--- /dev/null
+/*
+ * A driver for the AverMedia MR 800 USB FM radio. This device plugs
+ * into both the USB and an analog audio input, so this thing
+ * only deals with initialization and frequency setting, the
+ * audio data has to be handled by a sound driver.
+ *
+ * Copyright (c) 2008 Alexey Klimov <klimov.linux@gmail.com>
+ *
+ * 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
+ */
+
+/*
+ * Big thanks to authors of dsbr100.c and radio-si470x.c
+ *
+ * When work was looked pretty good, i discover this:
+ * http://av-usbradio.sourceforge.net/index.php
+ * http://sourceforge.net/projects/av-usbradio/
+ * Latest release of theirs project was in 2005.
+ * Probably, this driver could be improved trough using their
+ * achievements (specifications given).
+ * So, we have smth to begin with.
+ *
+ * History:
+ * Version 0.01:       First working version.
+ *                     It's required to blacklist AverMedia USB Radio
+ *                     in usbhid/hid-quirks.c
+ *
+ * Many things to do:
+ *     - Correct power managment of device (suspend & resume)
+ *     - Make x86 independance (little-endian and big-endian stuff)
+ *     - Add code for scanning and smooth tuning
+ *     - Checked and add stereo&mono stuff
+ *     - Add code for sensitivity value
+ *     - Correct mistakes
+ *     - In Japan another FREQ_MIN and FREQ_MAX
+ */
+
+/* kernel includes */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-ioctl.h>
+#include <linux/usb.h>
+#include <linux/version.h>     /* for KERNEL_VERSION MACRO */
+
+/* driver and module definitions */
+#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
+#define DRIVER_DESC "AverMedia MR 800 USB FM radio driver"
+#define DRIVER_VERSION "0.01"
+#define RADIO_VERSION KERNEL_VERSION(0, 0, 1)
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define USB_AMRADIO_VENDOR 0x07ca
+#define USB_AMRADIO_PRODUCT 0xb800
+
+/* Probably USB_TIMEOUT should be modified in module parameter */
+#define BUFFER_LENGTH 8
+#define USB_TIMEOUT 500
+
+/* Frequency limits in MHz -- these are European values.  For Japanese
+devices, that would be 76 and 91.  */
+#define FREQ_MIN  87.5
+#define FREQ_MAX 108.0
+#define FREQ_MUL 16000
+
+/* module parameter */
+static int radio_nr = -1;
+module_param(radio_nr, int, 0);
+MODULE_PARM_DESC(radio_nr, "Radio Nr");
+
+static struct v4l2_queryctrl radio_qctrl[] = {
+       {
+               .id            = V4L2_CID_AUDIO_MUTE,
+               .name          = "Mute",
+               .minimum       = 0,
+               .maximum       = 1,
+               .step          = 1,
+               .default_value = 1,
+               .type          = V4L2_CTRL_TYPE_BOOLEAN,
+       },
+/* HINT: the disabled controls are only here to satify kradio and such apps */
+       {       .id             = V4L2_CID_AUDIO_VOLUME,
+               .flags          = V4L2_CTRL_FLAG_DISABLED,
+       },
+       {
+               .id             = V4L2_CID_AUDIO_BALANCE,
+               .flags          = V4L2_CTRL_FLAG_DISABLED,
+       },
+       {
+               .id             = V4L2_CID_AUDIO_BASS,
+               .flags          = V4L2_CTRL_FLAG_DISABLED,
+       },
+       {
+               .id             = V4L2_CID_AUDIO_TREBLE,
+               .flags          = V4L2_CTRL_FLAG_DISABLED,
+       },
+       {
+               .id             = V4L2_CID_AUDIO_LOUDNESS,
+               .flags          = V4L2_CTRL_FLAG_DISABLED,
+       },
+};
+
+static int usb_amradio_probe(struct usb_interface *intf,
+                            const struct usb_device_id *id);
+static void usb_amradio_disconnect(struct usb_interface *intf);
+static int usb_amradio_open(struct inode *inode, struct file *file);
+static int usb_amradio_close(struct inode *inode, struct file *file);
+static int usb_amradio_suspend(struct usb_interface *intf,
+                               pm_message_t message);
+static int usb_amradio_resume(struct usb_interface *intf);
+
+/* Data for one (physical) device */
+struct amradio_device {
+       /* reference to USB and video device */
+       struct usb_device *usbdev;
+       struct video_device *videodev;
+
+       unsigned char *buffer;
+       struct mutex lock;      /* buffer locking */
+       int curfreq;
+       int stereo;
+       int users;
+       int removed;
+       int muted;
+};
+
+/* USB Device ID List */
+static struct usb_device_id usb_amradio_device_table[] = {
+       {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
+                                                       USB_CLASS_HID, 0, 0) },
+       { }                                             /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
