/*
 * i2c IR lirc driver for devices with zilog IR processors
 *
 * Copyright (c) 2000 Gerd Knorr <kraxel@goldbach.in-berlin.de>
 * modified for PixelView (BT878P+W/FM) by
 *      Michal Kochanowicz <mkochano@pld.org.pl>
 *      Christoph Bartelmus <lirc@bartelmus.de>
 * modified for KNC ONE TV Station/Anubis Typhoon TView Tuner by
 *      Ulrich Mueller <ulrich.mueller42@web.de>
 * modified for Asus TV-Box and Creative/VisionTek BreakOut-Box by
 *      Stefan Jahn <stefan@lkcc.org>
 * modified for inclusion into kernel sources by
 *      Jerome Brock <jbrock@users.sourceforge.net>
 * modified for Leadtek Winfast PVR2000 by
 *      Thomas Reitmayr (treitmayr@yahoo.com)
 * modified for Hauppauge PVR-150 IR TX device by
 *      Mark Weaver <mark@npsl.co.uk>
 * changed name from lirc_pvr150 to lirc_zilog, works on more than pvr-150
 *      Jarod Wilson <jarod@redhat.com>
 *
 * 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 <awalls@md.metrocast.net>
 *
 *  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/signal.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>

/* Max transfer size done by I2C transfer functions */
#define MAX_XFER_SIZE  64

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;


/* module parameters */
static bool debug;      /* debug output */
static bool tx_only;    /* only handle the IR Tx function */


/* 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) {
                lirc_unregister_driver(ir->l.minor);
                ir->l.minor = -1;
        }

        if (kfifo_initialized(&ir->rbuf.fifo))
                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)
                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 */
}

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)
                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_LIRCCODE;
        /* 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)) {
                dev_dbg(ir->l.dev, "buffer overflow\n");
                return -EOVERFLOW;
        }

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

        /* Ensure our rx->c i2c_client remains valid for the duration */
        mutex_lock(&rx->client_lock);
        if (!rx->c) {
                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) {
                        dev_err(ir->l.dev, "i2c_master_send failed with %d\n",
                                ret);
                        if (failures >= 3) {
                                mutex_unlock(&ir->ir_lock);
                                dev_err(ir->l.dev,
                                        "unable to read from the IR chip after 3 resets, giving up\n");
                                break;
                        }

                        /* Looks like the chip crashed, reset it */
                        dev_err(ir->l.dev,
                                "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)
                                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)) {
                        dev_err(ir->l.dev,
                                "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];
                        dev_dbg(ir->l.dev,
                                "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)
                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;

        dev_dbg(ir->l.dev, "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);
        }

        dev_dbg(ir->l.dev, "poll thread ended\n");
        return 0;
}

/* 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:
        pr_err("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];
                dev_dbg(tx->ir->l.dev, "%*ph", 5, buf);
                ret = i2c_master_send(tx->c, buf, tosend + 1);
                if (ret != tosend + 1) {
                        dev_err(tx->ir->l.dev,
                                "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) {
                dev_err(tx->ir->l.dev, "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) {
                dev_err(tx->ir->l.dev, "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) {
                dev_err(tx->ir->l.dev, "i2c_master_recv failed with %d\n", ret);
                return 0;
        }
        if ((buf[0] != 0x80) && (buf[0] != 0xa0)) {
                dev_err(tx->ir->l.dev, "unexpected IR TX init response: %02x\n",
                        buf[0]);
                return 0;
        }
        dev_notice(tx->ir->l.dev,
                   "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) {
                vfree(tx_data->code_sets);

                vfree(tx_data->datap);

                vfree(tx_data);
                tx_data = NULL;
                pr_debug("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) {
                dev_err(tx->ir->l.dev,
                        "firmware haup-ir-blaster.bin not available (%d)\n",
                        ret);
                ret = ret < 0 ? ret : -EFAULT;
                goto out;
        }
        dev_dbg(tx->ir->l.dev, "firmware of size %zu loaded\n", fw_entry->size);

        /* Parse the file */
        tx_data = vmalloc(sizeof(*tx_data));
        if (!tx_data) {
                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) {
                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) {
                dev_err(tx->ir->l.dev,
                        "unsupported code set file version (%u, expected 1) -- please upgrade to a newer driver\n",
                        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;

        dev_dbg(tx->ir->l.dev, "%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) {
                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:
        dev_err(tx->ir->l.dev, "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 __user *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);

        dev_dbg(ir->l.dev, "read called\n");
        if (n % rbuf->chunk_size) {
                dev_dbg(ir->l.dev, "read result = -EINVAL\n");
                return -EINVAL;
        }

        rx = get_ir_rx(ir);
        if (!rx)
                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[MAX_XFER_SIZE];

                        if (rbuf->chunk_size > sizeof(buf)) {
                                dev_err(ir->l.dev,
                                        "chunk_size is too big (%d)!\n",
                                        rbuf->chunk_size);
                                ret = -EINVAL;
                                break;
                        }
                        m = lirc_buffer_read(rbuf, buf);
                        if (m == rbuf->chunk_size) {
                                ret = copy_to_user(outbuf + written, buf,
                                                   rbuf->chunk_size);
                                written += rbuf->chunk_size;
                        } else {
                                retries++;
                        }
                        if (retries >= 5) {
                                dev_err(ir->l.dev, "Buffer read failed!\n");
                                ret = -EIO;
                        }
                }
        }

