static int pcsp_start_playing(struct snd_pcsp *chip)
{
unsigned long ns;
#if PCSP_DEBUG
printk(KERN_INFO "PCSP: start_playing called\n");
#endif
if (atomic_read(&chip->timer_active)) {
printk(KERN_ERR "PCSP: Timer already active\n");
return -EIO;
}
spin_lock(&i8253_lock);
chip->val61 = inb(0x61) | 0x03;
outb_p(0x92, 0x43); /* binary, mode 1, LSB only, ch 2 */
spin_unlock(&i8253_lock);
atomic_set(&chip->timer_active, 1);
chip->thalf = 0;
ns = pcsp_timer_update(&pcsp_chip.timer);
if (!ns)
return -EIO;
hrtimer_start(&pcsp_chip.timer, ktime_set(0, ns), HRTIMER_MODE_REL);
return 0;
}
enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
{
struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
struct snd_pcm_substream *substream;
int periods_elapsed, pointer_update;
size_t period_bytes, buffer_bytes;
unsigned long ns;
unsigned long flags;
pointer_update = !chip->thalf;
ns = pcsp_timer_update(handle);
if (!ns)
return HRTIMER_NORESTART;
/* update the playback position */
substream = chip->playback_substream;
if (!substream)
return HRTIMER_NORESTART;
period_bytes = snd_pcm_lib_period_bytes(substream);
buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
spin_lock_irqsave(&chip->substream_lock, flags);
chip->playback_ptr += PCSP_INDEX_INC() * chip->fmt_size;
periods_elapsed = chip->playback_ptr - chip->period_ptr;
if (periods_elapsed < 0) {
#if PCSP_DEBUG
printk(KERN_INFO "PCSP: buffer_bytes mod period_bytes != 0 ? "
"(%zi %zi %zi)\n",
chip->playback_ptr, period_bytes, buffer_bytes);
#endif
periods_elapsed += buffer_bytes;
}
periods_elapsed /= period_bytes;
/* wrap the pointer _before_ calling snd_pcm_period_elapsed(),
* or ALSA will BUG on us. */
chip->playback_ptr %= buffer_bytes;
if (periods_elapsed) {
chip->period_ptr += periods_elapsed * period_bytes;
chip->period_ptr %= buffer_bytes;
}
spin_unlock_irqrestore(&chip->substream_lock, flags);
if (periods_elapsed)
tasklet_schedule(&pcsp_pcm_tasklet);
hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
return HRTIMER_RESTART;
}
enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
{
struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
int pointer_update;
u64 ns;
if (!atomic_read(&chip->timer_active) || !chip->playback_substream)
return HRTIMER_NORESTART;
pointer_update = !chip->thalf;
ns = pcsp_timer_update(chip);
if (!ns) {
printk(KERN_WARNING "PCSP: unexpected stop\n");
return HRTIMER_NORESTART;
}
if (pointer_update)
pcsp_pointer_update(chip);
hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
return HRTIMER_RESTART;
}
