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.

Takashi Iwai committed 2 years ago

Commit fefbbdf1 parent a892b705 files · +30 −12Browse files

Unified · Split

5 files

include/uapi/sound/asequencer.h +4 −3
sound/core/seq/seq_clientmgr.c +4 −0
sound/core/seq/seq_queue.c +4 −2
sound/core/seq/seq_timer.c +15 −6
sound/core/seq/seq_timer.h +3 −1

include/uapi/sound/asequencer.h+4−3

@@ -10,7 +10,7 @@ · 9 unmodified lines
10	10	#include <sound/asound.h>
11	11
12	12	/** version of the sequencer */
13		−#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 3)
	13	+#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 4)
14	14
15	15	/**
16	16	* definition of sequencer event types
@@ -523,11 +523,12 @@ struct snd_seq_queue_status { · 506 unmodified lines
523	523	/* queue tempo */
524	524	struct snd_seq_queue_tempo {
525	525	int queue; /* sequencer queue */
526		− unsigned int tempo; /* current tempo, us/tick */
	526	+ unsigned int tempo; /* current tempo, us/tick (or different time-base below) */
527	527	int ppq; /* time resolution, ticks/quarter */
528	528	unsigned int skew_value; /* queue skew */
529	529	unsigned int skew_base; /* queue skew base */
530		− char reserved[24]; /* for the future */
	530	+ unsigned short tempo_base; /* tempo base in nsec unit; either 10 or 1000 */
	531	+ char reserved[22]; /* for the future */
531	532	};
532	533
533	534

sound/core/seq/seq_clientmgr.c+4−0

@@ -1718,6 +1718,8 @@ static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client, · 1717 unmodified lines
1718	1718	tempo->ppq = tmr->ppq;
1719	1719	tempo->skew_value = tmr->skew;
1720	1720	tempo->skew_base = tmr->skew_base;
	1721	+ if (client->user_pversion >= SNDRV_PROTOCOL_VERSION(1, 0, 4))
	1722	+ tempo->tempo_base = tmr->tempo_base;
1721	1723	queuefree(queue);
1722	1724
1723	1725	return 0;
@@ -1739,6 +1741,8 @@ static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client, · 15 unmodified lines
1739	1741	struct snd_seq_queue_tempo *tempo = arg;
1740	1742	int result;
1741	1743
	1744	+ if (client->user_pversion < SNDRV_PROTOCOL_VERSION(1, 0, 4))
	1745	+ tempo->tempo_base = 0;
1742	1746	result = snd_seq_set_queue_tempo(client->number, tempo);
1743	1747	return result < 0 ? result : 0;
1744	1748	}

sound/core/seq/seq_queue.c+4−2

@@ -460,7 +460,8 @@ int snd_seq_queue_timer_set_tempo(int queueid, int client, · 459 unmodified lines
460	460	return -EPERM;
461	461	}
462	462
463		− result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq);
	463	+ result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq,
	464	+ info->tempo_base);
464	465	if (result >= 0 && info->skew_base > 0)
465	466	result = snd_seq_timer_set_skew(q->timer, info->skew_value,
466	467	info->skew_base);
@@ -724,7 +725,7 @@ void snd_seq_info_queues_read(struct snd_info_entry *entry, · 257 unmodified lines
724	725
725	726	tmr = q->timer;
726	727	if (tmr->tempo)
727		− bpm = 60000000 / tmr->tempo;
	728	+ bpm = (60000 * tmr->tempo_base) / tmr->tempo;
728	729	else
729	730	bpm = 0;
730	731
@@ -741,6 +742,7 @@ void snd_seq_info_queues_read(struct snd_info_entry *entry, · 10 unmodified lines
741	742	snd_iprintf(buffer, "timer state : %s\n", tmr->running ? "Running" : "Stopped");
742	743	snd_iprintf(buffer, "timer PPQ : %d\n", tmr->ppq);
743	744	snd_iprintf(buffer, "current tempo : %d\n", tmr->tempo);
	745	+ snd_iprintf(buffer, "tempo base : %d ns\n", tmr->tempo_base);
744	746	snd_iprintf(buffer, "current BPM : %d\n", bpm);
745	747	snd_iprintf(buffer, "current time : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
746	748	snd_iprintf(buffer, "current tick : %d\n", tmr->tick.cur_tick);

