On 19. 05. 23 11:30, Takashi Iwai wrote:
This patch adds the support helpers for UMP (Universal MIDI Packet) in
ALSA core.
The basic design is that a rawmidi instance is assigned to each UMP
Endpoint. A UMP Endpoint provides a UMP stream, typically
bidirectional (but can be also uni-directional, too), which may hold
up to 16 UMP Groups, where each UMP (input/output) Group corresponds
to the traditional MIDI I/O Endpoint.
Additionally, the ALSA UMP abstraction provides the multiple UMP
Blocks that can be assigned to each UMP Endpoint. A UMP Block is a
metadata to hold the UMP Group clusters, and can represent the
functions assigned to each UMP Group. A typical implementation of UMP
Block is the Group Terminal Blocks of USB MIDI 2.0 specification.
For distinguishing from the legacy byte-stream MIDI device, a new
device "umpC*D*" will be created, instead of the standard (MIDI 1.0)
devices "midiC*D*". The UMP instance can be identified by the new
rawmidi info bit SNDRV_RAWMIDI_INFO_UMP, too.
A UMP rawmidi device reads/writes only in 4-bytes words alignment,
stored in CPU native endianness.
The transmit and receive functions take care of the input/out data
alignment, and may return zero or aligned size, and the params ioctl
may return -EINVAL when the given input/output buffer size isn't
aligned.
A few new UMP-specific ioctls are added for obtaining the new UMP
endpoint and block information.
As of this commit, no ALSA sequencer instance is attached to UMP
devices yet. They will be supported by later patches.
Along with those changes, the protocol version for rawmidi is bumped
to 2.0.3.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Reviewed-by: Jaroslav Kysela
except:
+/* UMP Endpoint information */
+struct snd_ump_endpoint_info {
+ int card; /* card number */
+ int device; /* device number */
I suspect that those two fields were added to enumerate devices in the control
API. But this extension seems to be missing in your patches. There is only
SNDRV_CTL_IOCTL_UMP_NEXT_DEVICE implemented. Otherwise those two fields are
not useful.
I also see the reference in the sequencer API
SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO, but I don't get the use there, too.
+/* UMP Block information */
+struct snd_ump_block_info {
+ int card; /* card number */
+ int device; /* device number */
... dtto ...
Jaroslav
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
