imx8mp SAI bit counter not working

[Brian_B]

I am working with the imx8mp processor, receiving serial data over SAI2.  The SAI's VERID register indicates version 3.1 with timestamp registers.  I have the SAI2 receive working and dumping the incoming data into a DMA buffer.  The master clock, bit clock, and frame clock are all generated externally.  I expected to get values in the timestamp counter (RTSR), bit counter (RBCR), and bit timestamp (RBCTR), but they stay at zero even as I am receiving valid data.  I have verified via readback that the receive timestamp control (RTCR) is 0x000003, which should allow the timestamp counter to increment even without the bit counter incrementing.  Is there anything else I need to configure to get the bit counter and timestamp working?

[Brian_B · Accepted solution]

Never mind - apparently the  regmap_read function I was using was reading back cached values.  I switched to readl and now I am getting valid values.

Thanks anyway!