sound/usb/proc.c

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

File Facts

System
Linux kernel
Corpus path
sound/usb/proc.c
Extension
.c
Size
7425 bytes
Lines
237
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 (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
			snd_iprintf(buffer, "    Rates: %d - %d (continuous)\n",
				    fp->rate_min, fp->rate_max);
		} else {
			unsigned int i;
			snd_iprintf(buffer, "    Rates: ");
			for (i = 0; i < fp->nr_rates; i++) {
				if (i > 0)
					snd_iprintf(buffer, ", ");
				snd_iprintf(buffer, "%d", fp->rate_table[i]);
			}
			snd_iprintf(buffer, "\n");
		}
		if (subs->speed != USB_SPEED_FULL)
			snd_iprintf(buffer, "    Data packet interval: %d us\n",
				    125 * (1 << fp->datainterval));
		snd_iprintf(buffer, "    Bits: %d\n", fp->fmt_bits);

		if (fp->dsd_raw)
			snd_iprintf(buffer, "    DSD raw: DOP=%d, bitrev=%d\n",
				    fp->dsd_dop, fp->dsd_bitrev);

		if (fp->chmap) {
			const struct snd_pcm_chmap_elem *map = fp->chmap;
			int c;

			snd_iprintf(buffer, "    Channel map:");
			for (c = 0; c < map->channels; c++) {
				if (map->map[c] >= ARRAY_SIZE(channel_labels) ||
				    !channel_labels[map->map[c]])
					snd_iprintf(buffer, " --");
				else
					snd_iprintf(buffer, " %s",
						    channel_labels[map->map[c]]);
			}
			snd_iprintf(buffer, "\n");
		}

		if (fp->sync_ep) {
			snd_iprintf(buffer, "    Sync Endpoint: 0x%02x (%d %s)\n",
				    fp->sync_ep,
				    fp->sync_ep & USB_ENDPOINT_NUMBER_MASK,
				    fp->sync_ep & USB_DIR_IN ? "IN" : "OUT");
			snd_iprintf(buffer, "    Sync EP Interface: %d\n",
				    fp->sync_iface);
			snd_iprintf(buffer, "    Sync EP Altset: %d\n",
				    fp->sync_altsetting);
			snd_iprintf(buffer, "    Implicit Feedback Mode: %s\n",
				    fp->implicit_fb ? "Yes" : "No");
		}

		// snd_iprintf(buffer, "    Max Packet Size = %d\n", fp->maxpacksize);
		// snd_iprintf(buffer, "    EP Attribute = %#x\n", fp->attributes);
	}
}

static void proc_dump_ep_status(struct snd_usb_substream *subs,
				struct snd_usb_endpoint *data_ep,
				struct snd_usb_endpoint *sync_ep,
				struct snd_info_buffer *buffer)
{
	if (!data_ep)
		return;
	snd_iprintf(buffer, "    Packet Size = %d\n", data_ep->curpacksize);
	snd_iprintf(buffer, "    Momentary freq = %u Hz (%#x.%04x)\n",
		    subs->speed == USB_SPEED_FULL
		    ? get_full_speed_hz(data_ep->freqm)
		    : get_high_speed_hz(data_ep->freqm),
		    data_ep->freqm >> 16, data_ep->freqm & 0xffff);
	if (sync_ep && data_ep->freqshift != INT_MIN) {
		int res = 16 - data_ep->freqshift;
		snd_iprintf(buffer, "    Feedback Format = %d.%d\n",
			    (sync_ep->syncmaxsize > 3 ? 32 : 24) - res, res);
	}
}

static void proc_dump_substream_status(struct snd_usb_audio *chip,
				       struct snd_usb_substream *subs,
				       struct snd_info_buffer *buffer)
{
	guard(mutex)(&chip->mutex);
	if (subs->running) {
		snd_iprintf(buffer, "  Status: Running\n");
		if (subs->cur_audiofmt) {
			snd_iprintf(buffer, "    Interface = %d\n", subs->cur_audiofmt->iface);
			snd_iprintf(buffer, "    Altset = %d\n", subs->cur_audiofmt->altsetting);
		}
		proc_dump_ep_status(subs, subs->data_endpoint, subs->sync_endpoint, buffer);
	} else {
		snd_iprintf(buffer, "  Status: Stop\n");

Annotation

Implementation Notes