/* * sound/oss/sound_timer.c */ /* * Copyright (C) by Hannu Savolainen 1993-1997 * * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL) * Version 2 (June 1991). See the "COPYING" file distributed with this software * for more info. */ /* * Thomas Sailer : ioctl code reworked (vmalloc/vfree removed) */ #include <linux/string.h> #include <linux/spinlock.h> #include "sound_config.h" static volatile int initialized, opened, tmr_running; static volatile time_t tmr_offs, tmr_ctr; static volatile unsigned long ticks_offs; static volatile int curr_tempo, curr_timebase; static volatile unsigned long curr_ticks; static volatile unsigned long next_event_time; static unsigned long prev_event_time; static volatile unsigned long usecs_per_tmr; /* Length of the current interval */ static struct sound_lowlev_timer *tmr; static spinlock_t lock; static unsigned long tmr2ticks(int tmr_value) { /* * Convert timer ticks to MIDI ticks */ unsigned long tmp; unsigned long scale; tmp = tmr_value * usecs_per_tmr; /* Convert to usecs */ scale = (60 * 1000000) / (curr_tempo * curr_timebase); /* usecs per MIDI tick */ return (tmp + (scale / 2)) / scale; } void reprogram_timer(void) { unsigned long usecs_per_tick; /* * The user is changing the timer rate before setting a timer * slap, bad bad not allowed. */ if(!tmr) return; usecs_per_tick = (60 * 1000000) / (curr_tempo * curr_timebase); /* * Don't kill the system by setting too high timer rate */ if (usecs_per_tick < 2000) usecs_per_tick = 2000; usecs_per_tmr = tmr->tmr_start(tmr->dev, usecs_per_tick); } void sound_timer_syncinterval(unsigned int new_usecs) { /* * This routine is called by the hardware level if * the clock frequency has changed for some reason. */ tmr_offs = tmr_ctr; ticks_offs += tmr2ticks(tmr_ctr); tmr_ctr = 0; usecs_per_tmr = new_usecs; } EXPORT_SYMBOL(sound_timer_syncinterval); static void tmr_reset(void) { unsigned long flags; spin_lock_irqsave(&lock,flags); tmr_offs = 0; ticks_offs = 0; tmr_ctr = 0; next_event_time = (unsigned long) -1; prev_event_time = 0; curr_ticks = 0; spin_unlock_irqrestore(&lock,flags); } static int timer_open(int dev, int mode) { if (opened) return -EBUSY; tmr_reset(); curr_tempo = 60; curr_timebase = 100; opened = 1; reprogram_timer(); return 0; } static void timer_close(int dev) { opened = tmr_running = 0; tmr->tmr_disable(tmr->dev); } static int timer_event(int dev, unsigned char *event) { unsigned char cmd = event[1]; unsigned long parm = *(int *) &event[4]; switch (cmd) { case TMR_WAIT_REL: parm += prev_event_time; case TMR_WAIT_ABS: if (parm > 0) { long time; if (parm <= curr_ticks) /* It's the time */ return TIMER_NOT_ARMED; time = parm; next_event_time = prev_event_time = time; return TIMER_ARMED; } break; case TMR_START: tmr_reset(); tmr_running = 1; reprogram_timer(); break; case TMR_STOP: tmr_running = 0; break; case TMR_CONTINUE: tmr_running = 1; reprogram_timer(); break; case TMR_TEMPO: if (parm) { if (parm < 8) parm = 8; if (parm > 250) parm = 250; tmr_offs = tmr_ctr; ticks_offs += tmr2ticks(tmr_ctr); tmr_ctr = 0; curr_tempo = parm; reprogram_timer(); } break; case TMR_ECHO: seq_copy_to_input(event, 8); break; default:; } return TIMER_NOT_ARMED; } static unsigned long timer_get_time(int dev) { if (!opened) return 0; return curr_ticks; } static int timer_ioctl(int dev, unsigned int cmd, void __user *arg) { int __user *p = arg; int val; switch (cmd) { case SNDCTL_TMR_SOURCE: val = TMR_INTERNAL; break; case SNDCTL_TMR_START: tmr_reset(); tmr_running = 1; return 0; case SNDCTL_TMR_STOP: tmr_running = 0; return 0; case SNDCTL_TMR_CONTINUE: tmr_running = 1; return 0; case SNDCTL_TMR_TIMEBASE: if (get_user(val, p)) return -EFAULT; if (val) { if (val < 1) val = 1; if (val > 1000) val = 1000; curr_timebase = val; } val = curr_timebase; break; case SNDCTL_TMR_TEMPO: if (get_user(val, p)) return -EFAULT; if (val) { if (val < 8) val = 8; if (val > 250) val = 250; tmr_offs = tmr_ctr; ticks_offs += tmr2ticks(tmr_ctr); tmr_ctr = 0; curr_tempo = val; reprogram_timer(); } val = curr_tempo; break; case SNDCTL_SEQ_CTRLRATE: if (get_user(val, p)) return -EFAULT; if (val != 0) /* Can't change */ return -EINVAL; val = ((curr_tempo * curr_timebase) + 30) / 60; break; case SNDCTL_SEQ_GETTIME: val = curr_ticks; break; case SNDCTL_TMR_METRONOME: default: return -EINVAL; } return put_user(val, p); } static void timer_arm(int dev, long time) { if (time < 0) time = curr_ticks + 1; else if (time <= curr_ticks) /* It's the time */ return; next_event_time = prev_event_time = time; return; } static struct sound_timer_operations sound_timer = { .owner = THIS_MODULE, .info = {"Sound Timer", 0}, .priority = 1, /* Priority */ .devlink = 0, /* Local device link */ .open = timer_open, .close = timer_close, .event = timer_event, .get_time = timer_get_time, .ioctl = timer_ioctl, .arm_timer = timer_arm }; void sound_timer_interrupt(void) { unsigned long flags; if (!opened) return; tmr->tmr_restart(tmr->dev); if (!tmr_running) return; spin_lock_irqsave(&lock,flags); tmr_ctr++; curr_ticks = ticks_offs + tmr2ticks(tmr_ctr); if (curr_ticks >= next_event_time) { next_event_time = (unsigned long) -1; sequencer_timer(0); } spin_unlock_irqrestore(&lock,flags); } EXPORT_SYMBOL(sound_timer_interrupt); void sound_timer_init(struct sound_lowlev_timer *t, char *name) { int n; if (initialized) { if (t->priority <= tmr->priority) return; /* There is already a similar or better timer */ tmr = t; return; } initialized = 1; tmr = t; n = sound_alloc_timerdev(); if (n == -1) n = 0; /* Overwrite the system timer */ strcpy(sound_timer.info.name, name); sound_timer_devs[n] = &sound_timer; } EXPORT_SYMBOL(sound_timer_init);