sound/usb/6fire/midi.c

Source file repositories/reference/linux-study-clean/sound/usb/6fire/midi.c

File Facts

System
Linux kernel
Corpus path
sound/usb/6fire/midi.c
Extension
.c
Size
4648 bytes
Lines
203
Domain
Driver Families
Bucket
sound/usb
Inferred role
Driver Families: implementation source
Status
source 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

if (ret > 0) { /* more data available, send next packet */
			rt->out_buffer[1] = ret + 2;
			rt->out_buffer[3] = rt->out_serial++;
			urb->transfer_buffer_length = ret + 4;

			ret = usb_submit_urb(urb, GFP_ATOMIC);
			if (ret < 0)
				dev_err(&urb->dev->dev,
					"midi out urb submit failed: %d\n",
					ret);
		} else /* no more data to transmit */
			rt->out = NULL;
	}
}

static void usb6fire_midi_in_received(
		struct midi_runtime *rt, u8 *data, int length)
{
	guard(spinlock_irqsave)(&rt->in_lock);
	if (rt->in)
		snd_rawmidi_receive(rt->in, data, length);
}

static int usb6fire_midi_out_open(struct snd_rawmidi_substream *alsa_sub)
{
	return 0;
}

static int usb6fire_midi_out_close(struct snd_rawmidi_substream *alsa_sub)
{
	return 0;
}

static void usb6fire_midi_out_trigger(
		struct snd_rawmidi_substream *alsa_sub, int up)
{
	struct midi_runtime *rt = alsa_sub->rmidi->private_data;
	struct urb *urb = &rt->out_urb;
	__s8 ret;

	guard(spinlock_irqsave)(&rt->out_lock);
	if (up) { /* start transfer */
		if (rt->out) /* we are already transmitting so just return */
			return;

		ret = snd_rawmidi_transmit(alsa_sub, rt->out_buffer + 4,
				MIDI_BUFSIZE - 4);
		if (ret > 0) {
			rt->out_buffer[1] = ret + 2;
			rt->out_buffer[3] = rt->out_serial++;
			urb->transfer_buffer_length = ret + 4;

			ret = usb_submit_urb(urb, GFP_ATOMIC);
			if (ret < 0)
				dev_err(&urb->dev->dev,
					"midi out urb submit failed: %d\n",
					ret);
			else
				rt->out = alsa_sub;
		}
	} else if (rt->out == alsa_sub)
		rt->out = NULL;
}

static void usb6fire_midi_out_drain(struct snd_rawmidi_substream *alsa_sub)
{
	struct midi_runtime *rt = alsa_sub->rmidi->private_data;
	int retry = 0;

	while (rt->out && retry++ < 100)
		msleep(10);
}

static int usb6fire_midi_in_open(struct snd_rawmidi_substream *alsa_sub)
{
	return 0;
}

static int usb6fire_midi_in_close(struct snd_rawmidi_substream *alsa_sub)
{
	return 0;
}

static void usb6fire_midi_in_trigger(
		struct snd_rawmidi_substream *alsa_sub, int up)
{
	struct midi_runtime *rt = alsa_sub->rmidi->private_data;

	guard(spinlock_irqsave)(&rt->in_lock);
	if (up)

Annotation

Implementation Notes