/*
 * 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/version.h>
#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_rx {
        /* RX device */
        struct i2c_client *c;

        /* RX device buffer & lock */
        struct lirc_buffer buf;
        struct mutex buf_lock;

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

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

struct IR_tx {
        /* TX device */
        struct i2c_client *c;

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

struct IR {
        struct lirc_driver l;

        struct mutex ir_lock;
        int open;

        struct i2c_adapter *adapter;
        struct IR_rx *rx;
        struct IR_tx *tx;
};

/* Minor -> data mapping */
static struct mutex ir_devices_lock;
static struct IR *ir_devices[MAX_IRCTL_DEVICES];

/* 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 int debug;       /* debug output */
static int 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)

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 IR_rx *rx = ir->rx;

        if (rx == NULL)
                return -ENXIO;

        if (lirc_buffer_full(&rx->buf)) {
                dprintk("buffer overflow\n");
                return -EOVERFLOW;
        }

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

                /*
                 * 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);
                        return -ENODATA;
                }

                /*
                 * 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");
                                return ret;
                        }

                        /* 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);
                                return -ENODATA;
                        }
                        schedule_timeout((100 * HZ + 999) / 1000);
                        ir->tx->need_boot = 1;

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

                if (kthread_should_stop()) {
                        mutex_unlock(&ir->ir_lock);
                        return -ENODATA;
                }
                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))
                                return 0;
                        else if (got_data && (keybuf[0] == 0x00))
                                return -ENODATA;
                } else if ((rx->b[0] & 0x80) == 0)
                        return got_data ? 0 : -ENODATA;

                /* 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(&rx->buf, codes);
                ++got_data;
        } while (!lirc_buffer_full(&rx->buf));

        return 0;
}

/*
 * 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 IR_rx *rx = ir->rx;

        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 (!ir->open) {
                        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(&rx->buf.wait_poll);
        }

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

static int set_use_inc(void *data)
{
        struct IR *ir = data;

        if (ir->l.owner == NULL || try_module_get(ir->l.owner) == 0)
                return -ENODEV;

        /* lock bttv in memory while /dev/lirc is in use  */
        /*
         * this is completely broken code. lirc_unregister_driver()
         * must be possible even when the device is open
         */
        if (ir->rx != NULL)
                i2c_use_client(ir->rx->c);
        if (ir->tx != NULL)
                i2c_use_client(ir->tx->c);

        return 0;
}

static void set_use_dec(void *data)
{
        struct IR *ir = data;

        if (ir->rx)
                i2c_release_client(ir->rx->c);
        if (ir->tx)
                i2c_release_client(ir->tx->c);
        if (ir->l.owner != NULL)
                module_put(ir->l.owner);
}

/* 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("%02x %02x %02x %02x %02x",
                        buf[0], buf[1], buf[2], buf[3], buf[4]);
                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->c->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;
}

/* initialise the IR TX device */
static int tx_init(struct IR_tx *tx)
{
        int ret;

        /* Load 'firmware' */
        ret = fw_load(tx);
        if (ret != 0)
                return ret;

        /* Send boot block */
        ret = send_boot_data(tx);
        if (ret != 0)
                return ret;
        tx->need_boot = 0;

        /* Looks good */
        return 0;
}

/* do nothing stub to make LIRC happy */
static loff_t lseek(struct file *filep, loff_t offset, int orig)
{
        return -ESPIPE;
}

/* 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 = ir->rx;
        int ret = 0, written = 0;
        DECLARE_WAITQUEUE(wait, current);

        dprintk("read called\n");
        if (rx == NULL)
                return -ENODEV;

        if (mutex_lock_interruptible(&rx->buf_lock))
                return -ERESTARTSYS;

        if (n % rx->buf.chunk_size) {
                dprintk("read result = -EINVAL\n");
                mutex_unlock(&rx->buf_lock);
                return -EINVAL;
        }

        /*
         * 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(&rx->buf.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(&rx->buf)) {
                        /*
                         * 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[rx->buf.chunk_size];
                        lirc_buffer_read(&rx->buf, buf);
                        ret = copy_to_user((void *)outbuf+written, buf,
                                           rx->buf.chunk_size);
                        written += rx->buf.chunk_size;
                }
        }

        remove_wait_queue(&rx->buf.wait_poll, &wait);
        set_current_state(TASK_RUNNING);
        mutex_unlock(&rx->buf_lock);

