[mirror_ubuntu-zesty-kernel.git] / drivers / media / IR / lirc_dev.c

/*
 * 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/errno.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/lirc.h>
#include <media/lirc_dev.h>

static int 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 task_struct *task;
	long jiffies_to_wait;

	struct cdev cdev;
};

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)
{
	dev_dbg(ir->d.dev, LOGHEAD "initializing irctl\n",
		ir->d.name, ir->d.minor);
	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 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,
};

static int lirc_cdev_add(struct irctl *ir)
{
	int retval;
	struct lirc_driver *d = &ir->d;

	if (d->fops) {
		cdev_init(&ir->cdev, d->fops);
		ir->cdev.owner = d->owner;
	} else {
		cdev_init(&ir->cdev, &lirc_dev_fops);
		ir->cdev.owner = THIS_MODULE;
	}
	kobject_set_name(&ir->cdev.kobj, "lirc%d", d->minor);

	retval = cdev_add(&ir->cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
	if (retval)
		kobject_put(&ir->cdev.kobj);

	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 (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;
	ir->d.minor = minor;

	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;

	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;
	}

	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(ir->cdev.owner);
		mutex_unlock(&ir->irctl_lock);
		cdev_del(&ir->cdev);
	} else {
		lirc_irctl_cleanup(ir);
		cdev_del(&ir->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;
	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 (try_module_get(ir->cdev.owner)) {
		++ir->open;
		retval = ir->d.set_use_inc(ir->d.data);

		if (retval) {
			module_put(ir->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);

	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)];

	dev_dbg(ir->d.dev, LOGHEAD "close called\n", ir->d.name, ir->d.minor);

	WARN_ON(mutex_lock_killable(&lirc_dev_lock));

	--ir->open;
	if (ir->attached) {
		ir->d.set_use_dec(ir->d.data);
		module_put(ir->cdev.owner);
	} else {
		lirc_irctl_cleanup(ir);
		irctls[ir->d.minor] = NULL;
		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->f_dentry->d_inode)];
	unsigned int ret;

	dev_dbg(ir->d.dev, LOGHEAD "poll called\n", ir->d.name, ir->d.minor);

	if (!ir->attached) {
		mutex_unlock(&ir->irctl_lock);
		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->f_dentry->d_inode)];

	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 *buffer,
			  size_t length,
			  loff_t *ppos)
{
	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
	unsigned char buf[ir->chunk_size];
	int ret = 0, written = 0;
	DECLARE_WAITQUEUE(wait, current);

	dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);

	if (mutex_lock_interruptible(&ir->irctl_lock))
		return -ERESTARTSYS;
	if (!ir->attached) {
		mutex_unlock(&ir->irctl_lock);
		return -ENODEV;
	}

	if (length % ir->chunk_size) {
		dev_dbg(ir->d.dev, LOGHEAD "read result = -EINVAL\n",
			ir->d.name, ir->d.minor);
		mutex_unlock(&ir->irctl_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 < 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);
			written += ir->buf->chunk_size;
		}
	}

	remove_wait_queue(&ir->buf->wait_poll, &wait);
	set_current_state(TASK_RUNNING);
	mutex_unlock(&ir->irctl_lock);

out_unlocked:
	dev_dbg(ir->d.dev, LOGHEAD "read result = %s (%d)\n",
		ir->d.name, ir->d.minor, ret ? "-EFAULT" : "OK", ret);

	return ret ? ret : written;
}
EXPORT_SYMBOL(lirc_dev_fop_read);

void *lirc_get_pdata(struct file *file)
{
	void *data = NULL;

	if (file && file->f_dentry && file->f_dentry->d_inode &&
	    file->f_dentry->d_inode->i_rdev) {
		struct irctl *ir;
		ir = irctls[iminor(file->f_dentry->d_inode)];
		data = ir->d.data;
	}

	return data;
}
EXPORT_SYMBOL(lirc_get_pdata);


ssize_t lirc_dev_fop_write(struct file *file, const char *buffer,
			   size_t length, loff_t *ppos)
{
	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];

