1 files changed, 506 insertions, 0 deletions

diff --git a/sound/core/seq/seq_timer.c b/sound/core/seq/seq_timer.c
new file mode 100644
index 000000000..9863be6fd
--- /dev/null
+++ b/sound/core/seq/seq_timer.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer Timer
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                              Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <sound/core.h>
+#include <linux/slab.h>
+#include "seq_timer.h"
+#include "seq_queue.h"
+#include "seq_info.h"
+
+/* allowed sequencer timer frequencies, in Hz */
+#define MIN_FREQUENCY		10
+#define MAX_FREQUENCY		6250
+#define DEFAULT_FREQUENCY	1000
+
+#define SKEW_BASE	0x10000	/* 16bit shift */
+
+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;
+	else {
+		/* might overflow.. */
+		unsigned int s;
+		s = tmr->tempo % tmr->ppq;
+		s = (s * 1000) / tmr->ppq;
+		tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
+		tmr->tick.resolution += s;
+	}
+	if (tmr->tick.resolution <= 0)
+		tmr->tick.resolution = 1;
+	snd_seq_timer_update_tick(&tmr->tick, 0);
+}
+
+/* create new timer (constructor) */
+struct snd_seq_timer *snd_seq_timer_new(void)
+{
+	struct snd_seq_timer *tmr;
+	
+	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
+	if (!tmr)
+		return NULL;
+	spin_lock_init(&tmr->lock);
+
+	/* reset setup to defaults */
+	snd_seq_timer_defaults(tmr);
+	
+	/* reset time */
+	snd_seq_timer_reset(tmr);
+	
+	return tmr;
+}
+
+/* delete timer (destructor) */
+void snd_seq_timer_delete(struct snd_seq_timer **tmr)
+{
+	struct snd_seq_timer *t = *tmr;
+	*tmr = NULL;
+
+	if (t == NULL) {
+		pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n");
+		return;
+	}
+	t->running = 0;
+
+	/* reset time */
+	snd_seq_timer_stop(t);
+	snd_seq_timer_reset(t);
+
+	kfree(t);
+}
+
+void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	/* setup defaults */
+	tmr->ppq = 96;		/* 96 PPQ */
+	tmr->tempo = 500000;	/* 120 BPM */
+	snd_seq_timer_set_tick_resolution(tmr);
+	tmr->running = 0;
+
+	tmr->type = SNDRV_SEQ_TIMER_ALSA;
+	tmr->alsa_id.dev_class = seq_default_timer_class;
+	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
+	tmr->alsa_id.card = seq_default_timer_card;
+	tmr->alsa_id.device = seq_default_timer_device;
+	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
+	tmr->preferred_resolution = seq_default_timer_resolution;
+
+	tmr->skew = tmr->skew_base = SKEW_BASE;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+}
+
+static void seq_timer_reset(struct snd_seq_timer *tmr)
+{
+	/* reset time & songposition */
+	tmr->cur_time.tv_sec = 0;
+	tmr->cur_time.tv_nsec = 0;
+
+	tmr->tick.cur_tick = 0;
+	tmr->tick.fraction = 0;
+}
+
+void snd_seq_timer_reset(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	seq_timer_reset(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+}
+
+
+/* called by timer interrupt routine. the period time since previous invocation is passed */
+static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
+				    unsigned long resolution,
+				    unsigned long ticks)
+{
+	unsigned long flags;
+	struct snd_seq_queue *q = timeri->callback_data;
+	struct snd_seq_timer *tmr;
+
+	if (q == NULL)
+		return;
+	tmr = q->timer;
+	if (tmr == NULL)
+		return;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if (!tmr->running) {
+		spin_unlock_irqrestore(&tmr->lock, flags);
+		return;
+	}
+
+	resolution *= ticks;
+	if (tmr->skew != tmr->skew_base) {
+		/* FIXME: assuming skew_base = 0x10000 */
+		resolution = (resolution >> 16) * tmr->skew +
+			(((resolution & 0xffff) * tmr->skew) >> 16);
+	}
+
+	/* update timer */
+	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
+
+	/* calculate current tick */
+	snd_seq_timer_update_tick(&tmr->tick, resolution);
+
+	/* register actual time of this timer update */
+	ktime_get_ts64(&tmr->last_update);
+
+	spin_unlock_irqrestore(&tmr->lock, flags);
