lirc_zilog.c

Go to the documentation of this file.

/*
 * i2c IR lirc driver for devices with zilog IR processors
 *
 * Copyright (c) 2000 Gerd Knorr <[email protected]>
 * modified for PixelView (BT878P+W/FM) by
 *      Michal Kochanowicz <[email protected]>
 *      Christoph Bartelmus <[email protected]>
 * modified for KNC ONE TV Station/Anubis Typhoon TView Tuner by
 *      Ulrich Mueller <[email protected]>
 * modified for Asus TV-Box and Creative/VisionTek BreakOut-Box by
 *      Stefan Jahn <[email protected]>
 * modified for inclusion into kernel sources by
 *      Jerome Brock <[email protected]>
 * modified for Leadtek Winfast PVR2000 by
 *      Thomas Reitmayr ([email protected])
 * modified for Hauppauge PVR-150 IR TX device by
 *      Mark Weaver <[email protected]>
 * changed name from lirc_pvr150 to lirc_zilog, works on more than pvr-150
 *  Jarod Wilson <[email protected]>
 *
 * parts are cut&pasted from the lirc_i2c.c driver
 *
 * Numerous changes updating lirc_zilog.c in kernel 2.6.38 and later are
 * Copyright (C) 2011 Andy Walls <[email protected]>
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/firmware.h>
#include <linux/vmalloc.h>

#include <linux/mutex.h>
#include <linux/kthread.h>

#include <media/lirc_dev.h>
#include <media/lirc.h>

struct IR;

struct IR_rx {
    struct kref ref;
    struct IR *ir;

    /* RX device */
    struct mutex client_lock;
    struct i2c_client *c;

    /* RX polling thread data */
    struct task_struct *task;

    /* RX read data */
    unsigned char b[3];
    bool hdpvr_data_fmt;
};

struct IR_tx {
    struct kref ref;
    struct IR *ir;

    /* TX device */
    struct mutex client_lock;
    struct i2c_client *c;

    /* TX additional actions needed */
    int need_boot;
    bool post_tx_ready_poll;
};

struct IR {
    struct kref ref;
    struct list_head list;

    /* FIXME spinlock access to l.features */
    struct lirc_driver l;
    struct lirc_buffer rbuf;

    struct mutex ir_lock;
    atomic_t open_count;

    struct i2c_adapter *adapter;

    spinlock_t rx_ref_lock; /* struct IR_rx kref get()/put() */
    struct IR_rx *rx;

    spinlock_t tx_ref_lock; /* struct IR_tx kref get()/put() */
    struct IR_tx *tx;
};

/* IR transceiver instance object list */
/*
 * This lock is used for the following:
 * a. ir_devices_list access, insertions, deletions
 * b. struct IR kref get()s and put()s
 * c. serialization of ir_probe() for the two i2c_clients for a Z8
 */
static DEFINE_MUTEX(ir_devices_lock);
static LIST_HEAD(ir_devices_list);

/* Block size for IR transmitter */
#define TX_BLOCK_SIZE   99

/* Hauppauge IR transmitter data */
struct tx_data_struct {
    /* Boot block */
    unsigned char *boot_data;

    /* Start of binary data block */
    unsigned char *datap;

    /* End of binary data block */
    unsigned char *endp;

    /* Number of installed codesets */
    unsigned int num_code_sets;

    /* Pointers to codesets */
    unsigned char **code_sets;

    /* Global fixed data template */
    int fixed[TX_BLOCK_SIZE];
};

static struct tx_data_struct *tx_data;
static struct mutex tx_data_lock;

#define zilog_notify(s, args...) printk(KERN_NOTICE KBUILD_MODNAME ": " s, \
                    ## args)
#define zilog_error(s, args...) printk(KERN_ERR KBUILD_MODNAME ": " s, ## args)
#define zilog_info(s, args...) printk(KERN_INFO KBUILD_MODNAME ": " s, ## args)

/* module parameters */
static bool debug;  /* debug output */
static bool tx_only;    /* only handle the IR Tx function */
static int minor = -1;  /* minor number */

#define dprintk(fmt, args...)                       \
    do {                                \
        if (debug)                      \
            printk(KERN_DEBUG KBUILD_MODNAME ": " fmt,  \
                 ## args);              \
    } while (0)


/* struct IR reference counting */
static struct IR *get_ir_device(struct IR *ir, bool ir_devices_lock_held)
{
    if (ir_devices_lock_held) {
        kref_get(&ir->ref);
    } else {
        mutex_lock(&ir_devices_lock);
        kref_get(&ir->ref);
        mutex_unlock(&ir_devices_lock);
    }
    return ir;
}

static void release_ir_device(struct kref *ref)
{
    struct IR *ir = container_of(ref, struct IR, ref);

    /*
     * Things should be in this state by now:
     * ir->rx set to NULL and deallocated - happens before ir->rx->ir put()
     * ir->rx->task kthread stopped - happens before ir->rx->ir put()
     * ir->tx set to NULL and deallocated - happens before ir->tx->ir put()
     * ir->open_count ==  0 - happens on final close()
     * ir_lock, tx_ref_lock, rx_ref_lock, all released
     */
    if (ir->l.minor >= 0 && ir->l.minor < MAX_IRCTL_DEVICES) {
        lirc_unregister_driver(ir->l.minor);
        ir->l.minor = MAX_IRCTL_DEVICES;
    }
    if (ir->rbuf.fifo_initialized)
        lirc_buffer_free(&ir->rbuf);
    list_del(&ir->list);
    kfree(ir);
}

static int put_ir_device(struct IR *ir, bool ir_devices_lock_held)
{
    int released;

    if (ir_devices_lock_held)
        return kref_put(&ir->ref, release_ir_device);

    mutex_lock(&ir_devices_lock);
    released = kref_put(&ir->ref, release_ir_device);
    mutex_unlock(&ir_devices_lock);

    return released;
}

/* struct IR_rx reference counting */
static struct IR_rx *get_ir_rx(struct IR *ir)
{
    struct IR_rx *rx;

    spin_lock(&ir->rx_ref_lock);
    rx = ir->rx;
    if (rx != NULL)
        kref_get(&rx->ref);
    spin_unlock(&ir->rx_ref_lock);
    return rx;
}

static void destroy_rx_kthread(struct IR_rx *rx, bool ir_devices_lock_held)
{
    /* end up polling thread */
    if (!IS_ERR_OR_NULL(rx->task)) {
        kthread_stop(rx->task);
        rx->task = NULL;
        /* Put the ir ptr that ir_probe() gave to the rx poll thread */
        put_ir_device(rx->ir, ir_devices_lock_held);
    }
}

static void release_ir_rx(struct kref *ref)
{
    struct IR_rx *rx = container_of(ref, struct IR_rx, ref);
    struct IR *ir = rx->ir;

