[media] hackrf: HackRF SDR driver

V4L2 driver for HackRF SDR. Very basic version, with reduced
feature set. Driver implements receiver only, hardware supports
also transmitter.

USB ID 1d50:6089. Model HackRF One

Signed-off-by: Antti Palosaari <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/usb/Kconfig

···
 
 if MEDIA_SDR_SUPPORT
 	comment "Software defined radio USB devices"
-source "drivers/media/usb/msi2500/Kconfig"
 source "drivers/media/usb/airspy/Kconfig"
+source "drivers/media/usb/hackrf/Kconfig"
+source "drivers/media/usb/msi2500/Kconfig"
 endif
 
 endif #MEDIA_USB_SUPPORT

drivers/media/usb/Makefile

···
 obj-$(CONFIG_USB_VIDEO_CLASS)	+= uvc/
 obj-$(CONFIG_USB_GSPCA)         += gspca/
 obj-$(CONFIG_USB_PWC)           += pwc/
-obj-$(CONFIG_USB_MSI2500)       += msi2500/
 obj-$(CONFIG_USB_AIRSPY)        += airspy/
+obj-$(CONFIG_USB_HACKRF)        += hackrf/
+obj-$(CONFIG_USB_MSI2500)       += msi2500/
 obj-$(CONFIG_VIDEO_CPIA2) += cpia2/
 obj-$(CONFIG_VIDEO_AU0828) += au0828/
 obj-$(CONFIG_VIDEO_HDPVR)	+= hdpvr/

drivers/media/usb/hackrf/Kconfig

···
+config USB_HACKRF
+	tristate "HackRF"
+	depends on VIDEO_V4L2
+	select VIDEOBUF2_VMALLOC
+	---help---
+	  This is a video4linux2 driver for HackRF SDR device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hackrf
+

drivers/media/usb/hackrf/Makefile

···
+obj-$(CONFIG_USB_HACKRF)              += hackrf.o

drivers/media/usb/hackrf/hackrf.c

···
+/*
+ * HackRF driver
+ *
+ * Copyright (C) 2014 Antti Palosaari <[e-mail]>
+ *
+ *    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.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-vmalloc.h>
+
+/* HackRF USB API commands (from HackRF Library) */
+enum {
+	CMD_SET_TRANSCEIVER_MODE           = 0x01,
+	CMD_SAMPLE_RATE_SET                = 0x06,
+	CMD_BASEBAND_FILTER_BANDWIDTH_SET  = 0x07,
+	CMD_BOARD_ID_READ                  = 0x0e,
+	CMD_VERSION_STRING_READ            = 0x0f,
+	CMD_SET_FREQ                       = 0x10,
+	CMD_SET_LNA_GAIN                   = 0x13,
+	CMD_SET_VGA_GAIN                   = 0x14,
+};
+
+/*
+ *       bEndpointAddress     0x81  EP 1 IN
+ *         Transfer Type            Bulk
+ *       wMaxPacketSize     0x0200  1x 512 bytes
+ */
+#define MAX_BULK_BUFS            (6)
+#define BULK_BUFFER_SIZE         (128 * 512)
+
+static const struct v4l2_frequency_band bands_adc[] = {
+	{
+		.tuner = 0,
+		.type = V4L2_TUNER_ADC,
+		.index = 0,
+		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+		.rangelow   =   200000,
+		.rangehigh  = 24000000,
+	},
+};
+
+static const struct v4l2_frequency_band bands_rf[] = {
+	{
+		.tuner = 1,
+		.type = V4L2_TUNER_RF,
+		.index = 0,
+		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+		.rangelow   =          1,
+		.rangehigh  = 4294967294, /* max u32, hw goes over 7GHz */
+	},
+};
+
+/* stream formats */
+struct hackrf_format {
+	char	*name;
+	u32	pixelformat;
+	u32	buffersize;
+};
+
+/* format descriptions for capture and preview */
+static struct hackrf_format formats[] = {
+	{
+		.name		= "Complex S8",
+		.pixelformat	= V4L2_SDR_FMT_CS8,
+		.buffersize	= BULK_BUFFER_SIZE,
+	},
+};
+
+static const unsigned int NUM_FORMATS = ARRAY_SIZE(formats);
+
+/* intermediate buffers with raw data from the USB device */
+struct hackrf_frame_buf {
+	struct vb2_buffer vb;   /* common v4l buffer stuff -- must be first */
+	struct list_head list;
+};
+
+struct hackrf_dev {
+#define POWER_ON           (1 << 1)
+#define URB_BUF            (1 << 2)
+#define USB_STATE_URB_BUF  (1 << 3)
+	unsigned long flags;
+
+	struct device *dev;
+	struct usb_device *udev;
+	struct video_device vdev;
+	struct v4l2_device v4l2_dev;
+
+	/* videobuf2 queue and queued buffers list */
+	struct vb2_queue vb_queue;
+	struct list_head queued_bufs;
+	spinlock_t queued_bufs_lock; /* Protects queued_bufs */
+	unsigned sequence;	     /* Buffer sequence counter */
+	unsigned int vb_full;        /* vb is full and packets dropped */
+
