[PATCH 0/3] Suspending i.MX watchdog in WAIT mode

Andrej Picej andrej.picej at norik.com
Wed Oct 19 22:21:59 PDT 2022


Hi Guenter,

On 19. 10. 22 17:30, Guenter Roeck wrote:
> On Wed, Oct 19, 2022 at 01:17:11PM +0200, Andrej Picej wrote:
>> The i.MX6 watchdog can't be stopped once started. This means that
>> special hardware suspend needs to be configured when the device enters
>> low-power modes.
>> Usually i.MX devices have two bits which deal with this:
>> - WDZST bit disables the timer in "deeper" low power modes and
>> - WDW bit disables the timer in "WAIT" mode which corresponds with
>> Linux's "freeze" low-power mode.
>>
>> WDZST bit support is already in place since 1a9c5efa576e ("watchdog: imx2_wdt: disable watchdog timer during low power mode").
>> WDW bit is not common for all imx2-wdt supported devices, therefore use
>> a new device-tree property "fsl,suspend-in-wait" which suspends the
>> watchdog in "WAIT" mode.
> 
> I think that needs to be validated using the "compatible" property;
> it should not be possible to set/accept the new flag for devices
> which don't support it.

Ok, I can add that to a v2.

Thanks,
Andrej

> 
> Thanks,
> Guenter
> 




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