    /*
     * This release function can't do all the work, as we want
     * to keep the rx_ref_lock a spinlock, and killing the poll thread
     * and releasing the ir reference can cause a sleep.  That work is
     * performed by put_ir_rx()
     */
    ir->l.features &= ~LIRC_CAN_REC_LIRCCODE;
    /* Don't put_ir_device(rx->ir) here; lock can't be freed yet */
    ir->rx = NULL;
    /* Don't do the kfree(rx) here; we still need to kill the poll thread */
    return;
}

static int put_ir_rx(struct IR_rx *rx, bool ir_devices_lock_held)
{
    int released;
    struct IR *ir = rx->ir;

    spin_lock(&ir->rx_ref_lock);
    released = kref_put(&rx->ref, release_ir_rx);
    spin_unlock(&ir->rx_ref_lock);
    /* Destroy the rx kthread while not holding the spinlock */
    if (released) {
        destroy_rx_kthread(rx, ir_devices_lock_held);
        kfree(rx);
        /* Make sure we're not still in a poll_table somewhere */
        wake_up_interruptible(&ir->rbuf.wait_poll);
    }
    /* Do a reference put() for the rx->ir reference, if we released rx */
    if (released)
        put_ir_device(ir, ir_devices_lock_held);
    return released;
}

/* struct IR_tx reference counting */
static struct IR_tx *get_ir_tx(struct IR *ir)
{
    struct IR_tx *tx;

    spin_lock(&ir->tx_ref_lock);
    tx = ir->tx;
    if (tx != NULL)
        kref_get(&tx->ref);
    spin_unlock(&ir->tx_ref_lock);
    return tx;
}

static void release_ir_tx(struct kref *ref)
{
    struct IR_tx *tx = container_of(ref, struct IR_tx, ref);
    struct IR *ir = tx->ir;

    ir->l.features &= ~LIRC_CAN_SEND_PULSE;
    /* Don't put_ir_device(tx->ir) here, so our lock doesn't get freed */
    ir->tx = NULL;
    kfree(tx);
}

static int put_ir_tx(struct IR_tx *tx, bool ir_devices_lock_held)
{
    int released;
    struct IR *ir = tx->ir;

    spin_lock(&ir->tx_ref_lock);
    released = kref_put(&tx->ref, release_ir_tx);
    spin_unlock(&ir->tx_ref_lock);
    /* Do a reference put() for the tx->ir reference, if we released tx */
    if (released)
        put_ir_device(ir, ir_devices_lock_held);
    return released;
}

static int add_to_buf(struct IR *ir)
{
    __u16 code;
    unsigned char codes[2];
    unsigned char keybuf[6];
    int got_data = 0;
    int ret;
    int failures = 0;
    unsigned char sendbuf[1] = { 0 };
    struct lirc_buffer *rbuf = ir->l.rbuf;
    struct IR_rx *rx;
    struct IR_tx *tx;

    if (lirc_buffer_full(rbuf)) {
        dprintk("buffer overflow\n");
        return -EOVERFLOW;
    }

    rx = get_ir_rx(ir);
    if (rx == NULL)
        return -ENXIO;

    /* Ensure our rx->c i2c_client remains valid for the duration */
    mutex_lock(&rx->client_lock);
    if (rx->c == NULL) {
        mutex_unlock(&rx->client_lock);
        put_ir_rx(rx, false);
        return -ENXIO;
    }

    tx = get_ir_tx(ir);

    /*
     * service the device as long as it is returning
     * data and we have space
     */
    do {
        if (kthread_should_stop()) {
            ret = -ENODATA;
            break;
        }

        /*
         * Lock i2c bus for the duration.  RX/TX chips interfere so
         * this is worth it
         */
        mutex_lock(&ir->ir_lock);

        if (kthread_should_stop()) {
            mutex_unlock(&ir->ir_lock);
            ret = -ENODATA;
            break;
        }

        /*
         * Send random "poll command" (?)  Windows driver does this
         * and it is a good point to detect chip failure.
         */
        ret = i2c_master_send(rx->c, sendbuf, 1);
        if (ret != 1) {
            zilog_error("i2c_master_send failed with %d\n", ret);
            if (failures >= 3) {
                mutex_unlock(&ir->ir_lock);
                zilog_error("unable to read from the IR chip "
                        "after 3 resets, giving up\n");
                break;
            }

            /* Looks like the chip crashed, reset it */
            zilog_error("polling the IR receiver chip failed, "
                    "trying reset\n");

            set_current_state(TASK_UNINTERRUPTIBLE);
            if (kthread_should_stop()) {
                mutex_unlock(&ir->ir_lock);
                ret = -ENODATA;
                break;
            }
            schedule_timeout((100 * HZ + 999) / 1000);
            if (tx != NULL)
                tx->need_boot = 1;

            ++failures;
            mutex_unlock(&ir->ir_lock);
            ret = 0;
            continue;
        }

        if (kthread_should_stop()) {
            mutex_unlock(&ir->ir_lock);
            ret = -ENODATA;
            break;
        }
        ret = i2c_master_recv(rx->c, keybuf, sizeof(keybuf));
        mutex_unlock(&ir->ir_lock);
        if (ret != sizeof(keybuf)) {
            zilog_error("i2c_master_recv failed with %d -- "
                    "keeping last read buffer\n", ret);
        } else {
            rx->b[0] = keybuf[3];
            rx->b[1] = keybuf[4];
            rx->b[2] = keybuf[5];
            dprintk("key (0x%02x/0x%02x)\n", rx->b[0], rx->b[1]);
        }

        /* key pressed ? */
        if (rx->hdpvr_data_fmt) {
            if (got_data && (keybuf[0] == 0x80)) {
                ret = 0;
                break;
            } else if (got_data && (keybuf[0] == 0x00)) {
                ret = -ENODATA;
                break;
            }
        } else if ((rx->b[0] & 0x80) == 0) {
            ret = got_data ? 0 : -ENODATA;
            break;
        }

