sound/usb/line6/driver.c

Source file repositories/reference/linux-study-clean/sound/usb/line6/driver.c

File Facts

System
Linux kernel
Corpus path
sound/usb/line6/driver.c
Extension
.c
Size
21916 bytes
Lines
901
Domain
Driver Families
Bucket
sound/usb
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct message {
	struct usb_line6 *line6;
	const char *buffer;
	int size;
	int done;
};

/*
	Forward declarations.
*/
static void line6_data_received(struct urb *urb);
static int line6_send_raw_message_async_part(struct message *msg,
					     struct urb *urb);

/*
	Start to listen on endpoint.
*/
static int line6_start_listen(struct usb_line6 *line6)
{
	int err;

	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
		usb_fill_int_urb(line6->urb_listen, line6->usbdev,
			usb_rcvintpipe(line6->usbdev, line6->properties->ep_ctrl_r),
			line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
			line6_data_received, line6, line6->interval);
	} else {
		usb_fill_bulk_urb(line6->urb_listen, line6->usbdev,
			usb_rcvbulkpipe(line6->usbdev, line6->properties->ep_ctrl_r),
			line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
			line6_data_received, line6);
	}

	/* sanity checks of EP before actually submitting */
	if (usb_urb_ep_type_check(line6->urb_listen)) {
		dev_err(line6->ifcdev, "invalid control EP\n");
		return -EINVAL;
	}

	line6->urb_listen->actual_length = 0;
	err = usb_submit_urb(line6->urb_listen, GFP_ATOMIC);
	return err;
}

/*
	Stop listening on endpoint.
*/
static void line6_stop_listen(struct usb_line6 *line6)
{
	usb_kill_urb(line6->urb_listen);
}

/*
	Send raw message in pieces of wMaxPacketSize bytes.
*/
int line6_send_raw_message(struct usb_line6 *line6, const char *buffer,
				  int size)
{
	int i, done = 0;
	const struct line6_properties *properties = line6->properties;

	for (i = 0; i < size; i += line6->max_packet_size) {
		int partial;
		const char *frag_buf = buffer + i;
		int frag_size = min(line6->max_packet_size, size - i);
		int retval;

		if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
			retval = usb_interrupt_msg(line6->usbdev,
						usb_sndintpipe(line6->usbdev, properties->ep_ctrl_w),
						(char *)frag_buf, frag_size,
						&partial, LINE6_TIMEOUT);
		} else {
			retval = usb_bulk_msg(line6->usbdev,
						usb_sndbulkpipe(line6->usbdev, properties->ep_ctrl_w),
						(char *)frag_buf, frag_size,
						&partial, LINE6_TIMEOUT);
		}

		if (retval) {
			dev_err(line6->ifcdev,
				"usb_bulk_msg failed (%d)\n", retval);
			break;
		}

		done += frag_size;
	}

	return done;
}

Annotation

Implementation Notes