/*
 * 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
 *
 *  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 {
	struct lirc_driver l;

	/* Device info */
	struct mutex ir_lock;
	int open;

	/* RX device */
	struct i2c_client c_rx;
	int have_rx;

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

	/* RX polling thread data */
	struct completion *t_notify;
	struct completion *t_notify2;
	int shutdown;
	struct task_struct *task;

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

	/* TX device */
	struct i2c_client c_tx;
	int need_boot;
	int have_tx;
};

/* Minor -> data mapping */
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_HAUPPAUGE_IR_RX_NAME "Zilog/Hauppauge IR RX"
#define ZILOG_HAUPPAUGE_IR_TX_NAME "Zilog/Hauppauge IR TX"

/* module parameters */
static int debug;	/* debug output */
static int disable_rx;	/* disable RX device */
static int disable_tx;	/* disable TX device */
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 };

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

	/*
	 * service the device as long as it is returning
	 * data and we have space
	 */
	do {
		/*
		 * Lock i2c bus for the duration.  RX/TX chips interfere so
		 * this is worth it
		 */
		mutex_lock(&ir->ir_lock);

		/*
		 * Send random "poll command" (?)  Windows driver does this
		 * and it is a good point to detect chip failure.
		 */
		ret = i2c_master_send(&ir->c_rx, 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);
			schedule_timeout((100 * HZ + 999) / 1000);
			ir->need_boot = 1;

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

		ret = i2c_master_recv(&ir->c_rx, 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 {
			ir->b[0] = keybuf[3];
			ir->b[1] = keybuf[4];
			ir->b[2] = keybuf[5];
			dprintk("key (0x%02x/0x%02x)\n", ir->b[0], ir->b[1]);
		}

		/* key pressed ? */
#ifdef I2C_HW_B_HDPVR
		if (ir->c_rx.adapter->id == I2C_HW_B_HDPVR) {
			if (got_data && (keybuf[0] == 0x80))
				return 0;
			else if (got_data && (keybuf[0] == 0x00))
				return -ENODATA;
		} else if ((ir->b[0] & 0x80) == 0)
#else
		if ((ir->b[0] & 0x80) == 0)
#endif
			return got_data ? 0 : -ENODATA;

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

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

		/* return it */
		lirc_buffer_write(&ir->buf, codes);
		++got_data;
	} while (!lirc_buffer_full(&ir->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;

	if (ir->t_notify != NULL)
		complete(ir->t_notify);

	dprintk("poll thread started\n");

	do {
		if (ir->open) {
			set_current_state(TASK_INTERRUPTIBLE);

			/*
			 * 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 (ir->shutdown)
				break;
			if (!add_to_buf(ir))
				wake_up_interruptible(&ir->buf.wait_poll);
		} else {
			/* if device not opened so we can sleep half a second */
			set_current_state(TASK_INTERRUPTIBLE);
			schedule_timeout(HZ/2);
		}
	} while (!ir->shutdown);

	if (ir->t_notify2 != NULL)
		wait_for_completion(ir->t_notify2);

	ir->task = NULL;
	if (ir->t_notify != NULL)
		complete(ir->t_notify);

	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->c_rx.addr)
		i2c_use_client(&ir->c_rx);
	if (ir->c_tx.addr)
		i2c_use_client(&ir->c_tx);

	return 0;
}

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

	if (ir->c_rx.addr)
		i2c_release_client(&ir->c_rx);
	if (ir->c_tx.addr)
		i2c_release_client(&ir->c_tx);
	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 *ir, 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(&ir->c_tx, 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 *ir)
{
	int ret;
	unsigned char buf[4];

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

	/* kick it off? */
	buf[0] = 0x00;
	buf[1] = 0x20;
	ret = i2c_master_send(&ir->c_tx, buf, 2);
	if (ret != 2) {
		zilog_error("i2c_master_send failed with %d\n", ret);
		return ret < 0 ? ret : -EFAULT;
	}
	ret = i2c_master_send(&ir->c_tx, buf, 1);
	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(&ir->c_tx, buf, 4);
	if (ret != 4) {
		zilog_error("i2c_master_recv failed with %d\n", ret);
		return 0;
	}
	if (buf[0] != 0x80) {
		zilog_error("unexpected IR TX 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 *ir)
{
	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", &ir->c_tx.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 *ir)
{
	int ret;

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

	/* Send boot block */
	ret = send_boot_data(ir);
	if (ret != 0)
		return ret;
	ir->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;
	unsigned char buf[ir->buf.chunk_size];
	int ret = 0, written = 0;
	DECLARE_WAITQUEUE(wait, current);

	dprintk("read called\n");
	if (ir->c_rx.addr == 0)
		return -ENODEV;