        /* look what we have */
        code = (((__u16)rx->b[0] & 0x7f) << 6) | (rx->b[1] >> 2);

        codes[0] = (code >> 8) & 0xff;
        codes[1] = code & 0xff;

        /* return it */
        lirc_buffer_write(rbuf, codes);
        ++got_data;
        ret = 0;
    } while (!lirc_buffer_full(rbuf));

    mutex_unlock(&rx->client_lock);
    if (tx != NULL)
        put_ir_tx(tx, false);
    put_ir_rx(rx, false);
    return ret;
}

/*
 * Main function of the polling thread -- from lirc_dev.
 * We don't fit the LIRC model at all anymore.  This is horrible, but
 * basically we have a single RX/TX device with a nasty failure mode
 * that needs to be accounted for across the pair.  lirc lets us provide
 * fops, but prevents us from using the internal polling, etc. if we do
 * so.  Hence the replication.  Might be neater to extend the LIRC model
 * to account for this but I'd think it's a very special case of seriously
 * messed up hardware.
 */
static int lirc_thread(void *arg)
{
    struct IR *ir = arg;
    struct lirc_buffer *rbuf = ir->l.rbuf;

    dprintk("poll thread started\n");

    while (!kthread_should_stop()) {
        set_current_state(TASK_INTERRUPTIBLE);

        /* if device not opened, we can sleep half a second */
        if (atomic_read(&ir->open_count) == 0) {
            schedule_timeout(HZ/2);
            continue;
        }

        /*
         * This is ~113*2 + 24 + jitter (2*repeat gap + code length).
         * We use this interval as the chip resets every time you poll
         * it (bad!).  This is therefore just sufficient to catch all
         * of the button presses.  It makes the remote much more
         * responsive.  You can see the difference by running irw and
         * holding down a button.  With 100ms, the old polling
         * interval, you'll notice breaks in the repeat sequence
         * corresponding to lost keypresses.
         */
        schedule_timeout((260 * HZ) / 1000);
        if (kthread_should_stop())
            break;
        if (!add_to_buf(ir))
            wake_up_interruptible(&rbuf->wait_poll);
    }

    dprintk("poll thread ended\n");
    return 0;
}

static int set_use_inc(void *data)
{
    return 0;
}

static void set_use_dec(void *data)
{
    return;
}

/* safe read of a uint32 (always network byte order) */
static int read_uint32(unsigned char **data,
                     unsigned char *endp, unsigned int *val)
{
    if (*data + 4 > endp)
        return 0;
    *val = ((*data)[0] << 24) | ((*data)[1] << 16) |
           ((*data)[2] << 8) | (*data)[3];
    *data += 4;
    return 1;
}

/* safe read of a uint8 */
static int read_uint8(unsigned char **data,
                    unsigned char *endp, unsigned char *val)
{
    if (*data + 1 > endp)
        return 0;
    *val = *((*data)++);
    return 1;
}

/* safe skipping of N bytes */
static int skip(unsigned char **data,
                  unsigned char *endp, unsigned int distance)
{
    if (*data + distance > endp)
        return 0;
    *data += distance;
    return 1;
}

/* decompress key data into the given buffer */
static int get_key_data(unsigned char *buf,
                 unsigned int codeset, unsigned int key)
{
    unsigned char *data, *endp, *diffs, *key_block;
    unsigned char keys, ndiffs, id;
    unsigned int base, lim, pos, i;

    /* Binary search for the codeset */
    for (base = 0, lim = tx_data->num_code_sets; lim; lim >>= 1) {
        pos = base + (lim >> 1);
        data = tx_data->code_sets[pos];

        if (!read_uint32(&data, tx_data->endp, &i))
            goto corrupt;

        if (i == codeset)
            break;
        else if (codeset > i) {
            base = pos + 1;
            --lim;
        }
    }
    /* Not found? */
    if (!lim)
        return -EPROTO;

    /* Set end of data block */
    endp = pos < tx_data->num_code_sets - 1 ?
        tx_data->code_sets[pos + 1] : tx_data->endp;

    /* Read the block header */
    if (!read_uint8(&data, endp, &keys) ||
        !read_uint8(&data, endp, &ndiffs) ||
        ndiffs > TX_BLOCK_SIZE || keys == 0)
        goto corrupt;

    /* Save diffs & skip */
    diffs = data;
    if (!skip(&data, endp, ndiffs))
        goto corrupt;

    /* Read the id of the first key */
    if (!read_uint8(&data, endp, &id))
        goto corrupt;

    /* Unpack the first key's data */
    for (i = 0; i < TX_BLOCK_SIZE; ++i) {
        if (tx_data->fixed[i] == -1) {
            if (!read_uint8(&data, endp, &buf[i]))
                goto corrupt;
        } else {
            buf[i] = (unsigned char)tx_data->fixed[i];
        }
    }

    /* Early out key found/not found */
    if (key == id)
        return 0;
    if (keys == 1)
        return -EPROTO;

    /* Sanity check */
    key_block = data;
    if (!skip(&data, endp, (keys - 1) * (ndiffs + 1)))
        goto corrupt;

    /* Binary search for the key */
    for (base = 0, lim = keys - 1; lim; lim >>= 1) {
        /* Seek to block */
        unsigned char *key_data;
        pos = base + (lim >> 1);
        key_data = key_block + (ndiffs + 1) * pos;

        if (*key_data == key) {
            /* skip key id */
            ++key_data;

            /* found, so unpack the diffs */
            for (i = 0; i < ndiffs; ++i) {
                unsigned char val;
                if (!read_uint8(&key_data, endp, &val) ||
                    diffs[i] >= TX_BLOCK_SIZE)
                    goto corrupt;
                buf[diffs[i]] = val;
            }

            return 0;
        } else if (key > *key_data) {
            base = pos + 1;
            --lim;
        }
    }
    /* Key not found */
    return -EPROTO;

corrupt:
    zilog_error("firmware is corrupt\n");
    return -EFAULT;
}

/* send a block of data to the IR TX device */
static int send_data_block(struct IR_tx *tx, unsigned char *data_block)
{
    int i, j, ret;
    unsigned char buf[5];

    for (i = 0; i < TX_BLOCK_SIZE;) {
        int tosend = TX_BLOCK_SIZE - i;
        if (tosend > 4)
            tosend = 4;
        buf[0] = (unsigned char)(i + 1);
        for (j = 0; j < tosend; ++j)
            buf[1 + j] = data_block[i + j];
        dprintk("%*ph", 5, buf);
        ret = i2c_master_send(tx->c, buf, tosend + 1);
        if (ret != tosend + 1) {
            zilog_error("i2c_master_send failed with %d\n", ret);
            return ret < 0 ? ret : -EFAULT;
        }
        i += tosend;
    }
    return 0;
}

