1 files changed, 834 insertions, 0 deletions

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
new file mode 100644
index 00000000000..dc5cbffcd5a
--- /dev/null
+++ b/drivers/media/rc/lirc_dev.c
@@ -0,0 +1,834 @@
+/*
+ * LIRC base driver
+ *
+ * by Artur Lipowski <alipowski@interia.pl>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/kthread.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+
+#include <media/rc-core.h>
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+static bool debug;
+
+#define IRCTL_DEV_NAME	"BaseRemoteCtl"
+#define NOPLUG		-1
+#define LOGHEAD		"lirc_dev (%s[%d]): "
+
+static dev_t lirc_base_dev;
+
+struct irctl {
+	struct lirc_driver d;
+	int attached;
+	int open;
+
+	struct mutex irctl_lock;
+	struct lirc_buffer *buf;
+	unsigned int chunk_size;
+
+	struct cdev *cdev;
+
+	struct task_struct *task;
+	long jiffies_to_wait;
+};
+
+static DEFINE_MUTEX(lirc_dev_lock);
+
+static struct irctl *irctls[MAX_IRCTL_DEVICES];
+
+/* Only used for sysfs but defined to void otherwise */
+static struct class *lirc_class;
+
+/*  helper function
+ *  initializes the irctl structure
+ */
+static void lirc_irctl_init(struct irctl *ir)
+{
+	mutex_init(&ir->irctl_lock);
+	ir->d.minor = NOPLUG;
+}
+
+static void lirc_irctl_cleanup(struct irctl *ir)
+{
+	dev_dbg(ir->d.dev, LOGHEAD "cleaning up\n", ir->d.name, ir->d.minor);
+
+	device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
+
+	if (ir->buf != ir->d.rbuf) {
+		lirc_buffer_free(ir->buf);
+		kfree(ir->buf);
+	}
+	ir->buf = NULL;
+}
+
+/*  helper function
+ *  reads key codes from driver and puts them into buffer
+ *  returns 0 on success
+ */
+static int lirc_add_to_buf(struct irctl *ir)
+{
+	if (ir->d.add_to_buf) {
+		int res = -ENODATA;
+		int got_data = 0;
+
+		/*
+		 * service the device as long as it is returning
+		 * data and we have space
+		 */
+get_data:
+		res = ir->d.add_to_buf(ir->d.data, ir->buf);
+		if (res == 0) {
+			got_data++;
+			goto get_data;
+		}
+
+		if (res == -ENODEV)
+			kthread_stop(ir->task);
+
+		return got_data ? 0 : res;
+	}
+
+	return 0;
+}
+
+/* main function of the polling thread
+ */
+static int lirc_thread(void *irctl)
+{
+	struct irctl *ir = irctl;
+
+	dev_dbg(ir->d.dev, LOGHEAD "poll thread started\n",
+		ir->d.name, ir->d.minor);
+
+	do {
+		if (ir->open) {
+			if (ir->jiffies_to_wait) {
+				set_current_state(TASK_INTERRUPTIBLE);
+				schedule_timeout(ir->jiffies_to_wait);
+			}
+			if (kthread_should_stop())
+				break;
+			if (!lirc_add_to_buf(ir))
+				wake_up_interruptible(&ir->buf->wait_poll);
+		} else {
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule();
+		}
+	} while (!kthread_should_stop());
+
+	dev_dbg(ir->d.dev, LOGHEAD "poll thread ended\n",
+		ir->d.name, ir->d.minor);
+
+	return 0;
+}
+
+
+static const struct file_operations lirc_dev_fops = {
+	.owner		= THIS_MODULE,
+	.read		= lirc_dev_fop_read,
+	.write		= lirc_dev_fop_write,
+	.poll		= lirc_dev_fop_poll,
+	.unlocked_ioctl	= lirc_dev_fop_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= lirc_dev_fop_ioctl,
+#endif
+	.open		= lirc_dev_fop_open,
+	.release	= lirc_dev_fop_close,
+	.llseek		= noop_llseek,
+};
+
+static int lirc_cdev_add(struct irctl *ir)
+{
+	int retval = -ENOMEM;
+	struct lirc_driver *d = &ir->d;
+	struct cdev *cdev;
+
+	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+	if (!cdev)
+		goto err_out;
+
+	if (d->fops) {
+		cdev_init(cdev, d->fops);
+		cdev->owner = d->owner;
+	} else {
+		cdev_init(cdev, &lirc_dev_fops);
+		cdev->owner = THIS_MODULE;
+	}
+	retval = kobject_set_name(&cdev->kobj, "lirc%d", d->minor);
+	if (retval)
+		goto err_out;