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

	if (n % ir->buf.chunk_size) {
		dprintk("read result = -EINVAL\n");
		mutex_unlock(&ir->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(&ir->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(&ir->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 {
			lirc_buffer_read(&ir->buf, buf);
			ret = copy_to_user((void *)outbuf+written, buf,
					   ir->buf.chunk_size);
			written += ir->buf.chunk_size;
		}
	}

	remove_wait_queue(&ir->buf.wait_poll, &wait);
	set_current_state(TASK_RUNNING);
	mutex_unlock(&ir->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 *ir, 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(ir, data_block);
	if (ret != 0)
		return ret;

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

#ifdef I2C_HW_B_HDPVR
	/*
	 * 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 (ir->c_rx.adapter->id == I2C_HW_B_HDPVR)
		goto done;
#endif

	/*
	 * 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(&ir->c_tx, 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(&ir->c_tx, 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;
	}

done:
	/* 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;
	size_t i;
	int failures = 0;

	if (ir->c_tx.addr == 0)
		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 (ir->need_boot == 1) {
			ret = send_boot_data(ir);
			if (ret == 0)
				ir->need_boot = 0;
		}

		/* Send the code */
		if (ret == 0) {
			ret = send_code(ir, (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);
			ir->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;
	unsigned int ret;

	dprintk("poll called\n");
	if (ir->c_rx.addr == 0)
		return -ENODEV;

	mutex_lock(&ir->buf_lock);

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

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

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

	mutex_unlock(&ir->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;

	if (ir->c_rx.addr != 0)
		features |= LIRC_CAN_REC_LIRCCODE;
	if (ir->c_tx.addr != 0)
		features |= LIRC_CAN_SEND_PULSE;

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

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

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

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

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

/*
 * 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;

	/* find our IR struct */
	unsigned minor = MINOR(node->i_rdev);
	if (minor >= MAX_IRCTL_DEVICES) {
		dprintk("minor %d: open result = -ENODEV\n",
			minor);
		return -ENODEV;
	}
	ir = ir_devices[minor];

	/* 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);
static int ir_command(struct i2c_client *client, unsigned int cmd, void *arg);

static const struct i2c_device_id ir_transceiver_id[] = {
	/* Generic entry for any IR transceiver */
	{ "ir_video", 0 },
	/* IR device specific entries should be added here */
	{ "ir_tx_z8f0811_haup", 0 },
	{ "ir_rx_z8f0811_haup", 0 },
	{ }
};

static struct i2c_driver driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "Zilog/Hauppauge i2c IR",
	},
	.probe		= ir_probe,
	.remove		= ir_remove,
	.command	= ir_command,
	.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 int ir_remove(struct i2c_client *client)
{
	struct IR *ir = i2c_get_clientdata(client);

	mutex_lock(&ir->ir_lock);

	if (ir->have_rx || ir->have_tx) {
		DECLARE_COMPLETION(tn);
		DECLARE_COMPLETION(tn2);

		/* end up polling thread */
		if (ir->task && !IS_ERR(ir->task)) {
			ir->t_notify = &tn;
			ir->t_notify2 = &tn2;
			ir->shutdown = 1;
			wake_up_process(ir->task);
			complete(&tn2);
			wait_for_completion(&tn);
			ir->t_notify = NULL;
			ir->t_notify2 = NULL;
		}

	} else {
		mutex_unlock(&ir->ir_lock);
		zilog_error("%s: detached from something we didn't "
			    "attach to\n", __func__);
		return -ENODEV;
	}

	/* unregister lirc driver */
	if (ir->l.minor >= 0 && ir->l.minor < MAX_IRCTL_DEVICES) {
		lirc_unregister_driver(ir->l.minor);
		ir_devices[ir->l.minor] = NULL;
	}

	/* free memory */
	lirc_buffer_free(&ir->buf);
	mutex_unlock(&ir->ir_lock);
	kfree(ir);

	return 0;
}

static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct IR *ir = NULL;
	struct i2c_adapter *adap = client->adapter;
	char buf;
	int ret;
	int have_rx = 0, have_tx = 0;

	dprintk("%s: adapter id=0x%x, client addr=0x%02x\n",
		__func__, adap->id, client->addr);

