static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
int channel, snd_pcm_uframes_t pos,
snd_pcm_uframes_t count)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
ssize_t b_count = frames_to_bytes(runtime , count);
ssize_t b_pos = frames_to_bytes(runtime , pos);
if (count < 0)
return -EINVAL;
if (!count)
return 0;
memset_io(chip->data_buffer + b_pos, 0, b_count);
chip->buffer_end = chip->data_buffer + b_pos + b_count;
if (chip->empty) {
chip->empty = 0;
dac_audio_start_timer(chip);
}
return 0;
}
static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream, int channel,
snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
{
/* channel is not used (interleaved data) */
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
ssize_t b_count = frames_to_bytes(runtime , count);
ssize_t b_pos = frames_to_bytes(runtime , pos);
if (count < 0)
return -EINVAL;
if (!count)
return 0;
memcpy_toio(chip->data_buffer + b_pos, src, b_count);
chip->buffer_end = chip->data_buffer + b_pos + b_count;
if (chip->empty) {
chip->empty = 0;
dac_audio_start_timer(chip);
}
return 0;
}
static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count,
loff_t * ppos)
{
int free;
int nbytes;
if (count < 0)
return -EINVAL;
if (!count) {
dac_audio_sync();
return 0;
}
free = buffer_begin - buffer_end;
if (free < 0)
free += BUFFER_SIZE;
if ((free == 0) && (empty))
free = BUFFER_SIZE;
if (count > free)
count = free;
if (buffer_begin > buffer_end) {
if (copy_from_user((void *)buffer_end, buf, count))
return -EFAULT;
buffer_end += count;
} else {
nbytes = data_buffer + BUFFER_SIZE - buffer_end;
if (nbytes > count) {
if (copy_from_user((void *)buffer_end, buf, count))
return -EFAULT;
buffer_end += count;
} else {
if (copy_from_user((void *)buffer_end, buf, nbytes))
return -EFAULT;
if (copy_from_user
((void *)data_buffer, buf + nbytes, count - nbytes))
return -EFAULT;
buffer_end = data_buffer + count - nbytes;
}
}
if (empty) {
empty = 0;
dac_audio_start_timer();
}
return count;
}
static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
dac_audio_start_timer(chip);
break;
case SNDRV_PCM_TRIGGER_STOP:
chip->buffer_begin = chip->buffer_end = chip->data_buffer;
chip->processed = 0;
chip->empty = 1;
dac_audio_stop_timer(chip);
break;
default:
return -EINVAL;
}
return 0;
}
