// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * AirSpy SDR driver
 *
 * Copyright (C) 2014 Antti Palosaari <crope@iki.fi>
 */

#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>

/* AirSpy USB API commands (from AirSpy Library) */
enum {
        CMD_INVALID                       = 0x00,
        CMD_RECEIVER_MODE                 = 0x01,
        CMD_SI5351C_WRITE                 = 0x02,
        CMD_SI5351C_READ                  = 0x03,
        CMD_R820T_WRITE                   = 0x04,
        CMD_R820T_READ                    = 0x05,
        CMD_SPIFLASH_ERASE                = 0x06,
        CMD_SPIFLASH_WRITE                = 0x07,
        CMD_SPIFLASH_READ                 = 0x08,
        CMD_BOARD_ID_READ                 = 0x09,
        CMD_VERSION_STRING_READ           = 0x0a,
        CMD_BOARD_PARTID_SERIALNO_READ    = 0x0b,
        CMD_SET_SAMPLE_RATE               = 0x0c,
        CMD_SET_FREQ                      = 0x0d,
        CMD_SET_LNA_GAIN                  = 0x0e,
        CMD_SET_MIXER_GAIN                = 0x0f,
        CMD_SET_VGA_GAIN                  = 0x10,
        CMD_SET_LNA_AGC                   = 0x11,
        CMD_SET_MIXER_AGC                 = 0x12,
        CMD_SET_PACKING                   = 0x13,
};

/*
 *       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[] = {
        {
                .tuner = 0,
                .type = V4L2_TUNER_ADC,
                .index = 0,
                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
                .rangelow   = 20000000,
                .rangehigh  = 20000000,
        },
};

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   =   24000000,
                .rangehigh  = 1750000000,
        },
};

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

/* format descriptions for capture and preview */
static struct airspy_format formats[] = {
        {
                .pixelformat    = V4L2_SDR_FMT_RU12LE,
                .buffersize     = BULK_BUFFER_SIZE,
        },
};

static const unsigned int NUM_FORMATS = ARRAY_SIZE(formats);

/* intermediate buffers with raw data from the USB device */
struct airspy_frame_buf {
        /* common v4l buffer stuff -- must be first */
        struct vb2_v4l2_buffer vb;
        struct list_head list;
};

struct airspy {
#define POWER_ON           1
#define USB_STATE_URB_BUF  2
        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 and capt_file */

        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 128
        u8 *buf;

        /* Current configuration */
        unsigned int f_adc;
        unsigned int f_rf;
        u32 pixelformat;
        u32 buffersize;

        /* Controls */
        struct v4l2_ctrl_handler hdl;
        struct v4l2_ctrl *lna_gain_auto;
        struct v4l2_ctrl *lna_gain;
        struct v4l2_ctrl *mixer_gain_auto;
        struct v4l2_ctrl *mixer_gain;
        struct v4l2_ctrl *if_gain;

        /* Sample rate calc */
        unsigned long jiffies_next;
        unsigned int sample;
        unsigned int sample_measured;
};

#define airspy_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 airspy_ctrl_msg(struct airspy *s, u8 request, u16 value, u16 index,
                u8 *data, u16 size)
{
        int ret;
        unsigned int pipe;
        u8 requesttype;

        switch (request) {
        case CMD_RECEIVER_MODE:
        case CMD_SET_FREQ:
                pipe = usb_sndctrlpipe(s->udev, 0);
                requesttype = (USB_TYPE_VENDOR | USB_DIR_OUT);
                break;
        case CMD_BOARD_ID_READ:
        case CMD_VERSION_STRING_READ:
        case CMD_BOARD_PARTID_SERIALNO_READ:
        case CMD_SET_LNA_GAIN:
        case CMD_SET_MIXER_GAIN:
        case CMD_SET_VGA_GAIN:
        case CMD_SET_LNA_AGC:
        case CMD_SET_MIXER_AGC:
                pipe = usb_rcvctrlpipe(s->udev, 0);
                requesttype = (USB_TYPE_VENDOR | USB_DIR_IN);
                break;
        default:
                dev_err(s->dev, "Unknown command %02x\n", request);
                ret = -EINVAL;
                goto err;
        }

