seq: Provide sequencer sound card number / PID via alsa-lib

rawmidi devices expose the card number via IOCTLs, which allows to
find the corresponding device in sysfs.

The sequencer provides no identifing data. Chromium works around this
issue by scanning rawmidi as well as sequencer devices and matching
them by using assumtions, how the kernel register sequencer devices.

This changes adds support for exposing the card number for kernel clients
as well as the PID for user client.

It supports kernels with and without the required support.

Signed-off-by: Martin Koegler <martin.koegler@chello.at>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/seq.h b/include/seq.h
index 95768220153857eb3ca2d67f03d660516678507d..d05940e8590f21fd535c6dd6579ec4e806fea032 100644 (file)
--- a/include/seq.h
+++ b/include/seq.h
@@ -143,6 +143,8 @@ snd_seq_client_type_t snd_seq_client_info_get_type(const snd_seq_client_info_t *
 const char *snd_seq_client_info_get_name(snd_seq_client_info_t *info);
 int snd_seq_client_info_get_broadcast_filter(const snd_seq_client_info_t *info);
 int snd_seq_client_info_get_error_bounce(const snd_seq_client_info_t *info);
+int snd_seq_client_info_get_card(const snd_seq_client_info_t *info);
+int snd_seq_client_info_get_pid(const snd_seq_client_info_t *info);
 const unsigned char *snd_seq_client_info_get_event_filter(const snd_seq_client_info_t *info);
 int snd_seq_client_info_get_num_ports(const snd_seq_client_info_t *info);
 int snd_seq_client_info_get_event_lost(const snd_seq_client_info_t *info);

diff --git a/include/sound/asequencer.h b/include/sound/asequencer.h
index af96f2044f91638a95c670525f7f06ff0d5c8b16..7b7659a79ac4c79cfac5061defb1af90e5c6f144 100644 (file)
--- a/include/sound/asequencer.h
+++ b/include/sound/asequencer.h
@@ -25,7 +25,7 @@
 #include <sound/asound.h>
 
 /** version of the sequencer */
-#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION (1, 0, 1)
+#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 2)
 
 /**
  * definition of sequencer event types
@@ -357,7 +357,9 @@ struct snd_seq_client_info {
        unsigned char event_filter[32]; /* event filter bitmap */
        int num_ports;                  /* RO: number of ports */
        int event_lost;                 /* number of lost events */
-       char reserved[64];              /* for future use */
+       int card;                       /* RO: card number[kernel] */
+       int pid;                        /* RO: pid[user] */
+       char reserved[56];              /* for future use */
 };
 
 

diff --git a/src/seq/seq.c b/src/seq/seq.c
index 620ca3f1896f14097473ecdb850f5fec186a2a9b..4405e68a7fe9cdf822d15a5311db04e3558a4b7e 100644 (file)
--- a/src/seq/seq.c
+++ b/src/seq/seq.c
@@ -1521,6 +1521,32 @@ int snd_seq_client_info_get_error_bounce(const snd_seq_client_info_t *info)
        return (info->filter & SNDRV_SEQ_FILTER_BOUNCE) ? 1 : 0;
 }
 
+/**
+ * \brief Get the sound card number.
+ * \param info client_info container
+ * \return card number or -1 if value is not available.
+ *
+ * Only available for SND_SEQ_KERNEL_CLIENT clients.
+ */
+int snd_seq_client_info_get_card(const snd_seq_client_info_t *info)
+{
+       assert(info);
+       return info->card;
+}
+
+/**
+ * \brief Get the owning PID.
+ * \param info client_info container
+ * \return pid or -1 if value is not available.
+ *
+ * Only available for SND_SEQ_USER_CLIENT clients.
+ */
+int snd_seq_client_info_get_pid(const snd_seq_client_info_t *info)
+{
+       assert(info);
+       return info->pid;
+}
+
 /**
  * \brief (DEPRECATED) Get the event filter bitmap of a client_info container
  * \param info client_info container

diff --git a/src/seq/seq_hw.c b/src/seq/seq_hw.c
index d033367389444e3a9c0a4ccffd8f1efb8bd0ddb3..578ef123577d9d9865623eeeebccc6879ab79519 100644 (file)
--- a/src/seq/seq_hw.c
+++ b/src/seq/seq_hw.c
@@ -32,10 +32,11 @@ const char *_snd_module_seq_hw = "";
 #ifndef DOC_HIDDEN
 #define SNDRV_FILE_SEQ         ALSA_DEVICE_DIRECTORY "seq"
 #define SNDRV_FILE_ALOADSEQ    ALOAD_DEVICE_DIRECTORY "aloadSEQ"
-#define SNDRV_SEQ_VERSION_MAX  SNDRV_PROTOCOL_VERSION(1, 0, 1)
+#define SNDRV_SEQ_VERSION_MAX  SNDRV_PROTOCOL_VERSION(1, 0, 2)
 
 typedef struct {
        int fd;
+       int version;
 } snd_seq_hw_t;
 #endif /* DOC_HIDDEN */
 
@@ -100,6 +101,10 @@ static int snd_seq_hw_get_client_info(snd_seq_t *seq, snd_seq_client_info_t * in
                /*SYSERR("SNDRV_SEQ_IOCTL_GET_CLIENT_INFO failed");*/
                return -errno;
        }
+       if (hw->version < SNDRV_PROTOCOL_VERSION(1, 0, 2)) {
+               info->card = -1;
+               info->pid = -1;
+       }
        return 0;
 }
 
@@ -368,6 +373,10 @@ static int snd_seq_hw_query_next_client(snd_seq_t *seq, snd_seq_client_info_t *i
                /*SYSERR("SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT failed");*/
                return -errno;
        }
+       if (hw->version < SNDRV_PROTOCOL_VERSION(1, 0, 2)) {
+               info->card = -1;
+               info->pid = -1;
+       }
        return 0;
 }
 
@@ -480,6 +489,7 @@ int snd_seq_hw_open(snd_seq_t **handle, const char *name, int streams, int mode)
                return -ENOMEM;
        }
        hw->fd = fd;
+       hw->version = ver;
        if (streams & SND_SEQ_OPEN_OUTPUT) {
                seq->obuf = (char *) malloc(seq->obufsize = SND_SEQ_OBUF_SIZE);
                if (!seq->obuf) {