/* send boot data to the IR TX device */
static int send_boot_data(struct IR_tx *tx)
{
    int ret, i;
    unsigned char buf[4];

    /* send the boot block */
    ret = send_data_block(tx, tx_data->boot_data);
    if (ret != 0)
        return ret;

    /* Hit the go button to activate the new boot data */
    buf[0] = 0x00;
    buf[1] = 0x20;
    ret = i2c_master_send(tx->c, buf, 2);
    if (ret != 2) {
        zilog_error("i2c_master_send failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /*
     * Wait for zilog to settle after hitting go post boot block upload.
     * Without this delay, the HD-PVR and HVR-1950 both return an -EIO
     * upon attempting to get firmware revision, and tx probe thus fails.
     */
    for (i = 0; i < 10; i++) {
        ret = i2c_master_send(tx->c, buf, 1);
        if (ret == 1)
            break;
        udelay(100);
    }

    if (ret != 1) {
        zilog_error("i2c_master_send failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /* Here comes the firmware version... (hopefully) */
    ret = i2c_master_recv(tx->c, buf, 4);
    if (ret != 4) {
        zilog_error("i2c_master_recv failed with %d\n", ret);
        return 0;
    }
    if ((buf[0] != 0x80) && (buf[0] != 0xa0)) {
        zilog_error("unexpected IR TX init response: %02x\n", buf[0]);
        return 0;
    }
    zilog_notify("Zilog/Hauppauge IR blaster firmware version "
             "%d.%d.%d loaded\n", buf[1], buf[2], buf[3]);

    return 0;
}

/* unload "firmware", lock held */
static void fw_unload_locked(void)
{
    if (tx_data) {
        if (tx_data->code_sets)
            vfree(tx_data->code_sets);

        if (tx_data->datap)
            vfree(tx_data->datap);

        vfree(tx_data);
        tx_data = NULL;
        dprintk("successfully unloaded IR blaster firmware\n");
    }
}

/* unload "firmware" for the IR TX device */
static void fw_unload(void)
{
    mutex_lock(&tx_data_lock);
    fw_unload_locked();
    mutex_unlock(&tx_data_lock);
}

/* load "firmware" for the IR TX device */
static int fw_load(struct IR_tx *tx)
{
    int ret;
    unsigned int i;
    unsigned char *data, version, num_global_fixed;
    const struct firmware *fw_entry;

    /* Already loaded? */
    mutex_lock(&tx_data_lock);
    if (tx_data) {
        ret = 0;
        goto out;
    }

    /* Request codeset data file */
    ret = request_firmware(&fw_entry, "haup-ir-blaster.bin", tx->ir->l.dev);
    if (ret != 0) {
        zilog_error("firmware haup-ir-blaster.bin not available "
                "(%d)\n", ret);
        ret = ret < 0 ? ret : -EFAULT;
        goto out;
    }
    dprintk("firmware of size %zu loaded\n", fw_entry->size);

    /* Parse the file */
    tx_data = vmalloc(sizeof(*tx_data));
    if (tx_data == NULL) {
        zilog_error("out of memory\n");
        release_firmware(fw_entry);
        ret = -ENOMEM;
        goto out;
    }
    tx_data->code_sets = NULL;

    /* Copy the data so hotplug doesn't get confused and timeout */
    tx_data->datap = vmalloc(fw_entry->size);
    if (tx_data->datap == NULL) {
        zilog_error("out of memory\n");
        release_firmware(fw_entry);
        vfree(tx_data);
        ret = -ENOMEM;
        goto out;
    }
    memcpy(tx_data->datap, fw_entry->data, fw_entry->size);
    tx_data->endp = tx_data->datap + fw_entry->size;
    release_firmware(fw_entry); fw_entry = NULL;

    /* Check version */
    data = tx_data->datap;
    if (!read_uint8(&data, tx_data->endp, &version))
        goto corrupt;
    if (version != 1) {
        zilog_error("unsupported code set file version (%u, expected"
                "1) -- please upgrade to a newer driver",
                version);
        fw_unload_locked();
        ret = -EFAULT;
        goto out;
    }

    /* Save boot block for later */
    tx_data->boot_data = data;
    if (!skip(&data, tx_data->endp, TX_BLOCK_SIZE))
        goto corrupt;

    if (!read_uint32(&data, tx_data->endp,
                  &tx_data->num_code_sets))
        goto corrupt;

    dprintk("%u IR blaster codesets loaded\n", tx_data->num_code_sets);

    tx_data->code_sets = vmalloc(
        tx_data->num_code_sets * sizeof(char *));
    if (tx_data->code_sets == NULL) {
        fw_unload_locked();
        ret = -ENOMEM;
        goto out;
    }

    for (i = 0; i < TX_BLOCK_SIZE; ++i)
        tx_data->fixed[i] = -1;

    /* Read global fixed data template */
    if (!read_uint8(&data, tx_data->endp, &num_global_fixed) ||
        num_global_fixed > TX_BLOCK_SIZE)
        goto corrupt;
    for (i = 0; i < num_global_fixed; ++i) {
        unsigned char pos, val;
        if (!read_uint8(&data, tx_data->endp, &pos) ||
            !read_uint8(&data, tx_data->endp, &val) ||
            pos >= TX_BLOCK_SIZE)
            goto corrupt;
        tx_data->fixed[pos] = (int)val;
    }

    /* Filch out the position of each code set */
    for (i = 0; i < tx_data->num_code_sets; ++i) {
        unsigned int id;
        unsigned char keys;
        unsigned char ndiffs;

        /* Save the codeset position */
        tx_data->code_sets[i] = data;

