drivers/media/radio/radio-mr800.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * 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.
  */

 /*
  * Big thanks to authors and contributors 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 through using their
  * achievements (specifications given).
  * Also, Faidon Liambotis <paravoid@debian.org> wrote nice driver for this radio
  * in 2007. He allowed to use his driver to improve current mr800 radio driver.
  * http://www.spinics.net/lists/linux-usb-devel/msg10109.html
  *
  * Version 0.01:	First working version.
  * 			It's required to blacklist AverMedia USB Radio
  * 			in usbhid/hid-quirks.c
  * Version 0.10:	A lot of cleanups and fixes: unpluging the device,
  * 			few mutex locks were added, codinstyle issues, etc.
  * 			Added stereo support. Thanks to
  * 			Douglas Schilling Landgraf <dougsland@gmail.com> and
  * 			David Ellingsworth <david@identd.dyndns.org>
  * 			for discussion, help and support.
  * Version 0.11:	Converted to v4l2_device.
  *
  * Many things to do:
  * 	- Correct power management of device (suspend & resume)
  * 	- Add code for scanning and smooth tuning
  * 	- 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-device.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-event.h>
 #include <linux/usb.h>
 #include <linux/mutex.h>

 /* 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 "0.1.2"

 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRIVER_VERSION);

 #define USB_AMRADIO_VENDOR 0x07ca
 #define USB_AMRADIO_PRODUCT 0xb800

 /* dev_warn macro with driver name */
 #define MR800_DRIVER_NAME "radio-mr800"
 #define amradio_dev_warn(dev, fmt, arg...)				\
 		dev_warn(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

 #define amradio_dev_err(dev, fmt, arg...) \
 		dev_err(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

 /* 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

 /*
  * Commands that device should understand
  * List isn't full and will be updated with implementation of new functions
  */
 #define AMRADIO_SET_FREQ	0xa4
 #define AMRADIO_GET_READY_FLAG	0xa5
 #define AMRADIO_GET_SIGNAL	0xa7
 #define AMRADIO_GET_FREQ	0xa8
 #define AMRADIO_SET_SEARCH_UP	0xa9
 #define AMRADIO_SET_SEARCH_DOWN	0xaa
 #define AMRADIO_SET_MUTE	0xab
 #define AMRADIO_SET_RIGHT_MUTE	0xac
 #define AMRADIO_SET_LEFT_MUTE	0xad
 #define AMRADIO_SET_MONO	0xae
 #define AMRADIO_SET_SEARCH_LVL	0xb0
 #define AMRADIO_STOP_SEARCH	0xb1

 /* Comfortable defines for amradio_set_stereo */
 #define WANT_STEREO		0x00
 #define WANT_MONO		0x01

 /* module parameter */
 static int radio_nr = -1;
 module_param(radio_nr, int, 0);
 MODULE_PARM_DESC(radio_nr, "Radio Nr");

 /* Data for one (physical) device */
 struct amradio_device {
 	/* reference to USB and video device */
 	struct usb_device *usbdev;
 	struct usb_interface *intf;
 	struct video_device vdev;
 	struct v4l2_device v4l2_dev;
 	struct v4l2_ctrl_handler hdl;

 	u8 *buffer;
 	struct mutex lock;	/* buffer locking */
 	int curfreq;
 	int stereo;
 	int muted;
 };

 static inline struct amradio_device *to_amradio_dev(struct v4l2_device *v4l2_dev)
 {
 	return container_of(v4l2_dev, struct amradio_device, v4l2_dev);
 }

 static int amradio_send_cmd(struct amradio_device *radio, u8 cmd, u8 arg,
 		u8 *extra, u8 extralen, bool reply)
 {
 	int retval;
 	int size;

 	radio->buffer[0] = 0x00;
 	radio->buffer[1] = 0x55;
 	radio->buffer[2] = 0xaa;
 	radio->buffer[3] = extralen;
 	radio->buffer[4] = cmd;
 	radio->buffer[5] = arg;
 	radio->buffer[6] = 0x00;
 	radio->buffer[7] = extra || reply ? 8 : 0;

