[U-Boot] i.MX28 AUTO_RESTART, watchdog, battery and poweroff

[U-Boot] i.MX28 AUTO_RESTART, watchdog, battery and poweroff

[Hector Palacios]

Greetings,

I'm not sure I understand the function mxs_power_clear_auto_restart() in spl_power_init.c

The name of the function seems to indicate that its purpose is to *clear* the 
AUTO_RESTART bit, but it is actually setting it:

	setbits_le32(&rtc_regs->hw_rtc_persistent0,
			RTC_PERSISTENT0_AUTO_RESTART);

I believe though, that setting this bit is OK because it guarantees that the target 
can be reset from a reset button or a watchdog reset even when powered from the battery.

Am I missing something? Otherwise I think this function should be renamed to 
mxs_power_set_auto_restart().

Best regards,
--
Hector Palacios

[U-Boot] i.MX28 AUTO_RESTART, watchdog, battery and poweroff

[Marek Vasut]

Dear Hector Palacios,

> Greetings,
> 
> I'm not sure I understand the function mxs_power_clear_auto_restart() in
> spl_power_init.c

We're on the same board there. According to FSL, this is needed on some versions 
of MX28 (translation from the techsupp language: we have no idea where this code 
came from nor what it does, so we will tell you it's important and you shouldn't 
touch it).

I believe the powercode will need a revision and I'll likely get to it once I'm 
done with my current hacking.

> The name of the function seems to indicate that its purpose is to *clear*
> the AUTO_RESTART bit, but it is actually setting it:
> 
> 	setbits_le32(&rtc_regs->hw_rtc_persistent0,
> 			RTC_PERSISTENT0_AUTO_RESTART);
> 
> I believe though, that setting this bit is OK because it guarantees that
> the target can be reset from a reset button or a watchdog reset even when
> powered from the battery.
> 
> Am I missing something? Otherwise I think this function should be renamed
> to mxs_power_set_auto_restart().

I'd ack the rename. Fabio?

Best regards,
Marek Vasut

[U-Boot] i.MX28 AUTO_RESTART, watchdog, battery and poweroff

[Fabio Estevam]

On Wed, Jul 24, 2013 at 8:40 AM, Marek Vasut <marex@denx.de> wrote:

>> Am I missing something? Otherwise I think this function should be renamed
>> to mxs_power_set_auto_restart().
>
> I'd ack the rename. Fabio?

Sounds good. Please submit a patch, Hector.

Thanks,

Fabio Estevam