CCS/AM3352: GPIO register dump

Egbert Liu

Part Number: AM3352

Tool/software: Code Composer Studio

Hi Ti Team,

We design the customer board reference the TI Sitara Start kit board,

At present, we design the WIFI module to connect to the MMC3 interface different from the public board. It is found that the WIFI module cannot be detected when booting. It is suspected that the WIFI control pin has the

conflict with the kernel setting, so I would like to ask how to dump the GPIO settings. Look, CCS tools have this feature, Thank you。

Egbert Liu

over 7 years ago

0 Yordan Kovachev over 7 years ago

TI__Guru**** 161600 points

Hi,

Which operating system are you using on your board? RTOS or Linux?

Best Regards,
Yordan

0 Egbert Liu over 7 years ago in reply to Yordan Kovachev

Intellectual 710 points

Hi Yordan,

I operating system is usering Linux and Ubuntu 16.04 on my board.

I debug my platform by UART (TX,RX) link my Oracle VM VirtualBox .

Is there any tool to go to dump GPIO status with config ?

Does CCS have this feature?

BR
Egbert Liu

0 Yordan Kovachev over 7 years ago in reply to Egbert Liu

TI__Guru**** 161600 points

Hi,

You can't debug the Linux OS (after the kernel boot) with CCS.
If you wish to get the GPIO register values you should use printk() along with reads from the kernel driver. This way you will have the configuration printed on your debug console upon bootup.

If you want to get the register values from user space you should use devmem2 command.

Best Regards,
Yordan

0 Egbert Liu over 7 years ago in reply to Yordan Kovachev

Intellectual 710 points

Hi Yordan,

Can you Provide the example that how to use the devmem2 command in AM335X platform

There is another question I want to ask if I use below Cat command to dump register,

Is this the right way?

cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins

Is it different from devmem2 command?

Thank you very much

Egbert Liu

0 Yordan Kovachev over 7 years ago in reply to Egbert Liu

TI__Guru**** 161600 points

Hi,

Pinmux configurations should be protected and shouldn't be accessible through user space.
You should use the read functions in the kernel driver to get the pinmux registers' values.

Best Regards,
Yordan

0 Egbert Liu over 7 years ago in reply to Yordan Kovachev

Intellectual 710 points

Hi Yordan,

Ok, I know you mean, thanks. but I don`t know How to implement this way?

Example, how to use the kernel driver to get the pinmux register value?

because I am not yet familiar with this Linux kernel environment.

Egbert Liu

0 Yordan Kovachev over 7 years ago in reply to Egbert Liu

TI__Guru**** 161600 points

Hi,

Here is an example how you should read register values & print them in kernel space:
#define REGISTER_ADDRESS 0x44E10804 //this is just an example
void __iomem *gpio_pinmux_addr = NULL;
gpio_pinmux_addr = ioremap( (unsigned int) REGISTER_ADDRESS, 4096);
printk("Register value is %x\n", __raw_readl(gpio_pinmux_addr));

Best Regards,
Yordan

0 Egbert Liu over 7 years ago in reply to Yordan Kovachev

Intellectual 710 points

Hi Yordan,

Thank you for considering my request.

But I don't know how to add this sample code to which Linux kernel folder?

Could you give me some guidance? Thanks .

BR
Egbert Liu

0 Yordan Kovachev over 7 years ago in reply to Egbert Liu

TI__Guru**** 161600 points

Hi,

The driver is drivers/gpio/davinci-gpio.c. Add your code in the davinci_gpio_probe() function, somewhere at the end of the function, for example:
#endif
spin_lock_init(&chips->lock);
bank_base += ngpio;

for (gpio = 0, bank = 0; gpio < ngpio; gpio += 32, bank++)
chips->regs[bank] = gpio_base + offset_array[bank];

gpiochip_add_data(&chips->chip, chips);
platform_set_drvdata(pdev, chips);
davinci_gpio_irq_setup(pdev);
//add your code bellow

return 0;
}

Best Regards,
Yordan

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CCS/AM3352: GPIO register dump