i.MX ProcessorsのトピックRe: How set GPIO high at boot time on imx6ul

How set GPIO high at boot time on imx6ul

mihaitaivascu — Wed, 18 Jul 2018 16:13:50 GMT

Hello,

I would need to set some TAMPER GPIOs at boot time: MX6UL_PAD_SNVS_TAMPER4__GPIO5_IO06, e

It is enough to do it in the barebox device tree setting them ACTIVE HIGH. If so where exactly in the device tree?

Also I am trying to assign some signals to different GPIOs as the default GPIOs are used by other kernel modules.

I could not find programming model for imx6ul or GPIO details in the hardware manual/application processor manual.

Could somebody point me to the imx6ul documentation that explains GPIOs registers and functions ?

Thanks,

Mihaita

Re: How set GPIO high at boot time on imx6ul

igorpadykov — Wed, 18 Jul 2018 23:51:51 GMT

Hi Mihaita

I am afraid it is not possible to set gpio level in device tree setting, one can set it in

uboot/board/freescale/mx6ul_14x14_evk/mx6ul_14x14_evk.c or in plugin, if using plugin mode.

>Could somebody point me to the imx6ul documentation that explains GPIOs registers and functions ?

Chapter 26 General Purpose Input/Output (GPIO) i.MX6UL Reference Manual

http://www.nxp.com/docs/en/reference-manual/IMX6ULRM.pdf

For linux documentation one can look on documents provided on

i.MX Software|NXP

Best regards
igor
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Re: How set GPIO high at boot time on imx6ul

mihaitaivascu — Thu, 19 Jul 2018 06:28:41 GMT

Hi Igor,

Thanks for your answer.

I saw some examples where gpios were set high in device tree. The following will not do it?

Also I have looked at the imx6 manual but there is no programming model for it. I need to know the programming model for the imx6ul.

For example I have some GPIOs that I wanted to use for something but I see some kernel modules are already using them so I need to see which other GPIOs/ signals can be used for power or Wifi, etc. Also I need to know the GPIO registers mapping in memory. And the GPIO functions.

I could not find that information so far on NXP resources. In that document I found only this about GPIOs Tamper:

Thanks,

Mihaita

Re: How set GPIO high at boot time on imx6ul

igorpadykov — Thu, 19 Jul 2018 11:10:11 GMT

Hi Mihaita

you can get additional details (in particular for "enable-gpios") in linux/Documentation/devicetree/bindings

documentation. Tamper pins are described in

Security Reference Manual for the i.MX 6UltraLite Applications Processor (moderated link)
https://www.nxp.com/webapp/sps/download/mod_download.jsp?colCode=IMX6UL-SRM&appType=moderated&Parent_nodeId=1431012586080725871437&Parent_pageType=product

Best regards
igor