        /* write request */
        if (!(requesttype & USB_DIR_IN))
                memcpy(s->buf, data, size);

        ret = usb_control_msg(s->udev, pipe, request, requesttype, value,
                        index, s->buf, size, 1000);
        airspy_dbg_usb_control_msg(s->dev, request, requesttype, value,
                        index, s->buf, size);
        if (ret < 0) {
                dev_err(s->dev, "usb_control_msg() failed %d request %02x\n",
                                ret, request);
                goto err;
        }

        /* read request */
        if (requesttype & USB_DIR_IN)
                memcpy(data, s->buf, size);

        return 0;
err:
        return ret;
}

/* Private functions */
static struct airspy_frame_buf *airspy_get_next_fill_buf(struct airspy *s)
{
        unsigned long flags;
        struct airspy_frame_buf *buf = NULL;

        spin_lock_irqsave(&s->queued_bufs_lock, flags);
        if (list_empty(&s->queued_bufs))
                goto leave;

        buf = list_entry(s->queued_bufs.next,
                        struct airspy_frame_buf, list);
        list_del(&buf->list);
leave:
        spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
        return buf;
}

static unsigned int airspy_convert_stream(struct airspy *s,
                void *dst, void *src, unsigned int src_len)
{
        unsigned int dst_len;

        if (s->pixelformat == V4L2_SDR_FMT_RU12LE) {
                memcpy(dst, src, src_len);
                dst_len = src_len;
        } else {
                dst_len = 0;
        }

        /* calculate sample rate and output it in 10 seconds intervals */
        if (unlikely(time_is_before_jiffies(s->jiffies_next))) {
                #define MSECS 10000UL
                unsigned int msecs = jiffies_to_msecs(jiffies -
                                s->jiffies_next + msecs_to_jiffies(MSECS));
                unsigned int samples = s->sample - s->sample_measured;

                s->jiffies_next = jiffies + msecs_to_jiffies(MSECS);
                s->sample_measured = s->sample;
                dev_dbg(s->dev, "slen=%u samples=%u msecs=%u sample rate=%lu\n",
                                src_len, samples, msecs,
                                samples * 1000UL / msecs);
        }

        /* total number of samples */
        s->sample += src_len / 2;

        return dst_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 airspy_urb_complete(struct urb *urb)
{
        struct airspy *s = urb->context;
        struct airspy_frame_buf *fbuf;

        dev_dbg_ratelimited(s->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(s->dev, "URB failed %d\n", urb->status);
                break;
        }

        if (likely(urb->actual_length > 0)) {
                void *ptr;
                unsigned int len;
                /* get free framebuffer */
                fbuf = airspy_get_next_fill_buf(s);
                if (unlikely(fbuf == NULL)) {
                        s->vb_full++;
                        dev_notice_ratelimited(s->dev,
                                        "video buffer is full, %d packets dropped\n",
                                        s->vb_full);
                        goto skip;
                }

                /* fill framebuffer */
                ptr = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);
                len = airspy_convert_stream(s, ptr, urb->transfer_buffer,
                                urb->actual_length);
                vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0, len);
                fbuf->vb.vb2_buf.timestamp = ktime_get_ns();
                fbuf->vb.sequence = s->sequence++;
                vb2_buffer_done(&fbuf->vb.vb2_buf, VB2_BUF_STATE_DONE);
        }
skip:
        usb_submit_urb(urb, GFP_ATOMIC);
}

static int airspy_kill_urbs(struct airspy *s)
{
        int i;

        for (i = s->urbs_submitted - 1; i >= 0; i--) {
                dev_dbg(s->dev, "kill urb=%d\n", i);
                /* stop the URB */
                usb_kill_urb(s->urb_list[i]);
        }
        s->urbs_submitted = 0;

        return 0;
}

static int airspy_submit_urbs(struct airspy *s)
{
        int i, ret;

