[PATCH 32/36] ALSA: seq: ump: Create UMP Endpoint port for broadcast

From: Takashi Iwai
Date: Fri May 19 2023 - 05:33:26 EST


Create a sequencer port for broadcasting the all group inputs at the
port number 0. This corresponds to a UMP Endpoint connection;
application can read all UMP events from this port no matter which
group the UMP packet belongs to.

Unlike seq ports for other UMP groups, a UMP Endpoint port has no
SND_SEQ_PORT_TYPE_MIDI_GENERIC bit, so that it won't be treated as a
normal MIDI 1.0 device from legacy applications.

The port is named as "MIDI 2.0" to align with representations on other
operation systems.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/core/seq/seq_ump_client.c | 60 +++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)

diff --git a/sound/core/seq/seq_ump_client.c b/sound/core/seq/seq_ump_client.c
index 8d360655ff5d..600b061ac8c3 100644
--- a/sound/core/seq/seq_ump_client.c
+++ b/sound/core/seq/seq_ump_client.c
@@ -290,6 +290,62 @@ static void update_group_attrs(struct seq_ump_client *client)
}
}

+/* create a UMP Endpoint port */
+static int create_ump_endpoint_port(struct seq_ump_client *client)
+{
+ struct snd_seq_port_info *port;
+ struct snd_seq_port_callback pcallbacks;
+ unsigned int rawmidi_info = client->ump->core.info_flags;
+ int err;
+
+ port = kzalloc(sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+
+ port->addr.client = client->seq_client;
+ port->addr.port = 0; /* fixed */
+ port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+ port->capability = SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT;
+ if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
+ port->capability |= SNDRV_SEQ_PORT_CAP_READ |
+ SNDRV_SEQ_PORT_CAP_SYNC_READ |
+ SNDRV_SEQ_PORT_CAP_SUBS_READ;
+ port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+ }
+ if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
+ port->capability |= SNDRV_SEQ_PORT_CAP_WRITE |
+ SNDRV_SEQ_PORT_CAP_SYNC_WRITE |
+ SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+ port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+ }
+ if (rawmidi_info & SNDRV_RAWMIDI_INFO_DUPLEX)
+ port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+ port->ump_group = 0; /* no associated group, no conversion */
+ port->type = SNDRV_SEQ_PORT_TYPE_MIDI_UMP |
+ SNDRV_SEQ_PORT_TYPE_HARDWARE |
+ SNDRV_SEQ_PORT_TYPE_PORT;
+ port->midi_channels = 16;
+ strcpy(port->name, "MIDI 2.0");
+ memset(&pcallbacks, 0, sizeof(pcallbacks));
+ pcallbacks.owner = THIS_MODULE;
+ pcallbacks.private_data = client;
+ if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
+ pcallbacks.subscribe = seq_ump_subscribe;
+ pcallbacks.unsubscribe = seq_ump_unsubscribe;
+ }
+ if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
+ pcallbacks.use = seq_ump_use;
+ pcallbacks.unuse = seq_ump_unuse;
+ pcallbacks.event_input = seq_ump_process_event;
+ }
+ port->kernel = &pcallbacks;
+ err = snd_seq_kernel_client_ctl(client->seq_client,
+ SNDRV_SEQ_IOCTL_CREATE_PORT,
+ port);
+ kfree(port);
+ return err;
+}
+
/* release the client resources */
static void seq_ump_client_free(struct seq_ump_client *client)
{
@@ -353,6 +409,10 @@ static int snd_seq_ump_probe(struct device *_dev)
goto error;
}

+ err = create_ump_endpoint_port(client);
+ if (err < 0)
+ goto error;
+
ump->seq_client = client;
ump->seq_ops = &seq_ump_ops;
return 0;
--
2.35.3