 	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 		radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);

 	if (retval < 0 || size != BUFFER_LENGTH) {
 		if (video_is_registered(&radio->vdev))
 			amradio_dev_warn(&radio->vdev.dev,
 					"cmd %02x failed\n", cmd);
 		return retval ? retval : -EIO;
 	}
 	if (!extra && !reply)
 		return 0;

 	if (extra) {
 		memcpy(radio->buffer, extra, extralen);
 		memset(radio->buffer + extralen, 0, 8 - extralen);
 		retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 			radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
 	} else {
 		memset(radio->buffer, 0, 8);
 		retval = usb_bulk_msg(radio->usbdev, usb_rcvbulkpipe(radio->usbdev, 0x81),
 			radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
 	}
 	if (retval == 0 && size == BUFFER_LENGTH)
 		return 0;
 	if (video_is_registered(&radio->vdev) && cmd != AMRADIO_GET_READY_FLAG)
 		amradio_dev_warn(&radio->vdev.dev, "follow-up to cmd %02x failed\n", cmd);
 	return retval ? retval : -EIO;
 }

 /* switch on/off the radio. Send 8 bytes to device */
 static int amradio_set_mute(struct amradio_device *radio, bool mute)
 {
 	int ret = amradio_send_cmd(radio,
 			AMRADIO_SET_MUTE, mute, NULL, 0, false);

 	if (!ret)
 		radio->muted = mute;
 	return ret;
 }

 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
 static int amradio_set_freq(struct amradio_device *radio, int freq)
 {
 	unsigned short freq_send;
 	u8 buf[3];
 	int retval;

 	/* we need to be sure that frequency isn't out of range */
 	freq = clamp_t(unsigned, freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
 	freq_send = 0x10 + (freq >> 3) / 25;

 	/* frequency is calculated from freq_send and placed in first 2 bytes */
 	buf[0] = (freq_send >> 8) & 0xff;
 	buf[1] = freq_send & 0xff;
 	buf[2] = 0x01;

 	retval = amradio_send_cmd(radio, AMRADIO_SET_FREQ, 0, buf, 3, false);
 	if (retval)
 		return retval;
 	radio->curfreq = freq;
 	msleep(40);
 	return 0;
 }

 static int amradio_set_stereo(struct amradio_device *radio, bool stereo)
 {
 	int ret = amradio_send_cmd(radio,
 			AMRADIO_SET_MONO, !stereo, NULL, 0, false);

 	if (!ret)
 		radio->stereo = stereo;
 	return ret;
 }

 static int amradio_get_stat(struct amradio_device *radio, bool *is_stereo, u32 *signal)
 {
 	int ret = amradio_send_cmd(radio,
 			AMRADIO_GET_SIGNAL, 0, NULL, 0, true);

 	if (ret)
 		return ret;
 	*is_stereo = radio->buffer[2] >> 7;
 	*signal = (radio->buffer[3] & 0xf0) << 8;
 	return 0;
 }

 /* Handle unplugging the device.
  * We call video_unregister_device in any case.
  * The last function called in this procedure is
  * usb_amradio_device_release.
  */
 static void usb_amradio_disconnect(struct usb_interface *intf)
 {
 	struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));

 	mutex_lock(&radio->lock);
 	video_unregister_device(&radio->vdev);
 	amradio_set_mute(radio, true);
 	usb_set_intfdata(intf, NULL);
 	v4l2_device_disconnect(&radio->v4l2_dev);
 	mutex_unlock(&radio->lock);
 	v4l2_device_put(&radio->v4l2_dev);
 }

 /* vidioc_querycap - query device capabilities */
 static int vidioc_querycap(struct file *file, void *priv,
 					struct v4l2_capability *v)
 {
 	struct amradio_device *radio = video_drvdata(file);

 	strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
 	strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
 	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER |
 					V4L2_CAP_HW_FREQ_SEEK;
 	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
 	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_drvdata(file);
 	bool is_stereo = false;
 	int retval;

 	if (v->index > 0)
 		return -EINVAL;

 	v->signal = 0;
 	retval = amradio_get_stat(radio, &is_stereo, &v->signal);
 	if (retval)
 		return retval;

 	strcpy(v->name, "FM");
 	v->type = V4L2_TUNER_RADIO;
 	v->rangelow = FREQ_MIN * FREQ_MUL;
 	v->rangehigh = FREQ_MAX * FREQ_MUL;
 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
 		V4L2_TUNER_CAP_HWSEEK_WRAP;
 	v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
 	v->audmode = radio->stereo ?
 		V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
 	return 0;
 }

