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>

diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h
index 67532c46b115b86919fe00d391d0f6721fe6849f..eae1e0b0bf370970e6cd3cc6c971ad315ee1b966 100644 (file)
--- 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 */
 };
 
 

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 061b3e2bece1464cfee7834ba9159cfc82460948..33aa6c5c5c9ec68db0d02921c769e335b73ffa3b 100644 (file)
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -2440,6 +2440,17 @@ static void snd_seq_info_dump_subscribers(struct snd_info_buffer *buffer,
 
 #define FLAG_PERM_DUPLEX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_DUPLEX ? 'X' : '-')
 
+static const char *port_direction_name(unsigned char dir)
+{
+       static const char *names[4] = {
+               "-", "In", "Out", "In/Out"
+       };
+
+       if (dir > SNDRV_SEQ_PORT_DIR_BIDIRECTION)
+               return "Invalid";
+       return names[dir];
+}
+
 static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
                                    struct snd_seq_client *client)
 {
@@ -2449,12 +2460,13 @@ static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
        list_for_each_entry(p, &client->ports_list_head, list) {
                if (p->capability & SNDRV_SEQ_PORT_CAP_INACTIVE)
                        continue;
-               snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c)\n",
+               snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c) [%s]\n",
                            p->addr.port, p->name,
                            FLAG_PERM_RD(p->capability),
                            FLAG_PERM_WR(p->capability),
                            FLAG_PERM_EX(p->capability),
-                           FLAG_PERM_DUPLEX(p->capability));
+                           FLAG_PERM_DUPLEX(p->capability),
+                           port_direction_name(p->direction));
                snd_seq_info_dump_subscribers(buffer, &p->c_src, 1, "    Connecting To: ");
                snd_seq_info_dump_subscribers(buffer, &p->c_dest, 0, "    Connected From: ");
        }

diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
index 8c18d8c4177edd369a942bfb77909bc656a595f7..2e8844ee32eddaf60b801aab2cf9cf072f3618b0 100644 (file)
--- a/sound/core/seq/seq_dummy.c
+++ b/sound/core/seq/seq_dummy.c
@@ -127,6 +127,7 @@ create_port(int idx, int type)
        pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
        if (duplex)
                pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+       pinfo.direction = SNDRV_SEQ_PORT_DIR_BIDIRECTION;
        pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
                | SNDRV_SEQ_PORT_TYPE_SOFTWARE
                | SNDRV_SEQ_PORT_TYPE_PORT;

diff --git a/sound/core/seq/seq_midi.c b/sound/core/seq/seq_midi.c
index 2b5fff80de58dddf6a7ca0350f28bae407a7acbc..44302d98950e89aca5de30ca166b5e3ba6de9c7c 100644 (file)
--- a/sound/core/seq/seq_midi.c
+++ b/sound/core/seq/seq_midi.c
@@ -367,6 +367,10 @@ snd_seq_midisynth_probe(struct device *_dev)
                if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
                    info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
                        port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+               if (port->capability & SNDRV_SEQ_PORT_CAP_READ)
+                       port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+               if (port->capability & SNDRV_SEQ_PORT_CAP_WRITE)
+                       port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
                port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
                        | SNDRV_SEQ_PORT_TYPE_HARDWARE
                        | SNDRV_SEQ_PORT_TYPE_PORT;

diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
index 42f4172d47667f6483a46938938de1d26362ff5f..5574341f49eb69b5d6917a90a35c79d327f1045c 100644 (file)
--- a/sound/core/seq/seq_ports.c
+++ b/sound/core/seq/seq_ports.c
@@ -356,6 +356,16 @@ int snd_seq_set_port_info(struct snd_seq_client_port * port,
        port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0;
        port->time_queue = info->time_queue;
 
+       /* direction */
+       port->direction = info->direction;
+       /* fill default port direction */
+       if (!port->direction) {
+               if (info->capability & SNDRV_SEQ_PORT_CAP_READ)
+                       port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+               if (info->capability & SNDRV_SEQ_PORT_CAP_WRITE)
+                       port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+       }
+
        return 0;
 }
 
@@ -393,6 +403,9 @@ int snd_seq_get_port_info(struct snd_seq_client_port * port,
                info->time_queue = port->time_queue;
        }
 
+       /* direction */
+       info->direction = port->direction;
+
        return 0;
 }
 

diff --git a/sound/core/seq/seq_ports.h b/sound/core/seq/seq_ports.h
index 44f0e9e96bbf7f44d31f54965814d4d263c8f5e2..dce733ab2398a0672a6f6fa539ed16b15f58ca46 100644 (file)
--- a/sound/core/seq/seq_ports.h
+++ b/sound/core/seq/seq_ports.h
@@ -72,6 +72,8 @@ struct snd_seq_client_port {
        int midi_voices;
        int synth_voices;
                
+       /* direction */
+       unsigned char direction;
 };
 
 struct snd_seq_client;

diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c
index f5cae49500c81447d8bbabf8a800ebd483409d4a..1b9260108e48219b35fc66b04149db647c2a6775 100644 (file)
--- a/sound/core/seq/seq_virmidi.c
+++ b/sound/core/seq/seq_virmidi.c
@@ -385,6 +385,7 @@ static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
        pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
        pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
        pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+       pinfo->direction = SNDRV_SEQ_PORT_DIR_BIDIRECTION;
        pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
                | SNDRV_SEQ_PORT_TYPE_SOFTWARE
                | SNDRV_SEQ_PORT_TYPE_PORT;