[i.MX8M Plus] config SION bit in dts

[sophiehu]

Hi NXP,

We have a custom I.MX8M plus board and need to config GPIO1_IO13 and GPIO1_IO14 to input. We can read value changing on GPIO1_IO13 but not on GPIO1_IO14. We also verify on EVK and it is the same.

We try to set SION bit of GPIO1_IO14 by memtool but it shows bus error. So we try to set SION bit of GPIO1_IO14 in uboot by "mw 0x3033004C 0x10" and check io value by "gpio status -a" and then it works.

Now we need to config dts in kernel. I have tried to config like below. All of the them do not work. I can only read 0 on GPIO1_IO14.

first I try:

second:

third:


1. Could you show me how to config dts of GPIO1_IO14 for input?
2. I can read GPIO1_IO13 value changing but not GPIO1_IO14 even the dts configs of both are the same. How to know which IO I need to set SION bit or else?

Best Regards,
Sophie

[joanxie · Accepted solution]

refer to the dts file, GPIO1_IO14 is already defined as below

pinctrl_usb1_vbus: usb1grp {
		fsl,pins = <
			MX8MP_IOMUXC_GPIO1_IO14__GPIO1_IO14	0x19
		>;
	};

if you want to set one gpio as input, you can set it 0x1C4, but you need confirm if your HW design firstly

[sophiehu]

Hi Joanxie,

Thank you, it works.

BTW, we also config GPIO1_IO13 to gpio input. Why doesn't GPIO1_IO13 need to set the bit and work? How do I know if I need to set SION or HSY bit when config IO to input?

Rwst Regards,
Sophie

[joanxie]

Why doesn't GPIO1_IO13 need to set the bit and work?

>which bit do you mean?

[sophiehu]

I mean, GPIO1_IO13 can work with dts 0x126 or 0x106. Why GPIO1_IO14 cannot and need to set to 0x1C4? How do I know if I need to set to 0x1C4 for other GPIO?

[joanxie]

0x126 should be output, pls double check it, if you want to set GPIO as input, you need check bit7, set bit7 as 1 for input