drivers/media/usb/hackrf/hackrf.c

/*
 * HackRF driver
 *
 * Copyright (C) 2014 Antti Palosaari <crope@iki.fi>
 *
 *    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-v4l2.h>
#include <media/videobuf2-vmalloc.h>

/*
 * Used Avago MGA-81563 RF amplifier could be destroyed pretty easily with too
 * strong signal or transmitting to bad antenna.
 * Set RF gain control to 'grabbed' state by default for sure.
 */
static bool hackrf_enable_rf_gain_ctrl;
module_param_named(enable_rf_gain_ctrl, hackrf_enable_rf_gain_ctrl, bool, 0644);
MODULE_PARM_DESC(enable_rf_gain_ctrl, "enable RX/TX RF amplifier control (warn: could damage amplifier)");

/* 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_AMP_ENABLE                     = 0x11,
	CMD_SET_LNA_GAIN                   = 0x13,
	CMD_SET_VGA_GAIN                   = 0x14,
	CMD_SET_TXVGA_GAIN                 = 0x15,
};

/*
 *       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_dac[] = {
	{
		.tuner = 0,
		.type = V4L2_TUNER_SDR,
		.index = 0,
		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow   =   200000,
		.rangehigh  = 24000000,
	},
};

static const struct v4l2_frequency_band bands_rx_tx[] = {
	{
		.tuner = 1,
		.type = V4L2_TUNER_RF,
		.index = 0,
		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow   =          1,
		.rangehigh  = 4294967294LL, /* max u32, hw goes over 7GHz */
	},
};

/* stream formats */
struct hackrf_format {
	u32	pixelformat;
	u32	buffersize;
};

/* format descriptions for capture and preview */
static struct hackrf_format formats[] = {
	{
		.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_buffer {
	struct vb2_v4l2_buffer vb;
	struct list_head list;
};

struct hackrf_dev {
#define USB_STATE_URB_BUF                1 /* XXX: set manually */
#define RX_ON                            4
#define TX_ON                            5
#define RX_ADC_FREQUENCY                11
#define TX_DAC_FREQUENCY                12
#define RX_BANDWIDTH                    13
#define TX_BANDWIDTH                    14
#define RX_RF_FREQUENCY                 15
#define TX_RF_FREQUENCY                 16
#define RX_RF_GAIN                      17
#define TX_RF_GAIN                      18
#define RX_IF_GAIN                      19
#define RX_LNA_GAIN                     20
#define TX_LNA_GAIN                     21
	unsigned long flags;

	struct usb_interface *intf;
	struct device *dev;
	struct usb_device *udev;
	struct video_device rx_vdev;
	struct video_device tx_vdev;
	struct v4l2_device v4l2_dev;

	/* videobuf2 queue and queued buffers list */
	struct vb2_queue rx_vb2_queue;
	struct vb2_queue tx_vb2_queue;
	struct list_head rx_buffer_list;
	struct list_head tx_buffer_list;
	spinlock_t buffer_list_lock; /* Protects buffer_list */
	unsigned int sequence;	     /* Buffer sequence counter */
	unsigned int vb_full;        /* vb is full and packets dropped */
	unsigned int vb_empty;       /* vb is empty 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_dac;
	unsigned int f_rx;
	unsigned int f_tx;
	u32 pixelformat;
	u32 buffersize;

	/* Controls */
	struct v4l2_ctrl_handler rx_ctrl_handler;
	struct v4l2_ctrl *rx_bandwidth_auto;
	struct v4l2_ctrl *rx_bandwidth;
	struct v4l2_ctrl *rx_rf_gain;
	struct v4l2_ctrl *rx_lna_gain;
	struct v4l2_ctrl *rx_if_gain;
	struct v4l2_ctrl_handler tx_ctrl_handler;
	struct v4l2_ctrl *tx_bandwidth_auto;
	struct v4l2_ctrl *tx_bandwidth;
	struct v4l2_ctrl *tx_rf_gain;
	struct v4l2_ctrl *tx_lna_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_AMP_ENABLE:
	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:
	case CMD_SET_TXVGA_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;
}

static int hackrf_set_params(struct hackrf_dev *dev)
{
	struct usb_interface *intf = dev->intf;
	int ret, i;
	u8 buf[8], u8tmp;
	unsigned int uitmp, uitmp1, uitmp2;
	const bool rx = test_bit(RX_ON, &dev->flags);
	const bool tx = test_bit(TX_ON, &dev->flags);
	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 */
	};