        for (i = 0; i < s->urbs_initialized; i++) {
                dev_dbg(s->dev, "submit urb=%d\n", i);
                ret = usb_submit_urb(s->urb_list[i], GFP_ATOMIC);
                if (ret) {
                        dev_err(s->dev, "Could not submit URB no. %d - get them all back\n",
                                        i);
                        airspy_kill_urbs(s);
                        return ret;
                }
                s->urbs_submitted++;
        }

        return 0;
}

static int airspy_free_stream_bufs(struct airspy *s)
{
        if (test_bit(USB_STATE_URB_BUF, &s->flags)) {
                while (s->buf_num) {
                        s->buf_num--;
                        dev_dbg(s->dev, "free buf=%d\n", s->buf_num);
                        usb_free_coherent(s->udev, s->buf_size,
                                          s->buf_list[s->buf_num],
                                          s->dma_addr[s->buf_num]);
                }
        }
        clear_bit(USB_STATE_URB_BUF, &s->flags);

        return 0;
}

static int airspy_alloc_stream_bufs(struct airspy *s)
{
        s->buf_num = 0;
        s->buf_size = BULK_BUFFER_SIZE;

        dev_dbg(s->dev, "all in all I will use %u bytes for streaming\n",
                        MAX_BULK_BUFS * BULK_BUFFER_SIZE);

        for (s->buf_num = 0; s->buf_num < MAX_BULK_BUFS; s->buf_num++) {
                s->buf_list[s->buf_num] = usb_alloc_coherent(s->udev,
                                BULK_BUFFER_SIZE, GFP_ATOMIC,
                                &s->dma_addr[s->buf_num]);
                if (!s->buf_list[s->buf_num]) {
                        dev_dbg(s->dev, "alloc buf=%d failed\n", s->buf_num);
                        airspy_free_stream_bufs(s);
                        return -ENOMEM;
                }

                dev_dbg(s->dev, "alloc buf=%d %p (dma %llu)\n", s->buf_num,
                                s->buf_list[s->buf_num],
                                (long long)s->dma_addr[s->buf_num]);
                set_bit(USB_STATE_URB_BUF, &s->flags);
        }

        return 0;
}

static int airspy_free_urbs(struct airspy *s)
{
        int i;

        airspy_kill_urbs(s);

        for (i = s->urbs_initialized - 1; i >= 0; i--) {
                if (s->urb_list[i]) {
                        dev_dbg(s->dev, "free urb=%d\n", i);
                        /* free the URBs */
                        usb_free_urb(s->urb_list[i]);
                }
        }
        s->urbs_initialized = 0;

        return 0;
}

static int airspy_alloc_urbs(struct airspy *s)
{
        int i, j;

        /* allocate the URBs */
        for (i = 0; i < MAX_BULK_BUFS; i++) {
                dev_dbg(s->dev, "alloc urb=%d\n", i);
                s->urb_list[i] = usb_alloc_urb(0, GFP_ATOMIC);
                if (!s->urb_list[i]) {
                        for (j = 0; j < i; j++) {
                                usb_free_urb(s->urb_list[j]);
                                s->urb_list[j] = NULL;
                        }
                        s->urbs_initialized = 0;
                        return -ENOMEM;
                }
                usb_fill_bulk_urb(s->urb_list[i],
                                s->udev,
                                usb_rcvbulkpipe(s->udev, 0x81),
                                s->buf_list[i],
                                BULK_BUFFER_SIZE,
                                airspy_urb_complete, s);

                s->urb_list[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
                s->urb_list[i]->transfer_dma = s->dma_addr[i];
                s->urbs_initialized++;
        }

        return 0;
}

/* Must be called with vb_queue_lock hold */
static void airspy_cleanup_queued_bufs(struct airspy *s)
{
        unsigned long flags;

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

        spin_lock_irqsave(&s->queued_bufs_lock, flags);
        while (!list_empty(&s->queued_bufs)) {
                struct airspy_frame_buf *buf;

                buf = list_entry(s->queued_bufs.next,
                                struct airspy_frame_buf, list);
                list_del(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
        }
        spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
}