        /* Read header */
        if (!read_uint32(&data, tx_data->endp, &id) ||
            !read_uint8(&data, tx_data->endp, &keys) ||
            !read_uint8(&data, tx_data->endp, &ndiffs) ||
            ndiffs > TX_BLOCK_SIZE || keys == 0)
            goto corrupt;

        /* skip diff positions */
        if (!skip(&data, tx_data->endp, ndiffs))
            goto corrupt;

        /*
         * After the diffs we have the first key id + data -
         * global fixed
         */
        if (!skip(&data, tx_data->endp,
                   1 + TX_BLOCK_SIZE - num_global_fixed))
            goto corrupt;

        /* Then we have keys-1 blocks of key id+diffs */
        if (!skip(&data, tx_data->endp,
                   (ndiffs + 1) * (keys - 1)))
            goto corrupt;
    }
    ret = 0;
    goto out;

corrupt:
    zilog_error("firmware is corrupt\n");
    fw_unload_locked();
    ret = -EFAULT;

out:
    mutex_unlock(&tx_data_lock);
    return ret;
}

/* copied from lirc_dev */
static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos)
{
    struct IR *ir = filep->private_data;
    struct IR_rx *rx;
    struct lirc_buffer *rbuf = ir->l.rbuf;
    int ret = 0, written = 0, retries = 0;
    unsigned int m;
    DECLARE_WAITQUEUE(wait, current);

    dprintk("read called\n");
    if (n % rbuf->chunk_size) {
        dprintk("read result = -EINVAL\n");
        return -EINVAL;
    }

    rx = get_ir_rx(ir);
    if (rx == NULL)
        return -ENXIO;

    /*
     * we add ourselves to the task queue before buffer check
     * to avoid losing scan code (in case when queue is awaken somewhere
     * between while condition checking and scheduling)
     */
    add_wait_queue(&rbuf->wait_poll, &wait);
    set_current_state(TASK_INTERRUPTIBLE);

    /*
     * while we didn't provide 'length' bytes, device is opened in blocking
     * mode and 'copy_to_user' is happy, wait for data.
     */
    while (written < n && ret == 0) {
        if (lirc_buffer_empty(rbuf)) {
            /*
             * According to the read(2) man page, 'written' can be
             * returned as less than 'n', instead of blocking
             * again, returning -EWOULDBLOCK, or returning
             * -ERESTARTSYS
             */
            if (written)
                break;
            if (filep->f_flags & O_NONBLOCK) {
                ret = -EWOULDBLOCK;
                break;
            }
            if (signal_pending(current)) {
                ret = -ERESTARTSYS;
                break;
            }
            schedule();
            set_current_state(TASK_INTERRUPTIBLE);
        } else {
            unsigned char buf[rbuf->chunk_size];
            m = lirc_buffer_read(rbuf, buf);
            if (m == rbuf->chunk_size) {
                ret = copy_to_user((void *)outbuf+written, buf,
                           rbuf->chunk_size);
                written += rbuf->chunk_size;
            } else {
                retries++;
            }
            if (retries >= 5) {
                zilog_error("Buffer read failed!\n");
                ret = -EIO;
            }
        }
    }

    remove_wait_queue(&rbuf->wait_poll, &wait);
    put_ir_rx(rx, false);
    set_current_state(TASK_RUNNING);

    dprintk("read result = %d (%s)\n", ret, ret ? "Error" : "OK");

    return ret ? ret : written;
}

/* send a keypress to the IR TX device */
static int send_code(struct IR_tx *tx, unsigned int code, unsigned int key)
{
    unsigned char data_block[TX_BLOCK_SIZE];
    unsigned char buf[2];
    int i, ret;

    /* Get data for the codeset/key */
    ret = get_key_data(data_block, code, key);

    if (ret == -EPROTO) {
        zilog_error("failed to get data for code %u, key %u -- check "
                "lircd.conf entries\n", code, key);
        return ret;
    } else if (ret != 0)
        return ret;

    /* Send the data block */
    ret = send_data_block(tx, data_block);
    if (ret != 0)
        return ret;

    /* Send data block length? */
    buf[0] = 0x00;
    buf[1] = 0x40;
    ret = i2c_master_send(tx->c, buf, 2);
    if (ret != 2) {
        zilog_error("i2c_master_send failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /* Give the z8 a moment to process data block */
    for (i = 0; i < 10; i++) {
        ret = i2c_master_send(tx->c, buf, 1);
        if (ret == 1)
            break;
        udelay(100);
    }

    if (ret != 1) {
        zilog_error("i2c_master_send failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /* Send finished download? */
    ret = i2c_master_recv(tx->c, buf, 1);
    if (ret != 1) {
        zilog_error("i2c_master_recv failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }
    if (buf[0] != 0xA0) {
        zilog_error("unexpected IR TX response #1: %02x\n",
            buf[0]);
        return -EFAULT;
    }

    /* Send prepare command? */
    buf[0] = 0x00;
    buf[1] = 0x80;
    ret = i2c_master_send(tx->c, buf, 2);
    if (ret != 2) {
        zilog_error("i2c_master_send failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /*
     * The sleep bits aren't necessary on the HD PVR, and in fact, the
     * last i2c_master_recv always fails with a -5, so for now, we're
     * going to skip this whole mess and say we're done on the HD PVR
     */
    if (!tx->post_tx_ready_poll) {
        dprintk("sent code %u, key %u\n", code, key);
        return 0;
    }

    /*
     * This bit NAKs until the device is ready, so we retry it
     * sleeping a bit each time.  This seems to be what the windows
     * driver does, approximately.
     * Try for up to 1s.
     */
    for (i = 0; i < 20; ++i) {
        set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout((50 * HZ + 999) / 1000);
        ret = i2c_master_send(tx->c, buf, 1);
        if (ret == 1)
            break;
        dprintk("NAK expected: i2c_master_send "
            "failed with %d (try %d)\n", ret, i+1);
    }
    if (ret != 1) {
        zilog_error("IR TX chip never got ready: last i2c_master_send "
                "failed with %d\n", ret);
        return ret < 0 ? ret : -EFAULT;
    }

    /* Seems to be an 'ok' response */
    i = i2c_master_recv(tx->c, buf, 1);
    if (i != 1) {
        zilog_error("i2c_master_recv failed with %d\n", ret);
        return -EFAULT;
    }
    if (buf[0] != 0x80) {
        zilog_error("unexpected IR TX response #2: %02x\n", buf[0]);
        return -EFAULT;
    }