+
+	/* check queues and dispatch events */
+	snd_seq_check_queue(q, 1, 0);
+}
+
+/* set current tempo */
+int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tempo <= 0)
+		return -EINVAL;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if ((unsigned int)tempo != tmr->tempo) {
+		tmr->tempo = tempo;
+		snd_seq_timer_set_tick_resolution(tmr);
+	}
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	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)
+{
+	int changed;
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tempo <= 0 || ppq <= 0)
+		return -EINVAL;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if (tmr->running && (ppq != tmr->ppq)) {
+		/* refuse to change ppq on running timers */
+		/* because it will upset the song position (ticks) */
+		spin_unlock_irqrestore(&tmr->lock, flags);
+		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
+		return -EBUSY;
+	}
+	changed = (tempo != tmr->tempo) || (ppq != tmr->ppq);
+	tmr->tempo = tempo;
+	tmr->ppq = ppq;
+	if (changed)
+		snd_seq_timer_set_tick_resolution(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set current tick position */
+int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
+				    snd_seq_tick_time_t position)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->tick.cur_tick = position;
+	tmr->tick.fraction = 0;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set current real-time position */
+int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
+				    snd_seq_real_time_t position)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	snd_seq_sanity_real_time(&position);
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->cur_time = position;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set timer skew */
+int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
+			   unsigned int base)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	/* FIXME */
+	if (base != SKEW_BASE) {
+		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
+		return -EINVAL;
+	}
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->skew = skew;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+int snd_seq_timer_open(struct snd_seq_queue *q)
+{
+	struct snd_timer_instance *t;
+	struct snd_seq_timer *tmr;
+	char str[32];
+	int err;
+
+	tmr = q->timer;
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tmr->timeri)
+		return -EBUSY;
+	sprintf(str, "sequencer queue %i", q->queue);
+	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
+		return -EINVAL;
+	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
+		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
+	t = snd_timer_instance_new(str);
+	if (!t)
+		return -ENOMEM;
+	t->callback = snd_seq_timer_interrupt;
+	t->callback_data = q;
+	t->flags |= SNDRV_TIMER_IFLG_AUTO;
+	err = snd_timer_open(t, &tmr->alsa_id, q->queue);
+	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
+		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
+		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
+			struct snd_timer_id tid;
+			memset(&tid, 0, sizeof(tid));
+			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
+			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
+			tid.card = -1;
+			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
+			err = snd_timer_open(t, &tid, q->queue);
+		}
+	}
+	if (err < 0) {
+		pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
+		snd_timer_instance_free(t);
+		return err;
+	}
+	spin_lock_irq(&tmr->lock);
+	if (tmr->timeri)
+		err = -EBUSY;
+	else
+		tmr->timeri = t;
+	spin_unlock_irq(&tmr->lock);
+	if (err < 0) {
+		snd_timer_close(t);
+		snd_timer_instance_free(t);
+		return err;
+	}
+	return 0;
+}
+
+int snd_seq_timer_close(struct snd_seq_queue *q)
+{
+	struct snd_seq_timer *tmr;
+	struct snd_timer_instance *t;
+	
+	tmr = q->timer;
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	spin_lock_irq(&tmr->lock);