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

        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 = ir->tx;
        size_t i;
        int failures = 0;

        if (tx == NULL)
                return -ENODEV;

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

        /* 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);
                        return -EFAULT;
                }

                /* Send boot data first if required */
                if (tx->need_boot == 1) {
                        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);
                                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);
                                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);

        /* 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 = ir->rx;
        unsigned int ret;

        dprintk("poll called\n");
        if (rx == NULL)
                return -ENODEV;

        mutex_lock(&rx->buf_lock);

        poll_wait(filep, &rx->buf.wait_poll, wait);

        dprintk("poll result = %s\n",
                lirc_buffer_empty(&rx->buf) ? "0" : "POLLIN|POLLRDNORM");

        ret = lirc_buffer_empty(&rx->buf) ? 0 : (POLLIN|POLLRDNORM);

        mutex_unlock(&rx->buf_lock);
        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 = 0;

        features |= LIRC_CAN_SEND_PULSE;
        if (ir->rx != NULL)
                features |= LIRC_CAN_REC_LIRCCODE;

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

/* ir_devices_lock must be held */
static struct IR *find_ir_device_by_minor(unsigned int minor)
{
        if (minor >= MAX_IRCTL_DEVICES)
                return NULL;

        return ir_devices[minor];
}

/*
 * 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;
        int ret;
        unsigned int minor = MINOR(node->i_rdev);

        /* find our IR struct */
        mutex_lock(&ir_devices_lock);
        ir = find_ir_device_by_minor(minor);
        mutex_unlock(&ir_devices_lock);

        if (ir == NULL)
                return -ENODEV;

        /* increment in use count */
        mutex_lock(&ir->ir_lock);
        ++ir->open;
        ret = set_use_inc(ir);
        if (ret != 0) {
                --ir->open;
                mutex_unlock(&ir->ir_lock);
                return ret;
        }
        mutex_unlock(&ir->ir_lock);

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

        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;
        }

        /* decrement in use count */
        mutex_lock(&ir->ir_lock);
        --ir->open;
        set_use_dec(ir);
        mutex_unlock(&ir->ir_lock);

        return 0;
}

static struct lirc_driver lirc_template = {
        .name           = "lirc_zilog",
        .set_use_inc    = set_use_inc,
        .set_use_dec    = set_use_dec,
        .owner          = THIS_MODULE
};

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         = lseek,
        .read           = read,
        .write          = write,
        .poll           = poll,
        .unlocked_ioctl = ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl   = ioctl,
#endif
        .open           = open,
        .release        = close
};

static void destroy_rx_kthread(struct IR_rx *rx)
{
        /* end up polling thread */
        if (rx != NULL && !IS_ERR_OR_NULL(rx->task)) {
                kthread_stop(rx->task);
                rx->task = NULL;
        }
}

/* ir_devices_lock must be held */
static int add_ir_device(struct IR *ir)
{
        int i;

        for (i = 0; i < MAX_IRCTL_DEVICES; i++)
                if (ir_devices[i] == NULL) {
                        ir_devices[i] = ir;
                        break;
                }

        return i == MAX_IRCTL_DEVICES ? -ENOMEM : i;
}

/* ir_devices_lock must be held */
static void del_ir_device(struct IR *ir)
{
        int i;

        for (i = 0; i < MAX_IRCTL_DEVICES; i++)
                if (ir_devices[i] == ir) {
                        ir_devices[i] = NULL;
                        break;
                }
}

static int ir_remove(struct i2c_client *client)
{
        struct IR *ir = i2c_get_clientdata(client);

        mutex_lock(&ir_devices_lock);

        if (ir == NULL) {
                /* We destroyed everything when the first client came through */
                mutex_unlock(&ir_devices_lock);
                return 0;
        }

        /* Good-bye LIRC */
        lirc_unregister_driver(ir->l.minor);

        /* Good-bye Rx */
        destroy_rx_kthread(ir->rx);
        if (ir->rx != NULL) {
                if (ir->rx->buf.fifo_initialized)
                        lirc_buffer_free(&ir->rx->buf);
                i2c_set_clientdata(ir->rx->c, NULL);
                kfree(ir->rx);
        }

        /* Good-bye Tx */
        i2c_set_clientdata(ir->tx->c, NULL);
        kfree(ir->tx);