	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");
Commit	Line	Data
4a62a5ab JW	1	/*
	2	* LIRC base driver
	3	*
	4	* by Artur Lipowski <alipowski@interia.pl>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
	22	#include <linux/module.h>
	23	#include <linux/kernel.h>
	24	#include <linux/sched.h>
	25	#include <linux/errno.h>
	26	#include <linux/ioctl.h>
	27	#include <linux/fs.h>
	28	#include <linux/poll.h>
	29	#include <linux/completion.h>
	30	#include <linux/errno.h>
	31	#include <linux/mutex.h>
	32	#include <linux/wait.h>
	33	#include <linux/unistd.h>
	34	#include <linux/kthread.h>
	35	#include <linux/bitops.h>
	36	#include <linux/device.h>
	37	#include <linux/cdev.h>
	38
	39	#include <media/lirc.h>
5690085e	40	#include <media/lirc_dev.h>
4a62a5ab JW	41
	42	static int debug;
	43
	44	#define IRCTL_DEV_NAME "BaseRemoteCtl"
	45	#define NOPLUG -1
	46	#define LOGHEAD "lirc_dev (%s[%d]): "
	47
	48	static dev_t lirc_base_dev;
	49
	50	struct irctl {
	51	struct lirc_driver d;
	52	int attached;
	53	int open;
	54
	55	struct mutex irctl_lock;
	56	struct lirc_buffer *buf;
	57	unsigned int chunk_size;
	58
	59	struct task_struct *task;
	60	long jiffies_to_wait;
	61
	62	struct cdev cdev;
	63	};
	64
	65	static DEFINE_MUTEX(lirc_dev_lock);
	66
	67	static struct irctl *irctls[MAX_IRCTL_DEVICES];
	68
	69	/* Only used for sysfs but defined to void otherwise */
	70	static struct class *lirc_class;
	71
	72	/* helper function
	73	* initializes the irctl structure
	74	*/
578fcb8e	75	static void lirc_irctl_init(struct irctl *ir)
4a62a5ab JW	76	{
	77	dev_dbg(ir->d.dev, LOGHEAD "initializing irctl\n",
	78	ir->d.name, ir->d.minor);
	79	mutex_init(&ir->irctl_lock);
	80	ir->d.minor = NOPLUG;
	81	}
	82
578fcb8e	83	static void lirc_irctl_cleanup(struct irctl *ir)
4a62a5ab JW	84	{
	85	dev_dbg(ir->d.dev, LOGHEAD "cleaning up\n", ir->d.name, ir->d.minor);
	86
	87	device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
	88
	89	if (ir->buf != ir->d.rbuf) {
	90	lirc_buffer_free(ir->buf);
	91	kfree(ir->buf);
	92	}
	93	ir->buf = NULL;
	94	}
	95
	96	/* helper function
	97	* reads key codes from driver and puts them into buffer
	98	* returns 0 on success
	99	*/
578fcb8e	100	static int lirc_add_to_buf(struct irctl *ir)
4a62a5ab JW	101	{
	102	if (ir->d.add_to_buf) {
	103	int res = -ENODATA;
	104	int got_data = 0;
	105
	106	/*
	107	* service the device as long as it is returning
	108	* data and we have space
	109	*/
	110	get_data:
	111	res = ir->d.add_to_buf(ir->d.data, ir->buf);
	112	if (res == 0) {
	113	got_data++;
	114	goto get_data;
	115	}
	116
	117	if (res == -ENODEV)
	118	kthread_stop(ir->task);
	119
	120	return got_data ? 0 : res;
	121	}
	122
	123	return 0;
	124	}
	125
	126	/* main function of the polling thread
	127	*/
	128	static int lirc_thread(void *irctl)
	129	{
	130	struct irctl *ir = irctl;
	131
	132	dev_dbg(ir->d.dev, LOGHEAD "poll thread started\n",
	133	ir->d.name, ir->d.minor);
	134
	135	do {
	136	if (ir->open) {
	137	if (ir->jiffies_to_wait) {
	138	set_current_state(TASK_INTERRUPTIBLE);
	139	schedule_timeout(ir->jiffies_to_wait);
	140	}
	141	if (kthread_should_stop())
	142	break;
578fcb8e	143	if (!lirc_add_to_buf(ir))
4a62a5ab JW	144	wake_up_interruptible(&ir->buf->wait_poll);
	145	} else {
	146	set_current_state(TASK_INTERRUPTIBLE);
	147	schedule();
	148	}
	149	} while (!kthread_should_stop());
	150
	151	dev_dbg(ir->d.dev, LOGHEAD "poll thread ended\n",