+	t = tmr->timeri;
+	tmr->timeri = NULL;
+	spin_unlock_irq(&tmr->lock);
+	if (t) {
+		snd_timer_close(t);
+		snd_timer_instance_free(t);
+	}
+	return 0;
+}
+
+static int seq_timer_stop(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (!tmr->running)
+		return 0;
+	tmr->running = 0;
+	snd_timer_pause(tmr->timeri);
+	return 0;
+}
+
+int snd_seq_timer_stop(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_stop(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+static int initialize_timer(struct snd_seq_timer *tmr)
+{
+	struct snd_timer *t;
+	unsigned long freq;
+
+	t = tmr->timeri->timer;
+	if (!t)
+		return -EINVAL;
+
+	freq = tmr->preferred_resolution;
+	if (!freq)
+		freq = DEFAULT_FREQUENCY;
+	else if (freq < MIN_FREQUENCY)
+		freq = MIN_FREQUENCY;
+	else if (freq > MAX_FREQUENCY)
+		freq = MAX_FREQUENCY;
+
+	tmr->ticks = 1;
+	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
+		unsigned long r = snd_timer_resolution(tmr->timeri);
+		if (r) {
+			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
+			if (! tmr->ticks)
+				tmr->ticks = 1;
+		}
+	}
+	tmr->initialized = 1;
+	return 0;
+}
+
+static int seq_timer_start(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (tmr->running)
+		seq_timer_stop(tmr);
+	seq_timer_reset(tmr);
+	if (initialize_timer(tmr) < 0)
+		return -EINVAL;
+	snd_timer_start(tmr->timeri, tmr->ticks);
+	tmr->running = 1;
+	ktime_get_ts64(&tmr->last_update);
+	return 0;
+}
+
+int snd_seq_timer_start(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_start(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+static int seq_timer_continue(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (tmr->running)
+		return -EBUSY;
+	if (! tmr->initialized) {
+		seq_timer_reset(tmr);
+		if (initialize_timer(tmr) < 0)
+			return -EINVAL;
+	}
+	snd_timer_start(tmr->timeri, tmr->ticks);
+	tmr->running = 1;
+	ktime_get_ts64(&tmr->last_update);
+	return 0;
+}
+
+int snd_seq_timer_continue(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_continue(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+/* return current 'real' time. use timeofday() to get better granularity. */
+snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
+					       bool adjust_ktime)
+{
+	snd_seq_real_time_t cur_time;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	cur_time = tmr->cur_time;
+	if (adjust_ktime && tmr->running) {
+		struct timespec64 tm;
+
+		ktime_get_ts64(&tm);
+		tm = timespec64_sub(tm, tmr->last_update);
+		cur_time.tv_nsec += tm.tv_nsec;
+		cur_time.tv_sec += tm.tv_sec;
+		snd_seq_sanity_real_time(&cur_time);
+	}
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return cur_time;	
+}
+
+/* TODO: use interpolation on tick queue (will only be useful for very
+ high PPQ values) */
+snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
+{
+	snd_seq_tick_time_t cur_tick;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	cur_tick = tmr->tick.cur_tick;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return cur_tick;
+}
+
+
+#ifdef CONFIG_SND_PROC_FS
+/* exported to seq_info.c */
+void snd_seq_info_timer_read(struct snd_info_entry *entry,
+			     struct snd_info_buffer *buffer)
+{
+	int idx;
+	struct snd_seq_queue *q;
+	struct snd_seq_timer *tmr;
+	struct snd_timer_instance *ti;
+	unsigned long resolution;
+	
+	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
+		q = queueptr(idx);
+		if (q == NULL)
+			continue;
+		mutex_lock(&q->timer_mutex);
+		tmr = q->timer;
+		if (!tmr)
+			goto unlock;
+		ti = tmr->timeri;
+		if (!ti)
+			goto unlock;
+		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
+		resolution = snd_timer_resolution(ti) * tmr->ticks;
+		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
+		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
+unlock:
+		mutex_unlock(&q->timer_mutex);
+		queuefree(q);
+ 	}
+}
+#endif /* CONFIG_SND_PROC_FS */
+