SPI2 MISO not working.

[mmonto58]

Im having some issues with the spi MISO. The MOSI, CLK, and Chip selects all seem to function correctly on the SPI2 (set up the same was as the blog entry) However to me it seems like something isnt being set properly for the MISO. Its almost like its being configured as an output instead of an input.

The issue is its pulling all output sources to 0, whether im running a loop back test or from an FPGA the outputs are all pulled to 0 when connected to the MISO. Is there perhaps a problem in the kernel configuration for the SPI2 interface?

Im using pins 5 6 7 8 on the LCD connecter as noted above. If i dont connect my MOSI to my MISO my output looks fine, as soon as i connect them my MOSI is only outputting 0x00

My entry from the device tree is: MX6QDL_PAD_DISP0_DAT17__ECSPI2_MISO 0x100b1

[igorpadykov]

Hi matthew

most simple way to printf (or check with jtag) iomux register

of this pad, description can be found in IOMUX Chapter of Reference Manual.

For narrowing down problem one can check issue in uboot, or baremetal

test to exclude hardware layout errors.

Best regards
igor
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[mmonto58]

Hi Igor,

I've now seen the issue on multiple boards. Both custom and a Boundary Devices IMX6 SOM/Carrier. 

Ive used devmem to check the mux settings below:

0x020e01b4   is set to 0x2, which sets DISP0_DAT17 to ECSPI_MOSI

0x020e0810 is set to 0x1 which sets input select to ECSPI_MOSI

0x020e04c8 is set to 0x100b1 which should be correct settings based on information from boundary on the SOM.