/* The user yanked out the cable... */
static void airspy_disconnect(struct usb_interface *intf)
{
        struct v4l2_device *v = usb_get_intfdata(intf);
        struct airspy *s = container_of(v, struct airspy, v4l2_dev);

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

        mutex_lock(&s->vb_queue_lock);
        mutex_lock(&s->v4l2_lock);
        /* No need to keep the urbs around after disconnection */
        s->udev = NULL;
        v4l2_device_disconnect(&s->v4l2_dev);
        video_unregister_device(&s->vdev);
        mutex_unlock(&s->v4l2_lock);
        mutex_unlock(&s->vb_queue_lock);

        v4l2_device_put(&s->v4l2_dev);
}

/* Videobuf2 operations */
static int airspy_queue_setup(struct vb2_queue *vq,
                unsigned int *nbuffers,
                unsigned int *nplanes, unsigned int sizes[], struct device *alloc_devs[])
{
        struct airspy *s = vb2_get_drv_priv(vq);
        unsigned int q_num_bufs = vb2_get_num_buffers(vq);

        dev_dbg(s->dev, "nbuffers=%d\n", *nbuffers);

        /* Need at least 8 buffers */
        if (q_num_bufs + *nbuffers < 8)
                *nbuffers = 8 - q_num_bufs;
        *nplanes = 1;
        sizes[0] = PAGE_ALIGN(s->buffersize);

        dev_dbg(s->dev, "nbuffers=%d sizes[0]=%d\n", *nbuffers, sizes[0]);
        return 0;
}

static void airspy_buf_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct airspy *s = vb2_get_drv_priv(vb->vb2_queue);
        struct airspy_frame_buf *buf =
                        container_of(vbuf, struct airspy_frame_buf, vb);
        unsigned long flags;

        /* Check the device has not disconnected between prep and queuing */
        if (unlikely(!s->udev)) {
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
                return;
        }

        spin_lock_irqsave(&s->queued_bufs_lock, flags);
        list_add_tail(&buf->list, &s->queued_bufs);
        spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
}

static int airspy_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct airspy *s = vb2_get_drv_priv(vq);
        int ret;

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

        if (!s->udev)
                return -ENODEV;

        mutex_lock(&s->v4l2_lock);

        s->sequence = 0;

        set_bit(POWER_ON, &s->flags);

        ret = airspy_alloc_stream_bufs(s);
        if (ret)
                goto err_clear_bit;

        ret = airspy_alloc_urbs(s);
        if (ret)
                goto err_free_stream_bufs;

        ret = airspy_submit_urbs(s);
        if (ret)
                goto err_free_urbs;

        /* start hardware streaming */
        ret = airspy_ctrl_msg(s, CMD_RECEIVER_MODE, 1, 0, NULL, 0);
        if (ret)
                goto err_kill_urbs;

        goto exit_mutex_unlock;

err_kill_urbs:
        airspy_kill_urbs(s);
err_free_urbs:
        airspy_free_urbs(s);
err_free_stream_bufs:
        airspy_free_stream_bufs(s);
err_clear_bit:
        clear_bit(POWER_ON, &s->flags);

        /* return all queued buffers to vb2 */
        {
                struct airspy_frame_buf *buf, *tmp;

                list_for_each_entry_safe(buf, tmp, &s->queued_bufs, list) {
                        list_del(&buf->list);
                        vb2_buffer_done(&buf->vb.vb2_buf,
                                        VB2_BUF_STATE_QUEUED);
                }
        }

exit_mutex_unlock:
        mutex_unlock(&s->v4l2_lock);

        return ret;
}

static void airspy_stop_streaming(struct vb2_queue *vq)
{
        struct airspy *s = vb2_get_drv_priv(vq);

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

        mutex_lock(&s->v4l2_lock);