+
+/* USB subsystem interface */
+static struct usb_driver usb_amradio_driver = {
+       .name                   = "radio-mr800",
+       .probe                  = usb_amradio_probe,
+       .disconnect             = usb_amradio_disconnect,
+       .suspend                = usb_amradio_suspend,
+       .resume                 = usb_amradio_resume,
+       .reset_resume           = usb_amradio_resume,
+       .id_table               = usb_amradio_device_table,
+       .supports_autosuspend   = 1,
+};
+
+/* switch on radio. Send 8 bytes to device. */
+static int amradio_start(struct amradio_device *radio)
+{
+       int retval;
+       int size;
+
+       mutex_lock(&radio->lock);
+
+       radio->buffer[0] = 0x00;
+       radio->buffer[1] = 0x55;
+       radio->buffer[2] = 0xaa;
+       radio->buffer[3] = 0x00;
+       radio->buffer[4] = 0xab;
+       radio->buffer[5] = 0x00;
+       radio->buffer[6] = 0x00;
+       radio->buffer[7] = 0x00;
+
+       retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
+               (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
+
+       if (retval) {
+               mutex_unlock(&radio->lock);
+               return retval;
+       }
+
+       mutex_unlock(&radio->lock);
+
+       radio->muted = 0;
+
+       return retval;
+}
+
+/* switch off radio */
+static int amradio_stop(struct amradio_device *radio)
+{
+       int retval;
+       int size;
+
+       mutex_lock(&radio->lock);
+
+       radio->buffer[0] = 0x00;
+       radio->buffer[1] = 0x55;
+       radio->buffer[2] = 0xaa;
+       radio->buffer[3] = 0x00;
+       radio->buffer[4] = 0xab;
+       radio->buffer[5] = 0x01;
+       radio->buffer[6] = 0x00;
+       radio->buffer[7] = 0x00;
+
+       retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
+               (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
+
+       if (retval) {
+               mutex_unlock(&radio->lock);
+               return retval;
+       }
+
+       mutex_unlock(&radio->lock);
+
+       radio->muted = 1;
+
+       return retval;
+}
+
+/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
+static int amradio_setfreq(struct amradio_device *radio, int freq)
+{
+       int retval;
+       int size;
+       unsigned short freq_send = 0x13 + (freq >> 3) / 25;
+
+       mutex_lock(&radio->lock);
+
+       radio->buffer[0] = 0x00;
+       radio->buffer[1] = 0x55;
+       radio->buffer[2] = 0xaa;
+       radio->buffer[3] = 0x03;
+       radio->buffer[4] = 0xa4;
+       radio->buffer[5] = 0x00;
+       radio->buffer[6] = 0x00;
+       radio->buffer[7] = 0x08;
+
+       retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
+               (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
+
+       if (retval) {
+               mutex_unlock(&radio->lock);
+               return retval;
+       }
+
+       /* frequency is calculated from freq_send and placed in first 2 bytes */
+       radio->buffer[0] = (freq_send >> 8) & 0xff;
+       radio->buffer[1] = freq_send & 0xff;
+       radio->buffer[2] = 0x01;
+       radio->buffer[3] = 0x00;
+       radio->buffer[4] = 0x00;
+       /* 5 and 6 bytes of buffer already = 0x00 */
+       radio->buffer[7] = 0x00;
+
+       retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
+               (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
+
+       if (retval) {
+               mutex_unlock(&radio->lock);
+               return retval;
+       }
+
+       mutex_unlock(&radio->lock);
+
+       radio->stereo = 0;
+
+       return retval;
+}
+
+/* USB subsystem interface begins here */
+
+/* handle unplugging of the device, release data structures
+if nothing keeps us from doing it.  If something is still
+keeping us busy, the release callback of v4l will take care
+of releasing it. */
+static void usb_amradio_disconnect(struct usb_interface *intf)
+{
+       struct amradio_device *radio = usb_get_intfdata(intf);
+
+       usb_set_intfdata(intf, NULL);
+
+       if (radio) {
+               video_unregister_device(radio->videodev);
+               radio->videodev = NULL;
+               if (radio->users) {
+                       kfree(radio->buffer);
+                       kfree(radio);
+               } else {
+                       radio->removed = 1;
+               }
+       }
+}
+
+/* vidioc_querycap - query device capabilities */
+static int vidioc_querycap(struct file *file, void *priv,
+                                       struct v4l2_capability *v)
+{
+       strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
+       strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
+       sprintf(v->bus_info, "USB");