 /* vidioc_s_tuner - set tuner attributes */
 static int vidioc_s_tuner(struct file *file, void *priv,
 				const struct v4l2_tuner *v)
 {
 	struct amradio_device *radio = video_drvdata(file);

 	if (v->index > 0)
 		return -EINVAL;

 	/* mono/stereo selector */
 	switch (v->audmode) {
 	case V4L2_TUNER_MODE_MONO:
 		return amradio_set_stereo(radio, WANT_MONO);
 	default:
 		return amradio_set_stereo(radio, WANT_STEREO);
 	}
 }

 /* vidioc_s_frequency - set tuner radio frequency */
 static int vidioc_s_frequency(struct file *file, void *priv,
 				const struct v4l2_frequency *f)
 {
 	struct amradio_device *radio = video_drvdata(file);

 	if (f->tuner != 0)
 		return -EINVAL;
 	return amradio_set_freq(radio, f->frequency);
 }

 /* 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_drvdata(file);

 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 		return -EINVAL;
 	f->type = V4L2_TUNER_RADIO;
 	f->frequency = radio->curfreq;

 	return 0;
 }

 static int vidioc_s_hw_freq_seek(struct file *file, void *priv,
 		const struct v4l2_hw_freq_seek *seek)
 {
 	static u8 buf[8] = {
 		0x3d, 0x32, 0x0f, 0x08, 0x3d, 0x32, 0x0f, 0x08
 	};
 	struct amradio_device *radio = video_drvdata(file);
 	unsigned long timeout;
 	int retval;

 	if (seek->tuner != 0 || !seek->wrap_around)
 		return -EINVAL;

 	if (file->f_flags & O_NONBLOCK)
 		return -EWOULDBLOCK;

 	retval = amradio_send_cmd(radio,
 			AMRADIO_SET_SEARCH_LVL, 0, buf, 8, false);
 	if (retval)
 		return retval;
 	amradio_set_freq(radio, radio->curfreq);
 	retval = amradio_send_cmd(radio,
 		seek->seek_upward ? AMRADIO_SET_SEARCH_UP : AMRADIO_SET_SEARCH_DOWN,
 		0, NULL, 0, false);
 	if (retval)
 		return retval;
 	timeout = jiffies + msecs_to_jiffies(30000);
 	for (;;) {
 		if (time_after(jiffies, timeout)) {
 			retval = -ENODATA;
 			break;
 		}
 		if (schedule_timeout_interruptible(msecs_to_jiffies(10))) {
 			retval = -ERESTARTSYS;
 			break;
 		}
 		retval = amradio_send_cmd(radio, AMRADIO_GET_READY_FLAG,
 				0, NULL, 0, true);
 		if (retval)
 			continue;
 		amradio_send_cmd(radio, AMRADIO_GET_FREQ, 0, NULL, 0, true);
 		if (radio->buffer[1] || radio->buffer[2]) {
 			/* To check: sometimes radio->curfreq is set to out of range value */
 			radio->curfreq = (radio->buffer[1] << 8) | radio->buffer[2];
 			radio->curfreq = (radio->curfreq - 0x10) * 200;
 			amradio_send_cmd(radio, AMRADIO_STOP_SEARCH,
 					0, NULL, 0, false);
 			amradio_set_freq(radio, radio->curfreq);
 			retval = 0;
 			break;
 		}
 	}
 	amradio_send_cmd(radio, AMRADIO_STOP_SEARCH, 0, NULL, 0, false);
 	amradio_set_freq(radio, radio->curfreq);
 	return retval;
 }

 static int usb_amradio_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct amradio_device *radio =
 		container_of(ctrl->handler, struct amradio_device, hdl);

 	switch (ctrl->id) {
 	case V4L2_CID_AUDIO_MUTE:
 		return amradio_set_mute(radio, ctrl->val);
 	}

 	return -EINVAL;
 }

 static int usb_amradio_init(struct amradio_device *radio)
 {
 	int retval;

 	retval = amradio_set_mute(radio, true);
 	if (retval)
 		goto out_err;
 	retval = amradio_set_stereo(radio, true);
 	if (retval)
 		goto out_err;
 	retval = amradio_set_freq(radio, radio->curfreq);
 	if (retval)
 		goto out_err;
 	return 0;

 out_err:
 	amradio_dev_err(&radio->vdev.dev, "initialization failed\n");
 	return retval;
 }

