McASP master mode on DM8168

Yaroslav Pokrovsky

Hi!

I have to use McASP on DM8168 in I2S master mode: just generate on pins MCA2_ACLKX and MCA2_AFSX frequency and frame sync signals appropriately. Data is transmitted through MCA2_AXR0 and MCA2_AXR1.

I made the next changes in machine driver:

davinci-evm.c:

#define AUDIO_FORMAT (SND_SOC_DAIFMT_DSP_B | \
SND_SOC_DAIFMT_CBS_CFS | SND_SOC_DAIFMT_IB_NF

After that I tried to record and play sound, but my attempts were failed. Using oscilloscope I didn't see any frequency on MCA2_ACLKX: only permanent +1.6V.

What's wrong? Does DM8168 support I2S master mode?

Thanks!

over 12 years ago

0 Hyun Kim over 12 years ago

TI__Genius 14965 points

Hi,

Yes, DM8168 should support I2S master mode. Have you set pinmux to use proper pins first?

Regards,

Hyun

0 Yaroslav Pokrovsky over 12 years ago in reply to Hyun Kim

Prodigy 50 points

Well, McASP works fine when it is configured as a slave, pinmux wasn't changed since that. Anyway, I tried explicitly select in board file necessary pins for McASP:

static struct omap_board_mux board_mux[] __initdata = {

...

TI816X_MUX(MCA2_ACLKR, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_AHCLKR, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_AFSR, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_ACLKX, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_ACLKHX, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_AFSX, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_AXR0, OMAP_MUX_MODE0),
TI816X_MUX(MCA2_AXR1, OMAP_MUX_MODE0),

...

}

but it didn't help :(

0 Hyun Kim over 12 years ago in reply to Yaroslav Pokrovsky

TI__Genius 14965 points

Hi,

Well, I think you have to change more McASP registers then looking for Transmit Frame Sync Control Register (AFSXCTL) and Transmit Clock Control Register (ACLKXCTL) register settings explained TRM McASP seciton http://www.ti.com/lit/ug/sprugx8b/sprugx8b.pdf.

Regards,

Hyun

Processors

Processors forum

McASP master mode on DM8168