--- /dev/null
+/*
+ * ALSA sequencer Timer
+ * Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ * Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#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)
+{
+ /* 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;
+}
+
+void snd_seq_timer_reset(struct snd_seq_timer * tmr)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tmr->lock, flags);
+
+ /* reset time & songposition */
+ tmr->cur_time.tv_sec = 0;
+ tmr->cur_time.tv_nsec = 0;
+
+ tmr->tick.cur_tick = 0;
+ tmr->tick.fraction = 0;
+
+ 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;
+ if (!tmr->running)
+ return;
+
+ resolution *= ticks;
+ if (tmr->skew != tmr->skew_base) {
+ /* FIXME: assuming skew_base = 0x10000 */
+ resolution = (resolution >> 16) * tmr->skew +
+ (((resolution & 0xffff) * tmr->skew) >> 16);
+ }
+
+ spin_lock_irqsave(&tmr->lock, flags);
+
+ /* 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 */
+ do_gettimeofday(&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 ppq */
+int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq)
+{
+ unsigned long flags;
+
+ if (snd_BUG_ON(!tmr))
+ return -EINVAL;
+ if (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;
+ }
+
+ tmr->ppq = ppq;
+ 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;
+ err = snd_timer_open(&t, str, &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, str, &tid, q->queue);
+ }
+ }
+ if (err < 0) {
+ pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
+ return err;
+ }
+ t->callback = snd_seq_timer_interrupt;
+ t->callback_data = q;
+ t->flags |= SNDRV_TIMER_IFLG_AUTO;
+ tmr->timeri = t;
+ return 0;
+}
+
+int snd_seq_timer_close(struct snd_seq_queue *q)
+{
+ struct snd_seq_timer *tmr;
+
+ tmr = q->timer;
+ if (snd_BUG_ON(!tmr))
+ return -EINVAL;
+ if (tmr->timeri) {
+ snd_timer_stop(tmr->timeri);
+ snd_timer_close(tmr->timeri);
+ tmr->timeri = NULL;
+ }
+ return 0;
+}
+
+int snd_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;
+}
+
+static int initialize_timer(struct snd_seq_timer *tmr)
+{
+ struct snd_timer *t;
+ unsigned long freq;
+
+ t = tmr->timeri->timer;
+ if (snd_BUG_ON(!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 = t->hw.resolution;
+ if (! r && t->hw.c_resolution)
+ r = t->hw.c_resolution(t);
+ if (r) {
+ tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
+ if (! tmr->ticks)
+ tmr->ticks = 1;
+ }
+ }
+ tmr->initialized = 1;
+ return 0;
+}
+
+int snd_seq_timer_start(struct snd_seq_timer * tmr)
+{
+ if (! tmr->timeri)
+ return -EINVAL;
+ if (tmr->running)
+ snd_seq_timer_stop(tmr);
+ snd_seq_timer_reset(tmr);
+ if (initialize_timer(tmr) < 0)
+ return -EINVAL;
+ snd_timer_start(tmr->timeri, tmr->ticks);
+ tmr->running = 1;
+ do_gettimeofday(&tmr->last_update);
+ return 0;
+}
+
+int snd_seq_timer_continue(struct snd_seq_timer * tmr)
+{
+ if (! tmr->timeri)
+ return -EINVAL;
+ if (tmr->running)
+ return -EBUSY;
+ if (! tmr->initialized) {
+ snd_seq_timer_reset(tmr);
+ if (initialize_timer(tmr) < 0)
+ return -EINVAL;
+ }
+ snd_timer_start(tmr->timeri, tmr->ticks);
+ tmr->running = 1;
+ do_gettimeofday(&tmr->last_update);
+ return 0;
+}
+
+/* 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)
+{
+ snd_seq_real_time_t cur_time;
+
+ cur_time = tmr->cur_time;
+ if (tmr->running) {
+ struct timeval tm;
+ int usec;
+ do_gettimeofday(&tm);
+ usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
+ if (usec < 0) {
+ cur_time.tv_nsec += (1000000 + usec) * 1000;
+ cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
+ } else {
+ cur_time.tv_nsec += usec * 1000;
+ cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
+ }
+ snd_seq_sanity_real_time(&cur_time);
+ }
+
+ 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)
+{
+ return tmr->tick.cur_tick;
+}
+
+
+#ifdef CONFIG_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;
+ if ((tmr = q->timer) == NULL ||
+ (ti = tmr->timeri) == NULL) {
+ queuefree(q);
+ continue;
+ }
+ 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);
+ queuefree(q);
+ }
+}
+#endif /* CONFIG_PROC_FS */
+
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