	if (!rx && !tx) {
		dev_dbg(&intf->dev, "device is sleeping\n");
		return 0;
	}

	/* ADC / DAC frequency */
	if (rx && test_and_clear_bit(RX_ADC_FREQUENCY, &dev->flags)) {
		dev_dbg(&intf->dev, "RX ADC frequency=%u Hz\n", dev->f_adc);
		uitmp1 = dev->f_adc;
		uitmp2 = 1;
		set_bit(TX_DAC_FREQUENCY, &dev->flags);
	} else if (tx && test_and_clear_bit(TX_DAC_FREQUENCY, &dev->flags)) {
		dev_dbg(&intf->dev, "TX DAC frequency=%u Hz\n", dev->f_dac);
		uitmp1 = dev->f_dac;
		uitmp2 = 1;
		set_bit(RX_ADC_FREQUENCY, &dev->flags);
	} else {
		uitmp1 = uitmp2 = 0;
	}
	if (uitmp1 || uitmp2) {
		buf[0] = (uitmp1 >>  0) & 0xff;
		buf[1] = (uitmp1 >>  8) & 0xff;
		buf[2] = (uitmp1 >> 16) & 0xff;
		buf[3] = (uitmp1 >> 24) & 0xff;
		buf[4] = (uitmp2 >>  0) & 0xff;
		buf[5] = (uitmp2 >>  8) & 0xff;
		buf[6] = (uitmp2 >> 16) & 0xff;
		buf[7] = (uitmp2 >> 24) & 0xff;
		ret = hackrf_ctrl_msg(dev, CMD_SAMPLE_RATE_SET, 0, 0, buf, 8);
		if (ret)
			goto err;
	}

	/* bandwidth */
	if (rx && test_and_clear_bit(RX_BANDWIDTH, &dev->flags)) {
		if (dev->rx_bandwidth_auto->val == true)
			uitmp = dev->f_adc;
		else
			uitmp = dev->rx_bandwidth->val;

		for (i = 0; i < ARRAY_SIZE(bandwidth_lut); i++) {
			if (uitmp <= bandwidth_lut[i].freq) {
				uitmp = bandwidth_lut[i].freq;
				break;
			}
		}
		dev->rx_bandwidth->val = uitmp;
		dev->rx_bandwidth->cur.val = uitmp;
		dev_dbg(&intf->dev, "RX bandwidth selected=%u\n", uitmp);
		set_bit(TX_BANDWIDTH, &dev->flags);
	} else if (tx && test_and_clear_bit(TX_BANDWIDTH, &dev->flags)) {
		if (dev->tx_bandwidth_auto->val == true)
			uitmp = dev->f_dac;
		else
			uitmp = dev->tx_bandwidth->val;

		for (i = 0; i < ARRAY_SIZE(bandwidth_lut); i++) {
			if (uitmp <= bandwidth_lut[i].freq) {
				uitmp = bandwidth_lut[i].freq;
				break;
			}
		}
		dev->tx_bandwidth->val = uitmp;
		dev->tx_bandwidth->cur.val = uitmp;
		dev_dbg(&intf->dev, "TX bandwidth selected=%u\n", uitmp);
		set_bit(RX_BANDWIDTH, &dev->flags);
	} else {
		uitmp = 0;
	}
	if (uitmp) {
		uitmp1 = uitmp2 = 0;
		uitmp1 |= ((uitmp >>  0) & 0xff) << 0;
		uitmp1 |= ((uitmp >>  8) & 0xff) << 8;
		uitmp2 |= ((uitmp >> 16) & 0xff) << 0;
		uitmp2 |= ((uitmp >> 24) & 0xff) << 8;
		ret = hackrf_ctrl_msg(dev, CMD_BASEBAND_FILTER_BANDWIDTH_SET,
				      uitmp1, uitmp2, NULL, 0);
		if (ret)
			goto err;
	}

	/* RX / TX RF frequency */
	if (rx && test_and_clear_bit(RX_RF_FREQUENCY, &dev->flags)) {
		dev_dbg(&intf->dev, "RX RF frequency=%u Hz\n", dev->f_rx);
		uitmp1 = dev->f_rx / 1000000;
		uitmp2 = dev->f_rx % 1000000;
		set_bit(TX_RF_FREQUENCY, &dev->flags);
	} else if (tx && test_and_clear_bit(TX_RF_FREQUENCY, &dev->flags)) {
		dev_dbg(&intf->dev, "TX RF frequency=%u Hz\n", dev->f_tx);
		uitmp1 = dev->f_tx / 1000000;
		uitmp2 = dev->f_tx % 1000000;
		set_bit(RX_RF_FREQUENCY, &dev->flags);
	} else {
		uitmp1 = uitmp2 = 0;
	}
	if (uitmp1 || uitmp2) {
		buf[0] = (uitmp1 >>  0) & 0xff;
		buf[1] = (uitmp1 >>  8) & 0xff;
		buf[2] = (uitmp1 >> 16) & 0xff;
		buf[3] = (uitmp1 >> 24) & 0xff;
		buf[4] = (uitmp2 >>  0) & 0xff;
		buf[5] = (uitmp2 >>  8) & 0xff;
		buf[6] = (uitmp2 >> 16) & 0xff;
		buf[7] = (uitmp2 >> 24) & 0xff;
		ret = hackrf_ctrl_msg(dev, CMD_SET_FREQ, 0, 0, buf, 8);
		if (ret)
			goto err;
	}

	/* RX RF gain */
	if (rx && test_and_clear_bit(RX_RF_GAIN, &dev->flags)) {
		dev_dbg(&intf->dev, "RX RF gain val=%d->%d\n",
			dev->rx_rf_gain->cur.val, dev->rx_rf_gain->val);

		u8tmp = (dev->rx_rf_gain->val) ? 1 : 0;
		ret = hackrf_ctrl_msg(dev, CMD_AMP_ENABLE, u8tmp, 0, NULL, 0);
		if (ret)
			goto err;
		set_bit(TX_RF_GAIN, &dev->flags);
	}