+	/* Note if taking both locks v4l2_lock must always be locked first! */
+	struct mutex v4l2_lock;      /* Protects everything else */
+	struct mutex vb_queue_lock;  /* Protects vb_queue */
+
+	struct urb     *urb_list[MAX_BULK_BUFS];
+	int            buf_num;
+	unsigned long  buf_size;
+	u8             *buf_list[MAX_BULK_BUFS];
+	dma_addr_t     dma_addr[MAX_BULK_BUFS];
+	int            urbs_initialized;
+	int            urbs_submitted;
+
+	/* USB control message buffer */
+	#define BUF_SIZE 24
+	u8 buf[BUF_SIZE];
+
+	/* Current configuration */
+	unsigned int f_adc;
+	unsigned int f_rf;
+	u32 pixelformat;
+	u32 buffersize;
+
+	/* Controls */
+	struct v4l2_ctrl_handler hdl;
+	struct v4l2_ctrl *bandwidth_auto;
+	struct v4l2_ctrl *bandwidth;
+	struct v4l2_ctrl *lna_gain;
+	struct v4l2_ctrl *if_gain;
+
+	/* Sample rate calc */
+	unsigned long jiffies_next;
+	unsigned int sample;
+	unsigned int sample_measured;
+};
+
+#define hackrf_dbg_usb_control_msg(_dev, _r, _t, _v, _i, _b, _l) { \
+	char *_direction; \
+	if (_t & USB_DIR_IN) \
+		_direction = "<<<"; \
+	else \
+		_direction = ">>>"; \
+	dev_dbg(_dev, "%02x %02x %02x %02x %02x %02x %02x %02x %s %*ph\n", \
+			_t, _r, _v & 0xff, _v >> 8, _i & 0xff, \
+			_i >> 8, _l & 0xff, _l >> 8, _direction, _l, _b); \
+}
+
+/* execute firmware command */
+static int hackrf_ctrl_msg(struct hackrf_dev *dev, u8 request, u16 value,
+		u16 index, u8 *data, u16 size)
+{
+	int ret;
+	unsigned int pipe;
+	u8 requesttype;
+
+	switch (request) {
+	case CMD_SET_TRANSCEIVER_MODE:
+	case CMD_SET_FREQ:
+	case CMD_SAMPLE_RATE_SET:
+	case CMD_BASEBAND_FILTER_BANDWIDTH_SET:
+		pipe = usb_sndctrlpipe(dev->udev, 0);
+		requesttype = (USB_TYPE_VENDOR | USB_DIR_OUT);
+		break;
+	case CMD_BOARD_ID_READ:
+	case CMD_VERSION_STRING_READ:
+	case CMD_SET_LNA_GAIN:
+	case CMD_SET_VGA_GAIN:
+		pipe = usb_rcvctrlpipe(dev->udev, 0);
+		requesttype = (USB_TYPE_VENDOR | USB_DIR_IN);
+		break;
+	default:
+		dev_err(dev->dev, "Unknown command %02x\n", request);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	/* write request */
+	if (!(requesttype & USB_DIR_IN))
+		memcpy(dev->buf, data, size);
+
+	ret = usb_control_msg(dev->udev, pipe, request, requesttype, value,
+			index, dev->buf, size, 1000);
+	hackrf_dbg_usb_control_msg(dev->dev, request, requesttype, value,
+			index, dev->buf, size);
+	if (ret < 0) {
+		dev_err(dev->dev, "usb_control_msg() failed %d request %02x\n",
+				ret, request);
+		goto err;
+	}
+
+	/* read request */
+	if (requesttype & USB_DIR_IN)
+		memcpy(data, dev->buf, size);
+
+	return 0;
+err:
+	return ret;
+}
+
+/* Private functions */
+static struct hackrf_frame_buf *hackrf_get_next_fill_buf(struct hackrf_dev *dev)
+{
+	unsigned long flags;
+	struct hackrf_frame_buf *buf = NULL;
+
+	spin_lock_irqsave(&dev->queued_bufs_lock, flags);
+	if (list_empty(&dev->queued_bufs))
+		goto leave;
+
+	buf = list_entry(dev->queued_bufs.next, struct hackrf_frame_buf, list);
+	list_del(&buf->list);
+leave:
+	spin_unlock_irqrestore(&dev->queued_bufs_lock, flags);
+	return buf;
+}
+
+static unsigned int hackrf_convert_stream(struct hackrf_dev *dev,
+		void *dst, void *src, unsigned int src_len)
+{
+	memcpy(dst, src, src_len);
+
+	/* calculate sample rate and output it in 10 seconds intervals */
+	if (unlikely(time_is_before_jiffies(dev->jiffies_next))) {
+		#define MSECS 10000UL
+		unsigned int msecs = jiffies_to_msecs(jiffies -
+				dev->jiffies_next + msecs_to_jiffies(MSECS));
+		unsigned int samples = dev->sample - dev->sample_measured;
+
+		dev->jiffies_next = jiffies + msecs_to_jiffies(MSECS);
+		dev->sample_measured = dev->sample;
+		dev_dbg(dev->dev, "slen=%u samples=%u msecs=%u sample rate=%lu\n",
+				src_len, samples, msecs,
+				samples * 1000UL / msecs);
+	}
+
+	/* total number of samples */
+	dev->sample += src_len / 2;
+
+	return src_len;
+}
+
+/*
+ * This gets called for the bulk stream pipe. This is done in interrupt
+ * time, so it has to be fast, not crash, and not stall. Neat.
