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[linux-2.6.9-moxart.git] / drivers / parport / daisy.c

/*
 * IEEE 1284.3 Parallel port daisy chain and multiplexor code
 * 
 * Copyright (C) 1999, 2000  Tim Waugh <tim@cyberelk.demon.co.uk>
 *
 * 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.
 *
 * ??-12-1998: Initial implementation.
 * 31-01-1999: Make port-cloning transparent.
 * 13-02-1999: Move DeviceID technique from parport_probe.
 * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too.
 * 22-02-2000: Count devices that are actually detected.
 *
 * Any part of this program may be used in documents licensed under
 * the GNU Free Documentation License, Version 1.1 or any later version
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/parport.h>
#include <linux/delay.h>
#include <linux/sched.h>

#include <asm/current.h>
#include <asm/uaccess.h>

#undef DEBUG

#ifdef DEBUG
#define DPRINTK(stuff...) printk (stuff)
#else
#define DPRINTK(stuff...)
#endif

static struct daisydev {
        struct daisydev *next;
        struct parport *port;
        int daisy;
        int devnum;
} *topology = NULL;
static spinlock_t topology_lock = SPIN_LOCK_UNLOCKED;

static int numdevs = 0;

/* Forward-declaration of lower-level functions. */
static int mux_present (struct parport *port);
static int num_mux_ports (struct parport *port);
static int select_port (struct parport *port);
static int assign_addrs (struct parport *port);

/* Add a device to the discovered topology. */
static void add_dev (int devnum, struct parport *port, int daisy)
{
        struct daisydev *newdev, **p;
        newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL);
        if (newdev) {
                newdev->port = port;
                newdev->daisy = daisy;
                newdev->devnum = devnum;
                spin_lock(&topology_lock);
                for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next)
                        ;
                newdev->next = *p;
                *p = newdev;
                spin_unlock(&topology_lock);
        }
}

/* Clone a parport (actually, make an alias). */
static struct parport *clone_parport (struct parport *real, int muxport)
{
        struct parport *extra = parport_register_port (real->base,
                                                       real->irq,
                                                       real->dma,
                                                       real->ops);
        if (extra) {
                extra->portnum = real->portnum;
                extra->physport = real;
                extra->muxport = muxport;
                real->slaves[muxport-1] = extra;
        }

        return extra;
}

/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
 * Return value is number of devices actually detected. */
int parport_daisy_init (struct parport *port)
{
        int detected = 0;
        char *deviceid;
        static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
        int num_ports;
        int i;
        int last_try = 0;

again:
        /* Because this is called before any other devices exist,
         * we don't have to claim exclusive access.  */

        /* If mux present on normal port, need to create new
         * parports for each extra port. */
        if (port->muxport < 0 && mux_present (port) &&
            /* don't be fooled: a mux must have 2 or 4 ports. */
            ((num_ports = num_mux_ports (port)) == 2 || num_ports == 4)) {
                /* Leave original as port zero. */
                port->muxport = 0;
                printk (KERN_INFO
                        "%s: 1st (default) port of %d-way multiplexor\n",
                        port->name, num_ports);
                for (i = 1; i < num_ports; i++) {
                        /* Clone the port. */
                        struct parport *extra = clone_parport (port, i);
                        if (!extra) {
                                if (signal_pending (current))
                                        break;

                                schedule ();
                                continue;
                        }

                        printk (KERN_INFO
                                "%s: %d%s port of %d-way multiplexor on %s\n",
                                extra->name, i + 1, th[i + 1], num_ports,
                                port->name);

                        /* Analyse that port too.  We won't recurse
                           forever because of the 'port->muxport < 0'
                           test above. */
                        parport_daisy_init(extra);
                }
        }

        if (port->muxport >= 0)
                select_port (port);

        parport_daisy_deselect_all (port);
        detected += assign_addrs (port);

        /* Count the potential legacy device at the end. */
        add_dev (numdevs++, port, -1);

        /* Find out the legacy device's IEEE 1284 device ID. */
        deviceid = kmalloc (1000, GFP_KERNEL);
        if (deviceid) {
                if (parport_device_id (numdevs - 1, deviceid, 1000) > 2)
                        detected++;

                kfree (deviceid);
        }

        if (!detected && !last_try) {
                /* No devices were detected.  Perhaps they are in some
                   funny state; let's try to reset them and see if
                   they wake up. */
                parport_daisy_fini (port);
                parport_write_control (port, PARPORT_CONTROL_SELECT);
                udelay (50);
                parport_write_control (port,
                                       PARPORT_CONTROL_SELECT |
                                       PARPORT_CONTROL_INIT);
                udelay (50);
                last_try = 1;
                goto again;
        }

        return detected;
}

/* Forget about devices on a physical port. */
void parport_daisy_fini (struct parport *port)
{
        struct daisydev **p;

        spin_lock(&topology_lock);
        p = &topology;
        while (*p) {
                struct daisydev *dev = *p;
                if (dev->port != port) {
                        p = &dev->next;
                        continue;
                }
                *p = dev->next;
                kfree(dev);
        }