	/* TX RF gain */
	if (tx && test_and_clear_bit(TX_RF_GAIN, &dev->flags)) {
		dev_dbg(&intf->dev, "TX RF gain val=%d->%d\n",
			dev->tx_rf_gain->cur.val, dev->tx_rf_gain->val);

		u8tmp = (dev->tx_rf_gain->val) ? 1 : 0;
		ret = hackrf_ctrl_msg(dev, CMD_AMP_ENABLE, u8tmp, 0, NULL, 0);
		if (ret)
			goto err;
		set_bit(RX_RF_GAIN, &dev->flags);
	}

	/* RX LNA gain */
	if (rx && test_and_clear_bit(RX_LNA_GAIN, &dev->flags)) {
		dev_dbg(dev->dev, "RX LNA gain val=%d->%d\n",
			dev->rx_lna_gain->cur.val, dev->rx_lna_gain->val);

		ret = hackrf_ctrl_msg(dev, CMD_SET_LNA_GAIN, 0,
				      dev->rx_lna_gain->val, &u8tmp, 1);
		if (ret)
			goto err;
	}

	/* RX IF gain */
	if (rx && test_and_clear_bit(RX_IF_GAIN, &dev->flags)) {
		dev_dbg(&intf->dev, "IF gain val=%d->%d\n",
			dev->rx_if_gain->cur.val, dev->rx_if_gain->val);

		ret = hackrf_ctrl_msg(dev, CMD_SET_VGA_GAIN, 0,
				      dev->rx_if_gain->val, &u8tmp, 1);
		if (ret)
			goto err;
	}

	/* TX LNA gain */
	if (tx && test_and_clear_bit(TX_LNA_GAIN, &dev->flags)) {
		dev_dbg(&intf->dev, "TX LNA gain val=%d->%d\n",
			dev->tx_lna_gain->cur.val, dev->tx_lna_gain->val);

		ret = hackrf_ctrl_msg(dev, CMD_SET_TXVGA_GAIN, 0,
				      dev->tx_lna_gain->val, &u8tmp, 1);
		if (ret)
			goto err;
	}

	return 0;
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

/* Private functions */
static struct hackrf_buffer *hackrf_get_next_buffer(struct hackrf_dev *dev,
						    struct list_head *buffer_list)
{
	unsigned long flags;
	struct hackrf_buffer *buffer = NULL;

	spin_lock_irqsave(&dev->buffer_list_lock, flags);
	if (list_empty(buffer_list))
		goto leave;

	buffer = list_entry(buffer_list->next, struct hackrf_buffer, list);
	list_del(&buffer->list);
leave:
	spin_unlock_irqrestore(&dev->buffer_list_lock, flags);
	return buffer;
}

static void hackrf_copy_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;
}

/*
 * 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_in(struct urb *urb)
{
	struct hackrf_dev *dev = urb->context;
	struct usb_interface *intf = dev->intf;
	struct hackrf_buffer *buffer;
	unsigned int len;

	dev_dbg_ratelimited(&intf->dev, "status=%d length=%u/%u\n", urb->status,
			    urb->actual_length, urb->transfer_buffer_length);

	switch (urb->status) {
	case 0:             /* success */
	case -ETIMEDOUT:    /* NAK */
		break;
	case -ECONNRESET:   /* kill */
	case -ENOENT:
	case -ESHUTDOWN:
		return;
	default:            /* error */
		dev_err_ratelimited(&intf->dev, "URB failed %d\n", urb->status);
		goto exit_usb_submit_urb;
	}

	/* get buffer to write */
	buffer = hackrf_get_next_buffer(dev, &dev->rx_buffer_list);
	if (unlikely(buffer == NULL)) {
		dev->vb_full++;
		dev_notice_ratelimited(&intf->dev,
				       "buffer is full - %u packets dropped\n",
				       dev->vb_full);
		goto exit_usb_submit_urb;
	}

	len = min_t(unsigned long, vb2_plane_size(&buffer->vb.vb2_buf, 0),
		    urb->actual_length);
	hackrf_copy_stream(dev, vb2_plane_vaddr(&buffer->vb.vb2_buf, 0),
		    urb->transfer_buffer, len);
	vb2_set_plane_payload(&buffer->vb.vb2_buf, 0, len);
	buffer->vb.sequence = dev->sequence++;
	buffer->vb.vb2_buf.timestamp = ktime_get_ns();
	vb2_buffer_done(&buffer->vb.vb2_buf, VB2_BUF_STATE_DONE);
exit_usb_submit_urb:
	usb_submit_urb(urb, GFP_ATOMIC);
}

static void hackrf_urb_complete_out(struct urb *urb)
{
	struct hackrf_dev *dev = urb->context;
	struct usb_interface *intf = dev->intf;
	struct hackrf_buffer *buffer;
	unsigned int len;

	dev_dbg_ratelimited(&intf->dev, "status=%d length=%u/%u\n", urb->status,
			    urb->actual_length, urb->transfer_buffer_length);

	switch (urb->status) {
	case 0:             /* success */
	case -ETIMEDOUT:    /* NAK */
		break;
	case -ECONNRESET:   /* kill */
	case -ENOENT:
	case -ESHUTDOWN:
		return;
	default:            /* error */
		dev_err_ratelimited(&intf->dev, "URB failed %d\n", urb->status);
	}

