Hi,
thanks for your replies, unfortunately, the codec has to be slave, it
doesn't support yet to send clock via i2s. I have another question, it might
be seem simple but it will clarify some of my thoughts.
>From omap3beagle.c hw_params:
* /* Set the codec system clock for DAC and ADC */
ret = snd_soc_dai_set_sysclk(codec_dai, 0, 26000000,
SND_SOC_CLOCK_IN);*
The sysclk is set to 26Mhz and it is coming from the TWL which acts as
master.
I had it configured to 12288000(info from datasheet) which was suppose to
work until I knew the codec I'm using can't be master. (It is still is on
12288000)
How should it be configured to make the OMAP Master? Should I leave it as
26Mhz and do manually all the divisions?
I'm using SND_SOC_DAIFMT_CBS_CFS for the Beagle.
Thank you for your help
BR,
Ernesto
On Wed, May 13, 2009 at 5:41 AM, Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>wrote:
> On Wednesday 13 May 2009 02:28:58 ext Ernesto Torres wrote:
> > Hi,
> >
> > I would like to know the actual configuration for the output of the
> Beagle
> > Board I2S, from the OMAP35x Reference Manual, on page 2887:
>
> Is you external codec supports master mode (provides the needed clocks on
> the
> I2S bus)?
> I would suggest to use it in that way, since configuring OMAP to provide
> close
> enough frequency can be tricky.
> I have did this for experimenting on our custom board, just to see how it
> works.
> This is the code is taken from the soc board file's hw_params function:
>
> div = clk_id = freq = 0;
> switch (params_rate(params)) {
> case 44100: /* 44.117 */
> div = 68;
> clk_id = OMAP_MCBSP_SYSCLK_CLKS_FCLK;
> freq = 96000000;
> break;
> case 48000: /* 48.032 */
> div = 54;
> clk_id = OMAP_MCBSP_SYSCLK_CLK;
> freq = 83000000;
> break;
> default:
> printk(KERN_ERR "hw params: unknown rate %d\n",
> params_rate(params));
> return -EINVAL;
> }
>
> ret = snd_soc_dai_set_sysclk(cpu_dai, clk_id, freq, SND_SOC_CLOCK_IN);
> if (ret < 0) {
> printk(KERN_ERR "can't set cpu system clock\n");
> return ret;
> }
>
> ret = cpu_dai->dai_ops.set_clkdiv(cpu_dai, OMAP_MCBSP_CLKGDV, div);
> if (ret < 0) {
> printk(KERN_ERR "can't set cpu clock divider\n");
> }
>
> As you can see I needed to select different clock source for 44.1 and 48
> KHz
> sample rate for OMAP to use as a base for the dividing...
>
> So: try to use the OMAP as slave, if it is possible.
>
> --
> Péter
>
--
___________
EhTd
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