ALSA: seq: Add tempo base unit for MIDI2 Set Tempo messages

MIDI2 Set Tempo message defines the tempo in 10ns unit for finer
accuracy, while MIDI1 was defined in 1us unit.  For adapting this
different unit, introduce "tempo_base" field to snd_seq_queue_tempo
struct so that user-space can pass the proper tempo base unit.

The accepted value is limited, it must be either 0, 10 or 1000.

The protocol version is bumped to 1.0.4 along with this.

The access with the older protocol version ignores the tempo-base
value in ioctls and always treats as 1000.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://patch.msgid.link/20240705160344.6481-1-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 c85fdd8895d844c9c02d2d419d49878b94b8ff86..39b37edcf81316b678158eca3e2572b22e5d7f84 100644 (file)
--- a/include/uapi/sound/asequencer.h
+++ b/include/uapi/sound/asequencer.h
@@ -10,7 +10,7 @@
 #include <sound/asound.h>
 
 /** version of the sequencer */
-#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 3)
+#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 4)
 
 /**
  * definition of sequencer event types
@@ -523,11 +523,12 @@ struct snd_seq_queue_status {
 /* queue tempo */
 struct snd_seq_queue_tempo {
        int queue;                      /* sequencer queue */
-       unsigned int tempo;             /* current tempo, us/tick */
+       unsigned int tempo;             /* current tempo, us/tick (or different time-base below) */
        int ppq;                        /* time resolution, ticks/quarter */
        unsigned int skew_value;        /* queue skew */
        unsigned int skew_base;         /* queue skew base */
-       char reserved[24];              /* for the future */
+       unsigned short tempo_base;      /* tempo base in nsec unit; either 10 or 1000 */
+       char reserved[22];              /* for the future */
 };
 
 

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 42a7051410501826b4b0716cd1ef3009da5c3e90..8c4ee5066afe5b7f9077d957435a3b6e06dd6fce 100644 (file)
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1718,6 +1718,8 @@ static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client,
        tempo->ppq = tmr->ppq;
        tempo->skew_value = tmr->skew;
        tempo->skew_base = tmr->skew_base;
+       if (client->user_pversion >= SNDRV_PROTOCOL_VERSION(1, 0, 4))
+               tempo->tempo_base = tmr->tempo_base;
        queuefree(queue);
 
        return 0;
@@ -1739,6 +1741,8 @@ static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client,
        struct snd_seq_queue_tempo *tempo = arg;
        int result;
 
+       if (client->user_pversion < SNDRV_PROTOCOL_VERSION(1, 0, 4))
+               tempo->tempo_base = 0;
        result = snd_seq_set_queue_tempo(client->number, tempo);
        return result < 0 ? result : 0;
 }

diff --git a/sound/core/seq/seq_queue.c b/sound/core/seq/seq_queue.c
index 500ee6b19c717746af1b3f723d4e667825813b33..5df26788dda418ebf9bffc1d289cbaa1fab790b0 100644 (file)
--- a/sound/core/seq/seq_queue.c
+++ b/sound/core/seq/seq_queue.c
@@ -460,7 +460,8 @@ int snd_seq_queue_timer_set_tempo(int queueid, int client,
                return -EPERM;
        }
 
-       result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq);
+       result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq,
+                                            info->tempo_base);
        if (result >= 0 && info->skew_base > 0)
                result = snd_seq_timer_set_skew(q->timer, info->skew_value,
                                                info->skew_base);
@@ -724,7 +725,7 @@ void snd_seq_info_queues_read(struct snd_info_entry *entry,
 
                tmr = q->timer;
                if (tmr->tempo)
-                       bpm = 60000000 / tmr->tempo;
+                       bpm = (60000 * tmr->tempo_base) / tmr->tempo;
                else
                        bpm = 0;
 
