[GIT PULL] STM32 DT fixes for v5.10 #1

[Ahmad Fatoum]

Hello Alex,

On 10/28/20 4:28 PM, Alexandre Torgue wrote:
> Hi Arnd, Olof and Kevin,
> 
> On v5.10-rc1 STM32 boards cannot boot. It is linked to a change in regulator framework which highlights that our supplies are not well described. This PR fixes it for STM32 boards that I have on my desk: ED1 and DKx.

Which change triggered the regression?
 
> I assume that same patch has to be done for other STM32 boards, but as I don't have schematics I can't provide it. So a round2 has to be done for:
> - stinger96
> - MC-1
> - Odyssey SOM
> - DHCOR /DHCOM
> 
> Mani, Marek, Ahmad, Marcin can you please have a look on it and provide patches (then I'll provide round2). Thanks in advance.

Your change doesn't look right. If I set vref_ddr-supply to a fixed regulator,
the MC-1 now boots again as well, but that seems to just mask the real issue:

 - vref_ddr is an _output_ of the PMIC, why should one have to specify a supply for it?

 - This is actually incompatible with the binding. vref_ddr-supply isn't specified
   as an allowed property (not to mention a required one)

 - Isn't the kernel supposed to stay compatible to old device trees?

I think the stpmic driver is at fault here and that the regulator framework change just
made that apparent.

Cheers,
Ahmad

> 
> 
> Regards
> Alex
> 
> 
> The following changes since commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec:
> 
>   Linux 5.10-rc1 (2020-10-25 15:14:11 -0700)
> 
> are available in the Git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git tags/stm32-dt-for-v5.10-fixes-1
> 
> for you to fetch changes up to 728a7e225ad807b4b4de3be3fb653424199f8a76:
> 
>   ARM: dts: stm32: Describe Vin power supply on stm32mp157c-edx board (2020-10-28 15:08:24 +0100)
> 
> ----------------------------------------------------------------
> STM32 DT fixes for v5.10, round 1
> 
> Highlights:
> -----------
> 
>  -On STM32MP157 DK & ED boards: Add Vin supply description to avoid
>   random kernel crash due to vref_ddr regulator issue.
> 
> ----------------------------------------------------------------
> Pascal Paillet (2):
>       ARM: dts: stm32: Describe Vin power supply on stm32mp15xx-dkx board
>       ARM: dts: stm32: Describe Vin power supply on stm32mp157c-edx board
> 
>  arch/arm/boot/dts/stm32mp157c-ed1.dts  | 15 +++++++++++++++
>  arch/arm/boot/dts/stm32mp15xx-dkx.dtsi | 17 +++++++++++++++++
>  2 files changed, 32 insertions(+)
> 

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