+
+	retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
+	if (retval) {
+		kobject_put(&cdev->kobj);
+		goto err_out;
+	}
+
+	ir->cdev = cdev;
+
+	return 0;
+
+err_out:
+	kfree(cdev);
+	return retval;
+}
+
+int lirc_register_driver(struct lirc_driver *d)
+{
+	struct irctl *ir;
+	int minor;
+	int bytes_in_key;
+	unsigned int chunk_size;
+	unsigned int buffer_size;
+	int err;
+
+	if (!d) {
+		printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+		       "driver pointer must be not NULL!\n");
+		err = -EBADRQC;
+		goto out;
+	}
+
+	if (!d->dev) {
+		printk(KERN_ERR "%s: dev pointer not filled in!\n", __func__);
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (MAX_IRCTL_DEVICES <= d->minor) {
+		dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+			"\"minor\" must be between 0 and %d (%d)!\n",
+			MAX_IRCTL_DEVICES - 1, d->minor);
+		err = -EBADRQC;
+		goto out;
+	}
+
+	if (1 > d->code_length || (BUFLEN * 8) < d->code_length) {
+		dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+			"code length in bits for minor (%d) "
+			"must be less than %d!\n",
+			d->minor, BUFLEN * 8);
+		err = -EBADRQC;
+		goto out;
+	}
+
+	dev_dbg(d->dev, "lirc_dev: lirc_register_driver: sample_rate: %d\n",
+		d->sample_rate);
+	if (d->sample_rate) {
+		if (2 > d->sample_rate || HZ < d->sample_rate) {
+			dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+				"sample_rate must be between 2 and %d!\n", HZ);
+			err = -EBADRQC;
+			goto out;
+		}
+		if (!d->add_to_buf) {
+			dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+				"add_to_buf cannot be NULL when "
+				"sample_rate is set\n");
+			err = -EBADRQC;
+			goto out;
+		}
+	} else if (!(d->fops && d->fops->read) && !d->rbuf) {
+		dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+			"fops->read and rbuf cannot all be NULL!\n");
+		err = -EBADRQC;
+		goto out;
+	} else if (!d->rbuf) {
+		if (!(d->fops && d->fops->read && d->fops->poll &&
+		      d->fops->unlocked_ioctl)) {
+			dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+				"neither read, poll nor unlocked_ioctl can be NULL!\n");
+			err = -EBADRQC;
+			goto out;
+		}
+	}
+
+	mutex_lock(&lirc_dev_lock);
+
+	minor = d->minor;
+
+	if (minor < 0) {
+		/* find first free slot for driver */
+		for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
+			if (!irctls[minor])
+				break;
+		if (MAX_IRCTL_DEVICES == minor) {
+			dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+				"no free slots for drivers!\n");
+			err = -ENOMEM;
+			goto out_lock;
+		}
+	} else if (irctls[minor]) {
+		dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+			"minor (%d) just registered!\n", minor);
+		err = -EBUSY;
+		goto out_lock;
+	}
+
+	ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
+	if (!ir) {
+		err = -ENOMEM;
+		goto out_lock;
+	}
+	lirc_irctl_init(ir);
+	irctls[minor] = ir;
+	d->minor = minor;
+
+	if (d->sample_rate) {
+		ir->jiffies_to_wait = HZ / d->sample_rate;
+	} else {
+		/* it means - wait for external event in task queue */
+		ir->jiffies_to_wait = 0;
+	}
+
+	/* some safety check 8-) */
+	d->name[sizeof(d->name)-1] = '\0';
+
+	bytes_in_key = BITS_TO_LONGS(d->code_length) +
+			(d->code_length % 8 ? 1 : 0);
+	buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
+	chunk_size  = d->chunk_size  ? d->chunk_size  : bytes_in_key;
+
+	if (d->rbuf) {
+		ir->buf = d->rbuf;
+	} else {
+		ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
+		if (!ir->buf) {
+			err = -ENOMEM;
+			goto out_lock;
+		}
+		err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
+		if (err) {
+			kfree(ir->buf);
+			goto out_lock;
+		}
+	}