        /* Gaps in the numbering could be handled better.  How should
           someone enumerate through all IEEE1284.3 devices in the
           topology?. */
        if (!topology) numdevs = 0;
        spin_unlock(&topology_lock);
        return;
}

/**
 *      parport_open - find a device by canonical device number
 *      @devnum: canonical device number
 *      @name: name to associate with the device
 *      @pf: preemption callback
 *      @kf: kick callback
 *      @irqf: interrupt handler
 *      @flags: registration flags
 *      @handle: driver data
 *
 *      This function is similar to parport_register_device(), except
 *      that it locates a device by its number rather than by the port
 *      it is attached to.  See parport_find_device() and
 *      parport_find_class().
 *
 *      All parameters except for @devnum are the same as for
 *      parport_register_device().  The return value is the same as
 *      for parport_register_device().
 **/

struct pardevice *parport_open (int devnum, const char *name,
                                int (*pf) (void *), void (*kf) (void *),
                                void (*irqf) (int, void *, struct pt_regs *),
                                int flags, void *handle)
{
        struct daisydev *p = topology;
        struct parport *port;
        struct pardevice *dev;
        int daisy;

        spin_lock(&topology_lock);
        while (p && p->devnum != devnum)
                p = p->next;

        if (!p) {
                spin_unlock(&topology_lock);
                return NULL;
        }

        daisy = p->daisy;
        port = parport_get_port(p->port);
        spin_unlock(&topology_lock);

        dev = parport_register_device (port, name, pf, kf,
                                       irqf, flags, handle);
        parport_put_port(port);
        if (!dev)
                return NULL;

        dev->daisy = daisy;

        /* Check that there really is a device to select. */
        if (daisy >= 0) {
                int selected;
                parport_claim_or_block (dev);
                selected = port->daisy;
                parport_release (dev);

                if (selected != port->daisy) {
                        /* No corresponding device. */
                        parport_unregister_device (dev);
                        return NULL;
                }
        }

        return dev;
}

/**
 *      parport_close - close a device opened with parport_open()
 *      @dev: device to close
 *
 *      This is to parport_open() as parport_unregister_device() is to
 *      parport_register_device().
 **/

void parport_close (struct pardevice *dev)
{
        parport_unregister_device (dev);
}

/**
 *      parport_device_num - convert device coordinates
 *      @parport: parallel port number
 *      @mux: multiplexor port number (-1 for no multiplexor)
 *      @daisy: daisy chain address (-1 for no daisy chain address)
 *
 *      This tries to locate a device on the given parallel port,
 *      multiplexor port and daisy chain address, and returns its
 *      device number or -NXIO if no device with those coordinates
 *      exists.
 **/

int parport_device_num (int parport, int mux, int daisy)
{
        int res = -ENXIO;
        struct daisydev *dev;

        spin_lock(&topology_lock);
        dev = topology;
        while (dev && dev->port->portnum != parport &&
               dev->port->muxport != mux && dev->daisy != daisy)
                dev = dev->next;
        if (dev)
                res = dev->devnum;
        spin_unlock(&topology_lock);

        return res;
}

/**
 *      parport_device_coords - convert canonical device number
 *      @devnum: device number
 *      @parport: pointer to storage for parallel port number
 *      @mux: pointer to storage for multiplexor port number
 *      @daisy: pointer to storage for daisy chain address
 *
 *      This function converts a device number into its coordinates in
 *      terms of which parallel port in the system it is attached to,
 *      which multiplexor port it is attached to if there is a
 *      multiplexor on that port, and which daisy chain address it has
 *      if it is in a daisy chain.
 *
 *      The caller must allocate storage for @parport, @mux, and
 *      @daisy.
 *
 *      If there is no device with the specified device number, -ENXIO
 *      is returned.  Otherwise, the values pointed to by @parport,
 *      @mux, and @daisy are set to the coordinates of the device,
 *      with -1 for coordinates with no value.
 *
 *      This function is not actually very useful, but this interface
 *      was suggested by IEEE 1284.3.
 **/

int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
{
        struct daisydev *dev;

        spin_lock(&topology_lock);

        dev = topology;
        while (dev && dev->devnum != devnum)
                dev = dev->next;

        if (!dev) {
                spin_unlock(&topology_lock);
                return -ENXIO;
        }

        if (parport) *parport = dev->port->portnum;
        if (mux) *mux = dev->port->muxport;
        if (daisy) *daisy = dev->daisy;
        spin_unlock(&topology_lock);
        return 0;
}