+ */
+static void hackrf_urb_complete(struct urb *urb)
+{
+	struct hackrf_dev *dev = urb->context;
+	struct hackrf_frame_buf *fbuf;
+
+	dev_dbg_ratelimited(dev->dev, "status=%d length=%d/%d errors=%d\n",
+			urb->status, urb->actual_length,
+			urb->transfer_buffer_length, urb->error_count);
+
+	switch (urb->status) {
+	case 0:             /* success */
+	case -ETIMEDOUT:    /* NAK */
+		break;
+	case -ECONNRESET:   /* kill */
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:            /* error */
+		dev_err_ratelimited(dev->dev, "URB failed %d\n", urb->status);
+		break;
+	}
+
+	if (likely(urb->actual_length > 0)) {
+		void *ptr;
+		unsigned int len;
+		/* get free framebuffer */
+		fbuf = hackrf_get_next_fill_buf(dev);
+		if (unlikely(fbuf == NULL)) {
+			dev->vb_full++;
+			dev_notice_ratelimited(dev->dev,
+					"videobuf is full, %d packets dropped\n",
+					dev->vb_full);
+			goto skip;
+		}
+
+		/* fill framebuffer */
+		ptr = vb2_plane_vaddr(&fbuf->vb, 0);
+		len = hackrf_convert_stream(dev, ptr, urb->transfer_buffer,
+				urb->actual_length);
+		vb2_set_plane_payload(&fbuf->vb, 0, len);
+		v4l2_get_timestamp(&fbuf->vb.v4l2_buf.timestamp);
+		fbuf->vb.v4l2_buf.sequence = dev->sequence++;
+		vb2_buffer_done(&fbuf->vb, VB2_BUF_STATE_DONE);
+	}
+skip:
+	usb_submit_urb(urb, GFP_ATOMIC);
+}
+
+static int hackrf_kill_urbs(struct hackrf_dev *dev)
+{
+	int i;
+
+	for (i = dev->urbs_submitted - 1; i >= 0; i--) {
+		dev_dbg(dev->dev, "kill urb=%d\n", i);
+		/* stop the URB */
+		usb_kill_urb(dev->urb_list[i]);
+	}
+	dev->urbs_submitted = 0;
+
+	return 0;
+}
+
+static int hackrf_submit_urbs(struct hackrf_dev *dev)
+{
+	int i, ret;
+
+	for (i = 0; i < dev->urbs_initialized; i++) {
+		dev_dbg(dev->dev, "submit urb=%d\n", i);
+		ret = usb_submit_urb(dev->urb_list[i], GFP_ATOMIC);
+		if (ret) {
+			dev_err(dev->dev, "Could not submit URB no. %d - get them all back\n",
+					i);
+			hackrf_kill_urbs(dev);
+			return ret;
+		}
+		dev->urbs_submitted++;
+	}
+
+	return 0;
+}
+
+static int hackrf_free_stream_bufs(struct hackrf_dev *dev)
+{
+	if (dev->flags & USB_STATE_URB_BUF) {
+		while (dev->buf_num) {
+			dev->buf_num--;
+			dev_dbg(dev->dev, "free buf=%d\n", dev->buf_num);
+			usb_free_coherent(dev->udev, dev->buf_size,
+					  dev->buf_list[dev->buf_num],
+					  dev->dma_addr[dev->buf_num]);
+		}
+	}
+	dev->flags &= ~USB_STATE_URB_BUF;
+
+	return 0;
+}
+
+static int hackrf_alloc_stream_bufs(struct hackrf_dev *dev)
+{
+	dev->buf_num = 0;
+	dev->buf_size = BULK_BUFFER_SIZE;
+
+	dev_dbg(dev->dev, "all in all I will use %u bytes for streaming\n",
+			MAX_BULK_BUFS * BULK_BUFFER_SIZE);
+
+	for (dev->buf_num = 0; dev->buf_num < MAX_BULK_BUFS; dev->buf_num++) {
+		dev->buf_list[dev->buf_num] = usb_alloc_coherent(dev->udev,
+				BULK_BUFFER_SIZE, GFP_ATOMIC,
+				&dev->dma_addr[dev->buf_num]);
+		if (!dev->buf_list[dev->buf_num]) {
+			dev_dbg(dev->dev, "alloc buf=%d failed\n",
+					dev->buf_num);
+			hackrf_free_stream_bufs(dev);
+			return -ENOMEM;
+		}
+
+		dev_dbg(dev->dev, "alloc buf=%d %p (dma %llu)\n", dev->buf_num,
+				dev->buf_list[dev->buf_num],
+				(long long)dev->dma_addr[dev->buf_num]);
+		dev->flags |= USB_STATE_URB_BUF;
+	}
+
+	return 0;
+}
+
+static int hackrf_free_urbs(struct hackrf_dev *dev)
+{
+	int i;
+
+	hackrf_kill_urbs(dev);
+
+	for (i = dev->urbs_initialized - 1; i >= 0; i--) {
+		if (dev->urb_list[i]) {
+			dev_dbg(dev->dev, "free urb=%d\n", i);
+			/* free the URBs */
+			usb_free_urb(dev->urb_list[i]);
+		}
+	}
+	dev->urbs_initialized = 0;
+
+	return 0;
+}
+
+static int hackrf_alloc_urbs(struct hackrf_dev *dev)
+{
+	int i, j;
+
+	/* allocate the URBs */
+	for (i = 0; i < MAX_BULK_BUFS; i++) {
+		dev_dbg(dev->dev, "alloc urb=%d\n", i);
+		dev->urb_list[i] = usb_alloc_urb(0, GFP_ATOMIC);
+		if (!dev->urb_list[i]) {
+			dev_dbg(dev->dev, "failed\n");
+			for (j = 0; j < i; j++)
+				usb_free_urb(dev->urb_list[j]);
+			return -ENOMEM;