    /* Oh good, it worked */
    dprintk("sent code %u, key %u\n", code, key);
    return 0;
}

/*
 * Write a code to the device.  We take in a 32-bit number (an int) and then
 * decode this to a codeset/key index.  The key data is then decompressed and
 * sent to the device.  We have a spin lock as per i2c documentation to prevent
 * multiple concurrent sends which would probably cause the device to explode.
 */
static ssize_t write(struct file *filep, const char *buf, size_t n,
              loff_t *ppos)
{
    struct IR *ir = filep->private_data;
    struct IR_tx *tx;
    size_t i;
    int failures = 0;

    /* Validate user parameters */
    if (n % sizeof(int))
        return -EINVAL;

    /* Get a struct IR_tx reference */
    tx = get_ir_tx(ir);
    if (tx == NULL)
        return -ENXIO;

    /* Ensure our tx->c i2c_client remains valid for the duration */
    mutex_lock(&tx->client_lock);
    if (tx->c == NULL) {
        mutex_unlock(&tx->client_lock);
        put_ir_tx(tx, false);
        return -ENXIO;
    }

    /* Lock i2c bus for the duration */
    mutex_lock(&ir->ir_lock);

    /* Send each keypress */
    for (i = 0; i < n;) {
        int ret = 0;
        int command;

        if (copy_from_user(&command, buf + i, sizeof(command))) {
            mutex_unlock(&ir->ir_lock);
            mutex_unlock(&tx->client_lock);
            put_ir_tx(tx, false);
            return -EFAULT;
        }

        /* Send boot data first if required */
        if (tx->need_boot == 1) {
            /* Make sure we have the 'firmware' loaded, first */
            ret = fw_load(tx);
            if (ret != 0) {
                mutex_unlock(&ir->ir_lock);
                mutex_unlock(&tx->client_lock);
                put_ir_tx(tx, false);
                if (ret != -ENOMEM)
                    ret = -EIO;
                return ret;
            }
            /* Prep the chip for transmitting codes */
            ret = send_boot_data(tx);
            if (ret == 0)
                tx->need_boot = 0;
        }

        /* Send the code */
        if (ret == 0) {
            ret = send_code(tx, (unsigned)command >> 16,
                        (unsigned)command & 0xFFFF);
            if (ret == -EPROTO) {
                mutex_unlock(&ir->ir_lock);
                mutex_unlock(&tx->client_lock);
                put_ir_tx(tx, false);
                return ret;
            }
        }

        /*
         * Hmm, a failure.  If we've had a few then give up, otherwise
         * try a reset
         */
        if (ret != 0) {
            /* Looks like the chip crashed, reset it */
            zilog_error("sending to the IR transmitter chip "
                    "failed, trying reset\n");

            if (failures >= 3) {
                zilog_error("unable to send to the IR chip "
                        "after 3 resets, giving up\n");
                mutex_unlock(&ir->ir_lock);
                mutex_unlock(&tx->client_lock);
                put_ir_tx(tx, false);
                return ret;
            }
            set_current_state(TASK_UNINTERRUPTIBLE);
            schedule_timeout((100 * HZ + 999) / 1000);
            tx->need_boot = 1;
            ++failures;
        } else
            i += sizeof(int);
    }

    /* Release i2c bus */
    mutex_unlock(&ir->ir_lock);

    mutex_unlock(&tx->client_lock);

    /* Give back our struct IR_tx reference */
    put_ir_tx(tx, false);

    /* All looks good */
    return n;
}

/* copied from lirc_dev */
static unsigned int poll(struct file *filep, poll_table *wait)
{
    struct IR *ir = filep->private_data;
    struct IR_rx *rx;
    struct lirc_buffer *rbuf = ir->l.rbuf;
    unsigned int ret;

    dprintk("poll called\n");

    rx = get_ir_rx(ir);
    if (rx == NULL) {
        /*
         * Revisit this, if our poll function ever reports writeable
         * status for Tx
         */
        dprintk("poll result = POLLERR\n");
        return POLLERR;
    }

    /*
     * Add our lirc_buffer's wait_queue to the poll_table. A wake up on
     * that buffer's wait queue indicates we may have a new poll status.
     */
    poll_wait(filep, &rbuf->wait_poll, wait);

    /* Indicate what ops could happen immediately without blocking */
    ret = lirc_buffer_empty(rbuf) ? 0 : (POLLIN|POLLRDNORM);

    dprintk("poll result = %s\n", ret ? "POLLIN|POLLRDNORM" : "none");
    return ret;
}

static long ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
{
    struct IR *ir = filep->private_data;
    int result;
    unsigned long mode, features;

    features = ir->l.features;

    switch (cmd) {
    case LIRC_GET_LENGTH:
        result = put_user((unsigned long)13,
                  (unsigned long *)arg);
        break;
    case LIRC_GET_FEATURES:
        result = put_user(features, (unsigned long *) arg);
        break;
    case LIRC_GET_REC_MODE:
        if (!(features&LIRC_CAN_REC_MASK))
            return -ENOSYS;

        result = put_user(LIRC_REC2MODE
                  (features&LIRC_CAN_REC_MASK),
                  (unsigned long *)arg);
        break;
    case LIRC_SET_REC_MODE:
        if (!(features&LIRC_CAN_REC_MASK))
            return -ENOSYS;

        result = get_user(mode, (unsigned long *)arg);
        if (!result && !(LIRC_MODE2REC(mode) & features))
            result = -EINVAL;
        break;
    case LIRC_GET_SEND_MODE:
        if (!(features&LIRC_CAN_SEND_MASK))
            return -ENOSYS;

        result = put_user(LIRC_MODE_PULSE, (unsigned long *) arg);
        break;
    case LIRC_SET_SEND_MODE:
        if (!(features&LIRC_CAN_SEND_MASK))
            return -ENOSYS;

        result = get_user(mode, (unsigned long *) arg);
        if (!result && mode != LIRC_MODE_PULSE)
            return -EINVAL;
        break;
    default:
        return -EINVAL;
    }
    return result;
}

static struct IR *get_ir_device_by_minor(unsigned int minor)
{
    struct IR *ir;
    struct IR *ret = NULL;

    mutex_lock(&ir_devices_lock);

    if (!list_empty(&ir_devices_list)) {
        list_for_each_entry(ir, &ir_devices_list, list) {
            if (ir->l.minor == minor) {
                ret = get_ir_device(ir, true);
                break;
            }
        }
    }

    mutex_unlock(&ir_devices_lock);
    return ret;
}

/*
 * Open the IR device.  Get hold of our IR structure and
 * stash it in private_data for the file
 */
static int open(struct inode *node, struct file *filep)
{
    struct IR *ir;
    unsigned int minor = MINOR(node->i_rdev);