sound/core/seq/seq_timer.c+15−6

@@ -20,14 +20,17 @@ · 19 unmodified lines
20	20
21	21	static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
22	22	{
23		− if (tmr->tempo < 1000000)
24		− tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
	23	+ unsigned int threshold =
	24	+ tmr->tempo_base == 1000 ? 1000000 : 10000;
	25	+
	26	+ if (tmr->tempo < threshold)
	27	+ tmr->tick.resolution = (tmr->tempo * tmr->tempo_base) / tmr->ppq;
25	28	else {
26	29	/* might overflow.. */
27	30	unsigned int s;
28	31	s = tmr->tempo % tmr->ppq;
29		− s = (s * 1000) / tmr->ppq;
30		− tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
	32	+ s = (s * tmr->tempo_base) / tmr->ppq;
	33	+ tmr->tick.resolution = (tmr->tempo / tmr->ppq) * tmr->tempo_base;
31	34	tmr->tick.resolution += s;
32	35	}
33	36	if (tmr->tick.resolution <= 0)
@@ -79,6 +82,7 @@ void snd_seq_timer_defaults(struct snd_seq_timer * tmr) · 45 unmodified lines
79	82	/* setup defaults */
80	83	tmr->ppq = 96; /* 96 PPQ */
81	84	tmr->tempo = 500000; /* 120 BPM */
	85	+ tmr->tempo_base = 1000; /* 1us */
82	86	snd_seq_timer_set_tick_resolution(tmr);
83	87	tmr->running = 0;
84	88
@@ -164,8 +168,9 @@ int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo) · 79 unmodified lines
164	168	return 0;
165	169	}
166	170
167		−/* set current tempo and ppq in a shot */
168		−int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
	171	+/* set current tempo, ppq and base in a shot */
	172	+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq,
	173	+ unsigned int tempo_base)
169	174	{
170	175	int changed;
171	176
@@ -173,6 +178,9 @@ int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq) · 1 unmodified line
173	178	return -EINVAL;
174	179	if (tempo <= 0 \|\| ppq <= 0)
175	180	return -EINVAL;
	181	+ /* allow only 10ns or 1us tempo base for now */
	182	+ if (tempo_base && tempo_base != 10 && tempo_base != 1000)
	183	+ return -EINVAL;
176	184	guard(spinlock_irqsave)(&tmr->lock);
177	185	if (tmr->running && (ppq != tmr->ppq)) {
178	186	/* 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) · 4 unmodified lines
183	191	changed = (tempo != tmr->tempo) \|\| (ppq != tmr->ppq);
184	192	tmr->tempo = tempo;
185	193	tmr->ppq = ppq;
	194	+ tmr->tempo_base = tempo_base ? tempo_base : 1000;
186	195	if (changed)
187	196	snd_seq_timer_set_tick_resolution(tmr);
188	197	return 0;

sound/core/seq/seq_timer.h+3−1

@@ -36,6 +36,7 @@ struct snd_seq_timer { · 35 unmodified lines
36	36
37	37	unsigned int skew;
38	38	unsigned int skew_base;
	39	+ unsigned int tempo_base;
39	40
40	41	struct timespec64 last_update; /* time of last clock update, used for interpolation */
41	42
@@ -116,7 +117,8 @@ int snd_seq_timer_stop(struct snd_seq_timer *tmr); · 74 unmodified lines
116	117	int snd_seq_timer_start(struct snd_seq_timer *tmr);
117	118	int snd_seq_timer_continue(struct snd_seq_timer *tmr);
118	119	int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
119		−int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq);
	120	+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq,
	121	+ unsigned int tempo_base);
120	122	int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
121	123	int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
122	124	int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);