+	ir->chunk_size = ir->buf->chunk_size;
+
+	if (d->features == 0)
+		d->features = LIRC_CAN_REC_LIRCCODE;
+
+	ir->d = *d;
+
+	device_create(lirc_class, ir->d.dev,
+		      MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
+		      "lirc%u", ir->d.minor);
+
+	if (d->sample_rate) {
+		/* try to fire up polling thread */
+		ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
+		if (IS_ERR(ir->task)) {
+			dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+				"cannot run poll thread for minor = %d\n",
+				d->minor);
+			err = -ECHILD;
+			goto out_sysfs;
+		}
+	}
+
+	err = lirc_cdev_add(ir);
+	if (err)
+		goto out_sysfs;
+
+	ir->attached = 1;
+	mutex_unlock(&lirc_dev_lock);
+
+	dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
+		 ir->d.name, ir->d.minor);
+	return minor;
+
+out_sysfs:
+	device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
+out_lock:
+	mutex_unlock(&lirc_dev_lock);
+out:
+	return err;
+}
+EXPORT_SYMBOL(lirc_register_driver);
+
+int lirc_unregister_driver(int minor)
+{
+	struct irctl *ir;
+	struct cdev *cdev;
+
+	if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
+		printk(KERN_ERR "lirc_dev: %s: minor (%d) must be between "
+		       "0 and %d!\n", __func__, minor, MAX_IRCTL_DEVICES - 1);
+		return -EBADRQC;
+	}
+
+	ir = irctls[minor];
+	if (!ir) {
+		printk(KERN_ERR "lirc_dev: %s: failed to get irctl struct "
+		       "for minor %d!\n", __func__, minor);
+		return -ENOENT;
+	}
+
+	cdev = ir->cdev;
+
+	mutex_lock(&lirc_dev_lock);
+
+	if (ir->d.minor != minor) {
+		printk(KERN_ERR "lirc_dev: %s: minor (%d) device not "
+		       "registered!\n", __func__, minor);
+		mutex_unlock(&lirc_dev_lock);
+		return -ENOENT;
+	}
+
+	/* end up polling thread */
+	if (ir->task)
+		kthread_stop(ir->task);
+
+	dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
+		ir->d.name, ir->d.minor);
+
+	ir->attached = 0;
+	if (ir->open) {
+		dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
+			ir->d.name, ir->d.minor);
+		wake_up_interruptible(&ir->buf->wait_poll);
+		mutex_lock(&ir->irctl_lock);
+		ir->d.set_use_dec(ir->d.data);
+		module_put(cdev->owner);
+		mutex_unlock(&ir->irctl_lock);
+	} else {
+		lirc_irctl_cleanup(ir);
+		cdev_del(cdev);
+		kfree(cdev);
+		kfree(ir);
+		irctls[minor] = NULL;
+	}
+
+	mutex_unlock(&lirc_dev_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(lirc_unregister_driver);
+
+int lirc_dev_fop_open(struct inode *inode, struct file *file)
+{
+	struct irctl *ir;
+	struct cdev *cdev;
+	int retval = 0;
+
+	if (iminor(inode) >= MAX_IRCTL_DEVICES) {
+		printk(KERN_WARNING "lirc_dev [%d]: open result = -ENODEV\n",
+		       iminor(inode));
+		return -ENODEV;
+	}
+
+	if (mutex_lock_interruptible(&lirc_dev_lock))
+		return -ERESTARTSYS;
+
+	ir = irctls[iminor(inode)];
+	if (!ir) {
+		retval = -ENODEV;
+		goto error;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);
+
+	if (ir->d.minor == NOPLUG) {
+		retval = -ENODEV;
+		goto error;
+	}
+
+	if (ir->open) {
+		retval = -EBUSY;
+		goto error;
+	}
+
+	if (ir->d.rdev) {
+		retval = rc_open(ir->d.rdev);
+		if (retval)
+			goto error;
+	}
+
+	cdev = ir->cdev;
+	if (try_module_get(cdev->owner)) {
+		ir->open++;
+		retval = ir->d.set_use_inc(ir->d.data);
+
+		if (retval) {
+			module_put(cdev->owner);
+			ir->open--;
+		} else {
+			lirc_buffer_clear(ir->buf);
+		}
+		if (ir->task)
+			wake_up_process(ir->task);
+	}
+
+error:
+	if (ir)
+		dev_dbg(ir->d.dev, LOGHEAD "open result = %d\n",
+			ir->d.name, ir->d.minor, retval);
+
+	mutex_unlock(&lirc_dev_lock);
+
+	nonseekable_open(inode, file);
+
+	return retval;
+}
+EXPORT_SYMBOL(lirc_dev_fop_open);
+