    /* find our IR struct */
    ir = get_ir_device_by_minor(minor);

    if (ir == NULL)
        return -ENODEV;

    atomic_inc(&ir->open_count);

    /* stash our IR struct */
    filep->private_data = ir;

    nonseekable_open(node, filep);
    return 0;
}

/* Close the IR device */
static int close(struct inode *node, struct file *filep)
{
    /* find our IR struct */
    struct IR *ir = filep->private_data;
    if (ir == NULL) {
        zilog_error("close: no private_data attached to the file!\n");
        return -ENODEV;
    }

    atomic_dec(&ir->open_count);

    put_ir_device(ir, false);
    return 0;
}

static int ir_remove(struct i2c_client *client);
static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id);

#define ID_FLAG_TX  0x01
#define ID_FLAG_HDPVR   0x02

static const struct i2c_device_id ir_transceiver_id[] = {
    { "ir_tx_z8f0811_haup",  ID_FLAG_TX                 },
    { "ir_rx_z8f0811_haup",  0                          },
    { "ir_tx_z8f0811_hdpvr", ID_FLAG_HDPVR | ID_FLAG_TX },
    { "ir_rx_z8f0811_hdpvr", ID_FLAG_HDPVR              },
    { }
};

static struct i2c_driver driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "Zilog/Hauppauge i2c IR",
    },
    .probe      = ir_probe,
    .remove     = ir_remove,
    .id_table   = ir_transceiver_id,
};

static const struct file_operations lirc_fops = {
    .owner      = THIS_MODULE,
    .llseek     = no_llseek,
    .read       = read,
    .write      = write,
    .poll       = poll,
    .unlocked_ioctl = ioctl,
#ifdef CONFIG_COMPAT
    .compat_ioctl   = ioctl,
#endif
    .open       = open,
    .release    = close
};

static struct lirc_driver lirc_template = {
    .name       = "lirc_zilog",
    .minor      = -1,
    .code_length    = 13,
    .buffer_size    = BUFLEN / 2,
    .sample_rate    = 0, /* tell lirc_dev to not start its own kthread */
    .chunk_size = 2,
    .set_use_inc    = set_use_inc,
    .set_use_dec    = set_use_dec,
    .fops       = &lirc_fops,
    .owner      = THIS_MODULE,
};

static int ir_remove(struct i2c_client *client)
{
    if (strncmp("ir_tx_z8", client->name, 8) == 0) {
        struct IR_tx *tx = i2c_get_clientdata(client);
        if (tx != NULL) {
            mutex_lock(&tx->client_lock);
            tx->c = NULL;
            mutex_unlock(&tx->client_lock);
            put_ir_tx(tx, false);
        }
    } else if (strncmp("ir_rx_z8", client->name, 8) == 0) {
        struct IR_rx *rx = i2c_get_clientdata(client);
        if (rx != NULL) {
            mutex_lock(&rx->client_lock);
            rx->c = NULL;
            mutex_unlock(&rx->client_lock);
            put_ir_rx(rx, false);
        }
    }
    return 0;
}


/* ir_devices_lock must be held */
static struct IR *get_ir_device_by_adapter(struct i2c_adapter *adapter)
{
    struct IR *ir;

    if (list_empty(&ir_devices_list))
        return NULL;

    list_for_each_entry(ir, &ir_devices_list, list)
        if (ir->adapter == adapter) {
            get_ir_device(ir, true);
            return ir;
        }

    return NULL;
}

static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    struct IR *ir;
    struct IR_tx *tx;
    struct IR_rx *rx;
    struct i2c_adapter *adap = client->adapter;
    int ret;
    bool tx_probe = false;

    dprintk("%s: %s on i2c-%d (%s), client addr=0x%02x\n",
        __func__, id->name, adap->nr, adap->name, client->addr);

    /*
     * The IR receiver    is at i2c address 0x71.
     * The IR transmitter is at i2c address 0x70.
     */

    if (id->driver_data & ID_FLAG_TX)
        tx_probe = true;
    else if (tx_only) /* module option */
        return -ENXIO;

    zilog_info("probing IR %s on %s (i2c-%d)\n",
           tx_probe ? "Tx" : "Rx", adap->name, adap->nr);

    mutex_lock(&ir_devices_lock);

    /* Use a single struct IR instance for both the Rx and Tx functions */
    ir = get_ir_device_by_adapter(adap);
    if (ir == NULL) {
        ir = kzalloc(sizeof(struct IR), GFP_KERNEL);
        if (ir == NULL) {
            ret = -ENOMEM;
            goto out_no_ir;
        }
        kref_init(&ir->ref);

        /* store for use in ir_probe() again, and open() later on */
        INIT_LIST_HEAD(&ir->list);
        list_add_tail(&ir->list, &ir_devices_list);

        ir->adapter = adap;
        mutex_init(&ir->ir_lock);
        atomic_set(&ir->open_count, 0);
        spin_lock_init(&ir->tx_ref_lock);
        spin_lock_init(&ir->rx_ref_lock);

        /* set lirc_dev stuff */
        memcpy(&ir->l, &lirc_template, sizeof(struct lirc_driver));
        /*
         * FIXME this is a pointer reference to us, but no refcount.
         *
         * This OK for now, since lirc_dev currently won't touch this
         * buffer as we provide our own lirc_fops.
         *
         * Currently our own lirc_fops rely on this ir->l.rbuf pointer
         */
        ir->l.rbuf = &ir->rbuf;
        ir->l.dev  = &adap->dev;
        ret = lirc_buffer_init(ir->l.rbuf,
                       ir->l.chunk_size, ir->l.buffer_size);
        if (ret)
            goto out_put_ir;
    }

    if (tx_probe) {
        /* Get the IR_rx instance for later, if already allocated */
        rx = get_ir_rx(ir);

