps2port->padev = dev;
    ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
    spin_lock_init(&ps2port->lock);

    gscps2_reset(ps2port);
    ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;

    snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
         (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
    strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
    serio->id.type      = SERIO_8042;
    serio->write        = gscps2_write;
    serio->open     = gscps2_open;
    serio->close        = gscps2_close;
    serio->port_data    = ps2port;
    serio->dev.parent   = &dev->dev;

    ret = -EBUSY;
    if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
        goto fail_miserably;

    if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
        printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
                hpa, ps2port->id);
        ret = -ENODEV;
        goto fail;
    }

#if 0
    if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
        goto fail;
#endif

    printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
        ps2port->port->name,
        ps2port->addr,
        ps2port->padev->irq,
        ps2port->port->phys);

    serio_register_port(ps2port->port);

    list_add_tail(&ps2port->node, &ps2port_list);

    return 0;

fail:
    free_irq(dev->irq, ps2port);

fail_miserably:
    iounmap(ps2port->addr);
    release_mem_region(dev->hpa.start, GSC_STATUS + 4);

fail_nomem:
    kfree(ps2port);
    kfree(serio);
    return ret;
}

static int __devexit gscps2_remove(struct parisc_device *dev)
{
    struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);

    serio_unregister_port(ps2port->port);
    free_irq(dev->irq, ps2port);
    gscps2_flush(ps2port);
    list_del(&ps2port->node);
    iounmap(ps2port->addr);
#if 0
    release_mem_region(dev->hpa, GSC_STATUS + 4);
#endif
    dev_set_drvdata(&dev->dev, NULL);
    kfree(ps2port);
    return 0;
}


static struct parisc_device_id gscps2_device_tbl[] = {
    { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
#ifdef DINO_TESTED
    { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
#endif
    { 0, }  /* 0 terminated list */
};

static struct parisc_driver parisc_ps2_driver = {
    .name       = "gsc_ps2",
    .id_table   = gscps2_device_tbl,
    .probe      = gscps2_probe,
    .remove     = __devexit_p(gscps2_remove),
};

static int __init gscps2_init(void)
{
    register_parisc_driver(&parisc_ps2_driver);
    return 0;
}

static void __exit gscps2_exit(void)
{
    unregister_parisc_driver(&parisc_ps2_driver);
}


module_init(gscps2_init);
module_exit(gscps2_exit);