diff options
Diffstat (limited to 'sound/oss/sound_timer.c')
| -rw-r--r-- | sound/oss/sound_timer.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/sound/oss/sound_timer.c b/sound/oss/sound_timer.c new file mode 100644 index 000000000000..bc2777dd2ef9 --- /dev/null +++ b/sound/oss/sound_timer.c @@ -0,0 +1,323 @@ +/* + * sound/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; +} + +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); +} + +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; +} |