        /* stop hardware streaming */
        airspy_ctrl_msg(s, CMD_RECEIVER_MODE, 0, 0, NULL, 0);

        airspy_kill_urbs(s);
        airspy_free_urbs(s);
        airspy_free_stream_bufs(s);

        airspy_cleanup_queued_bufs(s);

        clear_bit(POWER_ON, &s->flags);

        mutex_unlock(&s->v4l2_lock);
}

static const struct vb2_ops airspy_vb2_ops = {
        .queue_setup            = airspy_queue_setup,
        .buf_queue              = airspy_buf_queue,
        .start_streaming        = airspy_start_streaming,
        .stop_streaming         = airspy_stop_streaming,
};

static int airspy_querycap(struct file *file, void *fh,
                struct v4l2_capability *cap)
{
        struct airspy *s = video_drvdata(file);

        strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
        strscpy(cap->card, s->vdev.name, sizeof(cap->card));
        usb_make_path(s->udev, cap->bus_info, sizeof(cap->bus_info));
        return 0;
}

static int airspy_enum_fmt_sdr_cap(struct file *file, void *priv,
                struct v4l2_fmtdesc *f)
{
        if (f->index >= NUM_FORMATS)
                return -EINVAL;

        f->pixelformat = formats[f->index].pixelformat;

        return 0;
}

static int airspy_g_fmt_sdr_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
        struct airspy *s = video_drvdata(file);

        f->fmt.sdr.pixelformat = s->pixelformat;
        f->fmt.sdr.buffersize = s->buffersize;

        return 0;
}

static int airspy_s_fmt_sdr_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
        struct airspy *s = video_drvdata(file);
        struct vb2_queue *q = &s->vb_queue;
        int i;

        if (vb2_is_busy(q))
                return -EBUSY;

        for (i = 0; i < NUM_FORMATS; i++) {
                if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
                        s->pixelformat = formats[i].pixelformat;
                        s->buffersize = formats[i].buffersize;
                        f->fmt.sdr.buffersize = formats[i].buffersize;
                        return 0;
                }
        }

        s->pixelformat = formats[0].pixelformat;
        s->buffersize = formats[0].buffersize;
        f->fmt.sdr.pixelformat = formats[0].pixelformat;
        f->fmt.sdr.buffersize = formats[0].buffersize;

        return 0;
}

static int airspy_try_fmt_sdr_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
        int i;

        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 airspy_s_tuner(struct file *file, void *priv,
                const struct v4l2_tuner *v)
{
        int ret;

        if (v->index == 0)
                ret = 0;
        else if (v->index == 1)
                ret = 0;
        else
                ret = -EINVAL;

        return ret;
}

static int airspy_g_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
{
        int ret;

        if (v->index == 0) {
                strscpy(v->name, "AirSpy ADC", sizeof(v->name));
                v->type = V4L2_TUNER_ADC;
                v->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
                v->rangelow  = bands[0].rangelow;
                v->rangehigh = bands[0].rangehigh;
                ret = 0;
        } else if (v->index == 1) {
                strscpy(v->name, "AirSpy 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 airspy_g_frequency(struct file *file, void *priv,
                struct v4l2_frequency *f)
{
        struct airspy *s = video_drvdata(file);
        int ret;

        if (f->tuner == 0) {
                f->type = V4L2_TUNER_ADC;
                f->frequency = s->f_adc;
                dev_dbg(s->dev, "ADC frequency=%u Hz\n", s->f_adc);
                ret = 0;
        } else if (f->tuner == 1) {
                f->type = V4L2_TUNER_RF;
                f->frequency = s->f_rf;
                dev_dbg(s->dev, "RF frequency=%u Hz\n", s->f_rf);
                ret = 0;
        } else {
                ret = -EINVAL;
        }

        return ret;
}

static int airspy_s_frequency(struct file *file, void *priv,
                const struct v4l2_frequency *f)
{
        struct airspy *s = video_drvdata(file);
        int ret;
        u8 buf[4];