@@ -741,6 +742,7 @@ void snd_seq_info_queues_read(struct snd_info_entry *entry,
                snd_iprintf(buffer, "timer state        : %s\n", tmr->running ? "Running" : "Stopped");
                snd_iprintf(buffer, "timer PPQ          : %d\n", tmr->ppq);
                snd_iprintf(buffer, "current tempo      : %d\n", tmr->tempo);
+               snd_iprintf(buffer, "tempo base         : %d ns\n", tmr->tempo_base);
                snd_iprintf(buffer, "current BPM        : %d\n", bpm);
                snd_iprintf(buffer, "current time       : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
                snd_iprintf(buffer, "current tick       : %d\n", tmr->tick.cur_tick);

diff --git a/sound/core/seq/seq_timer.c b/sound/core/seq/seq_timer.c
index ad2b97e2762d998c140eabf2a783340c8ed02e5a..c9f0392ac7f156cc6bfeb1f70721baa3f9193bd7 100644 (file)
--- a/sound/core/seq/seq_timer.c
+++ b/sound/core/seq/seq_timer.c
@@ -20,14 +20,17 @@
 
 static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
 {
-       if (tmr->tempo < 1000000)
-               tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
+       unsigned int threshold =
+               tmr->tempo_base == 1000 ? 1000000 : 10000;
+
+       if (tmr->tempo < threshold)
+               tmr->tick.resolution = (tmr->tempo * tmr->tempo_base) / tmr->ppq;
        else {
                /* might overflow.. */
                unsigned int s;
                s = tmr->tempo % tmr->ppq;
-               s = (s * 1000) / tmr->ppq;
-               tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
+               s = (s * tmr->tempo_base) / tmr->ppq;
+               tmr->tick.resolution = (tmr->tempo / tmr->ppq) * tmr->tempo_base;
                tmr->tick.resolution += s;
        }
        if (tmr->tick.resolution <= 0)
@@ -79,6 +82,7 @@ void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
        /* setup defaults */
        tmr->ppq = 96;          /* 96 PPQ */
        tmr->tempo = 500000;    /* 120 BPM */
+       tmr->tempo_base = 1000; /* 1us */
        snd_seq_timer_set_tick_resolution(tmr);
        tmr->running = 0;
 
@@ -164,8 +168,9 @@ int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
        return 0;
 }
 
-/* set current tempo and ppq in a shot */
-int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
+/* set current tempo, ppq and base in a shot */
+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq,
+                               unsigned int tempo_base)
 {
        int changed;
 
@@ -173,6 +178,9 @@ int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
                return -EINVAL;
        if (tempo <= 0 || ppq <= 0)
                return -EINVAL;
+       /* allow only 10ns or 1us tempo base for now */
+       if (tempo_base && tempo_base != 10 && tempo_base != 1000)
+               return -EINVAL;
        guard(spinlock_irqsave)(&tmr->lock);
        if (tmr->running && (ppq != tmr->ppq)) {
                /* refuse to change ppq on running timers */
@@ -183,6 +191,7 @@ int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
        changed = (tempo != tmr->tempo) || (ppq != tmr->ppq);
        tmr->tempo = tempo;
        tmr->ppq = ppq;
+       tmr->tempo_base = tempo_base ? tempo_base : 1000;
        if (changed)
                snd_seq_timer_set_tick_resolution(tmr);
        return 0;

diff --git a/sound/core/seq/seq_timer.h b/sound/core/seq/seq_timer.h
index 4bec57df8158caf81e6cdba3248d7e252bd34643..3b906064bde1befccbd4e5755ad409d1a60f6b3a 100644 (file)
--- a/sound/core/seq/seq_timer.h
+++ b/sound/core/seq/seq_timer.h
@@ -36,6 +36,7 @@ struct snd_seq_timer {
 
        unsigned int skew;
        unsigned int skew_base;
+       unsigned int tempo_base;
 
        struct timespec64       last_update;     /* time of last clock update, used for interpolation */
 
@@ -116,7 +117,8 @@ int snd_seq_timer_stop(struct snd_seq_timer *tmr);
 int snd_seq_timer_start(struct snd_seq_timer *tmr);
 int snd_seq_timer_continue(struct snd_seq_timer *tmr);
 int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
-int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq);
+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq,
+                               unsigned int tempo_base);
 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);