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IMX6UL kernel hang when trying to read GPIO5 register

Question asked by ZC Tee on Aug 22, 2016
Latest reply on Aug 24, 2016 by igorpadykov

Hi all,

I am trying to read the GPIO5 register during the startup of the mxsfb_probe.

I had define the GPIO5 base address to 0x020AC000, as in the datasheet, as below:

#define MX6Q_GPIO5_BASE_ADDR     0x020AC000

 

And my coding on accessing the register as below:

u32 glp05;

void __iomem *gpio5_base = (void __iomem *)IMX_IO_P2V(MX6Q_GPIO5_BASE_ADDR);

 

glp05 = readl_relaxed(gpio5_base);

printk(KERN_INFO "gpio value is 0x%x\n", gpl05);

 

When the kernel runs until this line of code, it hangs. I tried to check for similiar readl_relaxed coding, and found out that in cpuidle_imx6ul.c, there are some readl_relaxed on MX6Q_ANATOP_BASE_ADDR, and the kernel had no problem running it.

May i know is there something that i missed out, or there is something that i need to add so that i can access the GPIO5 register directly?

 

Thank you.

 

Regards,

Tee

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