On 7/18/08, Jon Smirl <jonsmirl@xxxxxxxxx> wrote:
> The MPC5200 has three clock configurations
>
> 1) Clock out, normal master mode
> 2) Clock in, normal slave mode
> 3) Something Freescale calls cellphone slave but it is more like clock
> distribution.
>
> In cellslave mode one i2s port is in normal slave mode. The clock from
> this port is used to drive up to three other i2s ports in master mode.
>
> I have two choices for set_sysclk:
> #define SND_SOC_CLOCK_IN 0
> #define SND_SOC_CLOCK_OUT 1
>
> When the clock frequency changes I need to notify the i2s drivers for
> the dependent channels. Do we need a third choice,
> SND_SOC_CLOCK_SLAVE? Alternatively I can use another clock id value.
I can implement it like this, in cellslave mode I just record the
frequency, CLOCK_OUT not in cellslave mode needs to set up the
internal MPC clock generation (which can't make accurate audio
clocks).
static int psc_i2s_set_sysclk(struct snd_soc_cpu_dai *cpu_dai,
int clk_id, unsigned int freq, int dir)
{
struct psc_i2s *psc_i2s = cpu_dai->private_data;
dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, freq=%ui, dir=%i)\n",
cpu_dai, freq, dir);
switch (dir) {
case SND_SOC_CLOCK_IN:
return 0;
case SND_SOC_CLOCK_OUT:
default:
if (!(psc_i2s->sicr & MPC52xx_PSC_SICR_CELLSLAVE)) {
/* implement me */
/* compute and set the needed dividers for the internal clock */
return -EINVAL;
}
psc_i2s->sysclk = freq;
return -EINVAL;
}
}
static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
u32 sicr, rate, bits, bitblk, err, wordclk;
dev_dbg(psc_i2s->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
" periods=%i buffer_size=%i buffer_bytes=%i\n",
__FUNCTION__, substream, params_period_size(params),
params_period_bytes(params), params_periods(params),
params_buffer_size(params), params_buffer_bytes(params));
sicr = psc_i2s->sicr;
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S8:
sicr |= MPC52xx_PSC_SICR_SIM_CODEC_8;
bits = 8;
break;
case SNDRV_PCM_FORMAT_S16_BE:
sicr |= MPC52xx_PSC_SICR_SIM_CODEC_16;
bits = 16;
break;
case SNDRV_PCM_FORMAT_S24_BE:
sicr |= MPC52xx_PSC_SICR_SIM_CODEC_24;
bits = 24;
break;
case SNDRV_PCM_FORMAT_S32_BE:
sicr |= MPC52xx_PSC_SICR_SIM_CODEC_32;
bits = 32;
break;
default:
dev_dbg(psc_i2s->dev, "invalid format\n");
return -EINVAL;
}
out_be32(&psc_i2s->psc_regs->sicr, sicr);
if (psc_i2s->sysclk) {
switch (params_rate(params)) {
case SNDRV_PCM_RATE_5512: rate = 5512; break;
case SNDRV_PCM_RATE_8000: rate = 8000; break;
case SNDRV_PCM_RATE_11025: rate = 11025; break;
case SNDRV_PCM_RATE_16000: rate = 16000; break;
case SNDRV_PCM_RATE_22050: rate = 22050; break;
case SNDRV_PCM_RATE_32000: rate = 32000; break;
case SNDRV_PCM_RATE_44100: rate = 44100; break;
case SNDRV_PCM_RATE_48000: rate = 48000; break;
case SNDRV_PCM_RATE_64000: rate = 64000; break;
case SNDRV_PCM_RATE_88200: rate = 88200; break;
case SNDRV_PCM_RATE_96000: rate = 96000; break;
case SNDRV_PCM_RATE_176400: rate = 176400; break;
case SNDRV_PCM_RATE_192000: rate = 192000; break;
default:
dev_dbg(psc_i2s->dev, "invalid format\n");
return -EINVAL;
}
bitclk = psc_i2s->sysclk / rate;
wordclk = bitclk / bits;
out_be32(&psc_i2s->psc_regs->ccr, (bitclk - 1) << 24 | (wordclk << 16);
}
//rc = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
//if (rc) {
// dev_err(psc_i2s->dev, "could not allocate dma buffer\n");
// return rc;
//}
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
return 0;
}
>
>
> --
> Jon Smirl
> jonsmirl@xxxxxxxxx
>
--
Jon Smirl
jonsmirl@xxxxxxxxx
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