 /* 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 = to_amradio_dev(usb_get_intfdata(intf));

 	mutex_lock(&radio->lock);
 	if (!radio->muted) {
 		amradio_set_mute(radio, true);
 		radio->muted = false;
 	}
 	mutex_unlock(&radio->lock);

 	dev_info(&intf->dev, "going into suspend..\n");
 	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 = to_amradio_dev(usb_get_intfdata(intf));

 	mutex_lock(&radio->lock);
 	amradio_set_stereo(radio, radio->stereo);
 	amradio_set_freq(radio, radio->curfreq);

 	if (!radio->muted)
 		amradio_set_mute(radio, false);

 	mutex_unlock(&radio->lock);

 	dev_info(&intf->dev, "coming out of suspend..\n");
 	return 0;
 }

 static const struct v4l2_ctrl_ops usb_amradio_ctrl_ops = {
 	.s_ctrl = usb_amradio_s_ctrl,
 };

 /* File system interface */
 static const struct v4l2_file_operations usb_amradio_fops = {
 	.owner		= THIS_MODULE,
 	.open		= v4l2_fh_open,
 	.release	= v4l2_fh_release,
 	.poll		= v4l2_ctrl_poll,
 	.unlocked_ioctl	= video_ioctl2,
 };

 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_s_hw_freq_seek = vidioc_s_hw_freq_seek,
 	.vidioc_log_status  = v4l2_ctrl_log_status,
 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 };

 static void usb_amradio_release(struct v4l2_device *v4l2_dev)
 {
 	struct amradio_device *radio = to_amradio_dev(v4l2_dev);

 	/* free rest memory */
 	v4l2_ctrl_handler_free(&radio->hdl);
 	v4l2_device_unregister(&radio->v4l2_dev);
 	kfree(radio->buffer);
 	kfree(radio);
 }

 /* 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;
 	int retval = 0;

 	radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);

 	if (!radio) {
 		dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
 		retval = -ENOMEM;
 		goto err;
 	}

 	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);

 	if (!radio->buffer) {
 		dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
 		retval = -ENOMEM;
 		goto err_nobuf;
 	}

 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 	if (retval < 0) {
 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
 		goto err_v4l2;
 	}

 	v4l2_ctrl_handler_init(&radio->hdl, 1);
 	v4l2_ctrl_new_std(&radio->hdl, &usb_amradio_ctrl_ops,
 			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 	if (radio->hdl.error) {
 		retval = radio->hdl.error;
 		dev_err(&intf->dev, "couldn't register control\n");
 		goto err_ctrl;
 	}
 	mutex_init(&radio->lock);

 	radio->v4l2_dev.ctrl_handler = &radio->hdl;
 	radio->v4l2_dev.release = usb_amradio_release;
 	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
 		sizeof(radio->vdev.name));
 	radio->vdev.v4l2_dev = &radio->v4l2_dev;
 	radio->vdev.fops = &usb_amradio_fops;
 	radio->vdev.ioctl_ops = &usb_amradio_ioctl_ops;
 	radio->vdev.release = video_device_release_empty;
 	radio->vdev.lock = &radio->lock;

 	radio->usbdev = interface_to_usbdev(intf);
 	radio->intf = intf;
 	usb_set_intfdata(intf, &radio->v4l2_dev);
 	radio->curfreq = 95.16 * FREQ_MUL;

 	video_set_drvdata(&radio->vdev, radio);
 	retval = usb_amradio_init(radio);
 	if (retval)
 		goto err_vdev;

 	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
 					radio_nr);
 	if (retval < 0) {
 		dev_err(&intf->dev, "could not register video device\n");
 		goto err_vdev;
 	}

 	return 0;

 err_vdev:
 	v4l2_ctrl_handler_free(&radio->hdl);
 err_ctrl:
 	v4l2_device_unregister(&radio->v4l2_dev);
 err_v4l2:
 	kfree(radio->buffer);
 err_nobuf:
 	kfree(radio);
 err:
 	return retval;
 }

