read fuses from Linux

[antonio_santagi]

Hello,

regarding iMX8MM, is it possible to read fuses status from Linux ?

I know about commands to read and program them from U-Boot, but I haven't found anything mentioned about Linux, in the Yocto BSP user guide , for example. So, I guess it's not possible, or is it ?

thank you

[KingleyMarve]

I noticed that this thread is a couple of years old, but I hope my response can still be helpful. One tool you can try is ""imxotp,"" which is a Linux user space driver for reading fuses on i.MX SoCs. This tool can be used to read fuses from Linux by specifying the fuse bank and word you want to read. Another tool you can use is ""fuseread,"" which is a simple utility that allows you to read fuses by specifying the SoC and fuse bank. Also, if you need any support related to CentOS 7, feel free to check out this link https://tuxcare.com/extended-lifecycle-support/centos-7-extended-support/. It could come in handy for your project.

[antonio_santagi]

thank you ,

this is interesting. I checked on my device where we run a 4.19.35 Kernel .

I can see this : 

# ls /sys/devices/platform/30350000.ocotp-ctrl/
driver driver_override modalias of_node power subsystem uevent

So I can't find that node 

/sys/devices/platform/30350000.ocotp-ctrl/imx-ocotp0/nvmem

they are referring to in the post you linked.

I checked also in the subfolders and I can't see any imx-ocotp0/nvmem.

[joanxie]

I checked the source code of 4.19.35, the dtsi file is the same as 4.14.98 about OCOTP, you should get this, try to build again

"https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/fsl-imx8mm.d...

ocotp: ocotp-ctrl@30350000 {
		compatible = "fsl,imx8mq-ocotp", "fsl,imx7d-ocotp", "syscon";
		reg = <0 0x30350000 0 0x10000>;
		clocks = <&clk IMX8MM_CLK_OCOTP_ROOT>;
		/* For nvmem subnodes */
		#address-cells = <1>;
		#size-cells = <1>;
	};

[joanxie]

you can refer to the topic as below:

"https://community.nxp.com/t5/i-MX-Processors/OCOTP-write-support-on-i-mx8m/m-p/825028"