parport_gsc.c

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/*
 *      Low-level parallel-support for PC-style hardware integrated in the 
 *  LASI-Controller (on GSC-Bus) for HP-PARISC Workstations
 *
 *  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.
 *
 *  (C) 1999-2001 by Helge Deller <[email protected]>
 *
 * 
 * based on parport_pc.c by 
 *      Grant Guenther <[email protected]>
 *      Phil Blundell <[email protected]>
 *          Tim Waugh <[email protected]>
 *      Jose Renau <[email protected]>
 *          David Campbell
 *          Andrea Arcangeli
 */

#undef DEBUG    /* undef for production */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/sysctl.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>
#include <asm/superio.h>

#include <linux/parport.h>
#include <asm/pdc.h>
#include <asm/parisc-device.h>
#include <asm/hardware.h>
#include "parport_gsc.h"


MODULE_AUTHOR("Helge Deller <[email protected]>");
MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
MODULE_SUPPORTED_DEVICE("integrated PC-style parallel port");
MODULE_LICENSE("GPL");


/*
 * Clear TIMEOUT BIT in EPP MODE
 *
 * This is also used in SPP detection.
 */
static int clear_epp_timeout(struct parport *pb)
{
    unsigned char r;

    if (!(parport_gsc_read_status(pb) & 0x01))
        return 1;

    /* To clear timeout some chips require double read */
    parport_gsc_read_status(pb);
    r = parport_gsc_read_status(pb);
    parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
    parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
    r = parport_gsc_read_status(pb);

    return !(r & 0x01);
}

/*
 * Access functions.
 *
 * Most of these aren't static because they may be used by the
 * parport_xxx_yyy macros.  extern __inline__ versions of several
 * of these are in parport_gsc.h.
 */

void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s)
{
    s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
}

void parport_gsc_save_state(struct parport *p, struct parport_state *s)
{
    s->u.pc.ctr = parport_readb (CONTROL (p));
}

void parport_gsc_restore_state(struct parport *p, struct parport_state *s)
{
    parport_writeb (s->u.pc.ctr, CONTROL (p));
}

struct parport_operations parport_gsc_ops = 
{
    .write_data = parport_gsc_write_data,
    .read_data  = parport_gsc_read_data,

    .write_control  = parport_gsc_write_control,
    .read_control   = parport_gsc_read_control,
    .frob_control   = parport_gsc_frob_control,

    .read_status    = parport_gsc_read_status,

    .enable_irq = parport_gsc_enable_irq,
    .disable_irq    = parport_gsc_disable_irq,

    .data_forward   = parport_gsc_data_forward,
    .data_reverse   = parport_gsc_data_reverse,

    .init_state = parport_gsc_init_state,
    .save_state = parport_gsc_save_state,
    .restore_state  = parport_gsc_restore_state,

    .epp_write_data = parport_ieee1284_epp_write_data,
    .epp_read_data  = parport_ieee1284_epp_read_data,
    .epp_write_addr = parport_ieee1284_epp_write_addr,
    .epp_read_addr  = parport_ieee1284_epp_read_addr,

    .ecp_write_data = parport_ieee1284_ecp_write_data,
    .ecp_read_data  = parport_ieee1284_ecp_read_data,
    .ecp_write_addr = parport_ieee1284_ecp_write_addr,

    .compat_write_data  = parport_ieee1284_write_compat,
    .nibble_read_data   = parport_ieee1284_read_nibble,
    .byte_read_data     = parport_ieee1284_read_byte,

    .owner      = THIS_MODULE,
};

/* --- Mode detection ------------------------------------- */

/*
 * Checks for port existence, all ports support SPP MODE
 */
static int __devinit parport_SPP_supported(struct parport *pb)
{
    unsigned char r, w;

    /*
     * first clear an eventually pending EPP timeout 
     * I ([email protected]) have an SMSC chipset
     * that does not even respond to SPP cycles if an EPP
     * timeout is pending
     */
    clear_epp_timeout(pb);

    /* Do a simple read-write test to make sure the port exists. */
    w = 0xc;
    parport_writeb (w, CONTROL (pb));