	/*
	 * The external IR receiver is at i2c address 0x71.
	 * The IR transmitter is at 0x70.
	 */
	client->addr = 0x70;

	if (!disable_tx) {
		if (i2c_master_recv(client, &buf, 1) == 1)
			have_tx = 1;
		dprintk("probe 0x70 @ %s: %s\n",
			adap->name, have_tx ? "success" : "failed");
	}

	if (!disable_rx) {
		client->addr = 0x71;
		if (i2c_master_recv(client, &buf, 1) == 1)
			have_rx = 1;
		dprintk("probe 0x71 @ %s: %s\n",
			adap->name, have_rx ? "success" : "failed");
	}

	if (!(have_rx || have_tx)) {
		zilog_error("%s: no devices found\n", adap->name);
		goto out_nodev;
	}

	printk(KERN_INFO "lirc_zilog: chip found with %s\n",
		have_rx && have_tx ? "RX and TX" :
			have_rx ? "RX only" : "TX only");

	ir = kzalloc(sizeof(struct IR), GFP_KERNEL);

	if (!ir)
		goto out_nomem;

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

	mutex_init(&ir->ir_lock);
	mutex_init(&ir->buf_lock);
	ir->need_boot = 1;

	memcpy(&ir->l, &lirc_template, sizeof(struct lirc_driver));
	ir->l.minor = -1;

	/* I2C attach to device */
	i2c_set_clientdata(client, ir);

	/* initialise RX device */
	if (have_rx) {
		DECLARE_COMPLETION(tn);
		memcpy(&ir->c_rx, client, sizeof(struct i2c_client));

		ir->c_rx.addr = 0x71;
		strlcpy(ir->c_rx.name, ZILOG_HAUPPAUGE_IR_RX_NAME,
			I2C_NAME_SIZE);

		/* try to fire up polling thread */
		ir->t_notify = &tn;
		ir->task = kthread_run(lirc_thread, ir, "lirc_zilog");
		if (IS_ERR(ir->task)) {
			ret = PTR_ERR(ir->task);
			zilog_error("lirc_register_driver: cannot run "
				    "poll thread %d\n", ret);
			goto err;
		}
		wait_for_completion(&tn);
		ir->t_notify = NULL;
		ir->have_rx = 1;
	}

	/* initialise TX device */
	if (have_tx) {
		memcpy(&ir->c_tx, client, sizeof(struct i2c_client));
		ir->c_tx.addr = 0x70;
		strlcpy(ir->c_tx.name, ZILOG_HAUPPAUGE_IR_TX_NAME,
			I2C_NAME_SIZE);
		ir->have_tx = 1;
	}

	/* set lirc_dev stuff */
	ir->l.code_length = 13;
	ir->l.rbuf	  = &ir->buf;
	ir->l.fops	  = &lirc_fops;
	ir->l.data	  = ir;
	ir->l.minor       = minor;
	ir->l.dev         = &adap->dev;
	ir->l.sample_rate = 0;

	/* register with lirc */
	ir->l.minor = lirc_register_driver(&ir->l);
	if (ir->l.minor < 0 || ir->l.minor >= MAX_IRCTL_DEVICES) {
		zilog_error("ir_attach: \"minor\" must be between 0 and %d "
			    "(%d)!\n", MAX_IRCTL_DEVICES-1, ir->l.minor);
		ret = -EBADRQC;
		goto err;
	}

	/* store this for getting back in open() later on */
	ir_devices[ir->l.minor] = ir;

	/*
	 * 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.
	 */
	if (have_tx) {
		/* Special TX init */
		ret = tx_init(ir);
		if (ret != 0)
			goto err;
	}

	return 0;

err:
	/* undo everything, hopefully... */
	if (ir->c_rx.addr)
		ir_remove(&ir->c_rx);
	if (ir->c_tx.addr)
		ir_remove(&ir->c_tx);
	return ret;

out_nodev:
	zilog_error("no device found\n");
	return -ENODEV;

out_nomem:
	zilog_error("memory allocation failure\n");
	kfree(ir);
	return -ENOMEM;
}

static int ir_command(struct i2c_client *client, unsigned int cmd, void *arg)
{
	/* nothing */
	return 0;
}

static int __init zilog_init(void)
{
	int ret;

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

	mutex_init(&tx_data_lock);

	request_module("firmware_class");

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

	return ret;
}

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

module_init(zilog_init);
module_exit(zilog_exit);

MODULE_DESCRIPTION("Zilog/Hauppauge infrared transmitter driver (i2c stack)");
MODULE_AUTHOR("Gerd Knorr, Michal Kochanowicz, Christoph Bartelmus, "
	      "Ulrich Mueller, Stefan Jahn, Jerome Brock, Mark Weaver");
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(disable_rx, bool, 0644);
MODULE_PARM_DESC(disable_rx, "Disable the IR receiver device");

module_param(disable_tx, bool, 0644);
MODULE_PARM_DESC(disable_tx, "Disable the IR transmitter device");