TDA4VM: TDA4M J7 DRA8: rti watchdog driver

Please reply...does the watchdog reset clear itself on reboot and nothing extra needed to be done during boot.

Hi Annamalai,

Apologies for delay in response. 

Annamalai Lakshmanan said:

does the watchdog reset clear itself on reboot

The watchdog does not clear itself. Upon reset, the system will start executing back from the ROM code and if the issue due to which reset occurs is not resolved, the system will run into cyclic resets.

Can you please specify your use case here. We'll be able to provide pointed suggestions based on your use case.

Regards,
Parth

HI Parth,

I am trying to enable WWDT in a QNX RTOS, I am trying to follow sample linux driver for RTI WWDT.

I am not sure if the boot loader need to be modified as well to clear the watchdog (if the reset happens) ? If so please confirm , do you have any sample reference for

such boot loader implementations eg: uboot which clears the wwdt timer ?

With Regards,

Annamalai

I am not sure If i need to modify the custom boot loader to clear the watchdog or does it taken care automatically from ROM code provided by TI

Hi,

Annamalai Lakshmanan said:

I am not sure if the boot loader need to be modified as well to clear the watchdog (if the reset happens) ?

Watchdog timer is not supposed to be cleared upon reset, so you don't need to modify the bootloader. Once reset happens, the watchdog will also reset itself and will again cause a reset if some issue happens during boot.

Regards,
Parth

HI Parth,

I have another question: we are using J721E DRA829 WWDT RTI watch dog.

I see the SOC has many RTI watchdogs per domain basis.

I see there are 2 Watchdogs on A72 on a per core basis and both are capable of issuing per core reset.

Is there a global reset, or only an interrupt handler. what is the best way to handle is watchdog timer

(Global reset would be an ideal way)

Thanks

Annamalai

Just adding as per reference implementation in Linux only NMI mode is used:

is this correct ?

+	/* Generate NMI when wdt expires */
+	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);

HI

Any feedback So Far... ? Also, I am unable to write some thing to this register:

A write of A98559DAh following a readback gives 5312ACEDh, do you know why is this?

Regards,

Annamalai

Is this feature supported or not? since only readback of this register is not working but few other registers work. as per TRM: Can you please confirm ?

Hi Annamalai, 

Annamalai Lakshmanan said:

(Global reset would be an ideal way)

What do you mean by Global reset? Are you looking for a way to reset the core (MPU1_0 and MPU1_1) with the global reset or the complete SOC?

Annamalai Lakshmanan said:

A write of A98559DAh following a readback gives 5312ACEDh, do you know why is this?

At what point are you trying to write this register? Looks like this register can only be written once by application and can only be written again after a system reset.

Regards,
Parth

Also, you can refer to CSL RTI example from RTOS SDK available at PDK_Install_PATH\packages\ti\csl\example\rti\rti_dwwdtest_app

HI Path,

Thanks, the register is OTP per reset, now this seemed ok.

But, I dont see an NMI Interrupt in the application gic interrupt 240 during the timer expiry.

But the RTI_WSSTATUS = 0x32 (bit 4 is set inidicating wdog violation)

With Regards,

Annamalai

Hi, 

Are you using PDK for your use case? Can, you please share the code snippet, showing how you are configuring the interrupt?

Regards,
Parth 

HI Parth,

Thanks for your feedback, I have been following up on this task in privatee2e forum, the implementation is native to QNX. But I have been reading through some of forums I am not sure if this feature is validated to work.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/962030/tda4vm-rti-watchdog-can-not-trigger-gic-interrupt

Regards,

Annamalai

Hi Annamalai,

I confirm that: TDA4 only supports the Digital windowed watchdog & all other features including Captures/compares/interrupts are NOT supported.
What is the exact feature you are looking for?

- Keerthy