	/* get buffer to read */
	buffer = hackrf_get_next_buffer(dev, &dev->tx_buffer_list);
	if (unlikely(buffer == NULL)) {
		dev->vb_empty++;
		dev_notice_ratelimited(&intf->dev,
				       "buffer is empty - %u packets dropped\n",
				       dev->vb_empty);
		urb->actual_length = 0;
		goto exit_usb_submit_urb;
	}

	len = min_t(unsigned long, urb->transfer_buffer_length,
		    vb2_get_plane_payload(&buffer->vb.vb2_buf, 0));
	hackrf_copy_stream(dev, urb->transfer_buffer,
			   vb2_plane_vaddr(&buffer->vb.vb2_buf, 0), len);
	urb->actual_length = len;
	buffer->vb.sequence = dev->sequence++;
	buffer->vb.vb2_buf.timestamp = ktime_get_ns();
	vb2_buffer_done(&buffer->vb.vb2_buf, VB2_BUF_STATE_DONE);
exit_usb_submit_urb:
	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_KERNEL);
		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_KERNEL,
				&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, bool rcv)
{
	int i, j;
	unsigned int pipe;
	usb_complete_t complete;

	if (rcv) {
		pipe = usb_rcvbulkpipe(dev->udev, 0x81);
		complete = &hackrf_urb_complete_in;
	} else {
		pipe = usb_sndbulkpipe(dev->udev, 0x02);
		complete = &hackrf_urb_complete_out;
	}

	/* 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_KERNEL);
		if (!dev->urb_list[i]) {
			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,
				pipe,
				dev->buf_list[i],
				BULK_BUFFER_SIZE,
				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;
}

/* 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->tx_vdev);
	video_unregister_device(&dev->rx_vdev);
	mutex_unlock(&dev->v4l2_lock);
	mutex_unlock(&dev->vb_queue_lock);

	v4l2_device_put(&dev->v4l2_dev);
}

/* Videobuf2 operations */
static void hackrf_return_all_buffers(struct vb2_queue *vq,
				      enum vb2_buffer_state state)
{
	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
	struct usb_interface *intf = dev->intf;
	struct hackrf_buffer *buffer, *node;
	struct list_head *buffer_list;
	unsigned long flags;

	dev_dbg(&intf->dev, "\n");

	if (vq->type == V4L2_BUF_TYPE_SDR_CAPTURE)
		buffer_list = &dev->rx_buffer_list;
	else
		buffer_list = &dev->tx_buffer_list;

	spin_lock_irqsave(&dev->buffer_list_lock, flags);
	list_for_each_entry_safe(buffer, node, buffer_list, list) {
		dev_dbg(&intf->dev, "list_for_each_entry_safe\n");
		vb2_buffer_done(&buffer->vb.vb2_buf, state);
		list_del(&buffer->list);
	}
	spin_unlock_irqrestore(&dev->buffer_list_lock, flags);
}

static int hackrf_queue_setup(struct vb2_queue *vq,
		unsigned int *nbuffers,
		unsigned int *nplanes, unsigned int sizes[], struct device *alloc_devs[])
{
	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 vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct vb2_queue *vq = vb->vb2_queue;
	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
	struct hackrf_buffer *buffer = container_of(vbuf, struct hackrf_buffer, vb);
	struct list_head *buffer_list;
	unsigned long flags;

	dev_dbg_ratelimited(&dev->intf->dev, "\n");

	if (vq->type == V4L2_BUF_TYPE_SDR_CAPTURE)
		buffer_list = &dev->rx_buffer_list;
	else
		buffer_list = &dev->tx_buffer_list;

	spin_lock_irqsave(&dev->buffer_list_lock, flags);
	list_add_tail(&buffer->list, buffer_list);
	spin_unlock_irqrestore(&dev->buffer_list_lock, flags);
}

static int hackrf_start_streaming(struct vb2_queue *vq, unsigned int count)
{
	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
	struct usb_interface *intf = dev->intf;
	int ret;
	unsigned int mode;

	dev_dbg(&intf->dev, "count=%i\n", count);

	mutex_lock(&dev->v4l2_lock);

	/* Allow only RX or TX, not both same time */
	if (vq->type == V4L2_BUF_TYPE_SDR_CAPTURE) {
		if (test_bit(TX_ON, &dev->flags)) {
			ret = -EBUSY;
			goto err_hackrf_return_all_buffers;
		}

		mode = 1;
		set_bit(RX_ON, &dev->flags);
	} else {
		if (test_bit(RX_ON, &dev->flags)) {
			ret = -EBUSY;
			goto err_hackrf_return_all_buffers;
		}

		mode = 2;
		set_bit(TX_ON, &dev->flags);
	}

	dev->sequence = 0;

	ret = hackrf_alloc_stream_bufs(dev);
	if (ret)
		goto err;

	ret = hackrf_alloc_urbs(dev, (mode == 1));
	if (ret)
		goto err;

	ret = hackrf_submit_urbs(dev);
	if (ret)
		goto err;

	ret = hackrf_set_params(dev);
	if (ret)
		goto err;