 /* USB Device ID List */
 static const 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			= MR800_DRIVER_NAME,
 	.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,
 };

 module_usb_driver(usb_amradio_driver);
	/*
	* 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.
	*/

	/*
	* Big thanks to authors and contributors 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 through using their
	* achievements (specifications given).
	* Also, Faidon Liambotis <paravoid@debian.org> wrote nice driver for this radio
	* in 2007. He allowed to use his driver to improve current mr800 radio driver.
	* http://www.spinics.net/lists/linux-usb-devel/msg10109.html
	*
	* Version 0.01: First working version.
	* It's required to blacklist AverMedia USB Radio
	* in usbhid/hid-quirks.c
	* Version 0.10: A lot of cleanups and fixes: unpluging the device,
	* few mutex locks were added, codinstyle issues, etc.
	* Added stereo support. Thanks to
	* Douglas Schilling Landgraf <dougsland@gmail.com> and
	* David Ellingsworth <david@identd.dyndns.org>
	* for discussion, help and support.
	* Version 0.11: Converted to v4l2_device.
	*
	* Many things to do:
	* - Correct power management of device (suspend & resume)
	* - Add code for scanning and smooth tuning
	* - 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-device.h>
	#include <media/v4l2-ioctl.h>
	#include <media/v4l2-ctrls.h>
	#include <media/v4l2-event.h>
	#include <linux/usb.h>
	#include <linux/mutex.h>

	/* 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 "0.1.2"

	MODULE_AUTHOR(DRIVER_AUTHOR);
	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRIVER_VERSION);

	#define USB_AMRADIO_VENDOR 0x07ca
	#define USB_AMRADIO_PRODUCT 0xb800

	/* dev_warn macro with driver name */
	#define MR800_DRIVER_NAME "radio-mr800"
	#define amradio_dev_warn(dev, fmt, arg...) \
	dev_warn(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

	#define amradio_dev_err(dev, fmt, arg...) \
	dev_err(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

	/* 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

	/*
	* Commands that device should understand
	* List isn't full and will be updated with implementation of new functions
	*/
	#define AMRADIO_SET_FREQ 0xa4
	#define AMRADIO_GET_READY_FLAG 0xa5
	#define AMRADIO_GET_SIGNAL 0xa7
	#define AMRADIO_GET_FREQ 0xa8
	#define AMRADIO_SET_SEARCH_UP 0xa9
	#define AMRADIO_SET_SEARCH_DOWN 0xaa
	#define AMRADIO_SET_MUTE 0xab
	#define AMRADIO_SET_RIGHT_MUTE 0xac
	#define AMRADIO_SET_LEFT_MUTE 0xad
	#define AMRADIO_SET_MONO 0xae
	#define AMRADIO_SET_SEARCH_LVL 0xb0
	#define AMRADIO_STOP_SEARCH 0xb1

	/* Comfortable defines for amradio_set_stereo */
	#define WANT_STEREO 0x00
	#define WANT_MONO 0x01

	/* module parameter */
	static int radio_nr = -1;
	module_param(radio_nr, int, 0);
	MODULE_PARM_DESC(radio_nr, "Radio Nr");

	/* Data for one (physical) device */
	struct amradio_device {
	/* reference to USB and video device */
	struct usb_device *usbdev;
	struct usb_interface *intf;
	struct video_device vdev;
	struct v4l2_device v4l2_dev;
	struct v4l2_ctrl_handler hdl;

	u8 *buffer;
	struct mutex lock; /* buffer locking */
	int curfreq;
	int stereo;
	int muted;
	};

	static inline struct amradio_device to_amradio_dev(struct v4l2_device v4l2_dev)
	{
	return container_of(v4l2_dev, struct amradio_device, v4l2_dev);
	}

	static int amradio_send_cmd(struct amradio_device *radio, u8 cmd, u8 arg,
	u8 *extra, u8 extralen, bool reply)
	{
	int retval;
	int size;

	radio->buffer[0] = 0x00;
	radio->buffer[1] = 0x55;
	radio->buffer[2] = 0xaa;
	radio->buffer[3] = extralen;
	radio->buffer[4] = cmd;
	radio->buffer[5] = arg;
	radio->buffer[6] = 0x00;
	radio->buffer[7] = extra \|\| reply ? 8 : 0;

