V4L/DVB: staging/lirc: add lirc_zilog driver

Commonly found on several Hauppauge video capture devices.
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/lirc/lirc_zilog.c

+/*
+ * 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 = (struct 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 = (struct 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 = (struct 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 = (struct 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 = (struct 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 struct file_operations lirc_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= lseek,
+	.read		= read,
+	.write		= write,
+	.poll		= poll,
+	.unlocked_ioctl	= ioctl,
+	.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");