	/* start hardware streaming */
	ret = hackrf_ctrl_msg(dev, CMD_SET_TRANSCEIVER_MODE, mode, 0, NULL, 0);
	if (ret)
		goto err;

	mutex_unlock(&dev->v4l2_lock);

	return 0;
err:
	hackrf_kill_urbs(dev);
	hackrf_free_urbs(dev);
	hackrf_free_stream_bufs(dev);
	clear_bit(RX_ON, &dev->flags);
	clear_bit(TX_ON, &dev->flags);
err_hackrf_return_all_buffers:
	hackrf_return_all_buffers(vq, VB2_BUF_STATE_QUEUED);
	mutex_unlock(&dev->v4l2_lock);
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

static void hackrf_stop_streaming(struct vb2_queue *vq)
{
	struct hackrf_dev *dev = vb2_get_drv_priv(vq);
	struct usb_interface *intf = dev->intf;

	dev_dbg(&intf->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_return_all_buffers(vq, VB2_BUF_STATE_ERROR);

	if (vq->type == V4L2_BUF_TYPE_SDR_CAPTURE)
		clear_bit(RX_ON, &dev->flags);
	else
		clear_bit(TX_ON, &dev->flags);

	mutex_unlock(&dev->v4l2_lock);
}

static const 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);
	struct usb_interface *intf = dev->intf;
	struct video_device *vdev = video_devdata(file);

	dev_dbg(&intf->dev, "\n");

	cap->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
	if (vdev->vfl_dir == VFL_DIR_RX)
		cap->device_caps |= V4L2_CAP_SDR_CAPTURE | V4L2_CAP_TUNER;
	else
		cap->device_caps |= V4L2_CAP_SDR_OUTPUT | V4L2_CAP_MODULATOR;

	cap->capabilities = V4L2_CAP_SDR_CAPTURE | V4L2_CAP_TUNER |
			    V4L2_CAP_SDR_OUTPUT | V4L2_CAP_MODULATOR |
			    V4L2_CAP_DEVICE_CAPS | cap->device_caps;
	strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
	strscpy(cap->card, dev->rx_vdev.name, sizeof(cap->card));
	usb_make_path(dev->udev, cap->bus_info, sizeof(cap->bus_info));

	return 0;
}

static int hackrf_s_fmt_sdr(struct file *file, void *priv,
			    struct v4l2_format *f)
{
	struct hackrf_dev *dev = video_drvdata(file);
	struct video_device *vdev = video_devdata(file);
	struct vb2_queue *q;
	int i;

	dev_dbg(dev->dev, "pixelformat fourcc %4.4s\n",
			(char *)&f->fmt.sdr.pixelformat);

	if (vdev->vfl_dir == VFL_DIR_RX)
		q = &dev->rx_vb2_queue;
	else
		q = &dev->tx_vb2_queue;

	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(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(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(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;

	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) {
		strscpy(v->name, "HackRF ADC", sizeof(v->name));
		v->type = V4L2_TUNER_SDR;
		v->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
		v->rangelow  = bands_adc_dac[0].rangelow;
		v->rangehigh = bands_adc_dac[0].rangehigh;
		ret = 0;
	} else if (v->index == 1) {
		strscpy(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_rx_tx[0].rangelow;
		v->rangehigh = bands_rx_tx[0].rangehigh;
		ret = 0;
	} else {
		ret = -EINVAL;
	}

	return ret;
}

static int hackrf_s_modulator(struct file *file, void *fh,
			      const struct v4l2_modulator *a)
{
	struct hackrf_dev *dev = video_drvdata(file);

	dev_dbg(dev->dev, "index=%d\n", a->index);

	return a->index > 1 ? -EINVAL : 0;
}

static int hackrf_g_modulator(struct file *file, void *fh,
			      struct v4l2_modulator *a)
{
	struct hackrf_dev *dev = video_drvdata(file);
	int ret;

	dev_dbg(dev->dev, "index=%d\n", a->index);

	if (a->index == 0) {
		strscpy(a->name, "HackRF DAC", sizeof(a->name));
		a->type = V4L2_TUNER_SDR;
		a->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
		a->rangelow  = bands_adc_dac[0].rangelow;
		a->rangehigh = bands_adc_dac[0].rangehigh;
		ret = 0;
	} else if (a->index == 1) {
		strscpy(a->name, "HackRF RF", sizeof(a->name));
		a->type = V4L2_TUNER_RF;
		a->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
		a->rangelow  = bands_rx_tx[0].rangelow;
		a->rangehigh = bands_rx_tx[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);
	struct usb_interface *intf = dev->intf;
	struct video_device *vdev = video_devdata(file);
	int ret;
	unsigned int uitmp;

	dev_dbg(&intf->dev, "tuner=%d type=%d frequency=%u\n",
			f->tuner, f->type, f->frequency);

