Linux/PROCESSOR-SDK-AM437X: am437x

Swapna yendrapalli

Intellectual 625 points

Part Number: PROCESSOR-SDK-AM437X

Tool/software: Linux

Hello,

I am using an external watchdog max6329 and trying to use gpio bank5 pin number 31 on OMAP processor to kick watchdog.

My config file has following parameters enabled.

CONFIG_WATCHDOG

CONFIG_GPIO_WATCHDOG

and dts file has watchdog enabled as below

watchdog: watchdog {
compatible = "linux,wdt-gpio";
gpios = <&gpio5 31 GPIO_ACTIVE_LOW>;
hw_algo = "toggle";
hw_margin_ms = <1600>;
always-running = "on";
};

During bootup I see the below error:

[ 13.406690 ] watchdog: GPIO Watchdog: cannot register miscdev on minor=130 (err=-16).

[ 13.414578] watchdog: GPIO Watchdog: a legacy watchdog module

Could you please advise what might be wrong here?

Thanks in advance,

Priya

over 8 years ago

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Hi Priya,

It seems two modules are trying to register to do same thing. The 2nd module trying to register is unable to because the 1st already has. When you enable gpio_wdt driver, make sure you disable other wdt drivers, so there will be no conflict. Check if gpio_wdt is in conflict with omap_wdt and/or softdog. See also the below link:

bbs.archlinux.org/viewtopic.php

Regards,
Pavel

0 Pavel Botev over 8 years ago in reply to Pavel Botev

TI__Guru**** 170625 points

See also the AM335x WDT driver user guide, it is similar for AM437x:

processors.wiki.ti.com/.../AM335x_PSP_WDT_Driver_User_Guide
processors.wiki.ti.com/.../AM335x_to_AM437x_Hardware_Migration_Guide

Regards,
Pavel

0 Swapna yendrapalli over 8 years ago in reply to Pavel Botev

Intellectual 625 points

Thanks Pavel!!.

I confirmed I have enabled only gpio based watchdog and can see the same in the CONFIG file but looks like somehow this error is showing up during the boot process.

But keeping this a side the GPIO functionality is working as expected I am seeing resets when the watchdog is not kicked.

Follow up question - We are also planning to use watchdog daemon that would run tests before kicking the watchdog but I have not seen this daemon on our device.

Could you please advise how to enable the watchdog daemon in linux. we are using 4.1.13 version of the linux kernel.

Best Regards,

Priya

0 Pavel Botev over 8 years ago in reply to Swapna yendrapalli

TI__Guru**** 170625 points

Priya,

Regarding watchdog daemon in linux, see the below pointers:

linux-kernel/Documentation/watchdog/watchdog-api.txt
linux.die.net/.../watchdog
www.sat.dundee.ac.uk/.../watchdog-background.html
e2e.ti.com/.../363249
e2e.ti.com/.../265878

Note also that we have example application (saWatchdog.c) which comes with the AM387x EZSDK. You might re-use the approach for AM437x device.

processors.wiki.ti.com/.../TI81XX_PSP_WDT_Driver_User_Guide
processors.wiki.ti.com/.../AM335x-PSP_04.06.00.11_Features_and_Performance_Guide
processors.wiki.ti.com/.../AM335x_PSP_WDT_Driver_User_Guide

Regards,
Pavel

0 Swapna yendrapalli over 8 years ago in reply to Pavel Botev

Intellectual 625 points

Thank you!!

I have looked at the documents before but what I couldn't get to is on the current version of linux kernel 4.1.13 I don't see watchdog.conf and related files in my rootfs and also the executable watchdog daemon.

Is there a procedure to install this daemon and wondering if TI has anything similar to perform tests before kicking the watchdog.

Appreciate your help,
Priya

0 Pavel Botev over 8 years ago in reply to Swapna yendrapalli

TI__Guru**** 170625 points

Priya,

There is no watchdog.conf (configuration file for the watchdog daemon) and watchdog daemon executable available by default in the TI PSDK rootfs. You can try install and config by your own, there is nothing TI specific here, see the below e2e thread for some info:

e2e.ti.com/.../779184

What we have ready for use is sample application saWatchdog.

Regards,
Pavel

0 Swapna yendrapalli over 8 years ago in reply to Pavel Botev

Intellectual 625 points

OK . Thanks!!

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Linux/PROCESSOR-SDK-AM437X: am437x