	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
	radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);

	if (retval < 0 \|\| size != BUFFER_LENGTH) {
	if (video_is_registered(&radio->vdev))
	amradio_dev_warn(&radio->vdev.dev,
	"cmd %02x failed\n", cmd);
	return retval ? retval : -EIO;
	}
	if (!extra && !reply)
	return 0;

	if (extra) {
	memcpy(radio->buffer, extra, extralen);
	memset(radio->buffer + extralen, 0, 8 - extralen);
	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
	radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
	} else {
	memset(radio->buffer, 0, 8);
	retval = usb_bulk_msg(radio->usbdev, usb_rcvbulkpipe(radio->usbdev, 0x81),
	radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
	}
	if (retval == 0 && size == BUFFER_LENGTH)
	return 0;
	if (video_is_registered(&radio->vdev) && cmd != AMRADIO_GET_READY_FLAG)
	amradio_dev_warn(&radio->vdev.dev, "follow-up to cmd %02x failed\n", cmd);
	return retval ? retval : -EIO;
	}

	/* switch on/off the radio. Send 8 bytes to device */
	static int amradio_set_mute(struct amradio_device *radio, bool mute)
	{
	int ret = amradio_send_cmd(radio,
	AMRADIO_SET_MUTE, mute, NULL, 0, false);

	if (!ret)
	radio->muted = mute;
	return ret;
	}

	/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
	static int amradio_set_freq(struct amradio_device *radio, int freq)
	{
	unsigned short freq_send;
	u8 buf[3];
	int retval;

	/* we need to be sure that frequency isn't out of range */
	freq = clamp_t(unsigned, freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
	freq_send = 0x10 + (freq >> 3) / 25;

	/* frequency is calculated from freq_send and placed in first 2 bytes */
	buf[0] = (freq_send >> 8) & 0xff;
	buf[1] = freq_send & 0xff;
	buf[2] = 0x01;

	retval = amradio_send_cmd(radio, AMRADIO_SET_FREQ, 0, buf, 3, false);
	if (retval)
	return retval;
	radio->curfreq = freq;
	msleep(40);
	return 0;
	}

	static int amradio_set_stereo(struct amradio_device *radio, bool stereo)
	{
	int ret = amradio_send_cmd(radio,
	AMRADIO_SET_MONO, !stereo, NULL, 0, false);

	if (!ret)
	radio->stereo = stereo;
	return ret;
	}

	static int amradio_get_stat(struct amradio_device radio, bool is_stereo, u32 *signal)
	{
	int ret = amradio_send_cmd(radio,
	AMRADIO_GET_SIGNAL, 0, NULL, 0, true);

	if (ret)
	return ret;
	*is_stereo = radio->buffer[2] >> 7;
	*signal = (radio->buffer[3] & 0xf0) << 8;
	return 0;
	}

	/* Handle unplugging the device.
	* We call video_unregister_device in any case.
	* The last function called in this procedure is
	* usb_amradio_device_release.
	*/
	static void usb_amradio_disconnect(struct usb_interface *intf)
	{
	struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));

	mutex_lock(&radio->lock);
	video_unregister_device(&radio->vdev);
	amradio_set_mute(radio, true);
	usb_set_intfdata(intf, NULL);
	v4l2_device_disconnect(&radio->v4l2_dev);
	mutex_unlock(&radio->lock);
	v4l2_device_put(&radio->v4l2_dev);
	}

	/* vidioc_querycap - query device capabilities */
	static int vidioc_querycap(struct file file, void priv,
	struct v4l2_capability *v)
	{
	struct amradio_device *radio = video_drvdata(file);

	strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
	strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
	v->device_caps = V4L2_CAP_RADIO \| V4L2_CAP_TUNER \|
	V4L2_CAP_HW_FREQ_SEEK;
	v->capabilities = v->device_caps \| V4L2_CAP_DEVICE_CAPS;
	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_drvdata(file);
	bool is_stereo = false;
	int retval;

	if (v->index > 0)
	return -EINVAL;

	v->signal = 0;
	retval = amradio_get_stat(radio, &is_stereo, &v->signal);
	if (retval)
	return retval;

	strcpy(v->name, "FM");
	v->type = V4L2_TUNER_RADIO;
	v->rangelow = FREQ_MIN * FREQ_MUL;
	v->rangehigh = FREQ_MAX * FREQ_MUL;
	v->capability = V4L2_TUNER_CAP_LOW \| V4L2_TUNER_CAP_STEREO \|
	V4L2_TUNER_CAP_HWSEEK_WRAP;
	v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
	v->audmode = radio->stereo ?
	V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
	return 0;
	}

