imx6ull

[chenchenchen]

Hello:

        I try to use JTAG_TDI pad as a gpio, but I find that I can't control it's output

        and JTAG_TMS pin as a gpio works well.why? 

Thanks

[riteshmpatel]

Hi @chenchenchen,

I hope you are doing well.

In the attached image of Pad IO and control configurations, the 0x03b1 value will be written to the IOMUXC_SW_PAD_CTL_PAD_JTAG_TDI register.
MX6UL_PAD_JTAG_TDI__GPIO1_IO13       0x03b1

0x03b1 value will write to the [9:8] bitfield, which is reserved. One should use the default value 0x1b0b0.

Please apply the below change to dts:

- MX6UL_PAD_JTAG_TDI__GPIO1_IO13 0x03b1
+ MX6UL_PAD_JTAG_TDI__GPIO1_IO13 0x1b0b0

OR

Alternatively, one can configure this value according to one's requirements by referring to Section 32.6.150 SW_PAD_CTL_PAD_JTAG_TDI SW PAD Control in i.MX 6ULL Applications Processor Reference Manual.

Thanks & Regards,
Ritesh M Patel

[chenchenchen]

Hello：

      Thanks for your response.

       It is solved.

       I make a mistake to write GPIO5_IOx at devicetree of iomuxc, GPIO_IOx conf reg offset is equal to

      JTAG_XX mux mode reg offset. it is conflict.

[riteshmpatel]

Hi @chenchenchen,

Thanks for the update.

Since the issue is resolved, I am closing this case.

Please raise a new ticket, if you have any new questions.

Thanks & Regards,
Ritesh M Patel