/* Send a daisy-chain-style CPP command packet. */
static int cpp_daisy (struct parport *port, int cmd)
{
        unsigned char s;

        parport_data_forward (port);
        parport_write_data (port, 0xaa); udelay (2);
        parport_write_data (port, 0x55); udelay (2);
        parport_write_data (port, 0x00); udelay (2);
        parport_write_data (port, 0xff); udelay (2);
        s = parport_read_status (port) & (PARPORT_STATUS_BUSY
                                          | PARPORT_STATUS_PAPEROUT
                                          | PARPORT_STATUS_SELECT
                                          | PARPORT_STATUS_ERROR);
        if (s != (PARPORT_STATUS_BUSY
                  | PARPORT_STATUS_PAPEROUT
                  | PARPORT_STATUS_SELECT
                  | PARPORT_STATUS_ERROR)) {
                DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
                         port->name, s);
                return -ENXIO;
        }

        parport_write_data (port, 0x87); udelay (2);
        s = parport_read_status (port) & (PARPORT_STATUS_BUSY
                                          | PARPORT_STATUS_PAPEROUT
                                          | PARPORT_STATUS_SELECT
                                          | PARPORT_STATUS_ERROR);
        if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
                DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
                         port->name, s);
                return -ENXIO;
        }

        parport_write_data (port, 0x78); udelay (2);
        parport_write_data (port, cmd); udelay (2);
        parport_frob_control (port,
                              PARPORT_CONTROL_STROBE,
                              PARPORT_CONTROL_STROBE);
        udelay (1);
        parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
        udelay (1);
        s = parport_read_status (port);
        parport_write_data (port, 0xff); udelay (2);

        return s;
}

/* Send a mux-style CPP command packet. */
static int cpp_mux (struct parport *port, int cmd)
{
        unsigned char s;
        int rc;

        parport_data_forward (port);
        parport_write_data (port, 0xaa); udelay (2);
        parport_write_data (port, 0x55); udelay (2);
        parport_write_data (port, 0xf0); udelay (2);
        parport_write_data (port, 0x0f); udelay (2);
        parport_write_data (port, 0x52); udelay (2);
        parport_write_data (port, 0xad); udelay (2);
        parport_write_data (port, cmd); udelay (2);

        s = parport_read_status (port);
        if (!(s & PARPORT_STATUS_ACK)) {
                DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
                         port->name, cmd, s);
                return -EIO;
        }

        rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
              ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
              ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
              ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));

        return rc;
}

void parport_daisy_deselect_all (struct parport *port)
{
        cpp_daisy (port, 0x30);
}

int parport_daisy_select (struct parport *port, int daisy, int mode)
{
        switch (mode)
        {
                // For these modes we should switch to EPP mode:
                case IEEE1284_MODE_EPP:
                case IEEE1284_MODE_EPPSL:
                case IEEE1284_MODE_EPPSWE:
                        return (cpp_daisy (port, 0x20 + daisy) &
                                PARPORT_STATUS_ERROR);

                // For these modes we should switch to ECP mode:
                case IEEE1284_MODE_ECP:
                case IEEE1284_MODE_ECPRLE:
                case IEEE1284_MODE_ECPSWE: 
                        return (cpp_daisy (port, 0xd0 + daisy) &
                                PARPORT_STATUS_ERROR);

                // Nothing was told for BECP in Daisy chain specification.
                // May be it's wise to use ECP?
                case IEEE1284_MODE_BECP:
                // Others use compat mode
                case IEEE1284_MODE_NIBBLE:
                case IEEE1284_MODE_BYTE:
                case IEEE1284_MODE_COMPAT:
                default:
                        return (cpp_daisy (port, 0xe0 + daisy) &
                                PARPORT_STATUS_ERROR);
        }
}

static int mux_present (struct parport *port)
{
        return cpp_mux (port, 0x51) == 3;
}

static int num_mux_ports (struct parport *port)
{
        return cpp_mux (port, 0x58);
}

static int select_port (struct parport *port)
{
        int muxport = port->muxport;
        return cpp_mux (port, 0x60 + muxport) == muxport;
}

static int assign_addrs (struct parport *port)
{
        unsigned char s, last_dev;
        unsigned char daisy;
        int thisdev = numdevs;
        int detected;
        char *deviceid;

        parport_data_forward (port);
        parport_write_data (port, 0xaa); udelay (2);
        parport_write_data (port, 0x55); udelay (2);
        parport_write_data (port, 0x00); udelay (2);
        parport_write_data (port, 0xff); udelay (2);
        s = parport_read_status (port) & (PARPORT_STATUS_BUSY
                                          | PARPORT_STATUS_PAPEROUT
                                          | PARPORT_STATUS_SELECT
                                          | PARPORT_STATUS_ERROR);
        if (s != (PARPORT_STATUS_BUSY
                  | PARPORT_STATUS_PAPEROUT
                  | PARPORT_STATUS_SELECT
                  | PARPORT_STATUS_ERROR)) {
                DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
                         port->name, s);
                return 0;
        }