	152	ir->d.name, ir->d.minor);
	153
	154	return 0;
	155	}
	156
	157
578fcb8e	158	static struct file_operations lirc_dev_fops = {
4a62a5ab JW	159	.owner = THIS_MODULE,
	160	.read = lirc_dev_fop_read,
	161	.write = lirc_dev_fop_write,
	162	.poll = lirc_dev_fop_poll,
044e5878	163	.unlocked_ioctl = lirc_dev_fop_ioctl,
8be292cc JW	164	#ifdef CONFIG_COMPAT
	165	.compat_ioctl = lirc_dev_fop_ioctl,
	166	#endif
4a62a5ab JW	167	.open = lirc_dev_fop_open,
	168	.release = lirc_dev_fop_close,
	169	};
	170
	171	static int lirc_cdev_add(struct irctl *ir)
	172	{
	173	int retval;
	174	struct lirc_driver *d = &ir->d;
	175
	176	if (d->fops) {
	177	cdev_init(&ir->cdev, d->fops);
	178	ir->cdev.owner = d->owner;
	179	} else {
578fcb8e	180	cdev_init(&ir->cdev, &lirc_dev_fops);
4a62a5ab JW	181	ir->cdev.owner = THIS_MODULE;
	182	}
	183	kobject_set_name(&ir->cdev.kobj, "lirc%d", d->minor);
	184
	185	retval = cdev_add(&ir->cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
	186	if (retval)
	187	kobject_put(&ir->cdev.kobj);
	188
	189	return retval;
	190	}
	191
	192	int lirc_register_driver(struct lirc_driver *d)
	193	{
	194	struct irctl *ir;
	195	int minor;
	196	int bytes_in_key;
	197	unsigned int chunk_size;
	198	unsigned int buffer_size;
	199	int err;
	200
	201	if (!d) {
	202	printk(KERN_ERR "lirc_dev: lirc_register_driver: "
	203	"driver pointer must be not NULL!\n");
	204	err = -EBADRQC;
	205	goto out;
	206	}
	207
	208	if (MAX_IRCTL_DEVICES <= d->minor) {
	209	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	210	"\"minor\" must be between 0 and %d (%d)!\n",
	211	MAX_IRCTL_DEVICES-1, d->minor);
	212	err = -EBADRQC;
	213	goto out;
	214	}
	215
	216	if (1 > d->code_length \|\| (BUFLEN * 8) < d->code_length) {
	217	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	218	"code length in bits for minor (%d) "
	219	"must be less than %d!\n",
	220	d->minor, BUFLEN * 8);
	221	err = -EBADRQC;
	222	goto out;
	223	}
	224
	225	dev_dbg(d->dev, "lirc_dev: lirc_register_driver: sample_rate: %d\n",
	226	d->sample_rate);
	227	if (d->sample_rate) {
	228	if (2 > d->sample_rate \|\| HZ < d->sample_rate) {
	229	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	230	"sample_rate must be between 2 and %d!\n", HZ);
	231	err = -EBADRQC;
	232	goto out;
	233	}
	234	if (!d->add_to_buf) {
	235	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	236	"add_to_buf cannot be NULL when "
	237	"sample_rate is set\n");
	238	err = -EBADRQC;
	239	goto out;
	240	}
	241	} else if (!(d->fops && d->fops->read) && !d->rbuf) {
	242	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	243	"fops->read and rbuf cannot all be NULL!\n");
	244	err = -EBADRQC;
245	goto out;
246	} else if (!d->rbuf) {
247	if (!(d->fops && d->fops->read && d->fops->poll &&
044e5878	248	d->fops->unlocked_ioctl)) {
4a62a5ab	249	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
044e5878	250	"neither read, poll nor unlocked_ioctl can be NULL!\n");
4a62a5ab JW	251	err = -EBADRQC;
	252	goto out;
	253	}
	254	}
	255
	256	mutex_lock(&lirc_dev_lock);
	257
	258	minor = d->minor;
	259
	260	if (minor < 0) {
	261	/* find first free slot for driver */
	262	for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
	263	if (!irctls[minor])
	264	break;
	265	if (MAX_IRCTL_DEVICES == minor) {
	266	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	267	"no free slots for drivers!\n");
