Subversion Repositories test_project

/*

 * 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 DEFINE_SPINLOCK(topology_lock);

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(1024, GFP_KERNEL);

        if (deviceid) {

                if (parport_device_id(numdevs - 1, deviceid, 1024) > 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

 *

 *      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.

 *

 *      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)

{

        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, NULL, NULL, NULL, 0, NULL);

        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 != 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);

}

/* 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);

        s = parport_read_status(port);

        parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);

        udelay(1);

        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;

        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);

        s = parport_read_status(port);

        for (daisy = 0;

             (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT))

                     == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)

                     && 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);

                add_dev(numdevs++, port, daisy);

                /* See if this device thought it was the last in the

                 * chain. */

                if (!(s & PARPORT_STATUS_BUSY))

                        break;

                /* We are seeing pass through status now. We see

                   last_dev from next device or if last_dev does not

                   work status lines from some non-daisy chain

                   device. */

                s = parport_read_status(port);

        }

        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(1024, GFP_KERNEL);

        if (!deviceid) return 0;

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

                parport_device_id(thisdev, deviceid, 1024);

        kfree(deviceid);

        return detected;

}