paride.c

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/* 
        paride.c  (c) 1997-8  Grant R. Guenther <[email protected]>
                              Under the terms of the GNU General Public License.

    This is the base module for the family of device drivers
        that support parallel port IDE devices.  

*/

/* Changes:

    1.01    GRG 1998.05.03  Use spinlocks
    1.02    GRG 1998.05.05  init_proto, release_proto, ktti
    1.03    GRG 1998.08.15  eliminate compiler warning
    1.04    GRG 1998.11.28  added support for FRIQ 
    1.05    TMW 2000.06.06  use parport_find_number instead of
                parport_enumerate
    1.06    TMW 2001.03.26  more sane parport-or-not resource management
*/

#define PI_VERSION      "1.06"

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/sched.h>    /* TASK_* */
#include <linux/parport.h>

#include "paride.h"

MODULE_LICENSE("GPL");

#define MAX_PROTOS  32

static struct pi_protocol *protocols[MAX_PROTOS];

static DEFINE_SPINLOCK(pi_spinlock);

void pi_write_regr(PIA * pi, int cont, int regr, int val)
{
    pi->proto->write_regr(pi, cont, regr, val);
}

EXPORT_SYMBOL(pi_write_regr);

int pi_read_regr(PIA * pi, int cont, int regr)
{
    return pi->proto->read_regr(pi, cont, regr);
}

EXPORT_SYMBOL(pi_read_regr);

void pi_write_block(PIA * pi, char *buf, int count)
{
    pi->proto->write_block(pi, buf, count);
}

EXPORT_SYMBOL(pi_write_block);

void pi_read_block(PIA * pi, char *buf, int count)
{
    pi->proto->read_block(pi, buf, count);
}

EXPORT_SYMBOL(pi_read_block);

static void pi_wake_up(void *p)
{
    PIA *pi = (PIA *) p;
    unsigned long flags;
    void (*cont) (void) = NULL;

    spin_lock_irqsave(&pi_spinlock, flags);

    if (pi->claim_cont && !parport_claim(pi->pardev)) {
        cont = pi->claim_cont;
        pi->claim_cont = NULL;
        pi->claimed = 1;
    }

    spin_unlock_irqrestore(&pi_spinlock, flags);

    wake_up(&(pi->parq));

    if (cont)
        cont();
}

int pi_schedule_claimed(PIA * pi, void (*cont) (void))
{
    unsigned long flags;

    spin_lock_irqsave(&pi_spinlock, flags);
    if (pi->pardev && parport_claim(pi->pardev)) {
        pi->claim_cont = cont;
        spin_unlock_irqrestore(&pi_spinlock, flags);
        return 0;
    }
    pi->claimed = 1;
    spin_unlock_irqrestore(&pi_spinlock, flags);
    return 1;
}
EXPORT_SYMBOL(pi_schedule_claimed);

void pi_do_claimed(PIA * pi, void (*cont) (void))
{
    if (pi_schedule_claimed(pi, cont))
        cont();
}

EXPORT_SYMBOL(pi_do_claimed);

static void pi_claim(PIA * pi)
{
    if (pi->claimed)
        return;
    pi->claimed = 1;
    if (pi->pardev)
        wait_event(pi->parq,
               !parport_claim((struct pardevice *) pi->pardev));
}

static void pi_unclaim(PIA * pi)
{
    pi->claimed = 0;
    if (pi->pardev)
        parport_release((struct pardevice *) (pi->pardev));
}

void pi_connect(PIA * pi)
{
    pi_claim(pi);
    pi->proto->connect(pi);
}

EXPORT_SYMBOL(pi_connect);

void pi_disconnect(PIA * pi)
{
    pi->proto->disconnect(pi);
    pi_unclaim(pi);
}

EXPORT_SYMBOL(pi_disconnect);

static void pi_unregister_parport(PIA * pi)
{
    if (pi->pardev) {
        parport_unregister_device((struct pardevice *) (pi->pardev));
        pi->pardev = NULL;
    }
}

void pi_release(PIA * pi)
{
    pi_unregister_parport(pi);
    if (pi->proto->release_proto)
        pi->proto->release_proto(pi);
    module_put(pi->proto->owner);
}

EXPORT_SYMBOL(pi_release);

static int default_test_proto(PIA * pi, char *scratch, int verbose)
{
    int j, k;
    int e[2] = { 0, 0 };

    pi->proto->connect(pi);

    for (j = 0; j < 2; j++) {
        pi_write_regr(pi, 0, 6, 0xa0 + j * 0x10);
        for (k = 0; k < 256; k++) {
            pi_write_regr(pi, 0, 2, k ^ 0xaa);
            pi_write_regr(pi, 0, 3, k ^ 0x55);
            if (pi_read_regr(pi, 0, 2) != (k ^ 0xaa))
                e[j]++;
        }
    }
    pi->proto->disconnect(pi);

    if (verbose)
        printk("%s: %s: port 0x%x, mode  %d, test=(%d,%d)\n",
               pi->device, pi->proto->name, pi->port,
               pi->mode, e[0], e[1]);

    return (e[0] && e[1]);  /* not here if both > 0 */
}

static int pi_test_proto(PIA * pi, char *scratch, int verbose)
{
    int res;

    pi_claim(pi);
    if (pi->proto->test_proto)
        res = pi->proto->test_proto(pi, scratch, verbose);
    else
        res = default_test_proto(pi, scratch, verbose);
    pi_unclaim(pi);

    return res;
}

int paride_register(PIP * pr)
{
    int k;

    for (k = 0; k < MAX_PROTOS; k++)
        if (protocols[k] && !strcmp(pr->name, protocols[k]->name)) {
            printk("paride: %s protocol already registered\n",
                   pr->name);
            return -1;
        }
    k = 0;
    while ((k < MAX_PROTOS) && (protocols[k]))
        k++;
    if (k == MAX_PROTOS) {
        printk("paride: protocol table full\n");
        return -1;
    }
    protocols[k] = pr;
    pr->index = k;
    printk("paride: %s registered as protocol %d\n", pr->name, k);
    return 0;
}

