static int enable_rx(bladerf_device_t *dev) {
int ret;
int i;
unsigned int val;
val = 1;
if (dev->intnum != 1)
return -1;
if (dev->disconnecting)
return -ENODEV;
for (i = 0; i < NUM_DATA_URB; i++)
dev->data_in_bufs[i].valid = 1;
ret = __bladerf_snd_cmd(dev, BLADE_USB_CMD_RF_RX, &val, sizeof(val));
if (ret < 0)
goto err_out;
ret = 0;
dev->rx_en = 1;
for (i = 0; i < NUM_CONCURRENT; i++) {
if ((ret = __submit_rx_urb(dev, 0)) < 0) {
dev_err(&dev->interface->dev, "Error submitting initial RX URBs (%d/%d), error=%d\n", i, NUM_CONCURRENT, ret);
break;
}
}
err_out:
return ret;
}
static void __bladeRF_read_cb(struct urb *urb) {
bladerf_device_t *dev;
unsigned char *buf;
buf = (unsigned char *)urb->transfer_buffer;
dev = (bladerf_device_t *)urb->context;
if (dev->rx_en)
__submit_rx_urb(dev, GFP_ATOMIC);
wake_up_interruptible(&dev->data_in_wait);
}
static void __bladeRF_read_cb(struct urb *urb) {
bladerf_device_t *dev;
unsigned char *buf;
buf = (unsigned char *)urb->transfer_buffer;
dev = (bladerf_device_t *)urb->context;
usb_unanchor_urb(urb);
atomic_dec(&dev->data_in_inflight);
dev->bytes += DATA_BUF_SZ;
atomic_inc(&dev->data_in_cnt);
if (dev->rx_en)
__submit_rx_urb(dev, GFP_ATOMIC);
wake_up_interruptible(&dev->data_in_wait);
}
static ssize_t bladerf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
ssize_t ret = 0;
bladerf_device_t *dev;
unsigned long flags;
int read;
dev = (bladerf_device_t *)file->private_data;
if (dev->intnum != 1) {
return -1;
}
if (dev->reader) {
if (file != dev->reader) {
return -EPERM;
}
} else
dev->reader = file;
if (dev->disconnecting)
return -ENODEV;
if (!dev->rx_en) {
if (enable_rx(dev)) {
return -EINVAL;
}
}
read = 0;
while (!read) {
int reread;
reread = atomic_read(&dev->data_in_cnt);
if (reread) {
unsigned int idx;
spin_lock_irqsave(&dev->data_in_lock, flags);
atomic_dec(&dev->data_in_cnt);
atomic_dec(&dev->data_in_used);
idx = dev->data_in_consumer_idx++;
dev->data_in_consumer_idx &= (NUM_DATA_URB - 1);
spin_unlock_irqrestore(&dev->data_in_lock, flags);
if (copy_to_user(buf, dev->data_in_bufs[idx].addr, DATA_BUF_SZ)) {
ret = -EFAULT;
} else {
ret = 0;
}
dev->data_in_bufs[idx].valid = 1; // mark this RX packet as free
// in case all of the buffers were full, rx needs to be restarted
// samples may have also been dropped if this happens because the user-mode
// application is not reading samples fast enough
if (atomic_read(&dev->data_in_inflight) == 0)
__submit_rx_urb(dev, 0);
if (!ret)
ret = DATA_BUF_SZ;
break;
} else {
ret = wait_event_interruptible_timeout(dev->data_in_wait, atomic_read(&dev->data_in_cnt), 2 * HZ);
if (ret < 0) {
break;
} else if (ret == 0) {
ret = -ETIMEDOUT;
break;
} else {
ret = 0;
}
}
}
return ret;
}