sound/pci/ca0106/ca_midi.c

Source file repositories/reference/linux-study-clean/sound/pci/ca0106/ca_midi.c

File Facts

System
Linux kernel
Corpus path
sound/pci/ca0106/ca_midi.c
Extension
.c
Size
7333 bytes
Lines
282
Domain
Driver Families
Bucket
sound/pci
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 ((status & midi->ipr_rx) && ca_midi_input_avail(midi)) {
			if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
				ca_midi_clear_rx(midi);
			} else {
				byte = ca_midi_read_data(midi);
				if (midi->substream_input)
					snd_rawmidi_receive(midi->substream_input, &byte, 1);
			}
		}
	}

	scoped_guard(spinlock, &midi->output_lock) {
		if ((status & midi->ipr_tx) && ca_midi_output_ready(midi)) {
			if (midi->substream_output &&
			    snd_rawmidi_transmit(midi->substream_output, &byte, 1) == 1) {
				ca_midi_write_data(midi, byte);
			} else {
				midi->interrupt_disable(midi, midi->tx_enable);
			}
		}
	}
}

static void ca_midi_cmd(struct snd_ca_midi *midi, unsigned char cmd, int ack)
{
	int timeout, ok;

	scoped_guard(spinlock_irqsave, &midi->input_lock) {
		ca_midi_write_data(midi, 0x00);
		/* ca_midi_clear_rx(midi); */

		ca_midi_write_cmd(midi, cmd);
		if (ack) {
			ok = 0;
			timeout = 10000;
			while (!ok && timeout-- > 0) {
				if (ca_midi_input_avail(midi)) {
					if (ca_midi_read_data(midi) == midi->ack)
						ok = 1;
				}
			}
			if (!ok && ca_midi_read_data(midi) == midi->ack)
				ok = 1;
		} else {
			ok = 1;
		}
	}
	if (!ok)
		pr_err("ca_midi_cmd: 0x%x failed at 0x%x (status = 0x%x, data = 0x%x)!!!\n",
			   cmd,
			   midi->get_dev_id_port(midi->dev_id),
			   ca_midi_read_stat(midi),
			   ca_midi_read_data(midi));
}

static int ca_midi_input_open(struct snd_rawmidi_substream *substream)
{
	struct snd_ca_midi *midi = substream->rmidi->private_data;
	
	if (snd_BUG_ON(!midi->dev_id))
		return -ENXIO;
	scoped_guard(spinlock_irqsave, &midi->open_lock) {
		midi->midi_mode |= CA_MIDI_MODE_INPUT;
		midi->substream_input = substream;
		if (midi->midi_mode & CA_MIDI_MODE_OUTPUT)
			return 0;
	}
	ca_midi_cmd(midi, midi->reset, 1);
	ca_midi_cmd(midi, midi->enter_uart, 1);
	return 0;
}

static int ca_midi_output_open(struct snd_rawmidi_substream *substream)
{
	struct snd_ca_midi *midi = substream->rmidi->private_data;

	if (snd_BUG_ON(!midi->dev_id))
		return -ENXIO;
	scoped_guard(spinlock_irqsave, &midi->open_lock) {
		midi->midi_mode |= CA_MIDI_MODE_OUTPUT;
		midi->substream_output = substream;
		if (midi->midi_mode & CA_MIDI_MODE_INPUT)
			return 0;
	}
	ca_midi_cmd(midi, midi->reset, 1);
	ca_midi_cmd(midi, midi->enter_uart, 1);
	return 0;
}

static int ca_midi_input_close(struct snd_rawmidi_substream *substream)

Annotation

Implementation Notes