feat: deepsleep for QSPI flash

[TuEmb]

This PR is to push QSPI flash into deepsleep at bootup. That's an issue in zephyr nrf sdk v2.7.0

In v2.7.0, the CS pin keep low state in deepsleep --> it's not corrected and won't let qspi flash goes into deepsleep, the CS pin should be high state. My idea is still using the default pins setting for sleep without low-power-enable option in overlay file.

I also checked the latest zephyr project code. That issues was fixed by set the CS pin as pull-up in sleep mode. I belive the issue will be fixed if we upgrade the SDK version (no need to change overlay file anymore).

Result:

[TuEmb]

Hi @beastoin,

Could you help me take a look at this PR ?
I think 8 uA is good enough for the deepsleep mode

[beastoin]

that's good, btw questions:

• does this issue only happen on 2.7.0? since i am planning to upgrade ncs for devkit to 2.9.0 - which omi consumer is using. what do you think?

• where did you find this configs link ? and should we create a boards/devkit2 for devkit 2 that similar to omi consumer link

@TuEmb

[TuEmb]

- does this issue only happen on 2.7.0? since i am planning to upgrade ncs for devkit to 2.9.0 - which omi consumer is using. what do you think?

--> I checked https://github.com/nrfconnect/sdk-nrf/tree/v2.9.0 --> The issue was fixed at https://github.com/nrfconnect/sdk-zephyr/blob/v3.7.99-ncs2-branch/boards/seeed/xiao_ble/xiao_ble-pinctrl.dtsi

where did you find this configs ?

--> It's in <zephyr project>/boards/seeed/xiao_ble/xiao_ble-pinctrl.dtsi

should we create a boards/devkit2 for devkit 2 that similar to omi consumer ?

--> Basicially the devkit2 was designed almost the same as xiao_ble of seeed, I think we should inherit from it with a little modification (overlay file). No need to create a new board

Finally, I think we can upgrade the sdk from 2.7.0 to 2.9.0 to use the same SDK with omi consumer and also fix the qspi_flash issue. It should be a seperate task, if you accept, let me upgrade them and fix the changes from the firmware in another pull request.
@beastoin

[TuEmb]

FYI: I also check the firmware of omi consumer, I believe the deepsleep issue also occurs on it. But I will modify and test later when I have the omi consumer board in my hand to ensure

[beastoin]

let me upgrade them and fix the changes from the firmware in another pull request.

yes pls.

I also check the firmware of omi consumer, I believe the deepsleep issue also occurs on it

cool. my dms are open; just send me the address, and then i can ship you one.

@TuEmb