diff options
| author | Takashi Iwai <tiwai@suse.de> | 2023-05-23 09:53:49 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2023-05-23 12:11:25 +0200 |
| commit | ff166a9d19fab3d77f50e9413df046fb1d7c01cc (patch) | |
| tree | 83f10c67596229f116c898a0ee27622b16486cd6 /include/uapi/sound | |
| parent | 177ccf811df4a893df339a72dc732bb26b66d055 (diff) | |
ALSA: seq: Add port direction to snd_seq_port_info
Add a new field "direction" to snd_seq_port_info for allowing a client
to tell the expected direction of the port access. A port might still
allow subscriptions for read/write (e.g. for MIDI-CI) even if the
primary usage of the port is a single direction (either input or
output only). This new "direction" field can help to indicate such
cases.
When the direction is unspecified at creating a port and the port has
either read or write capability, the corresponding direction bits are
set automatically as default.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-29-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/uapi/sound')
| -rw-r--r-- | include/uapi/sound/asequencer.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h index 67532c46b115..eae1e0b0bf37 100644 --- a/include/uapi/sound/asequencer.h +++ b/include/uapi/sound/asequencer.h @@ -455,6 +455,12 @@ struct snd_seq_remove_events { #define SNDRV_SEQ_PORT_FLG_TIMESTAMP (1<<1) #define SNDRV_SEQ_PORT_FLG_TIME_REAL (1<<2) +/* port direction */ +#define SNDRV_SEQ_PORT_DIR_UNKNOWN 0 +#define SNDRV_SEQ_PORT_DIR_INPUT 1 +#define SNDRV_SEQ_PORT_DIR_OUTPUT 2 +#define SNDRV_SEQ_PORT_DIR_BIDIRECTION 3 + struct snd_seq_port_info { struct snd_seq_addr addr; /* client/port numbers */ char name[64]; /* port name */ @@ -471,7 +477,8 @@ struct snd_seq_port_info { void *kernel; /* reserved for kernel use (must be NULL) */ unsigned int flags; /* misc. conditioning */ unsigned char time_queue; /* queue # for timestamping */ - char reserved[59]; /* for future use */ + unsigned char direction; /* port usage direction (r/w/bidir) */ + char reserved[58]; /* for future use */ }; |