    /* Is there a control register that we can read from?  Some
     * ports don't allow reads, so read_control just returns a
     * software copy. Some ports _do_ allow reads, so bypass the
     * software copy here.  In addition, some bits aren't
     * writable. */
    r = parport_readb (CONTROL (pb));
    if ((r & 0xf) == w) {
        w = 0xe;
        parport_writeb (w, CONTROL (pb));
        r = parport_readb (CONTROL (pb));
        parport_writeb (0xc, CONTROL (pb));
        if ((r & 0xf) == w)
            return PARPORT_MODE_PCSPP;
    }

    /* Try the data register.  The data lines aren't tri-stated at
     * this stage, so we expect back what we wrote. */
    w = 0xaa;
    parport_gsc_write_data (pb, w);
    r = parport_gsc_read_data (pb);
    if (r == w) {
        w = 0x55;
        parport_gsc_write_data (pb, w);
        r = parport_gsc_read_data (pb);
        if (r == w)
            return PARPORT_MODE_PCSPP;
    }

    return 0;
}

/* Detect PS/2 support.
 *
 * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 * allows us to read data from the data lines.  In theory we would get back
 * 0xff but any peripheral attached to the port may drag some or all of the
 * lines down to zero.  So if we get back anything that isn't the contents
 * of the data register we deem PS/2 support to be present. 
 *
 * Some SPP ports have "half PS/2" ability - you can't turn off the line
 * drivers, but an external peripheral with sufficiently beefy drivers of
 * its own can overpower them and assert its own levels onto the bus, from
 * where they can then be read back as normal.  Ports with this property
 * and the right type of device attached are likely to fail the SPP test,
 * (as they will appear to have stuck bits) and so the fact that they might
 * be misdetected here is rather academic. 
 */

static int __devinit parport_PS2_supported(struct parport *pb)
{
    int ok = 0;
  
    clear_epp_timeout(pb);

    /* try to tri-state the buffer */
    parport_gsc_data_reverse (pb);
    
    parport_gsc_write_data(pb, 0x55);
    if (parport_gsc_read_data(pb) != 0x55) ok++;

    parport_gsc_write_data(pb, 0xaa);
    if (parport_gsc_read_data(pb) != 0xaa) ok++;

    /* cancel input mode */
    parport_gsc_data_forward (pb);

    if (ok) {
        pb->modes |= PARPORT_MODE_TRISTATE;
    } else {
        struct parport_gsc_private *priv = pb->private_data;
        priv->ctr_writable &= ~0x20;
    }

    return ok;
}


/* --- Initialisation code -------------------------------- */

struct parport *__devinit parport_gsc_probe_port (unsigned long base,
                         unsigned long base_hi,
                         int irq, int dma,
                         struct pci_dev *dev)
{
    struct parport_gsc_private *priv;
    struct parport_operations *ops;
    struct parport tmp;
    struct parport *p = &tmp;

    priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL);
    if (!priv) {
        printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base);
        return NULL;
    }
    ops = kmalloc (sizeof (struct parport_operations), GFP_KERNEL);
    if (!ops) {
        printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
            base);
        kfree (priv);
        return NULL;
    }
    memcpy (ops, &parport_gsc_ops, sizeof (struct parport_operations));
    priv->ctr = 0xc;
    priv->ctr_writable = 0xff;
    priv->dma_buf = 0;
    priv->dma_handle = 0;
    priv->dev = dev;
    p->base = base;
    p->base_hi = base_hi;
    p->irq = irq;
    p->dma = dma;
    p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
    p->ops = ops;
    p->private_data = priv;
    p->physport = p;
    if (!parport_SPP_supported (p)) {
        /* No port. */
        kfree (priv);
        kfree(ops);
        return NULL;
    }
    parport_PS2_supported (p);

    if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
                    PARPORT_DMA_NONE, ops))) {
        kfree (priv);
        kfree (ops);
        return NULL;
    }

    p->base_hi = base_hi;
    p->modes = tmp.modes;
    p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
    p->private_data = priv;

    printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base);
    p->irq = irq;
    if (p->irq == PARPORT_IRQ_AUTO) {
        p->irq = PARPORT_IRQ_NONE;
    }
    if (p->irq != PARPORT_IRQ_NONE) {
        printk(", irq %d", p->irq);

