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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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){ 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 * tmr->tempo_base) / tmr->ppq; tmr->tick.resolution = (tmr->tempo / tmr->ppq) * tmr->tempo_base; 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_obj(*tmr); 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; struct snd_timer_instance *ti;
if (t == NULL) { pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n"); return; }
scoped_guard(spinlock_irq, &t->lock) { ti = t->timeri; t->timeri = NULL; } if (ti) { snd_timer_close(ti); snd_timer_instance_free(ti); }
*tmr = NULL; 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){ guard(spinlock_irqsave)(&tmr->lock); /* 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;
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;}
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){ guard(spinlock_irqsave)(&tmr->lock); seq_timer_reset(tmr);}
/* 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){ struct snd_seq_queue *q = timeri->callback_data; struct snd_seq_timer *tmr;
if (q == NULL) return; tmr = q->timer; if (tmr == NULL) return;
scoped_guard(spinlock_irqsave, &tmr->lock) { 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); }
/* 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); }
/* 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){ if (snd_BUG_ON(!tmr)) return -EINVAL; if (tempo <= 0) return -EINVAL; guard(spinlock_irqsave)(&tmr->lock); if ((unsigned int)tempo != tmr->tempo) { tmr->tempo = tempo; snd_seq_timer_set_tick_resolution(tmr); } return 0;}
/* 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;
if (snd_BUG_ON(!tmr)) 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 */ /* because it will upset the song position (ticks) */ 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; tmr->tempo_base = tempo_base ? tempo_base : 1000; if (changed) snd_seq_timer_set_tick_resolution(tmr); return 0;}
/* set current tick position */int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position){ if (snd_BUG_ON(!tmr)) return -EINVAL;
guard(spinlock_irqsave)(&tmr->lock); tmr->tick.cur_tick = position; tmr->tick.fraction = 0; 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){ if (snd_BUG_ON(!tmr)) return -EINVAL;
snd_seq_sanity_real_time(&position); guard(spinlock_irqsave)(&tmr->lock); tmr->cur_time = position; return 0;}
/* set timer skew */int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base){ 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; } guard(spinlock_irqsave)(&tmr->lock); tmr->skew = skew; 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; } scoped_guard(spinlock_irq, &tmr->lock) { if (tmr->timeri) err = -EBUSY; else tmr->timeri = t; } 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; scoped_guard(spinlock_irq, &tmr->lock) { t = tmr->timeri; tmr->timeri = NULL; } 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){ guard(spinlock_irqsave)(&tmr->lock); return seq_timer_stop(tmr);}
static int initialize_timer(struct snd_seq_timer *tmr){ unsigned long freq;
struct snd_timer *t __free(snd_timeri_timer) = snd_timeri_timer_get(tmr->timeri); 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){ guard(spinlock_irqsave)(&tmr->lock); return seq_timer_start(tmr);}
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){ guard(spinlock_irqsave)(&tmr->lock); return seq_timer_continue(tmr);}
/* 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;
guard(spinlock_irqsave)(&tmr->lock); 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); } 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){ guard(spinlock_irqsave)(&tmr->lock); return tmr->tick.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_timer *tmr; struct snd_timer_instance *ti; unsigned long resolution; for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) { struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(idx);
if (q == NULL) continue; scoped_guard(mutex, &q->timer_mutex) { tmr = q->timer; if (!tmr) break; ti = tmr->timeri; if (!ti) break;
struct snd_timer *t __free(snd_timeri_timer) = snd_timeri_timer_get(ti); snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, t ? t->name : "DEAD"); 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); } }}#endif /* CONFIG_SND_PROC_FS */