/*
* prepare playback/capture stream
*/
static int snd_pmac_pcm_prepare(struct snd_pmac *chip, struct pmac_stream *rec, struct snd_pcm_substream *subs)
{
int i;
volatile struct dbdma_cmd __iomem *cp;
struct snd_pcm_runtime *runtime = subs->runtime;
int rate_index;
long offset;
struct pmac_stream *astr;
rec->dma_size = snd_pcm_lib_buffer_bytes(subs);
rec->period_size = snd_pcm_lib_period_bytes(subs);
rec->nperiods = rec->dma_size / rec->period_size;
rec->cur_period = 0;
rate_index = snd_pmac_rate_index(chip, rec, runtime->rate);
/* set up constraints */
astr = snd_pmac_get_stream(chip, another_stream(rec->stream));
if (! astr)
return -EINVAL;
astr->cur_freqs = 1 << rate_index;
astr->cur_formats = 1 << runtime->format;
chip->rate_index = rate_index;
chip->format = runtime->format;
/* We really want to execute a DMA stop command, after the AWACS
* is initialized.
* For reasons I don't understand, it stops the hissing noise
* common to many PowerBook G3 systems and random noise otherwise
* captured on iBook2's about every third time. -ReneR
*/
spin_lock_irq(&chip->reg_lock);
snd_pmac_dma_stop(rec);
chip->extra_dma.cmds->command = cpu_to_le16(DBDMA_STOP);
snd_pmac_dma_set_command(rec, &chip->extra_dma);
snd_pmac_dma_run(rec, RUN);
spin_unlock_irq(&chip->reg_lock);
mdelay(5);
spin_lock_irq(&chip->reg_lock);
/* continuous DMA memory type doesn't provide the physical address,
* so we need to resolve the address here...
*/
offset = runtime->dma_addr;
for (i = 0, cp = rec->cmd.cmds; i < rec->nperiods; i++, cp++) {
cp->phy_addr = cpu_to_le32(offset);
cp->req_count = cpu_to_le16(rec->period_size);
/*cp->res_count = cpu_to_le16(0);*/
cp->xfer_status = cpu_to_le16(0);
offset += rec->period_size;
}
/* make loop */
cp->command = cpu_to_le16(DBDMA_NOP + BR_ALWAYS);
cp->cmd_dep = cpu_to_le32(rec->cmd.addr);
snd_pmac_dma_stop(rec);
snd_pmac_dma_set_command(rec, &rec->cmd);
spin_unlock_irq(&chip->reg_lock);
return 0;
}
static int snd_pmac_pcm_close(struct snd_pmac *chip, struct pmac_stream *rec,
struct snd_pcm_substream *subs)
{
struct pmac_stream *astr;
snd_pmac_dma_stop(rec);
astr = snd_pmac_get_stream(chip, another_stream(rec->stream));
if (! astr)
return -EINVAL;
/* reset constraints */
astr->cur_freqs = chip->freqs_ok;
astr->cur_formats = chip->formats_ok;
return 0;
}
