ALSA: seq: ump: Create UMP Endpoint port for broadcast

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.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-34-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/seq/seq_ump_client.c b/sound/core/seq/seq_ump_client.c
index 8d36065..600b061 100644 (file)
--- 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;