        if (f->tuner == 0) {
                s->f_adc = clamp_t(unsigned int, f->frequency,
                                bands[0].rangelow,
                                bands[0].rangehigh);
                dev_dbg(s->dev, "ADC frequency=%u Hz\n", s->f_adc);
                ret = 0;
        } else if (f->tuner == 1) {
                s->f_rf = clamp_t(unsigned int, f->frequency,
                                bands_rf[0].rangelow,
                                bands_rf[0].rangehigh);
                dev_dbg(s->dev, "RF frequency=%u Hz\n", s->f_rf);
                buf[0] = (s->f_rf >>  0) & 0xff;
                buf[1] = (s->f_rf >>  8) & 0xff;
                buf[2] = (s->f_rf >> 16) & 0xff;
                buf[3] = (s->f_rf >> 24) & 0xff;
                ret = airspy_ctrl_msg(s, CMD_SET_FREQ, 0, 0, buf, 4);
        } else {
                ret = -EINVAL;
        }

        return ret;
}

static int airspy_enum_freq_bands(struct file *file, void *priv,
                struct v4l2_frequency_band *band)
{
        int ret;

        if (band->tuner == 0) {
                if (band->index >= ARRAY_SIZE(bands)) {
                        ret = -EINVAL;
                } else {
                        *band = bands[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 airspy_ioctl_ops = {
        .vidioc_querycap          = airspy_querycap,

        .vidioc_enum_fmt_sdr_cap  = airspy_enum_fmt_sdr_cap,
        .vidioc_g_fmt_sdr_cap     = airspy_g_fmt_sdr_cap,
        .vidioc_s_fmt_sdr_cap     = airspy_s_fmt_sdr_cap,
        .vidioc_try_fmt_sdr_cap   = airspy_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_g_tuner           = airspy_g_tuner,
        .vidioc_s_tuner           = airspy_s_tuner,

        .vidioc_g_frequency       = airspy_g_frequency,
        .vidioc_s_frequency       = airspy_s_frequency,
        .vidioc_enum_freq_bands   = airspy_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 airspy_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 const struct video_device airspy_template = {
        .name                     = "AirSpy SDR",
        .release                  = video_device_release_empty,
        .fops                     = &airspy_fops,
        .ioctl_ops                = &airspy_ioctl_ops,
};

static void airspy_video_release(struct v4l2_device *v)
{
        struct airspy *s = container_of(v, struct airspy, v4l2_dev);

        v4l2_ctrl_handler_free(&s->hdl);
        v4l2_device_unregister(&s->v4l2_dev);
        kfree(s->buf);
        kfree(s);
}

static int airspy_set_lna_gain(struct airspy *s)
{
        int ret;
        u8 u8tmp;

        dev_dbg(s->dev, "lna auto=%d->%d val=%d->%d\n",
                        s->lna_gain_auto->cur.val, s->lna_gain_auto->val,
                        s->lna_gain->cur.val, s->lna_gain->val);

        ret = airspy_ctrl_msg(s, CMD_SET_LNA_AGC, 0, s->lna_gain_auto->val,
                        &u8tmp, 1);
        if (ret)
                goto err;

        if (s->lna_gain_auto->val == false) {
                ret = airspy_ctrl_msg(s, CMD_SET_LNA_GAIN, 0, s->lna_gain->val,
                                &u8tmp, 1);
                if (ret)
                        goto err;
        }
err:
        if (ret)
                dev_dbg(s->dev, "failed=%d\n", ret);

        return ret;
}

static int airspy_set_mixer_gain(struct airspy *s)
{
        int ret;
        u8 u8tmp;

        dev_dbg(s->dev, "mixer auto=%d->%d val=%d->%d\n",
                        s->mixer_gain_auto->cur.val, s->mixer_gain_auto->val,
                        s->mixer_gain->cur.val, s->mixer_gain->val);

        ret = airspy_ctrl_msg(s, CMD_SET_MIXER_AGC, 0, s->mixer_gain_auto->val,
                        &u8tmp, 1);
        if (ret)
                goto err;