	268	err = -ENOMEM;
	269	goto out_lock;
	270	}
	271	} else if (irctls[minor]) {
	272	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	273	"minor (%d) just registered!\n", minor);
	274	err = -EBUSY;
	275	goto out_lock;
	276	}
	277
	278	ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
	279	if (!ir) {
	280	err = -ENOMEM;
	281	goto out_lock;
	282	}
578fcb8e	283	lirc_irctl_init(ir);
4a62a5ab JW	284	irctls[minor] = ir;
	285	d->minor = minor;
	286
	287	if (d->sample_rate) {
	288	ir->jiffies_to_wait = HZ / d->sample_rate;
	289	} else {
	290	/* it means - wait for external event in task queue */
	291	ir->jiffies_to_wait = 0;
	292	}
	293
	294	/* some safety check 8-) */
	295	d->name[sizeof(d->name)-1] = '\0';
	296
	297	bytes_in_key = BITS_TO_LONGS(d->code_length) +
	298	(d->code_length % 8 ? 1 : 0);
	299	buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
	300	chunk_size = d->chunk_size ? d->chunk_size : bytes_in_key;
	301
	302	if (d->rbuf) {
	303	ir->buf = d->rbuf;
	304	} else {
	305	ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
	306	if (!ir->buf) {
	307	err = -ENOMEM;
	308	goto out_lock;
	309	}
	310	err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
	311	if (err) {
	312	kfree(ir->buf);
	313	goto out_lock;
	314	}
	315	}
	316	ir->chunk_size = ir->buf->chunk_size;
	317
	318	if (d->features == 0)
	319	d->features = LIRC_CAN_REC_LIRCCODE;
	320
	321	ir->d = *d;
	322	ir->d.minor = minor;
	323
	324	device_create(lirc_class, ir->d.dev,
	325	MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
	326	"lirc%u", ir->d.minor);
	327
	328	if (d->sample_rate) {
	329	/* try to fire up polling thread */
	330	ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
	331	if (IS_ERR(ir->task)) {
	332	dev_err(d->dev, "lirc_dev: lirc_register_driver: "
	333	"cannot run poll thread for minor = %d\n",
	334	d->minor);
	335	err = -ECHILD;
	336	goto out_sysfs;
	337	}
	338	}
	339
	340	err = lirc_cdev_add(ir);
	341	if (err)
	342	goto out_sysfs;
	343
	344	ir->attached = 1;
	345	mutex_unlock(&lirc_dev_lock);
	346
	347	dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
348	ir->d.name, ir->d.minor);
349	return minor;
350
351	out_sysfs:
352	device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
353	out_lock:
354	mutex_unlock(&lirc_dev_lock);
355	out:
356	return err;
357	}
358	EXPORT_SYMBOL(lirc_register_driver);
359
360	int lirc_unregister_driver(int minor)
361	{
362	struct irctl *ir;
363
364	if (minor < 0 \|\| minor >= MAX_IRCTL_DEVICES) {
4fc21543 JW	365	printk(KERN_ERR "lirc_dev: %s: minor (%d) must be between "
4fc21543 JW	366	"0 and %d!\n", __func__, minor, MAX_IRCTL_DEVICES-1);
4a62a5ab JW	367	return -EBADRQC;
	368	}
	369
	370	ir = irctls[minor];
df1868e4	371	if (!ir) {
4fc21543 JW	372	printk(KERN_ERR "lirc_dev: %s: failed to get irctl struct "
4fc21543 JW	373	"for minor %d!\n", __func__, minor);
df1868e4 JW	374	return -ENOENT;
df1868e4 JW	375	}
4a62a5ab JW	376
	377	mutex_lock(&lirc_dev_lock);
	378
	379	if (ir->d.minor != minor) {
4fc21543 JW	380	printk(KERN_ERR "lirc_dev: %s: minor (%d) device not "
4fc21543 JW	381	"registered!\n", __func__, minor);
4a62a5ab JW	382	mutex_unlock(&lirc_dev_lock);
	383	return -ENOENT;
	384	}
	385
	386	/* end up polling thread */
	387	if (ir->task)
	388	kthread_stop(ir->task);
	389
	390	dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
	391	ir->d.name, ir->d.minor);
	392
