V4L/DVB: IR: add lirc device interface

v2: currently unused ioctls are included, but #if 0'd out

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

4 files changed, 999 insertions, 0 deletions

diff --git a/drivers/media/IR/Kconfig b/drivers/media/IR/Kconfig
index 797a6c36d984..5d2c37dcf11a 100644
--- a/drivers/media/IR/Kconfig
+++ b/drivers/media/IR/Kconfig
@@ -8,6 +8,17 @@ config VIDEO_IR
         depends on IR_CORE
         default IR_CORE
 
+config LIRC
+        tristate
+        default y
+
+        ---help---
+           Enable this option to build the Linux Infrared Remote
+           Control (LIRC) core device interface driver. The LIRC
+           interface passes raw IR to and from userspace, where the
+           LIRC daemon handles protocol decoding for IR reception ann
+           encoding for IR transmitting (aka "blasting").
+
 source "drivers/media/IR/keymaps/Kconfig"
 
 config IR_NEC_DECODER
diff --git a/drivers/media/IR/Makefile b/drivers/media/IR/Makefile
index b43fe36d88b2..3ba00bb8bea0 100644
--- a/drivers/media/IR/Makefile
+++ b/drivers/media/IR/Makefile
@@ -5,6 +5,7 @@ obj-y += keymaps/
 