+       v->version = RADIO_VERSION;
+       v->capabilities = V4L2_CAP_TUNER;
+       return 0;
+}
+
+/* vidioc_g_tuner - get tuner attributes */
+static int vidioc_g_tuner(struct file *file, void *priv,
+                               struct v4l2_tuner *v)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       if (v->index > 0)
+               return -EINVAL;
+
+/* TODO: Add function which look is signal stereo or not
+ *     amradio_getstat(radio);
+ */
+       radio->stereo = -1;
+       strcpy(v->name, "FM");
+       v->type = V4L2_TUNER_RADIO;
+       v->rangelow = FREQ_MIN * FREQ_MUL;
+       v->rangehigh = FREQ_MAX * FREQ_MUL;
+       v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
+       v->capability = V4L2_TUNER_CAP_LOW;
+       if (radio->stereo)
+               v->audmode = V4L2_TUNER_MODE_STEREO;
+       else
+               v->audmode = V4L2_TUNER_MODE_MONO;
+       v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
+       v->afc = 0; /* Don't know what is this */
+       return 0;
+}
+
+/* vidioc_s_tuner - set tuner attributes */
+static int vidioc_s_tuner(struct file *file, void *priv,
+                               struct v4l2_tuner *v)
+{
+       if (v->index > 0)
+               return -EINVAL;
+       return 0;
+}
+
+/* vidioc_s_frequency - set tuner radio frequency */
+static int vidioc_s_frequency(struct file *file, void *priv,
+                               struct v4l2_frequency *f)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       radio->curfreq = f->frequency;
+       if (amradio_setfreq(radio, radio->curfreq) < 0)
+               warn("Set frequency failed");
+       return 0;
+}
+
+/* vidioc_g_frequency - get tuner radio frequency */
+static int vidioc_g_frequency(struct file *file, void *priv,
+                               struct v4l2_frequency *f)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       f->type = V4L2_TUNER_RADIO;
+       f->frequency = radio->curfreq;
+       return 0;
+}
+
+/* vidioc_queryctrl - enumerate control items */
+static int vidioc_queryctrl(struct file *file, void *priv,
+                               struct v4l2_queryctrl *qc)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(radio_qctrl); i++) {
+               if (qc->id && qc->id == radio_qctrl[i].id) {
+                       memcpy(qc, &(radio_qctrl[i]),
+                                               sizeof(*qc));
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
+
+/* vidioc_g_ctrl - get the value of a control */
+static int vidioc_g_ctrl(struct file *file, void *priv,
+                               struct v4l2_control *ctrl)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       switch (ctrl->id) {
+       case V4L2_CID_AUDIO_MUTE:
+               ctrl->value = radio->muted;
+               return 0;
+       }
+       return -EINVAL;
+}
+
+/* vidioc_s_ctrl - set the value of a control */
+static int vidioc_s_ctrl(struct file *file, void *priv,
+                               struct v4l2_control *ctrl)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       switch (ctrl->id) {
+       case V4L2_CID_AUDIO_MUTE:
+               if (ctrl->value) {
+                       if (amradio_stop(radio) < 0) {
+                               warn("amradio_stop() failed");
+                               return -1;
+                       }
+               } else {
+                       if (amradio_start(radio) < 0) {
+                               warn("amradio_start() failed");
+                               return -1;
+                       }
+               }
+               return 0;
+       }
+       return -EINVAL;
+}
+
+/* vidioc_g_audio - get audio attributes */
+static int vidioc_g_audio(struct file *file, void *priv,
+                               struct v4l2_audio *a)
+{
+       if (a->index > 1)
+               return -EINVAL;
+
+       strcpy(a->name, "Radio");
+       a->capability = V4L2_AUDCAP_STEREO;
+       return 0;
+}
+
+/* vidioc_s_audio - set audio attributes  */
+static int vidioc_s_audio(struct file *file, void *priv,
+                                       struct v4l2_audio *a)
+{
+       if (a->index != 0)
+               return -EINVAL;
+       return 0;
+}
+
+/* vidioc_g_input - get input */
+static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
+{
+       *i = 0;
+       return 0;
+}
+
+/* vidioc_s_input - set input */
+static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
+{
+       if (i != 0)
+               return -EINVAL;
+       return 0;
+}
+
+/* open device - amradio_start() and amradio_setfreq() */