	393	ir->attached = 0;
	394	if (ir->open) {
	395	dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
	396	ir->d.name, ir->d.minor);
	397	wake_up_interruptible(&ir->buf->wait_poll);
	398	mutex_lock(&ir->irctl_lock);
	399	ir->d.set_use_dec(ir->d.data);
90dc4cfa	400	module_put(ir->cdev.owner);
4a62a5ab JW	401	mutex_unlock(&ir->irctl_lock);
	402	cdev_del(&ir->cdev);
	403	} else {
578fcb8e	404	lirc_irctl_cleanup(ir);
4a62a5ab JW	405	cdev_del(&ir->cdev);
	406	kfree(ir);
	407	irctls[minor] = NULL;
	408	}
	409
	410	mutex_unlock(&lirc_dev_lock);
	411
	412	return 0;
	413	}
	414	EXPORT_SYMBOL(lirc_unregister_driver);
	415
	416	int lirc_dev_fop_open(struct inode inode, struct file file)
	417	{
	418	struct irctl *ir;
	419	int retval = 0;
	420
	421	if (iminor(inode) >= MAX_IRCTL_DEVICES) {
	422	printk(KERN_WARNING "lirc_dev [%d]: open result = -ENODEV\n",
	423	iminor(inode));
	424	return -ENODEV;
	425	}
	426
	427	if (mutex_lock_interruptible(&lirc_dev_lock))
	428	return -ERESTARTSYS;
	429
	430	ir = irctls[iminor(inode)];
	431	if (!ir) {
	432	retval = -ENODEV;
	433	goto error;
	434	}
	435
	436	dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);
	437
	438	if (ir->d.minor == NOPLUG) {
	439	retval = -ENODEV;
	440	goto error;
	441	}
	442
	443	if (ir->open) {
	444	retval = -EBUSY;
	445	goto error;
	446	}
	447
90dc4cfa	448	if (try_module_get(ir->cdev.owner)) {
4a62a5ab JW	449	++ir->open;
	450	retval = ir->d.set_use_inc(ir->d.data);
	451
	452	if (retval) {
90dc4cfa	453	module_put(ir->cdev.owner);
4a62a5ab JW	454	--ir->open;
	455	} else {
	456	lirc_buffer_clear(ir->buf);
	457	}
	458	if (ir->task)
	459	wake_up_process(ir->task);
	460	}
	461
	462	error:
	463	if (ir)
	464	dev_dbg(ir->d.dev, LOGHEAD "open result = %d\n",
	465	ir->d.name, ir->d.minor, retval);
	466
	467	mutex_unlock(&lirc_dev_lock);
	468
	469	return retval;
	470	}
	471	EXPORT_SYMBOL(lirc_dev_fop_open);
	472
	473	int lirc_dev_fop_close(struct inode inode, struct file file)
	474	{
	475	struct irctl *ir = irctls[iminor(inode)];
	476
	477	dev_dbg(ir->d.dev, LOGHEAD "close called\n", ir->d.name, ir->d.minor);
	478
	479	WARN_ON(mutex_lock_killable(&lirc_dev_lock));
	480
	481	--ir->open;
	482	if (ir->attached) {
	483	ir->d.set_use_dec(ir->d.data);
90dc4cfa	484	module_put(ir->cdev.owner);
4a62a5ab	485	} else {
578fcb8e	486	lirc_irctl_cleanup(ir);
4a62a5ab JW	487	irctls[ir->d.minor] = NULL;
	488	kfree(ir);
	489	}
	490
	491	mutex_unlock(&lirc_dev_lock);
	492
	493	return 0;
	494	}
	495	EXPORT_SYMBOL(lirc_dev_fop_close);
	496
	497	unsigned int lirc_dev_fop_poll(struct file file, poll_table wait)
	498	{
	499	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
	500	unsigned int ret;
	501
	502	dev_dbg(ir->d.dev, LOGHEAD "poll called\n", ir->d.name, ir->d.minor);
	503
	504	if (!ir->attached) {
	505	mutex_unlock(&ir->irctl_lock);
	506	return POLLERR;
	507	}
	508
	509	poll_wait(file, &ir->buf->wait_poll, wait);
	510
	511	if (ir->buf)
	512	if (lirc_buffer_empty(ir->buf))
	513	ret = 0;
	514	else
	515	ret = POLLIN \| POLLRDNORM;
	516	else
	517	ret = POLLERR;
	518
	519	dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
	520	ir->d.name, ir->d.minor, ret);
	521
	522	return ret;
	523	}
	524	EXPORT_SYMBOL(lirc_dev_fop_poll);
	525
044e5878	526	long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4a62a5ab	527	{
be1f985f	528	__u32 mode;
4a62a5ab	529	int result = 0;