 obj-$(CONFIG_IR_CORE) += ir-core.o
 obj-$(CONFIG_VIDEO_IR) += ir-common.o
+obj-$(CONFIG_LIRC) += lirc_dev.o
 obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
 obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o
 obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o
diff --git a/drivers/media/IR/lirc_dev.c b/drivers/media/IR/lirc_dev.c
new file mode 100644
index 000000000000..9e141d51df91
--- /dev/null
+++ b/drivers/media/IR/lirc_dev.c
@@ -0,0 +1,761 @@
+/*
+ * 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 "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 init_irctl(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 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 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 (!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 fops = {
+        .owner          = THIS_MODULE,
+        .read           = lirc_dev_fop_read,
+        .write          = lirc_dev_fop_write,
+        .poll           = lirc_dev_fop_poll,
+        .ioctl          = lirc_dev_fop_ioctl,
+        .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, &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->ioctl)) {
+                        dev_err(d->dev, "lirc_dev: lirc_register_driver: "
+                                "neither read, poll nor 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;
+        }
+        init_irctl(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: lirc_unregister_driver: "
+                       "\"minor (%d)\" must be between 0 and %d!\n",
+                       minor, MAX_IRCTL_DEVICES-1);
+                return -EBADRQC;
+        }
+
+        ir = irctls[minor];
+
+        mutex_lock(&lirc_dev_lock);
+
+        if (ir->d.minor != minor) {
+                printk(KERN_ERR "lirc_dev: lirc_unregister_driver: "
+                       "minor (%d) device not registered!", 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->d.owner);
+                mutex_unlock(&ir->irctl_lock);
+                cdev_del(&ir->cdev);
+        } else {
+                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->d.owner)) {
+                ++ir->open;
+                retval = ir->d.set_use_inc(ir->d.data);
+
+                if (retval) {
+                        module_put(ir->d.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->d.owner);
+        } else {
+                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);
+
+int lirc_dev_fop_ioctl(struct inode *inode, struct file *file,
+                       unsigned int cmd, unsigned long arg)
+{
+        unsigned long mode;
+        int result = 0;
+        struct irctl *ir = irctls[iminor(inode)];
+
+        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, (unsigned long *)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),
+                                  (unsigned long *)arg);
+                break;
+        case LIRC_SET_REC_MODE:
+                if (!(ir->d.features & LIRC_CAN_REC_MASK)) {
+                        result = -ENOSYS;
+                        break;
+                }
+
+                result = get_user(mode, (unsigned long *)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, (unsigned long *)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, (unsigned long *)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, (unsigned long *)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;
+                                break;
+                        }
+
+                        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);
+
+        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");
diff --git a/drivers/media/IR/lirc_dev.h b/drivers/media/IR/lirc_dev.h
new file mode 100644
index 000000000000..4afd96a38a43
--- /dev/null
+++ b/drivers/media/IR/lirc_dev.h
@@ -0,0 +1,226 @@
+/*
+ * LIRC base driver
+ *
+ * by Artur Lipowski <alipowski@interia.pl>
+ *        This code is licensed under GNU GPL
+ *
+ */
+
+#ifndef _LINUX_LIRC_DEV_H
+#define _LINUX_LIRC_DEV_H
+
+#define MAX_IRCTL_DEVICES 4
+#define BUFLEN            16
+
+#define mod(n, div) ((n) % (div))
+
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/poll.h>
+#include <linux/kfifo.h>
+#include <media/lirc.h>
+
+struct lirc_buffer {
+        wait_queue_head_t wait_poll;
+        spinlock_t fifo_lock;
+        unsigned int chunk_size;
+        unsigned int size; /* in chunks */
+        /* Using chunks instead of bytes pretends to simplify boundary checking
+         * And should allow for some performance fine tunning later */
+        struct kfifo fifo;
+        u8 fifo_initialized;
+};
+
+static inline void lirc_buffer_clear(struct lirc_buffer *buf)
+{
+        unsigned long flags;
+
+        if (buf->fifo_initialized) {
+                spin_lock_irqsave(&buf->fifo_lock, flags);
+                kfifo_reset(&buf->fifo);
+                spin_unlock_irqrestore(&buf->fifo_lock, flags);
+        } else
+                WARN(1, "calling %s on an uninitialized lirc_buffer\n",
+                     __func__);
+}
+
+static inline int lirc_buffer_init(struct lirc_buffer *buf,
+                                    unsigned int chunk_size,
+                                    unsigned int size)
+{
+        int ret;
+
+        init_waitqueue_head(&buf->wait_poll);
+        spin_lock_init(&buf->fifo_lock);
+        buf->chunk_size = chunk_size;
+        buf->size = size;
+        ret = kfifo_alloc(&buf->fifo, size * chunk_size, GFP_KERNEL);
+        if (ret == 0)
+                buf->fifo_initialized = 1;
+
+        return ret;
+}
+
+static inline void lirc_buffer_free(struct lirc_buffer *buf)
+{
+        if (buf->fifo_initialized) {
+                kfifo_free(&buf->fifo);
+                buf->fifo_initialized = 0;
+        } else
+                WARN(1, "calling %s on an uninitialized lirc_buffer\n",
+                     __func__);
+}
+
+static inline int lirc_buffer_len(struct lirc_buffer *buf)
+{
+        int len;
+        unsigned long flags;
+
+        spin_lock_irqsave(&buf->fifo_lock, flags);
+        len = kfifo_len(&buf->fifo);
+        spin_unlock_irqrestore(&buf->fifo_lock, flags);
+
+        return len;
+}
+
+static inline int lirc_buffer_full(struct lirc_buffer *buf)
+{
+        return lirc_buffer_len(buf) == buf->size * buf->chunk_size;
+}
+
+static inline int lirc_buffer_empty(struct lirc_buffer *buf)
+{
+        return !lirc_buffer_len(buf);
+}
+
+static inline int lirc_buffer_available(struct lirc_buffer *buf)
+{
+        return buf->size - (lirc_buffer_len(buf) / buf->chunk_size);
+}
+
+static inline unsigned int lirc_buffer_read(struct lirc_buffer *buf,
+                                            unsigned char *dest)
+{
+        unsigned int ret = 0;
+
+        if (lirc_buffer_len(buf) >= buf->chunk_size)
+                ret = kfifo_out_locked(&buf->fifo, dest, buf->chunk_size,
+                                       &buf->fifo_lock);
+        return ret;
+
+}
+
+static inline unsigned int lirc_buffer_write(struct lirc_buffer *buf,
+                                             unsigned char *orig)
+{
+        unsigned int ret;
+
+        ret = kfifo_in_locked(&buf->fifo, orig, buf->chunk_size,
+                              &buf->fifo_lock);
+
+        return ret;
+}
+
+struct lirc_driver {
+        char name[40];
+        int minor;
+        unsigned long code_length;
+        unsigned int buffer_size; /* in chunks holding one code each */
+        int sample_rate;
+        unsigned long features;
+
+        unsigned int chunk_size;
+
+        void *data;
+        int min_timeout;
+        int max_timeout;
+        int (*add_to_buf) (void *data, struct lirc_buffer *buf);
+        struct lirc_buffer *rbuf;
+        int (*set_use_inc) (void *data);
+        void (*set_use_dec) (void *data);
+        struct file_operations *fops;
+        struct device *dev;
+        struct module *owner;
+};
+
+/* name:
+ * this string will be used for logs
+ *
+ * minor:
+ * indicates minor device (/dev/lirc) number for registered driver
+ * if caller fills it with negative value, then the first free minor
+ * number will be used (if available)
+ *
+ * code_length:
+ * length of the remote control key code expressed in bits
+ *
+ * sample_rate:
+ *
+ * data:
+ * it may point to any driver data and this pointer will be passed to
+ * all callback functions
+ *
+ * add_to_buf:
+ * add_to_buf will be called after specified period of the time or
+ * triggered by the external event, this behavior depends on value of
+ * the sample_rate this function will be called in user context. This
+ * routine should return 0 if data was added to the buffer and
+ * -ENODATA if none was available. This should add some number of bits
+ * evenly divisible by code_length to the buffer
+ *
+ * rbuf:
+ * if not NULL, it will be used as a read buffer, you will have to
+ * write to the buffer by other means, like irq's (see also
+ * lirc_serial.c).
+ *
+ * set_use_inc:
+ * set_use_inc will be called after device is opened
+ *
+ * set_use_dec:
+ * set_use_dec will be called after device is closed
+ *
+ * fops:
+ * file_operations for drivers which don't fit the current driver model.
+ *
+ * Some ioctl's can be directly handled by lirc_dev if the driver's
+ * ioctl function is NULL or if it returns -ENOIOCTLCMD (see also
+ * lirc_serial.c).
+ *
+ * owner:
+ * the module owning this struct
+ *
+ */
+
+
+/* following functions can be called ONLY from user context
+ *
+ * returns negative value on error or minor number
+ * of the registered device if success
+ * contents of the structure pointed by p is copied
+ */
+extern int lirc_register_driver(struct lirc_driver *d);
+
+/* returns negative value on error or 0 if success
+*/
+extern int lirc_unregister_driver(int minor);
+
+/* Returns the private data stored in the lirc_driver
+ * associated with the given device file pointer.
+ */
+void *lirc_get_pdata(struct file *file);
+
+/* default file operations
+ * used by drivers if they override only some operations
+ */
+int lirc_dev_fop_open(struct inode *inode, struct file *file);
+int lirc_dev_fop_close(struct inode *inode, struct file *file);
+unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
+int lirc_dev_fop_ioctl(struct inode *inode, struct file *file,
+                       unsigned int cmd, unsigned long arg);
+ssize_t lirc_dev_fop_read(struct file *file, char *buffer, size_t length,
+                          loff_t *ppos);
+ssize_t lirc_dev_fop_write(struct file *file, const char *buffer, size_t length,
+                           loff_t *ppos);
+
+#endif