+		}
+		usb_fill_bulk_urb(dev->urb_list[i],
+				dev->udev,
+				usb_rcvbulkpipe(dev->udev, 0x81),
+				dev->buf_list[i],
+				BULK_BUFFER_SIZE,
+				hackrf_urb_complete, dev);
+
+		dev->urb_list[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		dev->urb_list[i]->transfer_dma = dev->dma_addr[i];
+		dev->urbs_initialized++;
+	}
+
+	return 0;
+}
+
+/* Must be called with vb_queue_lock hold */
+static void hackrf_cleanup_queued_bufs(struct hackrf_dev *dev)
+{
+	unsigned long flags;
+
+	dev_dbg(dev->dev, "\n");
+
+	spin_lock_irqsave(&dev->queued_bufs_lock, flags);
+	while (!list_empty(&dev->queued_bufs)) {
+		struct hackrf_frame_buf *buf;
+
+		buf = list_entry(dev->queued_bufs.next,
+				struct hackrf_frame_buf, list);
+		list_del(&buf->list);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+	}
+	spin_unlock_irqrestore(&dev->queued_bufs_lock, flags);
+}
+
+/* The user yanked out the cable... */
+static void hackrf_disconnect(struct usb_interface *intf)
+{
+	struct v4l2_device *v = usb_get_intfdata(intf);
+	struct hackrf_dev *dev = container_of(v, struct hackrf_dev, v4l2_dev);
+
+	dev_dbg(dev->dev, "\n");
+
+	mutex_lock(&dev->vb_queue_lock);
+	mutex_lock(&dev->v4l2_lock);
+	/* No need to keep the urbs around after disconnection */
+	dev->udev = NULL;
+	v4l2_device_disconnect(&dev->v4l2_dev);
+	video_unregister_device(&dev->vdev);
+	mutex_unlock(&dev->v4l2_lock);
+	mutex_unlock(&dev->vb_queue_lock);
+
+	v4l2_device_put(&dev->v4l2_dev);
+}
+
+/* Videobuf2 operations */
+static int hackrf_queue_setup(struct vb2_queue *vq,
+		const struct v4l2_format *fmt, unsigned int *nbuffers,
+		unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
+
+	dev_dbg(dev->dev, "nbuffers=%d\n", *nbuffers);
+
+	/* Need at least 8 buffers */
+	if (vq->num_buffers + *nbuffers < 8)
+		*nbuffers = 8 - vq->num_buffers;
+	*nplanes = 1;
+	sizes[0] = PAGE_ALIGN(dev->buffersize);
+
+	dev_dbg(dev->dev, "nbuffers=%d sizes[0]=%d\n", *nbuffers, sizes[0]);
+	return 0;
+}
+
+static void hackrf_buf_queue(struct vb2_buffer *vb)
+{
+	struct hackrf_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+	struct hackrf_frame_buf *buf =
+			container_of(vb, struct hackrf_frame_buf, vb);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->queued_bufs_lock, flags);
+	list_add_tail(&buf->list, &dev->queued_bufs);
+	spin_unlock_irqrestore(&dev->queued_bufs_lock, flags);
+}
+
+static int hackrf_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
+	int ret;
+
+	dev_dbg(dev->dev, "\n");
+
+	if (!dev->udev)
+		return -ENODEV;
+
+	mutex_lock(&dev->v4l2_lock);
+
+	dev->sequence = 0;
+
+	set_bit(POWER_ON, &dev->flags);
+
+	ret = hackrf_alloc_stream_bufs(dev);
+	if (ret)
+		goto err;
+
+	ret = hackrf_alloc_urbs(dev);
+	if (ret)
+		goto err;
+
+	ret = hackrf_submit_urbs(dev);
+	if (ret)
+		goto err;
+
+	/* start hardware streaming */
+	ret = hackrf_ctrl_msg(dev, CMD_SET_TRANSCEIVER_MODE, 1, 0, NULL, 0);
+	if (ret)
+		goto err;
+
+	goto exit_mutex_unlock;
+err:
+	hackrf_kill_urbs(dev);
+	hackrf_free_urbs(dev);
+	hackrf_free_stream_bufs(dev);
+	clear_bit(POWER_ON, &dev->flags);
+
+	/* return all queued buffers to vb2 */
+	{
+		struct hackrf_frame_buf *buf, *tmp;
+
+		list_for_each_entry_safe(buf, tmp, &dev->queued_bufs, list) {
+			list_del(&buf->list);
+			vb2_buffer_done(&buf->vb, VB2_BUF_STATE_QUEUED);
+		}
+	}
+
+exit_mutex_unlock:
+	mutex_unlock(&dev->v4l2_lock);
+
+	return ret;
+}
+
+static void hackrf_stop_streaming(struct vb2_queue *vq)
+{
+	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
+
+	dev_dbg(dev->dev, "\n");
+
+	mutex_lock(&dev->v4l2_lock);
+
+	/* stop hardware streaming */
+	hackrf_ctrl_msg(dev, CMD_SET_TRANSCEIVER_MODE, 0, 0, NULL, 0);
+
+	hackrf_kill_urbs(dev);
+	hackrf_free_urbs(dev);
+	hackrf_free_stream_bufs(dev);
+
+	hackrf_cleanup_queued_bufs(dev);
+
+	clear_bit(POWER_ON, &dev->flags);
+
+	mutex_unlock(&dev->v4l2_lock);
+}
+
+static struct vb2_ops hackrf_vb2_ops = {