	if (f->tuner == 0) {
		uitmp = clamp(f->frequency, bands_adc_dac[0].rangelow,
			      bands_adc_dac[0].rangehigh);
		if (vdev->vfl_dir == VFL_DIR_RX) {
			dev->f_adc = uitmp;
			set_bit(RX_ADC_FREQUENCY, &dev->flags);
		} else {
			dev->f_dac = uitmp;
			set_bit(TX_DAC_FREQUENCY, &dev->flags);
		}
	} else if (f->tuner == 1) {
		uitmp = clamp(f->frequency, bands_rx_tx[0].rangelow,
			      bands_rx_tx[0].rangehigh);
		if (vdev->vfl_dir == VFL_DIR_RX) {
			dev->f_rx = uitmp;
			set_bit(RX_RF_FREQUENCY, &dev->flags);
		} else {
			dev->f_tx = uitmp;
			set_bit(TX_RF_FREQUENCY, &dev->flags);
		}
	} else {
		ret = -EINVAL;
		goto err;
	}

	ret = hackrf_set_params(dev);
	if (ret)
		goto err;

	return 0;
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

static int hackrf_g_frequency(struct file *file, void *priv,
		struct v4l2_frequency *f)
{
	struct hackrf_dev *dev = video_drvdata(file);
	struct usb_interface *intf = dev->intf;
	struct video_device *vdev = video_devdata(file);
	int ret;

	dev_dbg(dev->dev, "tuner=%d type=%d\n", f->tuner, f->type);

	if (f->tuner == 0) {
		f->type = V4L2_TUNER_SDR;
		if (vdev->vfl_dir == VFL_DIR_RX)
			f->frequency = dev->f_adc;
		else
			f->frequency = dev->f_dac;
	} else if (f->tuner == 1) {
		f->type = V4L2_TUNER_RF;
		if (vdev->vfl_dir == VFL_DIR_RX)
			f->frequency = dev->f_rx;
		else
			f->frequency = dev->f_tx;
	} else {
		ret = -EINVAL;
		goto err;
	}

	return 0;
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	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_dac)) {
			ret = -EINVAL;
		} else {
			*band = bands_adc_dac[band->index];
			ret = 0;
		}
	} else if (band->tuner == 1) {
		if (band->index >= ARRAY_SIZE(bands_rx_tx)) {
			ret = -EINVAL;
		} else {
			*band = bands_rx_tx[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,
	.vidioc_g_fmt_sdr_cap     = hackrf_g_fmt_sdr,
	.vidioc_enum_fmt_sdr_cap  = hackrf_enum_fmt_sdr,
	.vidioc_try_fmt_sdr_cap   = hackrf_try_fmt_sdr,

	.vidioc_s_fmt_sdr_out     = hackrf_s_fmt_sdr,
	.vidioc_g_fmt_sdr_out     = hackrf_g_fmt_sdr,
	.vidioc_enum_fmt_sdr_out  = hackrf_enum_fmt_sdr,
	.vidioc_try_fmt_sdr_out   = hackrf_try_fmt_sdr,

	.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_expbuf            = vb2_ioctl_expbuf,

	.vidioc_streamon          = vb2_ioctl_streamon,
	.vidioc_streamoff         = vb2_ioctl_streamoff,

	.vidioc_s_tuner           = hackrf_s_tuner,
	.vidioc_g_tuner           = hackrf_g_tuner,

	.vidioc_s_modulator       = hackrf_s_modulator,
	.vidioc_g_modulator       = hackrf_g_modulator,

	.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,
	.write                    = vb2_fop_write,
	.poll                     = vb2_fop_poll,
	.mmap                     = vb2_fop_mmap,
	.unlocked_ioctl           = video_ioctl2,
};

static const 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);

	dev_dbg(dev->dev, "\n");

	v4l2_ctrl_handler_free(&dev->rx_ctrl_handler);
	v4l2_ctrl_handler_free(&dev->tx_ctrl_handler);
	v4l2_device_unregister(&dev->v4l2_dev);
	kfree(dev);
}

static int hackrf_s_ctrl_rx(struct v4l2_ctrl *ctrl)
{
	struct hackrf_dev *dev = container_of(ctrl->handler,
			struct hackrf_dev, rx_ctrl_handler);
	struct usb_interface *intf = dev->intf;
	int ret;

	switch (ctrl->id) {
	case V4L2_CID_RF_TUNER_BANDWIDTH_AUTO:
	case V4L2_CID_RF_TUNER_BANDWIDTH:
		set_bit(RX_BANDWIDTH, &dev->flags);
		break;
	case  V4L2_CID_RF_TUNER_RF_GAIN:
		set_bit(RX_RF_GAIN, &dev->flags);
		break;
	case  V4L2_CID_RF_TUNER_LNA_GAIN:
		set_bit(RX_LNA_GAIN, &dev->flags);
		break;
	case  V4L2_CID_RF_TUNER_IF_GAIN:
		set_bit(RX_IF_GAIN, &dev->flags);
		break;
	default:
		dev_dbg(&intf->dev, "unknown ctrl: id=%d name=%s\n",
			ctrl->id, ctrl->name);
		ret = -EINVAL;
		goto err;
	}

	ret = hackrf_set_params(dev);
	if (ret)
		goto err;

	return 0;
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

static int hackrf_s_ctrl_tx(struct v4l2_ctrl *ctrl)
{
	struct hackrf_dev *dev = container_of(ctrl->handler,
			struct hackrf_dev, tx_ctrl_handler);
	struct usb_interface *intf = dev->intf;
	int ret;