+int lirc_dev_fop_close(struct inode *inode, struct file *file)
+{
+	struct irctl *ir = irctls[iminor(inode)];
+	struct cdev *cdev;
+
+	if (!ir) {
+		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
+		return -EINVAL;
+	}
+
+	cdev = ir->cdev;
+
+	dev_dbg(ir->d.dev, LOGHEAD "close called\n", ir->d.name, ir->d.minor);
+
+	WARN_ON(mutex_lock_killable(&lirc_dev_lock));
+
+	if (ir->d.rdev)
+		rc_close(ir->d.rdev);
+
+	ir->open--;
+	if (ir->attached) {
+		ir->d.set_use_dec(ir->d.data);
+		module_put(cdev->owner);
+	} else {
+		lirc_irctl_cleanup(ir);
+		cdev_del(cdev);
+		irctls[ir->d.minor] = NULL;
+		kfree(cdev);
+		kfree(ir);
+	}
+
+	mutex_unlock(&lirc_dev_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(lirc_dev_fop_close);
+
+unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
+{
+	struct irctl *ir = irctls[iminor(file_inode(file))];
+	unsigned int ret;
+
+	if (!ir) {
+		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
+		return POLLERR;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "poll called\n", ir->d.name, ir->d.minor);
+
+	if (!ir->attached)
+		return POLLERR;
+
+	poll_wait(file, &ir->buf->wait_poll, wait);
+
+	if (ir->buf)
+		if (lirc_buffer_empty(ir->buf))
+			ret = 0;
+		else
+			ret = POLLIN | POLLRDNORM;
+	else
+		ret = POLLERR;
+
+	dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
+		ir->d.name, ir->d.minor, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(lirc_dev_fop_poll);
+
+long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	__u32 mode;
+	int result = 0;
+	struct irctl *ir = irctls[iminor(file_inode(file))];
+
+	if (!ir) {
+		printk(KERN_ERR "lirc_dev: %s: no irctl found!\n", __func__);
+		return -ENODEV;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
+		ir->d.name, ir->d.minor, cmd);
+
+	if (ir->d.minor == NOPLUG || !ir->attached) {
+		dev_dbg(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
+			ir->d.name, ir->d.minor);
+		return -ENODEV;
+	}
+
+	mutex_lock(&ir->irctl_lock);
+
+	switch (cmd) {
+	case LIRC_GET_FEATURES:
+		result = put_user(ir->d.features, (__u32 *)arg);
+		break;
+	case LIRC_GET_REC_MODE:
+		if (!(ir->d.features & LIRC_CAN_REC_MASK)) {
+			result = -ENOSYS;
+			break;
+		}
+
+		result = put_user(LIRC_REC2MODE
+				  (ir->d.features & LIRC_CAN_REC_MASK),
+				  (__u32 *)arg);
+		break;
+	case LIRC_SET_REC_MODE:
+		if (!(ir->d.features & LIRC_CAN_REC_MASK)) {
+			result = -ENOSYS;
+			break;
+		}
+
+		result = get_user(mode, (__u32 *)arg);
+		if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
+			result = -EINVAL;
+		/*
+		 * FIXME: We should actually set the mode somehow but
+		 * for now, lirc_serial doesn't support mode changing either
+		 */
+		break;
+	case LIRC_GET_LENGTH:
+		result = put_user(ir->d.code_length, (__u32 *)arg);
+		break;
+	case LIRC_GET_MIN_TIMEOUT:
+		if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
+		    ir->d.min_timeout == 0) {
+			result = -ENOSYS;
+			break;
+		}
+
+		result = put_user(ir->d.min_timeout, (__u32 *)arg);
+		break;
+	case LIRC_GET_MAX_TIMEOUT:
+		if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
+		    ir->d.max_timeout == 0) {
+			result = -ENOSYS;
+			break;
+		}
+
+		result = put_user(ir->d.max_timeout, (__u32 *)arg);
+		break;
+	default:
+		result = -EINVAL;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "ioctl result = %d\n",
+		ir->d.name, ir->d.minor, result);
+
+	mutex_unlock(&ir->irctl_lock);
+
+	return result;
+}
+EXPORT_SYMBOL(lirc_dev_fop_ioctl);
+
+ssize_t lirc_dev_fop_read(struct file *file,
+			  char __user *buffer,
+			  size_t length,
+			  loff_t *ppos)
+{
+	struct irctl *ir = irctls[iminor(file_inode(file))];