+	.queue_setup            = hackrf_queue_setup,
+	.buf_queue              = hackrf_buf_queue,
+	.start_streaming        = hackrf_start_streaming,
+	.stop_streaming         = hackrf_stop_streaming,
+	.wait_prepare           = vb2_ops_wait_prepare,
+	.wait_finish            = vb2_ops_wait_finish,
+};
+
+static int hackrf_querycap(struct file *file, void *fh,
+		struct v4l2_capability *cap)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+
+	dev_dbg(dev->dev, "\n");
+
+	strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
+	strlcpy(cap->card, dev->vdev.name, sizeof(cap->card));
+	usb_make_path(dev->udev, cap->bus_info, sizeof(cap->bus_info));
+	cap->device_caps = V4L2_CAP_SDR_CAPTURE | V4L2_CAP_STREAMING |
+			V4L2_CAP_READWRITE | V4L2_CAP_TUNER;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+
+	return 0;
+}
+
+static int hackrf_s_fmt_sdr_cap(struct file *file, void *priv,
+		struct v4l2_format *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	struct vb2_queue *q = &dev->vb_queue;
+	int i;
+
+	dev_dbg(dev->dev, "pixelformat fourcc %4.4s\n",
+			(char *)&f->fmt.sdr.pixelformat);
+
+	if (vb2_is_busy(q))
+		return -EBUSY;
+
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	for (i = 0; i < NUM_FORMATS; i++) {
+		if (f->fmt.sdr.pixelformat == formats[i].pixelformat) {
+			dev->pixelformat = formats[i].pixelformat;
+			dev->buffersize = formats[i].buffersize;
+			f->fmt.sdr.buffersize = formats[i].buffersize;
+			return 0;
+		}
+	}
+
+	dev->pixelformat = formats[0].pixelformat;
+	dev->buffersize = formats[0].buffersize;
+	f->fmt.sdr.pixelformat = formats[0].pixelformat;
+	f->fmt.sdr.buffersize = formats[0].buffersize;
+
+	return 0;
+}
+
+static int hackrf_g_fmt_sdr_cap(struct file *file, void *priv,
+		struct v4l2_format *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+
+	dev_dbg(dev->dev, "pixelformat fourcc %4.4s\n",
+			(char *)&dev->pixelformat);
+
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	f->fmt.sdr.pixelformat = dev->pixelformat;
+	f->fmt.sdr.buffersize = dev->buffersize;
+
+	return 0;
+}
+
+static int hackrf_try_fmt_sdr_cap(struct file *file, void *priv,
+		struct v4l2_format *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int i;
+
+	dev_dbg(dev->dev, "pixelformat fourcc %4.4s\n",
+			(char *)&f->fmt.sdr.pixelformat);
+
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	for (i = 0; i < NUM_FORMATS; i++) {
+		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
+			f->fmt.sdr.buffersize = formats[i].buffersize;
+			return 0;
+		}
+	}
+
+	f->fmt.sdr.pixelformat = formats[0].pixelformat;
+	f->fmt.sdr.buffersize = formats[0].buffersize;
+
+	return 0;
+}
+
+static int hackrf_enum_fmt_sdr_cap(struct file *file, void *priv,
+		struct v4l2_fmtdesc *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+
+	dev_dbg(dev->dev, "index=%d\n", f->index);
+
+	if (f->index >= NUM_FORMATS)
+		return -EINVAL;
+
+	strlcpy(f->description, formats[f->index].name, sizeof(f->description));
+	f->pixelformat = formats[f->index].pixelformat;
+
+	return 0;
+}
+
+static int hackrf_s_tuner(struct file *file, void *priv,
+		const struct v4l2_tuner *v)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int ret;
+
+	dev_dbg(dev->dev, "index=%d\n", v->index);
+
+	if (v->index == 0)
+		ret = 0;
+	else if (v->index == 1)
+		ret = 0;
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static int hackrf_g_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int ret;
+
+	dev_dbg(dev->dev, "index=%d\n", v->index);
+
+	if (v->index == 0) {
+		strlcpy(v->name, "HackRF ADC", sizeof(v->name));
+		v->type = V4L2_TUNER_ADC;
+		v->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
+		v->rangelow  = bands_adc[0].rangelow;
+		v->rangehigh = bands_adc[0].rangehigh;
+		ret = 0;
+	} else if (v->index == 1) {
+		strlcpy(v->name, "HackRF RF", sizeof(v->name));
+		v->type = V4L2_TUNER_RF;
+		v->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