	/* vidioc_s_tuner - set tuner attributes */
	static int vidioc_s_tuner(struct file file, void priv,
	const struct v4l2_tuner *v)
	{
	struct amradio_device *radio = video_drvdata(file);

	if (v->index > 0)
	return -EINVAL;

	/* mono/stereo selector */
	switch (v->audmode) {
	case V4L2_TUNER_MODE_MONO:
	return amradio_set_stereo(radio, WANT_MONO);
	default:
	return amradio_set_stereo(radio, WANT_STEREO);
	}
	}

	/* vidioc_s_frequency - set tuner radio frequency */
	static int vidioc_s_frequency(struct file file, void priv,
	const struct v4l2_frequency *f)
	{
	struct amradio_device *radio = video_drvdata(file);

	if (f->tuner != 0)
	return -EINVAL;
	return amradio_set_freq(radio, f->frequency);
	}

	/* 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_drvdata(file);

	if (f->tuner != 0 \|\| f->type != V4L2_TUNER_RADIO)
	return -EINVAL;
	f->type = V4L2_TUNER_RADIO;
	f->frequency = radio->curfreq;

	return 0;
	}

	static int vidioc_s_hw_freq_seek(struct file file, void priv,
	const struct v4l2_hw_freq_seek *seek)
	{
	static u8 buf[8] = {
	0x3d, 0x32, 0x0f, 0x08, 0x3d, 0x32, 0x0f, 0x08
	};
	struct amradio_device *radio = video_drvdata(file);
	unsigned long timeout;
	int retval;

	if (seek->tuner != 0 \|\| !seek->wrap_around)
	return -EINVAL;

	if (file->f_flags & O_NONBLOCK)
	return -EWOULDBLOCK;

	retval = amradio_send_cmd(radio,
	AMRADIO_SET_SEARCH_LVL, 0, buf, 8, false);
	if (retval)
	return retval;
	amradio_set_freq(radio, radio->curfreq);
	retval = amradio_send_cmd(radio,
	seek->seek_upward ? AMRADIO_SET_SEARCH_UP : AMRADIO_SET_SEARCH_DOWN,
	0, NULL, 0, false);
	if (retval)
	return retval;
	timeout = jiffies + msecs_to_jiffies(30000);
	for (;;) {
	if (time_after(jiffies, timeout)) {
	retval = -ENODATA;
	break;
	}
	if (schedule_timeout_interruptible(msecs_to_jiffies(10))) {
	retval = -ERESTARTSYS;
	break;
	}
	retval = amradio_send_cmd(radio, AMRADIO_GET_READY_FLAG,
	0, NULL, 0, true);
	if (retval)
	continue;
	amradio_send_cmd(radio, AMRADIO_GET_FREQ, 0, NULL, 0, true);
	if (radio->buffer[1] \|\| radio->buffer[2]) {
	/* To check: sometimes radio->curfreq is set to out of range value */
	radio->curfreq = (radio->buffer[1] << 8) \| radio->buffer[2];
	radio->curfreq = (radio->curfreq - 0x10) * 200;
	amradio_send_cmd(radio, AMRADIO_STOP_SEARCH,
	0, NULL, 0, false);
	amradio_set_freq(radio, radio->curfreq);
	retval = 0;
	break;
	}
	}
	amradio_send_cmd(radio, AMRADIO_STOP_SEARCH, 0, NULL, 0, false);
	amradio_set_freq(radio, radio->curfreq);
	return retval;
	}

	static int usb_amradio_s_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct amradio_device *radio =
	container_of(ctrl->handler, struct amradio_device, hdl);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
	return amradio_set_mute(radio, ctrl->val);
	}

	return -EINVAL;
	}

	static int usb_amradio_init(struct amradio_device *radio)
	{
	int retval;

	retval = amradio_set_mute(radio, true);
	if (retval)
	goto out_err;
	retval = amradio_set_stereo(radio, true);
	if (retval)
	goto out_err;
	retval = amradio_set_freq(radio, radio->curfreq);
	if (retval)
	goto out_err;
	return 0;

	out_err:
	amradio_dev_err(&radio->vdev.dev, "initialization failed\n");
	return retval;
	}