d889a135	530	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
4a62a5ab	531
8be292cc JW	532	if (!ir) {
	533	printk(KERN_ERR "lirc_dev: %s: no irctl found!\n", __func__);
	534	return -ENODEV;
	535	}
	536
4a62a5ab JW	537	dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
	538	ir->d.name, ir->d.minor, cmd);
	539
	540	if (ir->d.minor == NOPLUG \|\| !ir->attached) {
	541	dev_dbg(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
	542	ir->d.name, ir->d.minor);
	543	return -ENODEV;
	544	}
	545
	546	mutex_lock(&ir->irctl_lock);
	547
	548	switch (cmd) {
	549	case LIRC_GET_FEATURES:
be1f985f	550	result = put_user(ir->d.features, (__u32 *)arg);
4a62a5ab JW	551	break;
	552	case LIRC_GET_REC_MODE:
	553	if (!(ir->d.features & LIRC_CAN_REC_MASK)) {
	554	result = -ENOSYS;
	555	break;
	556	}
	557
	558	result = put_user(LIRC_REC2MODE
	559	(ir->d.features & LIRC_CAN_REC_MASK),
be1f985f	560	(__u32 *)arg);
4a62a5ab JW	561	break;
	562	case LIRC_SET_REC_MODE:
	563	if (!(ir->d.features & LIRC_CAN_REC_MASK)) {
	564	result = -ENOSYS;
	565	break;
	566	}
	567
be1f985f	568	result = get_user(mode, (__u32 *)arg);
4a62a5ab JW	569	if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
	570	result = -EINVAL;
	571	/*
	572	* FIXME: We should actually set the mode somehow but
	573	* for now, lirc_serial doesn't support mode changing either
	574	*/
	575	break;
	576	case LIRC_GET_LENGTH:
be1f985f	577	result = put_user(ir->d.code_length, (__u32 *)arg);
4a62a5ab JW	578	break;
	579	case LIRC_GET_MIN_TIMEOUT:
	580	if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) \|\|
	581	ir->d.min_timeout == 0) {
	582	result = -ENOSYS;
	583	break;
	584	}
	585
be1f985f	586	result = put_user(ir->d.min_timeout, (__u32 *)arg);
4a62a5ab JW	587	break;
	588	case LIRC_GET_MAX_TIMEOUT:
	589	if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) \|\|
	590	ir->d.max_timeout == 0) {
	591	result = -ENOSYS;
	592	break;
	593	}
	594
be1f985f	595	result = put_user(ir->d.max_timeout, (__u32 *)arg);
4a62a5ab JW	596	break;
	597	default:
	598	result = -EINVAL;
	599	}
	600
	601	dev_dbg(ir->d.dev, LOGHEAD "ioctl result = %d\n",
	602	ir->d.name, ir->d.minor, result);
	603
	604	mutex_unlock(&ir->irctl_lock);
	605
	606	return result;
	607	}
	608	EXPORT_SYMBOL(lirc_dev_fop_ioctl);
	609
	610	ssize_t lirc_dev_fop_read(struct file *file,
	611	char *buffer,
	612	size_t length,
	613	loff_t *ppos)
	614	{
	615	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
	616	unsigned char buf[ir->chunk_size];
	617	int ret = 0, written = 0;
	618	DECLARE_WAITQUEUE(wait, current);
	619
	620	dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);
	621
	622	if (mutex_lock_interruptible(&ir->irctl_lock))
	623	return -ERESTARTSYS;
	624	if (!ir->attached) {
	625	mutex_unlock(&ir->irctl_lock);
	626	return -ENODEV;
	627	}
	628
	629	if (length % ir->chunk_size) {
	630	dev_dbg(ir->d.dev, LOGHEAD "read result = -EINVAL\n",
	631	ir->d.name, ir->d.minor);
	632	mutex_unlock(&ir->irctl_lock);
	633	return -EINVAL;
	634	}
	635
	636	/*
	637	* we add ourselves to the task queue before buffer check
	638	* to avoid losing scan code (in case when queue is awaken somewhere
	639	* between while condition checking and scheduling)
	640	*/
	641	add_wait_queue(&ir->buf->wait_poll, &wait);
	642	set_current_state(TASK_INTERRUPTIBLE);
	643
	644	/*
	645	* while we didn't provide 'length' bytes, device is opened in blocking
	646	* mode and 'copy_to_user' is happy, wait for data.