+		v->rangelow  = bands_rf[0].rangelow;
+		v->rangehigh = bands_rf[0].rangehigh;
+		ret = 0;
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int hackrf_s_frequency(struct file *file, void *priv,
+		const struct v4l2_frequency *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int ret;
+	unsigned int upper, lower;
+	u8 buf[8];
+
+	dev_dbg(dev->dev, "tuner=%d type=%d frequency=%u\n",
+			f->tuner, f->type, f->frequency);
+
+	if (f->tuner == 0) {
+		dev->f_adc = clamp_t(unsigned int, f->frequency,
+				bands_adc[0].rangelow, bands_adc[0].rangehigh);
+		dev_dbg(dev->dev, "ADC frequency=%u Hz\n", dev->f_adc);
+		upper = dev->f_adc;
+		lower = 1;
+		buf[0] = (upper >>  0) & 0xff;
+		buf[1] = (upper >>  8) & 0xff;
+		buf[2] = (upper >> 16) & 0xff;
+		buf[3] = (upper >> 24) & 0xff;
+		buf[4] = (lower >>  0) & 0xff;
+		buf[5] = (lower >>  8) & 0xff;
+		buf[6] = (lower >> 16) & 0xff;
+		buf[7] = (lower >> 24) & 0xff;
+		ret = hackrf_ctrl_msg(dev, CMD_SAMPLE_RATE_SET, 0, 0, buf, 8);
+	} else if (f->tuner == 1) {
+		dev->f_rf = clamp_t(unsigned int, f->frequency,
+				bands_rf[0].rangelow, bands_rf[0].rangehigh);
+		dev_dbg(dev->dev, "RF frequency=%u Hz\n", dev->f_rf);
+		upper = dev->f_rf / 1000000;
+		lower = dev->f_rf % 1000000;
+		buf[0] = (upper >>  0) & 0xff;
+		buf[1] = (upper >>  8) & 0xff;
+		buf[2] = (upper >> 16) & 0xff;
+		buf[3] = (upper >> 24) & 0xff;
+		buf[4] = (lower >>  0) & 0xff;
+		buf[5] = (lower >>  8) & 0xff;
+		buf[6] = (lower >> 16) & 0xff;
+		buf[7] = (lower >> 24) & 0xff;
+		ret = hackrf_ctrl_msg(dev, CMD_SET_FREQ, 0, 0, buf, 8);
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int hackrf_g_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *f)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int ret;
+
+	dev_dbg(dev->dev, "tuner=%d type=%d\n", f->tuner, f->type);
+
+	if (f->tuner == 0) {
+		f->type = V4L2_TUNER_ADC;
+		f->frequency = dev->f_adc;
+		ret = 0;
+	} else if (f->tuner == 1) {
+		f->type = V4L2_TUNER_RF;
+		f->frequency = dev->f_rf;
+		ret = 0;
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int hackrf_enum_freq_bands(struct file *file, void *priv,
+		struct v4l2_frequency_band *band)
+{
+	struct hackrf_dev *dev = video_drvdata(file);
+	int ret;
+
+	dev_dbg(dev->dev, "tuner=%d type=%d index=%d\n",
+			band->tuner, band->type, band->index);
+
+	if (band->tuner == 0) {
+		if (band->index >= ARRAY_SIZE(bands_adc)) {
+			ret = -EINVAL;
+		} else {
+			*band = bands_adc[band->index];
+			ret = 0;
+		}
+	} else if (band->tuner == 1) {
+		if (band->index >= ARRAY_SIZE(bands_rf)) {
+			ret = -EINVAL;
+		} else {
+			*band = bands_rf[band->index];
+			ret = 0;
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct v4l2_ioctl_ops hackrf_ioctl_ops = {
+	.vidioc_querycap          = hackrf_querycap,
+
+	.vidioc_s_fmt_sdr_cap     = hackrf_s_fmt_sdr_cap,
+	.vidioc_g_fmt_sdr_cap     = hackrf_g_fmt_sdr_cap,
+	.vidioc_enum_fmt_sdr_cap  = hackrf_enum_fmt_sdr_cap,
+	.vidioc_try_fmt_sdr_cap   = hackrf_try_fmt_sdr_cap,
+
+	.vidioc_reqbufs           = vb2_ioctl_reqbufs,
+	.vidioc_create_bufs       = vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf       = vb2_ioctl_prepare_buf,
+	.vidioc_querybuf          = vb2_ioctl_querybuf,
+	.vidioc_qbuf              = vb2_ioctl_qbuf,
+	.vidioc_dqbuf             = vb2_ioctl_dqbuf,
+
+	.vidioc_streamon          = vb2_ioctl_streamon,
+	.vidioc_streamoff         = vb2_ioctl_streamoff,
+
+	.vidioc_s_tuner           = hackrf_s_tuner,
+	.vidioc_g_tuner           = hackrf_g_tuner,
+
+	.vidioc_s_frequency       = hackrf_s_frequency,
+	.vidioc_g_frequency       = hackrf_g_frequency,
+	.vidioc_enum_freq_bands   = hackrf_enum_freq_bands,
+
+	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+	.vidioc_log_status        = v4l2_ctrl_log_status,
+};
+
+static const struct v4l2_file_operations hackrf_fops = {
+	.owner                    = THIS_MODULE,
+	.open                     = v4l2_fh_open,
