ALSA: seq: dummy: Allow UMP conversion

Although the purpose of dummy seq client is a direct pass-through,
it's sometimes helpful for debugging if it can convert to a certain
UMP MIDI version.  This patch adds an option to specify the UMP event
conversion.  As default, it skips the conversion and does
passthrough, while user can pass ump=1 or ump=2 to enforce the
conversion to UMP MIDI1 or MIDI2 format.

Message-ID: <20240419101105.15571-1-tiwai@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
index 9308194b2d9adf75d99d8dd799f94e4b6fe2b99a..783fc72c2ef67306836c9f1ad4c50f24dd05faeb 100644 (file)
--- a/sound/core/seq/seq_dummy.c
+++ b/sound/core/seq/seq_dummy.c
@@ -58,6 +58,12 @@ MODULE_PARM_DESC(ports, "number of ports to be created");
 module_param(duplex, bool, 0444);
 MODULE_PARM_DESC(duplex, "create DUPLEX ports");
 
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+static int ump;
+module_param(ump, int, 0444);
+MODULE_PARM_DESC(ump, "UMP conversion (0: no convert, 1: MIDI 1.0, 2: MIDI 2.0)");
+#endif
+
 struct snd_seq_dummy_port {
        int client;
        int port;
@@ -152,7 +158,9 @@ static int __init
 register_client(void)
 {
        struct snd_seq_dummy_port *rec1, *rec2;
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
        struct snd_seq_client *client;
+#endif
        int i;
 
        if (ports < 1) {
@@ -166,12 +174,24 @@ register_client(void)
        if (my_client < 0)
                return my_client;
 
-       /* don't convert events but just pass-through */
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
        client = snd_seq_kernel_client_get(my_client);
        if (!client)
                return -EINVAL;
-       client->filter = SNDRV_SEQ_FILTER_NO_CONVERT;
+       switch (ump) {
+       case 1:
+               client->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_1_0;
+               break;
+       case 2:
+               client->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_2_0;
+               break;
+       default:
+               /* don't convert events but just pass-through */
+               client->filter = SNDRV_SEQ_FILTER_NO_CONVERT;
+               break;
+       }
        snd_seq_kernel_client_put(client);
+#endif
 
        /* create ports */
        for (i = 0; i < ports; i++) {