        /* Good-bye IR */
        del_ir_device(ir);
        kfree(ir);

        mutex_unlock(&ir_devices_lock);
        return 0;
}


/* ir_devices_lock must be held */
static struct IR *find_ir_device_by_adapter(struct i2c_adapter *adapter)
{
        int i;
        struct IR *ir = NULL;

        for (i = 0; i < MAX_IRCTL_DEVICES; i++)
                if (ir_devices[i] != NULL &&
                    ir_devices[i]->adapter == adapter) {
                        ir = ir_devices[i];
                        break;
                }

        return ir;
}

static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
        struct IR *ir;
        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 = find_ir_device_by_adapter(adap);
        if (ir == NULL) {
                ir = kzalloc(sizeof(struct IR), GFP_KERNEL);
                if (ir == NULL) {
                        ret = -ENOMEM;
                        goto out_no_ir;
                }
                /* store for use in ir_probe() again, and open() later on */
                ret = add_ir_device(ir);
                if (ret)
                        goto out_free_ir;

                ir->adapter = adap;
                mutex_init(&ir->ir_lock);

                /* set lirc_dev stuff */
                memcpy(&ir->l, &lirc_template, sizeof(struct lirc_driver));
                ir->l.minor       = minor; /* module option */
                ir->l.code_length = 13;
                ir->l.rbuf        = NULL;
                ir->l.fops        = &lirc_fops;
                ir->l.data        = ir;
                ir->l.dev         = &adap->dev;
                ir->l.sample_rate = 0;
        }

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

                ir->tx->c = client;
                ir->tx->need_boot = 1;
                ir->tx->post_tx_ready_poll =
                               (id->driver_data & ID_FLAG_HDPVR) ? false : true;
        } else {
                /* Set up a struct IR_rx instance */
                ir->rx = kzalloc(sizeof(struct IR_rx), GFP_KERNEL);
                if (ir->rx == NULL) {
                        ret = -ENOMEM;
                        goto out_free_xx;
                }

                ret = lirc_buffer_init(&ir->rx->buf, 2, BUFLEN / 2);
                if (ret)
                        goto out_free_xx;

                mutex_init(&ir->rx->buf_lock);
                ir->rx->c = client;
                ir->rx->hdpvr_data_fmt =
                               (id->driver_data & ID_FLAG_HDPVR) ? true : false;

                /* set lirc_dev stuff */
                ir->l.rbuf = &ir->rx->buf;
        }

        i2c_set_clientdata(client, ir);

        /* Proceed only if we have the required Tx and Rx clients ready to go */
        if (ir->tx == NULL ||
            (ir->rx == NULL && !tx_only)) {
                zilog_info("probe of IR %s on %s (i2c-%d) done. Waiting on "
                           "IR %s.\n", tx_probe ? "Tx" : "Rx", adap->name,
                           adap->nr, tx_probe ? "Rx" : "Tx");
                goto out_ok;
        }

        /* initialise RX device */
        if (ir->rx != NULL) {
                /* try to fire up polling thread */
                ir->rx->task = kthread_run(lirc_thread, ir,
                                           "zilog-rx-i2c-%d", adap->nr);
                if (IS_ERR(ir->rx->task)) {
                        ret = PTR_ERR(ir->rx->task);
                        zilog_error("%s: could not start IR Rx polling thread"
                                    "\n", __func__);
                        goto out_free_xx;
                }
        }

        /* register with lirc */
        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_free_thread;
        }

        /*
         * if we have the tx device, load the 'firmware'.  We do this
         * after registering with lirc as otherwise hotplug seems to take
         * 10s to create the lirc device.
         */
        ret = tx_init(ir->tx);
        if (ret != 0)
                goto out_unregister;

        zilog_info("probe of IR %s on %s (i2c-%d) done. IR unit ready.\n",
                   tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
out_ok:
        mutex_unlock(&ir_devices_lock);
        return 0;

out_unregister:
        lirc_unregister_driver(ir->l.minor);
out_free_thread:
        destroy_rx_kthread(ir->rx);
out_free_xx:
        if (ir->rx != NULL) {
                if (ir->rx->buf.fifo_initialized)
                        lirc_buffer_free(&ir->rx->buf);
                if (ir->rx->c != NULL)
                        i2c_set_clientdata(ir->rx->c, NULL);
                kfree(ir->rx);
        }
        if (ir->tx != NULL) {
                if (ir->tx->c != NULL)
                        i2c_set_clientdata(ir->tx->c, NULL);
                kfree(ir->tx);
        }
out_free_ir:
        del_ir_device(ir);
        kfree(ir);
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);
        mutex_init(&ir_devices_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");