+	.release                  = vb2_fop_release,
+	.read                     = vb2_fop_read,
+	.poll                     = vb2_fop_poll,
+	.mmap                     = vb2_fop_mmap,
+	.unlocked_ioctl           = video_ioctl2,
+};
+
+static struct video_device hackrf_template = {
+	.name                     = "HackRF One",
+	.release                  = video_device_release_empty,
+	.fops                     = &hackrf_fops,
+	.ioctl_ops                = &hackrf_ioctl_ops,
+};
+
+static void hackrf_video_release(struct v4l2_device *v)
+{
+	struct hackrf_dev *dev = container_of(v, struct hackrf_dev, v4l2_dev);
+
+	v4l2_ctrl_handler_free(&dev->hdl);
+	v4l2_device_unregister(&dev->v4l2_dev);
+	kfree(dev);
+}
+
+static int hackrf_set_bandwidth(struct hackrf_dev *dev)
+{
+	int ret, i;
+	u16 u16tmp, u16tmp2;
+	unsigned int bandwidth;
+
+	static const struct {
+		u32 freq;
+	} bandwidth_lut[] = {
+		{ 1750000}, /*  1.75 MHz */
+		{ 2500000}, /*  2.5  MHz */
+		{ 3500000}, /*  3.5  MHz */
+		{ 5000000}, /*  5    MHz */
+		{ 5500000}, /*  5.5  MHz */
+		{ 6000000}, /*  6    MHz */
+		{ 7000000}, /*  7    MHz */
+		{ 8000000}, /*  8    MHz */
+		{ 9000000}, /*  9    MHz */
+		{10000000}, /* 10    MHz */
+		{12000000}, /* 12    MHz */
+		{14000000}, /* 14    MHz */
+		{15000000}, /* 15    MHz */
+		{20000000}, /* 20    MHz */
+		{24000000}, /* 24    MHz */
+		{28000000}, /* 28    MHz */
+	};
+
+	dev_dbg(dev->dev, "bandwidth auto=%d->%d val=%d->%d f_adc=%u\n",
+			dev->bandwidth_auto->cur.val,
+			dev->bandwidth_auto->val, dev->bandwidth->cur.val,
+			dev->bandwidth->val, dev->f_adc);
+
+	if (dev->bandwidth_auto->val == true)
+		bandwidth = dev->f_adc;
+	else
+		bandwidth = dev->bandwidth->val;
+
+	for (i = 0; i < ARRAY_SIZE(bandwidth_lut); i++) {
+		if (bandwidth <= bandwidth_lut[i].freq) {
+			bandwidth = bandwidth_lut[i].freq;
+			break;
+		}
+	}
+
+	dev->bandwidth->val = bandwidth;
+	dev->bandwidth->cur.val = bandwidth;
+
+	dev_dbg(dev->dev, "bandwidth selected=%d\n", bandwidth_lut[i].freq);
+
+	u16tmp = 0;
+	u16tmp |= ((bandwidth >> 0) & 0xff) << 0;
+	u16tmp |= ((bandwidth >> 8) & 0xff) << 8;
+	u16tmp2 = 0;
+	u16tmp2 |= ((bandwidth >> 16) & 0xff) << 0;
+	u16tmp2 |= ((bandwidth >> 24) & 0xff) << 8;
+
+	ret = hackrf_ctrl_msg(dev, CMD_BASEBAND_FILTER_BANDWIDTH_SET,
+				u16tmp, u16tmp2, NULL, 0);
+	if (ret)
+		dev_dbg(dev->dev, "failed=%d\n", ret);
+
+	return ret;
+}
+
+static int hackrf_set_lna_gain(struct hackrf_dev *dev)
+{
+	int ret;
+	u8 u8tmp;
+
+	dev_dbg(dev->dev, "lna val=%d->%d\n",
+			dev->lna_gain->cur.val, dev->lna_gain->val);
+
+	ret = hackrf_ctrl_msg(dev, CMD_SET_LNA_GAIN, 0, dev->lna_gain->val,
+			&u8tmp, 1);
+	if (ret)
+		dev_dbg(dev->dev, "failed=%d\n", ret);
+
+	return ret;
+}
+
+static int hackrf_set_if_gain(struct hackrf_dev *dev)
+{
+	int ret;
+	u8 u8tmp;
+
+	dev_dbg(dev->dev, "val=%d->%d\n",
+			dev->if_gain->cur.val, dev->if_gain->val);
+
+	ret = hackrf_ctrl_msg(dev, CMD_SET_VGA_GAIN, 0, dev->if_gain->val,
+			&u8tmp, 1);
+	if (ret)
+		dev_dbg(dev->dev, "failed=%d\n", ret);
+
+	return ret;
+}
+
+static int hackrf_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct hackrf_dev *dev = container_of(ctrl->handler,
+			struct hackrf_dev, hdl);
+	int ret;
+
+	switch (ctrl->id) {
+	case V4L2_CID_RF_TUNER_BANDWIDTH_AUTO:
+	case V4L2_CID_RF_TUNER_BANDWIDTH:
+		ret = hackrf_set_bandwidth(dev);
+		break;
+	case  V4L2_CID_RF_TUNER_LNA_GAIN:
+		ret = hackrf_set_lna_gain(dev);
+		break;
+	case  V4L2_CID_RF_TUNER_IF_GAIN:
+		ret = hackrf_set_if_gain(dev);
+		break;
+	default:
+		dev_dbg(dev->dev, "unknown ctrl: id=%d name=%s\n",
+				ctrl->id, ctrl->name);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct v4l2_ctrl_ops hackrf_ctrl_ops = {
+	.s_ctrl = hackrf_s_ctrl,
+};
+
+static int hackrf_probe(struct usb_interface *intf,
+		const struct usb_device_id *id)
+{
+	struct hackrf_dev *dev;
+	int ret;
+	u8 u8tmp, buf[BUF_SIZE];