	switch (ctrl->id) {
	case V4L2_CID_RF_TUNER_BANDWIDTH_AUTO:
	case V4L2_CID_RF_TUNER_BANDWIDTH:
		set_bit(TX_BANDWIDTH, &dev->flags);
		break;
	case  V4L2_CID_RF_TUNER_LNA_GAIN:
		set_bit(TX_LNA_GAIN, &dev->flags);
		break;
	case  V4L2_CID_RF_TUNER_RF_GAIN:
		set_bit(TX_RF_GAIN, &dev->flags);
		break;
	default:
		dev_dbg(&intf->dev, "unknown ctrl: id=%d name=%s\n",
			ctrl->id, ctrl->name);
		ret = -EINVAL;
		goto err;
	}

	ret = hackrf_set_params(dev);
	if (ret)
		goto err;

	return 0;
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

static const struct v4l2_ctrl_ops hackrf_ctrl_ops_rx = {
	.s_ctrl = hackrf_s_ctrl_rx,
};

static const struct v4l2_ctrl_ops hackrf_ctrl_ops_tx = {
	.s_ctrl = hackrf_s_ctrl_tx,
};

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) {
		ret = -ENOMEM;
		goto err;
	}

	mutex_init(&dev->v4l2_lock);
	mutex_init(&dev->vb_queue_lock);
	spin_lock_init(&dev->buffer_list_lock);
	INIT_LIST_HEAD(&dev->rx_buffer_list);
	INIT_LIST_HEAD(&dev->tx_buffer_list);
	dev->intf = intf;
	dev->dev = &intf->dev;
	dev->udev = interface_to_usbdev(intf);
	dev->pixelformat = formats[0].pixelformat;
	dev->buffersize = formats[0].buffersize;
	dev->f_adc = bands_adc_dac[0].rangelow;
	dev->f_dac = bands_adc_dac[0].rangelow;
	dev->f_rx = bands_rx_tx[0].rangelow;
	dev->f_tx = bands_rx_tx[0].rangelow;
	set_bit(RX_ADC_FREQUENCY, &dev->flags);
	set_bit(TX_DAC_FREQUENCY, &dev->flags);
	set_bit(RX_RF_FREQUENCY, &dev->flags);
	set_bit(TX_RF_FREQUENCY, &dev->flags);

	/* 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_kfree;
	}

	buf[BUF_SIZE - 1] = '\0';
	dev_info(dev->dev, "Board ID: %02x\n", u8tmp);
	dev_info(dev->dev, "Firmware version: %s\n", buf);

	/* Init vb2 queue structure for receiver */
	dev->rx_vb2_queue.type = V4L2_BUF_TYPE_SDR_CAPTURE;
	dev->rx_vb2_queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF |
				     VB2_READ;
	dev->rx_vb2_queue.ops = &hackrf_vb2_ops;
	dev->rx_vb2_queue.mem_ops = &vb2_vmalloc_memops;
	dev->rx_vb2_queue.drv_priv = dev;
	dev->rx_vb2_queue.buf_struct_size = sizeof(struct hackrf_buffer);
	dev->rx_vb2_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
	ret = vb2_queue_init(&dev->rx_vb2_queue);
	if (ret) {
		dev_err(dev->dev, "Could not initialize rx vb2 queue\n");
		goto err_kfree;
	}

	/* Init vb2 queue structure for transmitter */
	dev->tx_vb2_queue.type = V4L2_BUF_TYPE_SDR_OUTPUT;
	dev->tx_vb2_queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF |
				     VB2_WRITE;
	dev->tx_vb2_queue.ops = &hackrf_vb2_ops;
	dev->tx_vb2_queue.mem_ops = &vb2_vmalloc_memops;
	dev->tx_vb2_queue.drv_priv = dev;
	dev->tx_vb2_queue.buf_struct_size = sizeof(struct hackrf_buffer);
	dev->tx_vb2_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
	ret = vb2_queue_init(&dev->tx_vb2_queue);
	if (ret) {
		dev_err(dev->dev, "Could not initialize tx vb2 queue\n");
		goto err_kfree;
	}

	/* Register controls for receiver */
	v4l2_ctrl_handler_init(&dev->rx_ctrl_handler, 5);
	dev->rx_bandwidth_auto = v4l2_ctrl_new_std(&dev->rx_ctrl_handler,
		&hackrf_ctrl_ops_rx, V4L2_CID_RF_TUNER_BANDWIDTH_AUTO,
		0, 1, 0, 1);
	dev->rx_bandwidth = v4l2_ctrl_new_std(&dev->rx_ctrl_handler,
		&hackrf_ctrl_ops_rx, V4L2_CID_RF_TUNER_BANDWIDTH,
		1750000, 28000000, 50000, 1750000);
	v4l2_ctrl_auto_cluster(2, &dev->rx_bandwidth_auto, 0, false);
	dev->rx_rf_gain = v4l2_ctrl_new_std(&dev->rx_ctrl_handler,
		&hackrf_ctrl_ops_rx, V4L2_CID_RF_TUNER_RF_GAIN, 0, 12, 12, 0);
	dev->rx_lna_gain = v4l2_ctrl_new_std(&dev->rx_ctrl_handler,
		&hackrf_ctrl_ops_rx, V4L2_CID_RF_TUNER_LNA_GAIN, 0, 40, 8, 0);
	dev->rx_if_gain = v4l2_ctrl_new_std(&dev->rx_ctrl_handler,
		&hackrf_ctrl_ops_rx, V4L2_CID_RF_TUNER_IF_GAIN, 0, 62, 2, 0);
	if (dev->rx_ctrl_handler.error) {
		ret = dev->rx_ctrl_handler.error;
		dev_err(dev->dev, "Could not initialize controls\n");
		goto err_v4l2_ctrl_handler_free_rx;
	}
	v4l2_ctrl_grab(dev->rx_rf_gain, !hackrf_enable_rf_gain_ctrl);
	v4l2_ctrl_handler_setup(&dev->rx_ctrl_handler);