        if (p->dma == PARPORT_DMA_AUTO) {
            p->dma = PARPORT_DMA_NONE;
        }
    }
    if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq
                                           is mandatory (see above) */
        p->dma = PARPORT_DMA_NONE;

    printk(" [");
#define printmode(x) {if(p->modes&PARPORT_MODE_##x){printk("%s%s",f?",":"",#x);f++;}}
    {
        int f = 0;
        printmode(PCSPP);
        printmode(TRISTATE);
        printmode(COMPAT)
        printmode(EPP);
//      printmode(ECP);
//      printmode(DMA);
    }
#undef printmode
    printk("]\n");

    if (p->irq != PARPORT_IRQ_NONE) {
        if (request_irq (p->irq, parport_irq_handler,
                 0, p->name, p)) {
            printk (KERN_WARNING "%s: irq %d in use, "
                "resorting to polled operation\n",
                p->name, p->irq);
            p->irq = PARPORT_IRQ_NONE;
            p->dma = PARPORT_DMA_NONE;
        }
    }

    /* Done probing.  Now put the port into a sensible start-up state. */

    parport_gsc_write_data(p, 0);
    parport_gsc_data_forward (p);

    /* Now that we've told the sharing engine about the port, and
       found out its characteristics, let the high-level drivers
       know about it. */
    parport_announce_port (p);

    return p;
}


#define PARPORT_GSC_OFFSET 0x800

static int __devinitdata parport_count;

static int __devinit parport_init_chip(struct parisc_device *dev)
{
    struct parport *p;
    unsigned long port;

    if (!dev->irq) {
        printk(KERN_WARNING "IRQ not found for parallel device at 0x%llx\n",
            (unsigned long long)dev->hpa.start);
        return -ENODEV;
    }

    port = dev->hpa.start + PARPORT_GSC_OFFSET;
    
    /* some older machines with ASP-chip don't support
     * the enhanced parport modes.
     */
    if (boot_cpu_data.cpu_type > pcxt && !pdc_add_valid(port+4)) {

        /* Initialize bidirectional-mode (0x10) & data-tranfer-mode #1 (0x20) */
        printk("%s: initialize bidirectional-mode.\n", __func__);
        parport_writeb ( (0x10 + 0x20), port + 4);

    } else {
        printk("%s: enhanced parport-modes not supported.\n", __func__);
    }
    
    p = parport_gsc_probe_port(port, 0, dev->irq,
            /* PARPORT_IRQ_NONE */ PARPORT_DMA_NONE, NULL);
    if (p)
        parport_count++;
    dev_set_drvdata(&dev->dev, p);

    return 0;
}

static int __devexit parport_remove_chip(struct parisc_device *dev)
{
    struct parport *p = dev_get_drvdata(&dev->dev);
    if (p) {
        struct parport_gsc_private *priv = p->private_data;
        struct parport_operations *ops = p->ops;
        parport_remove_port(p);
        if (p->dma != PARPORT_DMA_NONE)
            free_dma(p->dma);
        if (p->irq != PARPORT_IRQ_NONE)
            free_irq(p->irq, p);
        if (priv->dma_buf)
            pci_free_consistent(priv->dev, PAGE_SIZE,
                        priv->dma_buf,
                        priv->dma_handle);
        kfree (p->private_data);
        parport_put_port(p);
        kfree (ops); /* hope no-one cached it */
    }
    return 0;
}

static struct parisc_device_id parport_tbl[] = {
    { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x74 },
    { 0, }
};

MODULE_DEVICE_TABLE(parisc, parport_tbl);

static struct parisc_driver parport_driver = {
    .name       = "Parallel",
    .id_table   = parport_tbl,
    .probe      = parport_init_chip,
    .remove     = __devexit_p(parport_remove_chip),
};

int __devinit parport_gsc_init(void)
{
    return register_parisc_driver(&parport_driver);
}

static void __devexit parport_gsc_exit(void)
{
    unregister_parisc_driver(&parport_driver);
}

module_init(parport_gsc_init);
module_exit(parport_gsc_exit);