Re: beagleboardxm 2.6.39rc4 mcbsp problems.

[Jarkko Nikula <jhnikula@gmail.com>]

Hi

On Mon, 16 May 2011 11:07:40 -0700
Steve Calfee <stevecalfee@gmail.com> wrote:

> On 05/16/11 01:54, Peter Ujfalusi wrote:
> > On Saturday 14 May 2011 05:47:33 Steve Calfee wrote:
> >> I put in a few debug statements. It appears that my DMA never gets
> >> started. I know it can work with a different machine and codec driver,
> >> but not mine. I don't see any explicit DMA init, but that must be the
> >> problem.  Any more ideas?
> > 
> > You mean neither omap_pcm_hw_params nor omap_pcm_trigger got called?
> > Could you post the output of dmesg related to ASoC? Does the connection 
> > between the CPU and codec DAI correct?
> > Does McBSP part got initialized (for example does omap_mcbsp_dai_hw_params, 
> > omap_mcbsp_dai_trigger got called)?
> > 
> No, they get called. I just don't get the clock on the bclk pin.
> 
> I think I have the mcbsp1 set up correctly - I explictly set the MUX:
> 
> static struct omap_board_mux board_mux[] __initdata = {
> #if 1
> 	/* McBSP 1 */
> 	OMAP3_MUX(MCBSP1_FSX, OMAP_MUX_MODE0 | OMAP_PIN_INPUT),
> 	OMAP3_MUX(MCBSP1_CLKX, OMAP_MUX_MODE0 | OMAP_PIN_INPUT),
> 	OMAP3_MUX(MCBSP1_DR, OMAP_MUX_MODE0 | OMAP_PIN_INPUT),
> 	OMAP3_MUX(MCBSP1_DX, OMAP_MUX_MODE0 | OMAP_PIN_OUTPUT),
> #endif
> 	{ .reg_offset = OMAP_MUX_TERMINATOR },
> };
> 
Did you try to run OMAP as an I2S master like what omap3pandora.c is
doing?

Missing clock in codec master configuration suggests that reason
is in codec side and reversed roles during development makes easier to
hunt it further as then OMAP can play data out independently of is the
codec correctly configured or not.

You could run OMAP as a master by specifying SND_SOC_DAIFMT_CBS_CFS
as a DAI format for both codec and OMAP and by setting McBSP to use
internal 96 MHz clock as a master clock. Something like below might work
for testing purposes:

snd_soc_dai_set_sysclk(cpu_dai, OMAP_MCBSP_SYSCLK_CLKS_FCLK,
		       96000000, SND_SOC_CLOCK_IN);

snd_soc_dai_set_clkdiv(cpu_dai, OMAP_MCBSP_CLKGDV,
		       62); /* 96M / 48k*32 */

-- 
Jarkko