	647	*/
	648	while (written < length && ret == 0) {
	649	if (lirc_buffer_empty(ir->buf)) {
	650	/* According to the read(2) man page, 'written' can be
	651	* returned as less than 'length', instead of blocking
	652	* again, returning -EWOULDBLOCK, or returning
	653	* -ERESTARTSYS */
	654	if (written)
	655	break;
	656	if (file->f_flags & O_NONBLOCK) {
	657	ret = -EWOULDBLOCK;
	658	break;
	659	}
660	if (signal_pending(current)) {
661	ret = -ERESTARTSYS;
662	break;
663	}
664
665	mutex_unlock(&ir->irctl_lock);
666	schedule();
667	set_current_state(TASK_INTERRUPTIBLE);
668
669	if (mutex_lock_interruptible(&ir->irctl_lock)) {
670	ret = -ERESTARTSYS;
69c271f3 JW	671	remove_wait_queue(&ir->buf->wait_poll, &wait);
	672	set_current_state(TASK_RUNNING);
	673	goto out_unlocked;
4a62a5ab JW	674	}
	675
	676	if (!ir->attached) {
	677	ret = -ENODEV;
	678	break;
	679	}
	680	} else {
	681	lirc_buffer_read(ir->buf, buf);
	682	ret = copy_to_user((void *)buffer+written, buf,
	683	ir->buf->chunk_size);
	684	written += ir->buf->chunk_size;
	685	}
	686	}
	687
	688	remove_wait_queue(&ir->buf->wait_poll, &wait);
	689	set_current_state(TASK_RUNNING);
	690	mutex_unlock(&ir->irctl_lock);
	691
69c271f3	692	out_unlocked:
4a62a5ab JW	693	dev_dbg(ir->d.dev, LOGHEAD "read result = %s (%d)\n",
	694	ir->d.name, ir->d.minor, ret ? "-EFAULT" : "OK", ret);
	695
	696	return ret ? ret : written;
	697	}
	698	EXPORT_SYMBOL(lirc_dev_fop_read);
	699
	700	void lirc_get_pdata(struct file file)
	701	{
	702	void *data = NULL;
	703
	704	if (file && file->f_dentry && file->f_dentry->d_inode &&
	705	file->f_dentry->d_inode->i_rdev) {
	706	struct irctl *ir;
	707	ir = irctls[iminor(file->f_dentry->d_inode)];
	708	data = ir->d.data;
	709	}
	710
	711	return data;
	712	}
	713	EXPORT_SYMBOL(lirc_get_pdata);
	714
	715
	716	ssize_t lirc_dev_fop_write(struct file file, const char buffer,
	717	size_t length, loff_t *ppos)
	718	{
	719	struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
	720
	721	dev_dbg(ir->d.dev, LOGHEAD "write called\n", ir->d.name, ir->d.minor);
	722
	723	if (!ir->attached)
	724	return -ENODEV;
	725
	726	return -EINVAL;
	727	}
	728	EXPORT_SYMBOL(lirc_dev_fop_write);
	729
	730
	731	static int __init lirc_dev_init(void)
	732	{
	733	int retval;
	734
	735	lirc_class = class_create(THIS_MODULE, "lirc");
	736	if (IS_ERR(lirc_class)) {
	737	retval = PTR_ERR(lirc_class);
	738	printk(KERN_ERR "lirc_dev: class_create failed\n");
	739	goto error;
	740	}
	741
	742	retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
	743	IRCTL_DEV_NAME);
	744	if (retval) {
	745	class_destroy(lirc_class);
	746	printk(KERN_ERR "lirc_dev: alloc_chrdev_region failed\n");
	747	goto error;
	748	}
	749
	750
	751	printk(KERN_INFO "lirc_dev: IR Remote Control driver registered, "
	752	"major %d \n", MAJOR(lirc_base_dev));
	753
	754	error:
	755	return retval;
	756	}
757
758
759
760	static void __exit lirc_dev_exit(void)
761	{
762	class_destroy(lirc_class);
763	unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
764	printk(KERN_INFO "lirc_dev: module unloaded\n");
765	}
766
767	module_init(lirc_dev_init);
768	module_exit(lirc_dev_exit);
769
770	MODULE_DESCRIPTION("LIRC base driver module");
771	MODULE_AUTHOR("Artur Lipowski");
772	MODULE_LICENSE("GPL");
773
774	module_param(debug, bool, S_IRUGO \| S_IWUSR);
775	MODULE_PARM_DESC(debug, "Enable debugging messages");