On Tue, 2020-03-31 at 21:29 +0200, Marek Szyprowski wrote:

Hi

On 2020-03-31 17:29, Paweł Chmiel wrote:

quoted

On Tue, 2020-03-31 at 15:55 +0200, Marek Szyprowski wrote:

quoted

Hi Paul,

On 2020-03-31 15:09, Paul Cercueil wrote:

quoted

Cc: Paweł Chmiel <redacted>

Hi Marek,

Le mar. 31 mars 2020 à 7:36, Marek Szyprowski
[off-list ref] a écrit :

quoted

Hi Paul,

On 2020-03-18 15:25, Paul Cercueil wrote:

quoted

quoted

quoted

   +    };
   +
   +    tsp_reg: regulator-1 {
   +        compatible = "regulator-fixed";
   +        regulator-name = "TSP_FIXED_VOLTAGES";
   +        regulator-min-microvolt = <3300000>;
   +        regulator-max-microvolt = <3300000>;
   +        gpio = <&gpl0 3 GPIO_ACTIVE_HIGH>;
   +        startup-delay-us = <70000>;
   +        enable-active-high;
   +        regulator-boot-on;
   +        regulator-always-on;

  always-on and boot-on should not be needed. You have a consumer
for this
  regulator.

  About this: the touchscreen driver does not use a regulator, so I
  believe that's why these properties were here.

  I sent patches upstream to address the issue:
  https://protect2.fireeye.com/url?k=e8aedc29-b53072b3-e8af5766-0cc47a336fae-759579fd576d8382&u=https://lkml.org/lkml/2020/3/15/94


  I believe this means I cannot merge the i9100 devicetree until it is
  acked.

One more information - similar change has been already posted, but it
looks it got lost then: https://patchwork.kernel.org/patch/10550903/

I was aware of this patch, but didn't know it was sent upstream.

This other patch uses two regulators, vdd/avdd but doesn't give any
reason why.

I've checked the UniversalC210 schematic, which uses the same
touchscreen chip. There are 2 supplies to the touchscreen chip: 2.8V VDD
and 3.3V AVDD. Both are enabled by the same GPIO pin though. There is
however no reset GPIO pin there.

Hi
Don't remember now how it worked on Galaxy S1, but it looks like it has
the same setup - two regulators enabled by one GPIO pin.

It is quite common for the regulators to share the enable GPIO line, so 
this is not an issue. Regulator framework supports such configuration 
for ages. I'm curious about the reset GPIO line, which were made 
mandatory for the regulators control in your patch. I didn't find it on 
any schematic of the devices with this touch screen, but I don't have a 
schematic of the Galaxy S1. IMHO the reset signal is simply derived from 
the supply regulators with some simple circuit, but I don't have 
schematic of that part.

Hi
Regarding this change - it was suggested during review of v1 version of
those patches. It's first reply here 
https://patchwork.kernel.org/patch/10524007/

Best regards

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