On 22. 05. 23 18:22, Takashi Iwai wrote:
On Mon, 22 May 2023 14:27:37 +0200,
Takashi Iwai wrote:
On Mon, 22 May 2023 12:27:11 +0200,
Takashi Iwai wrote:
On Mon, 22 May 2023 10:08:24 +0200,
Jaroslav Kysela wrote:
On 22. 05. 23 9:21, Takashi Iwai wrote:
On Mon, 22 May 2023 08:34:20 +0200,
Jaroslav Kysela wrote:
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.
The SNDRV_CTL_IOCTL_UMP_NEXT_DEVICE is looping over rawmidi, and
snd_rawmidi_info is provided for (kernel) UMP implementation.
Right. My point was that an application may be able to evaluate the
other UMP specific information from those new structures before the
rawmidi device is opened. So the CTL API extension may make sense.
Point taken, and indeed it might make more sense to change the ioctl
for looking at snd_ump_endpoint_info. Will try to cook with it.
FWIW, below is the patch to add two new ioctls for UMP EP/block
inquiries. It's together with a slight change of ioctl callback.
Will be included in v2 patch set I'll submit later.
The latest patches are found in topic/midi20 branch of sound git
tree.
There was a typo. The corrected version below.
Takashi
-- 8< --
From: Takashi Iwai <tiwai@xxxxxxx>
Subject: [PATCH] ALSA: ump: Add ioctls to inquiry UMP EP and Block info via
control API
It'd be convenient to have ioctls to inquiry the UMP Endpoint and UMP
Block information directly via the control API without opening the
rawmidi interface, just like SNDRV_CTL_IOCTL_RAWMIDI_INFO.
This patch extends the rawmidi ioctl handler to support those; new
ioctls, SNDRV_CTL_IOCTL_UMP_ENDPOINT_INFO and
SNDRV_CTL_IOCTL_UMP_BLOCK_INFO, return the snd_ump_endpoint and
snd_ump_block data that is specified by the device field,
respectively.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Thanks. It looks good.
Suggested-by: Jaroslav Kysela <perex@xxxxxxxx>
Reviewed-by: Jaroslav Kysela <perex@xxxxxxxx>
Jaroslav
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