        if (s->mixer_gain_auto->val == false) {
                ret = airspy_ctrl_msg(s, CMD_SET_MIXER_GAIN, 0,
                                s->mixer_gain->val, &u8tmp, 1);
                if (ret)
                        goto err;
        }
err:
        if (ret)
                dev_dbg(s->dev, "failed=%d\n", ret);

        return ret;
}

static int airspy_set_if_gain(struct airspy *s)
{
        int ret;
        u8 u8tmp;

        dev_dbg(s->dev, "val=%d->%d\n", s->if_gain->cur.val, s->if_gain->val);

        ret = airspy_ctrl_msg(s, CMD_SET_VGA_GAIN, 0, s->if_gain->val,
                        &u8tmp, 1);
        if (ret)
                dev_dbg(s->dev, "failed=%d\n", ret);

        return ret;
}

static int airspy_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct airspy *s = container_of(ctrl->handler, struct airspy, hdl);
        int ret;

        switch (ctrl->id) {
        case  V4L2_CID_RF_TUNER_LNA_GAIN_AUTO:
        case  V4L2_CID_RF_TUNER_LNA_GAIN:
                ret = airspy_set_lna_gain(s);
                break;
        case  V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO:
        case  V4L2_CID_RF_TUNER_MIXER_GAIN:
                ret = airspy_set_mixer_gain(s);
                break;
        case  V4L2_CID_RF_TUNER_IF_GAIN:
                ret = airspy_set_if_gain(s);
                break;
        default:
                dev_dbg(s->dev, "unknown ctrl: id=%d name=%s\n",
                                ctrl->id, ctrl->name);
                ret = -EINVAL;
        }

        return ret;
}

static const struct v4l2_ctrl_ops airspy_ctrl_ops = {
        .s_ctrl = airspy_s_ctrl,
};

static int airspy_probe(struct usb_interface *intf,
                const struct usb_device_id *id)
{
        struct airspy *s;
        int ret;
        u8 u8tmp, *buf;

        buf = NULL;
        ret = -ENOMEM;

        s = kzalloc_obj(struct airspy);
        if (s == NULL) {
                dev_err(&intf->dev, "Could not allocate memory for state\n");
                return -ENOMEM;
        }

        s->buf = kzalloc(BUF_SIZE, GFP_KERNEL);
        if (!s->buf)
                goto err_free_mem;
        buf = kzalloc(BUF_SIZE, GFP_KERNEL);
        if (!buf)
                goto err_free_mem;

        mutex_init(&s->v4l2_lock);
        mutex_init(&s->vb_queue_lock);
        spin_lock_init(&s->queued_bufs_lock);
        INIT_LIST_HEAD(&s->queued_bufs);
        s->dev = &intf->dev;
        s->udev = interface_to_usbdev(intf);
        s->f_adc = bands[0].rangelow;
        s->f_rf = bands_rf[0].rangelow;
        s->pixelformat = formats[0].pixelformat;
        s->buffersize = formats[0].buffersize;

        /* Detect device */
        ret = airspy_ctrl_msg(s, CMD_BOARD_ID_READ, 0, 0, &u8tmp, 1);
        if (ret == 0)
                ret = airspy_ctrl_msg(s, CMD_VERSION_STRING_READ, 0, 0,
                                buf, BUF_SIZE);
        if (ret) {
                dev_err(s->dev, "Could not detect board\n");
                goto err_free_mem;
        }

        buf[BUF_SIZE - 1] = '\0';

        dev_info(s->dev, "Board ID: %02x\n", u8tmp);
        dev_info(s->dev, "Firmware version: %s\n", buf);

        /* Init videobuf2 queue structure */
        s->vb_queue.type = V4L2_BUF_TYPE_SDR_CAPTURE;
        s->vb_queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
        s->vb_queue.drv_priv = s;
        s->vb_queue.buf_struct_size = sizeof(struct airspy_frame_buf);
        s->vb_queue.ops = &airspy_vb2_ops;
        s->vb_queue.mem_ops = &vb2_vmalloc_memops;
        s->vb_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        s->vb_queue.lock = &s->vb_queue_lock;
        ret = vb2_queue_init(&s->vb_queue);
        if (ret) {
                dev_err(s->dev, "Could not initialize vb2 queue\n");
                goto err_free_mem;
        }

