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ALSA: usb-audio: Create UMP blocks from USB MIDI GTBs

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USB MIDI spec defines the Group Terminal Blocks (GTB) that associate
multiple UMP Groups.  Those correspond to snd_ump_block entities in
ALSA UMP abstraction, and now we create those UMP Block objects for
each UMP Endpoint from the parsed GTB information.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-13-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2023-05-23 09:53:33 +02:00
parent 51701400a9
commit d9c9987686
1 changed files with 94 additions and 6 deletions
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100
sound/usb/midi2.c
View File

@ -599,14 +599,8 @@ find_group_terminal_block(struct snd_usb_midi2_interface *umidi, int id)
static int parse_group_terminal_block(struct snd_usb_midi2_ump *rmidi,
const struct usb_ms20_gr_trm_block_descriptor *desc)
{
struct snd_usb_audio *chip = rmidi->umidi->chip;
struct snd_ump_endpoint *ump = rmidi->ump;
usb_audio_dbg(chip,
"GTB id %d: groups = %d / %d, type = %d\n",
desc->bGrpTrmBlkID, desc->nGroupTrm, desc->nNumGroupTrm,
desc->bGrpTrmBlkType);
/* set default protocol */
switch (desc->bMIDIProtocol) {
case USB_MS_MIDI_PROTO_1_0_64:
@ -798,6 +792,94 @@ static int find_matching_ep_partner(struct snd_usb_midi2_interface *umidi,
return 0;
}
/* create a UMP block from a GTB entry */
static int create_gtb_block(struct snd_usb_midi2_ump *rmidi, int dir, int blk)
{
struct snd_usb_midi2_interface *umidi = rmidi->umidi;
const struct usb_ms20_gr_trm_block_descriptor *desc;
struct snd_ump_block *fb;
int type, err;
desc = find_group_terminal_block(umidi, blk);
if (!desc)
return 0;
usb_audio_dbg(umidi->chip,
"GTB %d: type=%d, group=%d/%d, protocol=%d, in bw=%d, out bw=%d\n",
blk, desc->bGrpTrmBlkType, desc->nGroupTrm,
desc->nNumGroupTrm, desc->bMIDIProtocol,
__le16_to_cpu(desc->wMaxInputBandwidth),
__le16_to_cpu(desc->wMaxOutputBandwidth));
/* assign the direction */
switch (desc->bGrpTrmBlkType) {
case USB_MS_GR_TRM_BLOCK_TYPE_BIDIRECTIONAL:
type = SNDRV_UMP_DIR_BIDIRECTION;
break;
case USB_MS_GR_TRM_BLOCK_TYPE_INPUT_ONLY:
type = SNDRV_UMP_DIR_INPUT;
break;
case USB_MS_GR_TRM_BLOCK_TYPE_OUTPUT_ONLY:
type = SNDRV_UMP_DIR_OUTPUT;
break;
default:
usb_audio_dbg(umidi->chip, "Unsupported GTB type %d\n",
desc->bGrpTrmBlkType);
return 0; /* unsupported */
}
/* guess work: set blk-1 as the (0-based) block ID */
err = snd_ump_block_new(rmidi->ump, blk - 1, type,
desc->nGroupTrm, desc->nNumGroupTrm,
&fb);
if (err == -EBUSY)
return 0; /* already present */
else if (err)
return err;
if (desc->iBlockItem)
usb_string(rmidi->dev, desc->iBlockItem,
fb->info.name, sizeof(fb->info.name));
if (__le16_to_cpu(desc->wMaxInputBandwidth) == 1 ||
__le16_to_cpu(desc->wMaxOutputBandwidth) == 1)
fb->info.flags |= SNDRV_UMP_BLOCK_IS_MIDI1 |
SNDRV_UMP_BLOCK_IS_LOWSPEED;
usb_audio_dbg(umidi->chip,
"Created a UMP block %d from GTB, name=%s\n",
blk, fb->info.name);
return 0;
}
/* Create UMP blocks for each UMP EP */
static int create_blocks_from_gtb(struct snd_usb_midi2_interface *umidi)
{
struct snd_usb_midi2_ump *rmidi;
int i, blk, err, dir;
list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
if (!rmidi->ump)
continue;
/* Blocks have been already created? */
if (rmidi->ump->info.num_blocks)
continue;
/* loop over GTBs */
for (dir = 0; dir < 2; dir++) {
if (!rmidi->eps[dir])
continue;
for (i = 0; i < rmidi->eps[dir]->ms_ep->bNumGrpTrmBlock; i++) {
blk = rmidi->eps[dir]->ms_ep->baAssoGrpTrmBlkID[i];
err = create_gtb_block(rmidi, dir, blk);
if (err < 0)
return err;
}
}
}
return 0;
}
static void snd_usb_midi_v2_free(struct snd_usb_midi2_interface *umidi)
{
free_all_midi2_endpoints(umidi);
@ -1009,6 +1091,12 @@ int snd_usb_midi_v2_create(struct snd_usb_audio *chip,
goto error;
}
err = create_blocks_from_gtb(umidi);
if (err < 0) {
usb_audio_err(chip, "Failed to create GTB blocks\n");
goto error;
}
set_fallback_rawmidi_names(umidi);
return 0;