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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [drivers/] [sound/] [sound_timer.c] - Rev 1777
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/* * sound/sound_timer.c */ /* * Copyright (C) by Hannu Savolainen 1993-1996 * * USS/Lite 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. */ #include <linux/config.h> #define SEQUENCER_C #include "sound_config.h" #if defined(CONFIG_SEQUENCER) static volatile int initialized = 0, opened = 0, tmr_running = 0; 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 = NULL; 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; } static void reprogram_timer (void) { unsigned long usecs_per_tick; 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; } static void tmr_reset (void) { unsigned long flags; save_flags (flags); cli (); tmr_offs = 0; ticks_offs = 0; tmr_ctr = 0; next_event_time = (unsigned long) -1; prev_event_time = 0; curr_ticks = 0; restore_flags (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, caddr_t arg) { switch (cmd) { case SNDCTL_TMR_SOURCE: return snd_ioctl_return ((int *) arg, TMR_INTERNAL); break; case SNDCTL_TMR_START: tmr_reset (); tmr_running = 1; return 0; break; case SNDCTL_TMR_STOP: tmr_running = 0; return 0; break; case SNDCTL_TMR_CONTINUE: tmr_running = 1; return 0; break; case SNDCTL_TMR_TIMEBASE: { int val = get_user ((int *) arg); if (val) { if (val < 1) val = 1; if (val > 1000) val = 1000; curr_timebase = val; } return snd_ioctl_return ((int *) arg, curr_timebase); } break; case SNDCTL_TMR_TEMPO: { int val = get_user ((int *) arg); 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 (); } return snd_ioctl_return ((int *) arg, curr_tempo); } break; case SNDCTL_SEQ_CTRLRATE: if (get_user ((int *) arg) != 0) /* Can't change */ return -(EINVAL); return snd_ioctl_return ((int *) arg, ((curr_tempo * curr_timebase) + 30) / 60); break; case SNDCTL_TMR_METRONOME: /* NOP */ break; default:; } return -(EINVAL); } 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 = { {"GUS Timer", 0}, 1, /* Priority */ 0, /* Local device link */ timer_open, timer_close, timer_event, timer_get_time, timer_ioctl, timer_arm }; void sound_timer_interrupt (void) { if (!opened) return; tmr->tmr_restart (tmr->dev); if (!tmr_running) return; tmr_ctr++; curr_ticks = ticks_offs + tmr2ticks (tmr_ctr); if (curr_ticks >= next_event_time) { next_event_time = (unsigned long) -1; sequencer_timer (0); } } void sound_timer_init (struct sound_lowlev_timer *t, char *name) { int n; if (initialized || t == NULL) return; /* There is already a similar timer */ initialized = 1; tmr = t; if (num_sound_timers >= MAX_TIMER_DEV) n = 0; /* Overwrite the system timer */ else n = num_sound_timers++; strcpy (sound_timer.info.name, name); sound_timer_devs[n] = &sound_timer; } #endif
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