        /* Set up a struct IR_tx instance */
        tx = kzalloc(sizeof(struct IR_tx), GFP_KERNEL);
        if (tx == NULL) {
            ret = -ENOMEM;
            goto out_put_xx;
        }
        kref_init(&tx->ref);
        ir->tx = tx;

        ir->l.features |= LIRC_CAN_SEND_PULSE;
        mutex_init(&tx->client_lock);
        tx->c = client;
        tx->need_boot = 1;
        tx->post_tx_ready_poll =
                   (id->driver_data & ID_FLAG_HDPVR) ? false : true;

        /* An ir ref goes to the struct IR_tx instance */
        tx->ir = get_ir_device(ir, true);

        /* A tx ref goes to the i2c_client */
        i2c_set_clientdata(client, get_ir_tx(ir));

        /*
         * Load the 'firmware'.  We do this before registering with
         * lirc_dev, so the first firmware load attempt does not happen
         * after a open() or write() call on the device.
         *
         * Failure here is not deemed catastrophic, so the receiver will
         * still be usable.  Firmware load will be retried in write(),
         * if it is needed.
         */
        fw_load(tx);

        /* Proceed only if the Rx client is also ready or not needed */
        if (rx == NULL && !tx_only) {
            zilog_info("probe of IR Tx on %s (i2c-%d) done. Waiting"
                   " on IR Rx.\n", adap->name, adap->nr);
            goto out_ok;
        }
    } else {
        /* Get the IR_tx instance for later, if already allocated */
        tx = get_ir_tx(ir);

        /* Set up a struct IR_rx instance */
        rx = kzalloc(sizeof(struct IR_rx), GFP_KERNEL);
        if (rx == NULL) {
            ret = -ENOMEM;
            goto out_put_xx;
        }
        kref_init(&rx->ref);
        ir->rx = rx;

        ir->l.features |= LIRC_CAN_REC_LIRCCODE;
        mutex_init(&rx->client_lock);
        rx->c = client;
        rx->hdpvr_data_fmt =
                   (id->driver_data & ID_FLAG_HDPVR) ? true : false;

        /* An ir ref goes to the struct IR_rx instance */
        rx->ir = get_ir_device(ir, true);

        /* An rx ref goes to the i2c_client */
        i2c_set_clientdata(client, get_ir_rx(ir));

        /*
         * Start the polling thread.
         * It will only perform an empty loop around schedule_timeout()
         * until we register with lirc_dev and the first user open()
         */
        /* An ir ref goes to the new rx polling kthread */
        rx->task = kthread_run(lirc_thread, get_ir_device(ir, true),
                       "zilog-rx-i2c-%d", adap->nr);
        if (IS_ERR(rx->task)) {
            ret = PTR_ERR(rx->task);
            zilog_error("%s: could not start IR Rx polling thread"
                    "\n", __func__);
            /* Failed kthread, so put back the ir ref */
            put_ir_device(ir, true);
            /* Failure exit, so put back rx ref from i2c_client */
            i2c_set_clientdata(client, NULL);
            put_ir_rx(rx, true);
            ir->l.features &= ~LIRC_CAN_REC_LIRCCODE;
            goto out_put_xx;
        }

        /* Proceed only if the Tx client is also ready */
        if (tx == NULL) {
            zilog_info("probe of IR Rx on %s (i2c-%d) done. Waiting"
                   " on IR Tx.\n", adap->name, adap->nr);
            goto out_ok;
        }
    }

    /* register with lirc */
    ir->l.minor = minor; /* module option: user requested minor number */
    ir->l.minor = lirc_register_driver(&ir->l);
    if (ir->l.minor < 0 || ir->l.minor >= MAX_IRCTL_DEVICES) {
        zilog_error("%s: \"minor\" must be between 0 and %d (%d)!\n",
                __func__, MAX_IRCTL_DEVICES-1, ir->l.minor);
        ret = -EBADRQC;
        goto out_put_xx;
    }
    zilog_info("IR unit on %s (i2c-%d) registered as lirc%d and ready\n",
           adap->name, adap->nr, ir->l.minor);

out_ok:
    if (rx != NULL)
        put_ir_rx(rx, true);
    if (tx != NULL)
        put_ir_tx(tx, true);
    put_ir_device(ir, true);
    zilog_info("probe of IR %s on %s (i2c-%d) done\n",
           tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
    mutex_unlock(&ir_devices_lock);
    return 0;

out_put_xx:
    if (rx != NULL)
        put_ir_rx(rx, true);
    if (tx != NULL)
        put_ir_tx(tx, true);
out_put_ir:
    put_ir_device(ir, true);
out_no_ir:
    zilog_error("%s: probing IR %s on %s (i2c-%d) failed with %d\n",
            __func__, tx_probe ? "Tx" : "Rx", adap->name, adap->nr,
           ret);
    mutex_unlock(&ir_devices_lock);
    return ret;
}

static int __init zilog_init(void)
{
    int ret;

    zilog_notify("Zilog/Hauppauge IR driver initializing\n");

    mutex_init(&tx_data_lock);

    request_module("firmware_class");

    ret = i2c_add_driver(&driver);
    if (ret)
        zilog_error("initialization failed\n");
    else
        zilog_notify("initialization complete\n");

    return ret;
}

static void __exit zilog_exit(void)
{
    i2c_del_driver(&driver);
    /* if loaded */
    fw_unload();
    zilog_notify("Zilog/Hauppauge IR driver unloaded\n");
}

module_init(zilog_init);
module_exit(zilog_exit);

MODULE_DESCRIPTION("Zilog/Hauppauge infrared transmitter driver (i2c stack)");
MODULE_AUTHOR("Gerd Knorr, Michal Kochanowicz, Christoph Bartelmus, "
          "Ulrich Mueller, Stefan Jahn, Jerome Brock, Mark Weaver, "
          "Andy Walls");
MODULE_LICENSE("GPL");
/* for compat with old name, which isn't all that accurate anymore */
MODULE_ALIAS("lirc_pvr150");

module_param(minor, int, 0444);
MODULE_PARM_DESC(minor, "Preferred minor device number");

module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Enable debugging messages");

module_param(tx_only, bool, 0644);
MODULE_PARM_DESC(tx_only, "Only handle the IR transmit function");