+static int usb_amradio_open(struct inode *inode, struct file *file)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       radio->users = 1;
+       radio->muted = 1;
+
+       if (amradio_start(radio) < 0) {
+               warn("Radio did not start up properly");
+               radio->users = 0;
+               return -EIO;
+       }
+       if (amradio_setfreq(radio, radio->curfreq) < 0)
+               warn("Set frequency failed");
+       return 0;
+}
+
+/*close device - free driver structures */
+static int usb_amradio_close(struct inode *inode, struct file *file)
+{
+       struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+       if (!radio)
+               return -ENODEV;
+       radio->users = 0;
+       if (radio->removed) {
+               kfree(radio->buffer);
+               kfree(radio);
+       }
+       return 0;
+}
+
+/* Suspend device - stop device. Need to be checked and fixed */
+static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
+{
+       struct amradio_device *radio = usb_get_intfdata(intf);
+
+       if (amradio_stop(radio) < 0)
+               warn("amradio_stop() failed");
+
+       info("radio-mr800: Going into suspend..");
+
+       return 0;
+}
+
+/* Resume device - start device. Need to be checked and fixed */
+static int usb_amradio_resume(struct usb_interface *intf)
+{
+       struct amradio_device *radio = usb_get_intfdata(intf);
+
+       if (amradio_start(radio) < 0)
+               warn("amradio_start() failed");
+
+       info("radio-mr800: Coming out of suspend..");
+
+       return 0;
+}
+
+/* File system interface */
+static const struct file_operations usb_amradio_fops = {
+       .owner          = THIS_MODULE,
+       .open           = usb_amradio_open,
+       .release        = usb_amradio_close,
+       .ioctl          = video_ioctl2,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = v4l_compat_ioctl32,
+#endif
+       .llseek         = no_llseek,
+};
+
+static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
+       .vidioc_querycap    = vidioc_querycap,
+       .vidioc_g_tuner     = vidioc_g_tuner,
+       .vidioc_s_tuner     = vidioc_s_tuner,
+       .vidioc_g_frequency = vidioc_g_frequency,
+       .vidioc_s_frequency = vidioc_s_frequency,
+       .vidioc_queryctrl   = vidioc_queryctrl,
+       .vidioc_g_ctrl      = vidioc_g_ctrl,
+       .vidioc_s_ctrl      = vidioc_s_ctrl,
+       .vidioc_g_audio     = vidioc_g_audio,
+       .vidioc_s_audio     = vidioc_s_audio,
+       .vidioc_g_input     = vidioc_g_input,
+       .vidioc_s_input     = vidioc_s_input,
+};
+
+/* V4L2 interface */
+static struct video_device amradio_videodev_template = {
+       .name           = "AverMedia MR 800 USB FM Radio",
+       .fops           = &usb_amradio_fops,
+       .ioctl_ops      = &usb_amradio_ioctl_ops,
+       .release        = video_device_release,
+};
+
+/* check if the device is present and register with v4l and
+usb if it is */
+static int usb_amradio_probe(struct usb_interface *intf,
+                               const struct usb_device_id *id)
+{
+       struct amradio_device *radio;
+
+       radio = kmalloc(sizeof(struct amradio_device), GFP_KERNEL);
+
+       if (!(radio))
+               return -ENOMEM;
+
+       radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+
+       if (!(radio->buffer)) {
+               kfree(radio);
+               return -ENOMEM;
+       }
+
+       radio->videodev = video_device_alloc();
+
+       if (!(radio->videodev)) {
+               kfree(radio->buffer);
+               kfree(radio);
+               return -ENOMEM;
+       }
+
+       memcpy(radio->videodev, &amradio_videodev_template,
+               sizeof(amradio_videodev_template));
+
+       radio->removed = 0;
+       radio->users = 0;
+       radio->usbdev = interface_to_usbdev(intf);
+       radio->curfreq = 95.16 * FREQ_MUL;
+
+       mutex_init(&radio->lock);
+
+       video_set_drvdata(radio->videodev, radio);
+       if (video_register_device(radio->videodev, VFL_TYPE_RADIO, radio_nr)) {
+               warn("Could not register video device");
+               video_device_release(radio->videodev);
+               kfree(radio->buffer);
+               kfree(radio);
+               return -EIO;
+       }
+
+       usb_set_intfdata(intf, radio);
+       return 0;
+}
+
+static int __init amradio_init(void)
+{
+       int retval = usb_register(&usb_amradio_driver);
+
+       info(DRIVER_VERSION " " DRIVER_DESC);
+       if (retval)
+               err("usb_register failed. Error number %d", retval);
+       return retval;
+}
+
+static void __exit amradio_exit(void)
+{
+       usb_deregister(&usb_amradio_driver);
+}
+
+module_init(amradio_init);
+module_exit(amradio_exit);
+