        /* Init video_device structure */
        s->vdev = airspy_template;
        s->vdev.queue = &s->vb_queue;
        video_set_drvdata(&s->vdev, s);

        /* Register the v4l2_device structure */
        s->v4l2_dev.release = airspy_video_release;
        ret = v4l2_device_register(&intf->dev, &s->v4l2_dev);
        if (ret) {
                dev_err(s->dev, "Failed to register v4l2-device (%d)\n", ret);
                goto err_free_mem;
        }

        /* Register controls */
        v4l2_ctrl_handler_init(&s->hdl, 5);
        s->lna_gain_auto = v4l2_ctrl_new_std(&s->hdl, &airspy_ctrl_ops,
                        V4L2_CID_RF_TUNER_LNA_GAIN_AUTO, 0, 1, 1, 0);
        s->lna_gain = v4l2_ctrl_new_std(&s->hdl, &airspy_ctrl_ops,
                        V4L2_CID_RF_TUNER_LNA_GAIN, 0, 14, 1, 8);
        v4l2_ctrl_auto_cluster(2, &s->lna_gain_auto, 0, false);
        s->mixer_gain_auto = v4l2_ctrl_new_std(&s->hdl, &airspy_ctrl_ops,
                        V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO, 0, 1, 1, 0);
        s->mixer_gain = v4l2_ctrl_new_std(&s->hdl, &airspy_ctrl_ops,
                        V4L2_CID_RF_TUNER_MIXER_GAIN, 0, 15, 1, 8);
        v4l2_ctrl_auto_cluster(2, &s->mixer_gain_auto, 0, false);
        s->if_gain = v4l2_ctrl_new_std(&s->hdl, &airspy_ctrl_ops,
                        V4L2_CID_RF_TUNER_IF_GAIN, 0, 15, 1, 0);
        if (s->hdl.error) {
                ret = s->hdl.error;
                dev_err(s->dev, "Could not initialize controls\n");
                goto err_free_controls;
        }

        v4l2_ctrl_handler_setup(&s->hdl);

        s->v4l2_dev.ctrl_handler = &s->hdl;
        s->vdev.v4l2_dev = &s->v4l2_dev;
        s->vdev.lock = &s->v4l2_lock;
        s->vdev.device_caps = V4L2_CAP_SDR_CAPTURE | V4L2_CAP_STREAMING |
                              V4L2_CAP_READWRITE | V4L2_CAP_TUNER;

        ret = video_register_device(&s->vdev, VFL_TYPE_SDR, -1);
        if (ret) {
                dev_err(s->dev, "Failed to register as video device (%d)\n",
                                ret);
                goto err_free_controls;
        }

        /* Free buf if success*/
        kfree(buf);

        dev_info(s->dev, "Registered as %s\n",
                        video_device_node_name(&s->vdev));
        dev_notice(s->dev, "SDR API is still slightly experimental and functionality changes may follow\n");
        return 0;

err_free_controls:
        v4l2_ctrl_handler_free(&s->hdl);
        v4l2_device_unregister(&s->v4l2_dev);
err_free_mem:
        kfree(buf);
        kfree(s->buf);
        kfree(s);
        return ret;
}

/* USB device ID list */
static const struct usb_device_id airspy_id_table[] = {
        { USB_DEVICE(0x1d50, 0x60a1) }, /* AirSpy */
        { }
};
MODULE_DEVICE_TABLE(usb, airspy_id_table);

/* USB subsystem interface */
static struct usb_driver airspy_driver = {
        .name                     = KBUILD_MODNAME,
        .probe                    = airspy_probe,
        .disconnect               = airspy_disconnect,
        .id_table                 = airspy_id_table,
};

module_usb_driver(airspy_driver);

MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
MODULE_DESCRIPTION("AirSpy SDR");
MODULE_LICENSE("GPL");