        parport_write_data (port, 0x87); udelay (2);
        s = parport_read_status (port) & (PARPORT_STATUS_BUSY
                                          | PARPORT_STATUS_PAPEROUT
                                          | PARPORT_STATUS_SELECT
                                          | PARPORT_STATUS_ERROR);
        if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
                DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
                         port->name, s);
                return 0;
        }

        parport_write_data (port, 0x78); udelay (2);
        last_dev = 0; /* We've just been speaking to a device, so we
                         know there must be at least _one_ out there. */

        for (daisy = 0; daisy < 4; daisy++) {
                parport_write_data (port, daisy);
                udelay (2);
                parport_frob_control (port,
                                      PARPORT_CONTROL_STROBE,
                                      PARPORT_CONTROL_STROBE);
                udelay (1);
                parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
                udelay (1);

                if (last_dev)
                        /* No more devices. */
                        break;

                last_dev = !(parport_read_status (port)
                             & PARPORT_STATUS_BUSY);

                add_dev (numdevs++, port, daisy);
        }

        parport_write_data (port, 0xff); udelay (2);
        detected = numdevs - thisdev;
        DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
                 detected);

        /* Ask the new devices to introduce themselves. */
        deviceid = kmalloc (1000, GFP_KERNEL);
        if (!deviceid) return 0;

        for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
                parport_device_id (thisdev, deviceid, 1000);

        kfree (deviceid);
        return detected;
}

/* Find a device with a particular manufacturer and model string,
   starting from a given device number.  Like the PCI equivalent,
   'from' itself is skipped. */

/**
 *      parport_find_device - find a specific device
 *      @mfg: required manufacturer string
 *      @mdl: required model string
 *      @from: previous device number found in search, or %NULL for
 *             new search
 *
 *      This walks through the list of parallel port devices looking
 *      for a device whose 'MFG' string matches @mfg and whose 'MDL'
 *      string matches @mdl in their IEEE 1284 Device ID.
 *
 *      When a device is found matching those requirements, its device
 *      number is returned; if there is no matching device, a negative
 *      value is returned.
 *
 *      A new search it initiated by passing %NULL as the @from
 *      argument.  If @from is not %NULL, the search continues from
 *      that device.
 **/

int parport_find_device (const char *mfg, const char *mdl, int from)
{
        struct daisydev *d;
        int res = -1;

        /* Find where to start. */

        spin_lock(&topology_lock);
        d = topology; /* sorted by devnum */
        while (d && d->devnum <= from)
                d = d->next;

        /* Search. */
        while (d) {
                struct parport_device_info *info;
                info = &d->port->probe_info[1 + d->daisy];
                if ((!mfg || !strcmp (mfg, info->mfr)) &&
                    (!mdl || !strcmp (mdl, info->model)))
                        break;

                d = d->next;
        }

        if (d)
                res = d->devnum;

        spin_unlock(&topology_lock);
        return res;
}

/**
 *      parport_find_class - find a device in a specified class
 *      @cls: required class
 *      @from: previous device number found in search, or %NULL for
 *             new search
 *
 *      This walks through the list of parallel port devices looking
 *      for a device whose 'CLS' string matches @cls in their IEEE
 *      1284 Device ID.
 *
 *      When a device is found matching those requirements, its device
 *      number is returned; if there is no matching device, a negative
 *      value is returned.
 *
 *      A new search it initiated by passing %NULL as the @from
 *      argument.  If @from is not %NULL, the search continues from
 *      that device.
 **/

int parport_find_class (parport_device_class cls, int from)
{
        struct daisydev *d;
        int res = -1;

        spin_lock(&topology_lock);
        d = topology; /* sorted by devnum */
        /* Find where to start. */
        while (d && d->devnum <= from)
                d = d->next;

        /* Search. */
        while (d && d->port->probe_info[1 + d->daisy].class != cls)
                d = d->next;

        if (d)
                res = d->devnum;

        spin_unlock(&topology_lock);
        return res;
}

EXPORT_SYMBOL(parport_open);
EXPORT_SYMBOL(parport_close);
EXPORT_SYMBOL(parport_device_num);
EXPORT_SYMBOL(parport_device_coords);
EXPORT_SYMBOL(parport_daisy_deselect_all);
EXPORT_SYMBOL(parport_daisy_select);
EXPORT_SYMBOL(parport_daisy_init);
EXPORT_SYMBOL(parport_find_device);
EXPORT_SYMBOL(parport_find_class);