EXPORT_SYMBOL(paride_register);

void paride_unregister(PIP * pr)
{
    if (!pr)
        return;
    if (protocols[pr->index] != pr) {
        printk("paride: %s not registered\n", pr->name);
        return;
    }
    protocols[pr->index] = NULL;
}

EXPORT_SYMBOL(paride_unregister);

static int pi_register_parport(PIA * pi, int verbose)
{
    struct parport *port;

    port = parport_find_base(pi->port);
    if (!port)
        return 0;

    pi->pardev = parport_register_device(port,
                         pi->device, NULL,
                         pi_wake_up, NULL, 0, (void *) pi);
    parport_put_port(port);
    if (!pi->pardev)
        return 0;

    init_waitqueue_head(&pi->parq);

    if (verbose)
        printk("%s: 0x%x is %s\n", pi->device, pi->port, port->name);

    pi->parname = (char *) port->name;

    return 1;
}

static int pi_probe_mode(PIA * pi, int max, char *scratch, int verbose)
{
    int best, range;

    if (pi->mode != -1) {
        if (pi->mode >= max)
            return 0;
        range = 3;
        if (pi->mode >= pi->proto->epp_first)
            range = 8;
        if ((range == 8) && (pi->port % 8))
            return 0;
        pi->reserved = range;
        return (!pi_test_proto(pi, scratch, verbose));
    }
    best = -1;
    for (pi->mode = 0; pi->mode < max; pi->mode++) {
        range = 3;
        if (pi->mode >= pi->proto->epp_first)
            range = 8;
        if ((range == 8) && (pi->port % 8))
            break;
        pi->reserved = range;
        if (!pi_test_proto(pi, scratch, verbose))
            best = pi->mode;
    }
    pi->mode = best;
    return (best > -1);
}

static int pi_probe_unit(PIA * pi, int unit, char *scratch, int verbose)
{
    int max, s, e;

    s = unit;
    e = s + 1;

    if (s == -1) {
        s = 0;
        e = pi->proto->max_units;
    }

    if (!pi_register_parport(pi, verbose))
        return 0;

    if (pi->proto->test_port) {
        pi_claim(pi);
        max = pi->proto->test_port(pi);
        pi_unclaim(pi);
    } else
        max = pi->proto->max_mode;

    if (pi->proto->probe_unit) {
        pi_claim(pi);
        for (pi->unit = s; pi->unit < e; pi->unit++)
            if (pi->proto->probe_unit(pi)) {
                pi_unclaim(pi);
                if (pi_probe_mode(pi, max, scratch, verbose))
                    return 1;
                pi_unregister_parport(pi);
                return 0;
            }
        pi_unclaim(pi);
        pi_unregister_parport(pi);
        return 0;
    }

    if (!pi_probe_mode(pi, max, scratch, verbose)) {
        pi_unregister_parport(pi);
        return 0;
    }
    return 1;

}

int pi_init(PIA * pi, int autoprobe, int port, int mode,
    int unit, int protocol, int delay, char *scratch,
    int devtype, int verbose, char *device)
{
    int p, k, s, e;
    int lpts[7] = { 0x3bc, 0x378, 0x278, 0x268, 0x27c, 0x26c, 0 };

    s = protocol;
    e = s + 1;

    if (!protocols[0])
        request_module("paride_protocol");

    if (autoprobe) {
        s = 0;
        e = MAX_PROTOS;
    } else if ((s < 0) || (s >= MAX_PROTOS) || (port <= 0) ||
           (!protocols[s]) || (unit < 0) ||
           (unit >= protocols[s]->max_units)) {
        printk("%s: Invalid parameters\n", device);
        return 0;
    }

    for (p = s; p < e; p++) {
        struct pi_protocol *proto = protocols[p];
        if (!proto)
            continue;
        /* still racy */
        if (!try_module_get(proto->owner))
            continue;
        pi->proto = proto;
        pi->private = 0;
        if (proto->init_proto && proto->init_proto(pi) < 0) {
            pi->proto = NULL;
            module_put(proto->owner);
            continue;
        }
        if (delay == -1)
            pi->delay = pi->proto->default_delay;
        else
            pi->delay = delay;
        pi->devtype = devtype;
        pi->device = device;

        pi->parname = NULL;
        pi->pardev = NULL;
        init_waitqueue_head(&pi->parq);
        pi->claimed = 0;
        pi->claim_cont = NULL;

        pi->mode = mode;
        if (port != -1) {
            pi->port = port;
            if (pi_probe_unit(pi, unit, scratch, verbose))
                break;
            pi->port = 0;
        } else {
            k = 0;
            while ((pi->port = lpts[k++]))
                if (pi_probe_unit
                    (pi, unit, scratch, verbose))
                    break;
            if (pi->port)
                break;
        }
        if (pi->proto->release_proto)
            pi->proto->release_proto(pi);
        module_put(proto->owner);
    }

    if (!pi->port) {
        if (autoprobe)
            printk("%s: Autoprobe failed\n", device);
        else
            printk("%s: Adapter not found\n", device);
        return 0;
    }

    if (pi->parname)
        printk("%s: Sharing %s at 0x%x\n", pi->device,
               pi->parname, pi->port);

    pi->proto->log_adapter(pi, scratch, verbose);

    return 1;
}

EXPORT_SYMBOL(pi_init);