	/* 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 = to_amradio_dev(usb_get_intfdata(intf));

	mutex_lock(&radio->lock);
	if (!radio->muted) {
	amradio_set_mute(radio, true);
	radio->muted = false;
	}
	mutex_unlock(&radio->lock);

	dev_info(&intf->dev, "going into suspend..\n");
	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 = to_amradio_dev(usb_get_intfdata(intf));

	mutex_lock(&radio->lock);
	amradio_set_stereo(radio, radio->stereo);
	amradio_set_freq(radio, radio->curfreq);

	if (!radio->muted)
	amradio_set_mute(radio, false);

	mutex_unlock(&radio->lock);

	dev_info(&intf->dev, "coming out of suspend..\n");
	return 0;
	}

	static const struct v4l2_ctrl_ops usb_amradio_ctrl_ops = {
	.s_ctrl = usb_amradio_s_ctrl,
	};

	/* File system interface */
	static const struct v4l2_file_operations usb_amradio_fops = {
	.owner = THIS_MODULE,
	.open = v4l2_fh_open,
	.release = v4l2_fh_release,
	.poll = v4l2_ctrl_poll,
	.unlocked_ioctl = video_ioctl2,
	};

	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_s_hw_freq_seek = vidioc_s_hw_freq_seek,
	.vidioc_log_status = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
	};

	static void usb_amradio_release(struct v4l2_device *v4l2_dev)
	{
	struct amradio_device *radio = to_amradio_dev(v4l2_dev);

	/* free rest memory */
	v4l2_ctrl_handler_free(&radio->hdl);
	v4l2_device_unregister(&radio->v4l2_dev);
	kfree(radio->buffer);
	kfree(radio);
	}

	/* 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;
	int retval = 0;

	radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);

	if (!radio) {
	dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
	retval = -ENOMEM;
	goto err;
	}

	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);

	if (!radio->buffer) {
	dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
	retval = -ENOMEM;
	goto err_nobuf;
	}

	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
	if (retval < 0) {
	dev_err(&intf->dev, "couldn't register v4l2_device\n");
	goto err_v4l2;
	}

	v4l2_ctrl_handler_init(&radio->hdl, 1);
	v4l2_ctrl_new_std(&radio->hdl, &usb_amradio_ctrl_ops,
	V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
	if (radio->hdl.error) {
	retval = radio->hdl.error;
	dev_err(&intf->dev, "couldn't register control\n");
	goto err_ctrl;
	}
	mutex_init(&radio->lock);

	radio->v4l2_dev.ctrl_handler = &radio->hdl;
	radio->v4l2_dev.release = usb_amradio_release;
	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
	sizeof(radio->vdev.name));
	radio->vdev.v4l2_dev = &radio->v4l2_dev;
	radio->vdev.fops = &usb_amradio_fops;
	radio->vdev.ioctl_ops = &usb_amradio_ioctl_ops;
	radio->vdev.release = video_device_release_empty;
	radio->vdev.lock = &radio->lock;

	radio->usbdev = interface_to_usbdev(intf);
	radio->intf = intf;
	usb_set_intfdata(intf, &radio->v4l2_dev);
	radio->curfreq = 95.16 * FREQ_MUL;

	video_set_drvdata(&radio->vdev, radio);
	retval = usb_amradio_init(radio);
	if (retval)
	goto err_vdev;

	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
	radio_nr);
	if (retval < 0) {
	dev_err(&intf->dev, "could not register video device\n");
	goto err_vdev;
	}

	return 0;

	err_vdev:
	v4l2_ctrl_handler_free(&radio->hdl);
	err_ctrl:
	v4l2_device_unregister(&radio->v4l2_dev);
	err_v4l2:
	kfree(radio->buffer);
	err_nobuf:
	kfree(radio);
	err:
	return retval;
	}

	/* USB Device ID List */
	static const 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 = MR800_DRIVER_NAME,
	.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,
	};

	module_usb_driver(usb_amradio_driver);