	/* Register controls for transmitter */
	v4l2_ctrl_handler_init(&dev->tx_ctrl_handler, 4);
	dev->tx_bandwidth_auto = v4l2_ctrl_new_std(&dev->tx_ctrl_handler,
		&hackrf_ctrl_ops_tx, V4L2_CID_RF_TUNER_BANDWIDTH_AUTO,
		0, 1, 0, 1);
	dev->tx_bandwidth = v4l2_ctrl_new_std(&dev->tx_ctrl_handler,
		&hackrf_ctrl_ops_tx, V4L2_CID_RF_TUNER_BANDWIDTH,
		1750000, 28000000, 50000, 1750000);
	v4l2_ctrl_auto_cluster(2, &dev->tx_bandwidth_auto, 0, false);
	dev->tx_lna_gain = v4l2_ctrl_new_std(&dev->tx_ctrl_handler,
		&hackrf_ctrl_ops_tx, V4L2_CID_RF_TUNER_LNA_GAIN, 0, 47, 1, 0);
	dev->tx_rf_gain = v4l2_ctrl_new_std(&dev->tx_ctrl_handler,
		&hackrf_ctrl_ops_tx, V4L2_CID_RF_TUNER_RF_GAIN, 0, 15, 15, 0);
	if (dev->tx_ctrl_handler.error) {
		ret = dev->tx_ctrl_handler.error;
		dev_err(dev->dev, "Could not initialize controls\n");
		goto err_v4l2_ctrl_handler_free_tx;
	}
	v4l2_ctrl_grab(dev->tx_rf_gain, !hackrf_enable_rf_gain_ctrl);
	v4l2_ctrl_handler_setup(&dev->tx_ctrl_handler);

	/* 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_v4l2_ctrl_handler_free_tx;
	}

	/* Init video_device structure for receiver */
	dev->rx_vdev = hackrf_template;
	dev->rx_vdev.queue = &dev->rx_vb2_queue;
	dev->rx_vdev.queue->lock = &dev->vb_queue_lock;
	dev->rx_vdev.v4l2_dev = &dev->v4l2_dev;
	dev->rx_vdev.ctrl_handler = &dev->rx_ctrl_handler;
	dev->rx_vdev.lock = &dev->v4l2_lock;
	dev->rx_vdev.vfl_dir = VFL_DIR_RX;
	video_set_drvdata(&dev->rx_vdev, dev);
	ret = video_register_device(&dev->rx_vdev, VFL_TYPE_SDR, -1);
	if (ret) {
		dev_err(dev->dev,
			"Failed to register as video device (%d)\n", ret);
		goto err_v4l2_device_unregister;
	}
	dev_info(dev->dev, "Registered as %s\n",
		 video_device_node_name(&dev->rx_vdev));

	/* Init video_device structure for transmitter */
	dev->tx_vdev = hackrf_template;
	dev->tx_vdev.queue = &dev->tx_vb2_queue;
	dev->tx_vdev.queue->lock = &dev->vb_queue_lock;
	dev->tx_vdev.v4l2_dev = &dev->v4l2_dev;
	dev->tx_vdev.ctrl_handler = &dev->tx_ctrl_handler;
	dev->tx_vdev.lock = &dev->v4l2_lock;
	dev->tx_vdev.vfl_dir = VFL_DIR_TX;
	video_set_drvdata(&dev->tx_vdev, dev);
	ret = video_register_device(&dev->tx_vdev, VFL_TYPE_SDR, -1);
	if (ret) {
		dev_err(dev->dev,
			"Failed to register as video device (%d)\n", ret);
		goto err_video_unregister_device_rx;
	}
	dev_info(dev->dev, "Registered as %s\n",
		 video_device_node_name(&dev->tx_vdev));

	dev_notice(dev->dev, "SDR API is still slightly experimental and functionality changes may follow\n");
	return 0;
err_video_unregister_device_rx:
	video_unregister_device(&dev->rx_vdev);
err_v4l2_device_unregister:
	v4l2_device_unregister(&dev->v4l2_dev);
err_v4l2_ctrl_handler_free_tx:
	v4l2_ctrl_handler_free(&dev->tx_ctrl_handler);
err_v4l2_ctrl_handler_free_rx:
	v4l2_ctrl_handler_free(&dev->rx_ctrl_handler);
err_kfree:
	kfree(dev);
err:
	dev_dbg(&intf->dev, "failed=%d\n", ret);
	return ret;
}

/* USB device ID list */
static const 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 <crope@iki.fi>");
MODULE_DESCRIPTION("HackRF");
MODULE_LICENSE("GPL");