+	unsigned char *buf;
+	int ret = 0, written = 0;
+	DECLARE_WAITQUEUE(wait, current);
+
+	if (!ir) {
+		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
+		return -ENODEV;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);
+
+	buf = kzalloc(ir->chunk_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	if (mutex_lock_interruptible(&ir->irctl_lock)) {
+		ret = -ERESTARTSYS;
+		goto out_unlocked;
+	}
+	if (!ir->attached) {
+		ret = -ENODEV;
+		goto out_locked;
+	}
+
+	if (length % ir->chunk_size) {
+		ret = -EINVAL;
+		goto out_locked;
+	}
+
+	/*
+	 * 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 < length && ret == 0) {
+		if (lirc_buffer_empty(ir->buf)) {
+			/* According to the read(2) man page, 'written' can be
+			 * returned as less than 'length', instead of blocking
+			 * again, returning -EWOULDBLOCK, or returning
+			 * -ERESTARTSYS */
+			if (written)
+				break;
+			if (file->f_flags & O_NONBLOCK) {
+				ret = -EWOULDBLOCK;
+				break;
+			}
+			if (signal_pending(current)) {
+				ret = -ERESTARTSYS;
+				break;
+			}
+
+			mutex_unlock(&ir->irctl_lock);
+			schedule();
+			set_current_state(TASK_INTERRUPTIBLE);
+
+			if (mutex_lock_interruptible(&ir->irctl_lock)) {
+				ret = -ERESTARTSYS;
+				remove_wait_queue(&ir->buf->wait_poll, &wait);
+				set_current_state(TASK_RUNNING);
+				goto out_unlocked;
+			}
+
+			if (!ir->attached) {
+				ret = -ENODEV;
+				break;
+			}
+		} else {
+			lirc_buffer_read(ir->buf, buf);
+			ret = copy_to_user((void *)buffer+written, buf,
+					   ir->buf->chunk_size);
+			if (!ret)
+				written += ir->buf->chunk_size;
+			else
+				ret = -EFAULT;
+		}
+	}
+
+	remove_wait_queue(&ir->buf->wait_poll, &wait);
+	set_current_state(TASK_RUNNING);
+
+out_locked:
+	mutex_unlock(&ir->irctl_lock);
+
+out_unlocked:
+	kfree(buf);
+	dev_dbg(ir->d.dev, LOGHEAD "read result = %s (%d)\n",
+		ir->d.name, ir->d.minor, ret ? "<fail>" : "<ok>", ret);
+
+	return ret ? ret : written;
+}
+EXPORT_SYMBOL(lirc_dev_fop_read);
+
+void *lirc_get_pdata(struct file *file)
+{
+	return irctls[iminor(file_inode(file))]->d.data;
+}
+EXPORT_SYMBOL(lirc_get_pdata);
+
+
+ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
+			   size_t length, loff_t *ppos)
+{
+	struct irctl *ir = irctls[iminor(file_inode(file))];
+
+	if (!ir) {
+		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
+		return -ENODEV;
+	}
+
+	dev_dbg(ir->d.dev, LOGHEAD "write called\n", ir->d.name, ir->d.minor);
+
+	if (!ir->attached)
+		return -ENODEV;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(lirc_dev_fop_write);
+
+
+static int __init lirc_dev_init(void)
+{
+	int retval;
+
+	lirc_class = class_create(THIS_MODULE, "lirc");
+	if (IS_ERR(lirc_class)) {
+		retval = PTR_ERR(lirc_class);
+		printk(KERN_ERR "lirc_dev: class_create failed\n");
+		goto error;
+	}
+
+	retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
+				     IRCTL_DEV_NAME);
+	if (retval) {
+		class_destroy(lirc_class);
+		printk(KERN_ERR "lirc_dev: alloc_chrdev_region failed\n");
+		goto error;
+	}
+
+
+	printk(KERN_INFO "lirc_dev: IR Remote Control driver registered, "
+	       "major %d \n", MAJOR(lirc_base_dev));
+
+error:
+	return retval;
+}
+
+
+
+static void __exit lirc_dev_exit(void)
+{
+	class_destroy(lirc_class);
+	unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
+	printk(KERN_INFO "lirc_dev: module unloaded\n");
+}
+
+module_init(lirc_dev_init);
+module_exit(lirc_dev_exit);
+
+MODULE_DESCRIPTION("LIRC base driver module");
+MODULE_AUTHOR("Artur Lipowski");
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Enable debugging messages");