What is the max SPI clock imx28 can handle in slave mode?

[mmaaxx]

Hello, I'm trying to make imx28 work at 20Mhz in slave mode.

I modified the mxs_spi driver, so it works in slave mode. And, it seems to work well at 4-10 Mhz, But when I'm trying to send the data at 12.5Mhz, SPI receives nothing, It doesn't even generate interrupts. 

I'm having a hard time figuring out what is the max SPI clock imx28's spi peripheral could handle in a slave mode. According to the datasheet, it could handle up to 50us min clock phase => 20Mhz total. 

Any suggestions?

Thanks!

[yongkimin]

I read your question! That is same what I consider it. I'd like to make SPI Slave driver in Linux platform.

Currently I designing my board using a i.XM28. The Kernel of Linux is 2.6.35.

But, the SPI driver of BSP is designed only Master mode. So I should modify it to Slave mode.

Can you assist me your experience. Thanks!

[MarekVasut]

Can you please share your modifications for the mxs spi driver to support spi slave? Thanks!