devmem2 giving bus error on imx8mq linux

[mahesh_hns]

Hello,

 I was trying to read the SW_MUX_CTL_PAD_SD1_DATA4 SW MUX Control register (0x3033_00B8) using devmem2 on imx8mQ processor running linux (5.15) and got this

devmem2 0x303300B8
/dev/mem opened.
Memory mapped at address 0xffff9abd1000.
Bus error

I never had any issues like these while reading the mux registers on imx8mP processor. 
Why is that? What do I  need to do to read the pad/mux registers on imx8mQ ?

Thanks in advance

[Zhiming_Liu]

Hi

We can read this register on EVK board. 

root@imx8mqevk:/unit_tests# ./memtool -32 0x303300B8 1
E
Reading 0x1 count starting at address 0x303300B8

0x303300B8:  00000000

Best Regards
Zhiming