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deps/hidapi/libusb/hid.c  view on Meta::CPAN

	}
	else {
		/* Unable to open any devices. */
		free_hid_device(dev);
		return NULL;
	}
}


int HID_API_EXPORT hid_write(hid_device *dev, const unsigned char *data, size_t length)
{
	int res;
	int report_number = data[0];
	int skipped_report_id = 0;

	if (report_number == 0x0) {
		data++;
		length--;
		skipped_report_id = 1;
	}


	if (dev->output_endpoint <= 0) {
		/* No interrupt out endpoint. Use the Control Endpoint */
		res = libusb_control_transfer(dev->device_handle,
			LIBUSB_REQUEST_TYPE_CLASS|LIBUSB_RECIPIENT_INTERFACE|LIBUSB_ENDPOINT_OUT,
			0x09/*HID Set_Report*/,
			(2/*HID output*/ << 8) | report_number,
			dev->interface,
			(unsigned char *)data, length,
			1000/*timeout millis*/);

		if (res < 0)
			return -1;

		if (skipped_report_id)
			length++;

		return length;
	}
	else {
		/* Use the interrupt out endpoint */
		int actual_length;
		res = libusb_interrupt_transfer(dev->device_handle,
			dev->output_endpoint,
			(unsigned char*)data,
			length,
			&actual_length, 1000);

		if (res < 0)
			return -1;

		if (skipped_report_id)
			actual_length++;

		return actual_length;
	}
}

/* Helper function, to simplify hid_read().
   This should be called with dev->mutex locked. */
static int return_data(hid_device *dev, unsigned char *data, size_t length)
{
	/* Copy the data out of the linked list item (rpt) into the
	   return buffer (data), and delete the liked list item. */
	struct input_report *rpt = dev->input_reports;
	size_t len = (length < rpt->len)? length: rpt->len;
	if (len > 0)
		memcpy(data, rpt->data, len);
	dev->input_reports = rpt->next;
	free(rpt->data);
	free(rpt);
	return len;
}

static void cleanup_mutex(void *param)
{
	hid_device *dev = param;
	pthread_mutex_unlock(&dev->mutex);
}


int HID_API_EXPORT hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds)
{
	int bytes_read = -1;

#if 0
	int transferred;
	int res = libusb_interrupt_transfer(dev->device_handle, dev->input_endpoint, data, length, &transferred, 5000);
	LOG("transferred: %d\n", transferred);
	return transferred;
#endif

	pthread_mutex_lock(&dev->mutex);
	pthread_cleanup_push(&cleanup_mutex, dev);

	/* There's an input report queued up. Return it. */
	if (dev->input_reports) {
		/* Return the first one */
		bytes_read = return_data(dev, data, length);
		goto ret;
	}

	if (dev->shutdown_thread) {
		/* This means the device has been disconnected.
		   An error code of -1 should be returned. */
		bytes_read = -1;
		goto ret;
	}

	if (milliseconds == -1) {
		/* Blocking */
		while (!dev->input_reports && !dev->shutdown_thread) {
			pthread_cond_wait(&dev->condition, &dev->mutex);
		}
		if (dev->input_reports) {
			bytes_read = return_data(dev, data, length);
		}
	}
	else if (milliseconds > 0) {
		/* Non-blocking, but called with timeout. */