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

        dev_dbg(ir->l.dev, "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) {
                dev_err(tx->ir->l.dev,
                        "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) {
                dev_err(tx->ir->l.dev, "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) {
                dev_err(tx->ir->l.dev, "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) {
                dev_err(tx->ir->l.dev, "i2c_master_recv failed with %d\n", ret);
                return ret < 0 ? ret : -EFAULT;
        }
        if (buf[0] != 0xA0) {
                dev_err(tx->ir->l.dev, "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) {
                dev_err(tx->ir->l.dev, "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) {
                dev_dbg(tx->ir->l.dev, "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;
                dev_dbg(tx->ir->l.dev,
                        "NAK expected: i2c_master_send failed with %d (try %d)\n",
                        ret, i + 1);
        }
        if (ret != 1) {
                dev_err(tx->ir->l.dev,
                        "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) {
                dev_err(tx->ir->l.dev, "i2c_master_recv failed with %d\n", ret);
                return -EFAULT;
        }
        if (buf[0] != 0x80) {
                dev_err(tx->ir->l.dev, "unexpected IR TX response #2: %02x\n",
                        buf[0]);
                return -EFAULT;
        }

        /* Oh good, it worked */
        dev_dbg(tx->ir->l.dev, "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 __user *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)
                return -ENXIO;

        /* Ensure our tx->c i2c_client remains valid for the duration */
        mutex_lock(&tx->client_lock);
        if (!tx->c) {
                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 int)command >> 16,
                                            (unsigned int)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 */
                        dev_err(tx->ir->l.dev,
                                "sending to the IR transmitter chip failed, trying reset\n");

                        if (failures >= 3) {
                                dev_err(tx->ir->l.dev,
                                        "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;

        dev_dbg(ir->l.dev, "%s called\n", __func__);

        rx = get_ir_rx(ir);
        if (!rx) {
                /*
                 * Revisit this, if our poll function ever reports writeable
                 * status for Tx
                 */
                dev_dbg(ir->l.dev, "%s result = POLLERR\n", __func__);
                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);

        dev_dbg(ir->l.dev, "%s result = %s\n", __func__,
                ret ? "POLLIN|POLLRDNORM" : "none");
        return ret;
}

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

        features = ir->l.features;

        switch (cmd) {
        case LIRC_GET_LENGTH:
                result = put_user(13UL, uptr);
                break;
        case LIRC_GET_FEATURES:
                result = put_user(features, uptr);
                break;
        case LIRC_GET_REC_MODE:
                if (!(features & LIRC_CAN_REC_MASK))
                        return -ENOTTY;

                result = put_user(LIRC_REC2MODE
                                  (features & LIRC_CAN_REC_MASK),
                                  uptr);
                break;
        case LIRC_SET_REC_MODE:
                if (!(features & LIRC_CAN_REC_MASK))
                        return -ENOTTY;

                result = get_user(mode, uptr);
                if (!result && !(LIRC_MODE2REC(mode) & features))
                        result = -ENOTTY;
                break;
        case LIRC_GET_SEND_MODE:
                if (!(features & LIRC_CAN_SEND_MASK))
                        return -ENOTTY;

                result = put_user(LIRC_MODE_LIRCCODE, uptr);
                break;
        case LIRC_SET_SEND_MODE:
                if (!(features & LIRC_CAN_SEND_MASK))
                        return -ENOTTY;

                result = get_user(mode, uptr);
                if (!result && mode != LIRC_MODE_LIRCCODE)
                        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)
                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) {
                pr_err("ir: %s: no private_data attached to the file!\n",
                       __func__);
                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              },
        { }
};
MODULE_DEVICE_TABLE(i2c, ir_transceiver_id);

static struct i2c_driver driver = {
        .driver = {
                .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,
        .chunk_size     = 2,
        .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) {
                        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) {
                        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;

        dev_dbg(&client->dev, "%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;

        pr_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) {
                ir = kzalloc(sizeof(*ir), GFP_KERNEL);
                if (!ir) {
                        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(*tx), GFP_KERNEL);
                if (!tx) {
                        ret = -ENOMEM;
                        goto out_put_xx;
                }
                kref_init(&tx->ref);
                ir->tx = tx;

                ir->l.features |= LIRC_CAN_SEND_LIRCCODE;
                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 && !tx_only) {
                        dev_info(tx->ir->l.dev,
                                 "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(*rx), GFP_KERNEL);
                if (!rx) {
                        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);
                        dev_err(tx->ir->l.dev,
                                "%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_tx;
                }

                /* Proceed only if the Tx client is also ready */
                if (!tx) {
                        pr_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 = lirc_register_driver(&ir->l);
        if (ir->l.minor < 0) {
                dev_err(tx->ir->l.dev,
                        "%s: lirc_register_driver() failed: %i\n",
                        __func__, ir->l.minor);
                ret = -EBADRQC;
                goto out_put_xx;
        }
        dev_info(ir->l.dev,
                 "IR unit on %s (i2c-%d) registered as lirc%d and ready\n",
                 adap->name, adap->nr, ir->l.minor);

out_ok:
        if (rx)
                put_ir_rx(rx, true);
        if (tx)
                put_ir_tx(tx, true);
        put_ir_device(ir, true);
        dev_info(ir->l.dev,
                 "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)
                put_ir_rx(rx, true);
out_put_tx:
        if (tx)
                put_ir_tx(tx, true);
out_put_ir:
        put_ir_device(ir, true);
out_no_ir:
        dev_err(&client->dev,
                "%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;

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

        mutex_init(&tx_data_lock);

        request_module("firmware_class");

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

        return ret;
}

static void __exit zilog_exit(void)
{
        i2c_del_driver(&driver);
        /* if loaded */
        fw_unload();
        pr_notice("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(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");