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL)
+		return -ENOMEM;
+
+	mutex_init(&dev->v4l2_lock);
+	mutex_init(&dev->vb_queue_lock);
+	spin_lock_init(&dev->queued_bufs_lock);
+	INIT_LIST_HEAD(&dev->queued_bufs);
+	dev->dev = &intf->dev;
+	dev->udev = interface_to_usbdev(intf);
+	dev->f_adc = bands_adc[0].rangelow;
+	dev->f_rf = bands_rf[0].rangelow;
+	dev->pixelformat = formats[0].pixelformat;
+	dev->buffersize = formats[0].buffersize;
+
+	/* Detect device */
+	ret = hackrf_ctrl_msg(dev, CMD_BOARD_ID_READ, 0, 0, &u8tmp, 1);
+	if (ret == 0)
+		ret = hackrf_ctrl_msg(dev, CMD_VERSION_STRING_READ, 0, 0,
+				buf, BUF_SIZE);
+	if (ret) {
+		dev_err(dev->dev, "Could not detect board\n");
+		goto err_free_mem;
+	}
+
+	buf[BUF_SIZE - 1] = '\0';
+
+	dev_info(dev->dev, "Board ID: %02x\n", u8tmp);
+	dev_info(dev->dev, "Firmware version: %s\n", buf);
+
+	/* Init videobuf2 queue structure */
+	dev->vb_queue.type = V4L2_BUF_TYPE_SDR_CAPTURE;
+	dev->vb_queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
+	dev->vb_queue.drv_priv = dev;
+	dev->vb_queue.buf_struct_size = sizeof(struct hackrf_frame_buf);
+	dev->vb_queue.ops = &hackrf_vb2_ops;
+	dev->vb_queue.mem_ops = &vb2_vmalloc_memops;
+	dev->vb_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	ret = vb2_queue_init(&dev->vb_queue);
+	if (ret) {
+		dev_err(dev->dev, "Could not initialize vb2 queue\n");
+		goto err_free_mem;
+	}
+
+	/* Init video_device structure */
+	dev->vdev = hackrf_template;
+	dev->vdev.queue = &dev->vb_queue;
+	dev->vdev.queue->lock = &dev->vb_queue_lock;
+	video_set_drvdata(&dev->vdev, dev);
+
+	/* Register the v4l2_device structure */
+	dev->v4l2_dev.release = hackrf_video_release;
+	ret = v4l2_device_register(&intf->dev, &dev->v4l2_dev);
+	if (ret) {
+		dev_err(dev->dev, "Failed to register v4l2-device (%d)\n", ret);
+		goto err_free_mem;
+	}
+
+	/* Register controls */
+	v4l2_ctrl_handler_init(&dev->hdl, 4);
+	dev->bandwidth_auto = v4l2_ctrl_new_std(&dev->hdl, &hackrf_ctrl_ops,
+			V4L2_CID_RF_TUNER_BANDWIDTH_AUTO, 0, 1, 1, 1);
+	dev->bandwidth = v4l2_ctrl_new_std(&dev->hdl, &hackrf_ctrl_ops,
+			V4L2_CID_RF_TUNER_BANDWIDTH,
+			1750000, 28000000, 50000, 1750000);
+	v4l2_ctrl_auto_cluster(2, &dev->bandwidth_auto, 0, false);
+	dev->lna_gain = v4l2_ctrl_new_std(&dev->hdl, &hackrf_ctrl_ops,
+			V4L2_CID_RF_TUNER_LNA_GAIN, 0, 40, 8, 0);
+	dev->if_gain = v4l2_ctrl_new_std(&dev->hdl, &hackrf_ctrl_ops,
+			V4L2_CID_RF_TUNER_IF_GAIN, 0, 62, 2, 0);
+	if (dev->hdl.error) {
+		ret = dev->hdl.error;
+		dev_err(dev->dev, "Could not initialize controls\n");
+		goto err_free_controls;
+	}
+
+	v4l2_ctrl_handler_setup(&dev->hdl);
+
+	dev->v4l2_dev.ctrl_handler = &dev->hdl;
+	dev->vdev.v4l2_dev = &dev->v4l2_dev;
+	dev->vdev.lock = &dev->v4l2_lock;
+
+	ret = video_register_device(&dev->vdev, VFL_TYPE_SDR, -1);
+	if (ret) {
+		dev_err(dev->dev, "Failed to register as video device (%d)\n",
+				ret);
+		goto err_unregister_v4l2_dev;
+	}
+	dev_info(dev->dev, "Registered as %s\n",
+			video_device_node_name(&dev->vdev));
+	dev_notice(dev->dev, "SDR API is still slightly experimental and functionality changes may follow\n");
+	return 0;
+
+err_free_controls:
+	v4l2_ctrl_handler_free(&dev->hdl);
+err_unregister_v4l2_dev:
+	v4l2_device_unregister(&dev->v4l2_dev);
+err_free_mem:
+	kfree(dev);
+	return ret;
+}
+
+/* USB device ID list */
+static struct usb_device_id hackrf_id_table[] = {
+	{ USB_DEVICE(0x1d50, 0x6089) }, /* HackRF One */
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, hackrf_id_table);
+
+/* USB subsystem interface */
+static struct usb_driver hackrf_driver = {
+	.name                     = KBUILD_MODNAME,
+	.probe                    = hackrf_probe,
+	.disconnect               = hackrf_disconnect,
+	.id_table                 = hackrf_id_table,
+};
+
+module_usb_driver(hackrf_driver);
+
+MODULE_AUTHOR("Antti Palosaari <[e-mail]>");
+MODULE_DESCRIPTION("HackRF");
+MODULE_LICENSE("GPL");