From 9bfad842f5222bd06e4cd68de3fb214c6f15ba7e Mon Sep 17 00:00:00 2001
From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Mon, 18 Nov 2019 13:22:44 +0900
Subject: [PATCH] rawmidi: stream_pair: add a API to get information of
 attached substream

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 src/rawmidi/alsarawmidi.map   |  1 +
 src/rawmidi/stream-pair.c     | 32 ++++++++++++++++++++++++++++++++
 src/rawmidi/stream-pair.h     |  6 ++++++
 tests/alsarawmidi-stream-pair |  1 +
 4 files changed, 40 insertions(+)

diff --git a/src/rawmidi/alsarawmidi.map b/src/rawmidi/alsarawmidi.map
index 6aace36..cc7edd7 100644
--- a/src/rawmidi/alsarawmidi.map
+++ b/src/rawmidi/alsarawmidi.map
@@ -14,6 +14,7 @@ ALSA_GOBJECT_0_0_0 {
     "alsarawmidi_stream_pair_get_type";
     "alsarawmidi_stream_pair_new";
     "alsarawmidi_stream_pair_open";
+    "alsarawmidi_stream_pair_get_substream_info";
   local:
     *;
 };
diff --git a/src/rawmidi/stream-pair.c b/src/rawmidi/stream-pair.c
index deb0c5f..d1f9a07 100644
--- a/src/rawmidi/stream-pair.c
+++ b/src/rawmidi/stream-pair.c
@@ -9,6 +9,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/ioctl.h>
 
 struct _ALSARawmidiStreamPairPrivate {
     int fd;
@@ -151,3 +152,34 @@ void alsarawmidi_stream_pair_open(ALSARawmidiStreamPair *self, guint card_id,
 
     priv->devnode = devnode;
 }
+
+/**
+ * alsarawmidi_stream_pair_get_substream_info:
+ * @self: A #ALSARawmidiStreamPair.
+ * @direction: The direction of substream attached to the stream pair.
+ * @substream_info: (out): The information for requested substream.
+ * @error: A #GError.
+ *
+ * Get information of substream attached to the stream pair.
+ */
+void alsarawmidi_stream_pair_get_substream_info(ALSARawmidiStreamPair *self,
+                                ALSARawmidiStreamDirection direction,
+                                ALSARawmidiSubstreamInfo **substream_info,
+                                GError **error)
+{
+    ALSARawmidiStreamPairPrivate *priv;
+    struct snd_rawmidi_info *info;
+
+    g_return_if_fail(ALSARAWMIDI_IS_STREAM_PAIR(self));
+    priv = alsarawmidi_stream_pair_get_instance_private(self);
+
+    *substream_info = g_object_new(ALSARAWMIDI_TYPE_SUBSTREAM_INFO, NULL);
+
+    rawmidi_substream_info_refer_private(*substream_info, &info);
+    info->stream = direction;
+    if (ioctl(priv->fd, SNDRV_RAWMIDI_IOCTL_INFO, info) < 0) {
+        generate_error(error, errno);
+        g_object_unref(*substream_info);
+        return;
+    }
+}
diff --git a/src/rawmidi/stream-pair.h b/src/rawmidi/stream-pair.h
index 46c4080..2400fbd 100644
--- a/src/rawmidi/stream-pair.h
+++ b/src/rawmidi/stream-pair.h
@@ -6,6 +6,7 @@
 #include <glib-object.h>
 
 #include <rawmidi/alsarawmidi-enums.h>
+#include <rawmidi/substream-info.h>
 
 G_BEGIN_DECLS
 
@@ -54,6 +55,11 @@ void alsarawmidi_stream_pair_open(ALSARawmidiStreamPair *self, guint card_id,
                                   ALSARawmidiStreamPairInfoFlag access_modes,
 				  gint open_flag, GError **error);
 
+void alsarawmidi_stream_pair_get_substream_info(ALSARawmidiStreamPair *self,
+                                ALSARawmidiStreamDirection direction,
+                                ALSARawmidiSubstreamInfo **substream_info,
+                                GError **error);
+
 G_END_DECLS
 
 #endif
diff --git a/tests/alsarawmidi-stream-pair b/tests/alsarawmidi-stream-pair
index 0419539..becebb1 100644
--- a/tests/alsarawmidi-stream-pair
+++ b/tests/alsarawmidi-stream-pair
@@ -16,6 +16,7 @@ props = (
 methods = (
     'new',
     'open',
+    'get_substream_info',
 )
 signals = ()
 
-- 
2.47.3