[U-Boot] PMIC initialization

[U-Boot] PMIC initialization

[Jeroen van der Laan]

Hi there,

I'm working on a board that is based on a i.Mx6soloX it has a PFUZE3000 PMIC the u-boot version we're using is 2016-03. The PMIC is by default configured with a voltage for our DRAM that is too low. We've discovered that this is an issue with some boards some of the time. The voltage is just below the bare minimum so I think the board has no big issue most of the time.

I want to adjust the voltage in u-boot in time for the board bring up. I'm afraid that a lot of issues will disappear but our tests will not cover if the initialization is too late. I want to be absolutely certain that it happens on time before the memory initialization.

what is the place to do this?
Should I use an SPL bootloader?
Is power_init_board soon enough, or does code in this place require RAM?
Are there any other options?

Best regards,
Jeroen van der Laan


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[U-Boot] PMIC initialization

[Lukasz Majewski]

Hi Jeroen van der Laan,

> Hi there,
> 
> I'm working on a board that is based on a i.Mx6soloX it has a
> PFUZE3000 PMIC the u-boot version we're using is 2016-03. The PMIC is
> by default configured with a voltage for our DRAM that is too low.
> We've discovered that this is an issue with some boards some of the
> time. The voltage is just below the bare minimum so I think the board
> has no big issue most of the time.
> 
> I want to adjust the voltage in u-boot in time for the board bring
> up. I'm afraid that a lot of issues will disappear but our tests will
> not cover if the initialization is too late. I want to be absolutely
> certain that it happens on time before the memory initialization.
> 
> what is the place to do this?
> Should I use an SPL bootloader?

You shall do it just before the DRAM init (and of course wait for some
time so the voltage can stabilize).

You don't need to use the PMIC DM/framework, just communicate with I2C
and change the values of registers of pfuze.

> Is power_init_board soon enough, or does code in this place require
> RAM? Are there any other options?

I think that board_early_init is a good place for this, but u-boot
2016.03 differs considerably from what we have now as massive DM/DTS
conversion is going on.

> 
> Best regards,
> Jeroen van der Laan
> 
> 
> [ICT zorgt voor mensen]<https://www.zorg-en-ict.nl/default.aspx>
> 
> 
> Dit e-mailbericht is uitsluitend bestemd voor de geadresseerde. Als
> dit bericht niet voor u bestemd is, wordt u vriendelijk verzocht dit
> aan de afzender te melden. Van Breda BV staat door de elektronische
> verzending van dit bericht niet in voor de juiste en volledige
> overbrenging van de inhoud, noch voor tijdige ontvangst daarvan. Voor
> informatie over Van Breda BV raadpleegt u
> www.vanbreda.nl<http://www.vanbreda.nl>.
> 
> This e-mail is intended for the addressee's eyes only. If you are not
> the intended recipient, you are hereby kindly requested to inform the
> sender of this. In view of the electronic nature of this
> communication, Van Breda BV is neither liable for the proper and
> complete transmission of the information contained therein nor for
> any delay in its receipt. For information about Van Breda BV, please
> visit www.vanbreda.nl<http://www.vanbreda.nl>.
> _______________________________________________ U-Boot mailing list
> U-Boot at lists.denx.de https://lists.denx.de/listinfo/u-boot




Best regards,

Lukasz Majewski

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