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[2/4] dt-bindings: display: amlogic, meson-dw-hdmi: Add optional HDMI 5V regulator

Message ID 1508227664-11171-3-git-send-email-narmstrong@baylibre.com (mailing list archive)
State New, archived
Headers show

Commit Message

Neil Armstrong Oct. 17, 2017, 8:07 a.m. UTC
On reference boards and derivatives, the HDMI Logic is powered by an external
5V regulator.
This regulator was set by the Vendor U-Boot, add optional support for it.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Rob Herring (Arm) Oct. 23, 2017, 10:46 p.m. UTC | #1
On Tue, Oct 17, 2017 at 10:07:42AM +0200, Neil Armstrong wrote:
> On reference boards and derivatives, the HDMI Logic is powered by an external
> 5V regulator.
> This regulator was set by the Vendor U-Boot, add optional support for it.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> index 7f040ed..bf4a180 100644
> --- a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> +++ b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> @@ -48,6 +48,10 @@ Required properties:
>    Documentation/devicetree/bindings/reset/reset.txt,
>    the reset-names should be "hdmitx_apb", "hdmitx", "hdmitx_phy"
>  
> +Optional properties:
> +- hdmi-supply: Optional phandle to an external 5V regulator to power the HDMI
> +  logic, as described in the file ../regulator/regulator.txt

5V into a modern SoC sounds strange. Is this really for the chip or for 
5V to the connector? The latter should be in the connector node.

Rob
Neil Armstrong Oct. 24, 2017, 8:09 a.m. UTC | #2
On 24/10/2017 00:46, Rob Herring wrote:
> On Tue, Oct 17, 2017 at 10:07:42AM +0200, Neil Armstrong wrote:
>> On reference boards and derivatives, the HDMI Logic is powered by an external
>> 5V regulator.
>> This regulator was set by the Vendor U-Boot, add optional support for it.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>  Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
>> index 7f040ed..bf4a180 100644
>> --- a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
>> +++ b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
>> @@ -48,6 +48,10 @@ Required properties:
>>    Documentation/devicetree/bindings/reset/reset.txt,
>>    the reset-names should be "hdmitx_apb", "hdmitx", "hdmitx_phy"
>>  
>> +Optional properties:
>> +- hdmi-supply: Optional phandle to an external 5V regulator to power the HDMI
>> +  logic, as described in the file ../regulator/regulator.txt
> 
> 5V into a modern SoC sounds strange. Is this really for the chip or for 
> 5V to the connector? The latter should be in the connector node.
> 
> Rob
> 

Hi Rob,

The chip does not get the 5V but multiple derived voltages, but depends on the 5V regulator to
enable this power supply for the connector and to the hdmi io bank.

So in my opinion it's not related to the connector but to the HDMI logic.

Neil
Rob Herring (Arm) Oct. 24, 2017, 3:49 p.m. UTC | #3
On Tue, Oct 24, 2017 at 10:09:15AM +0200, Neil Armstrong wrote:
> On 24/10/2017 00:46, Rob Herring wrote:
> > On Tue, Oct 17, 2017 at 10:07:42AM +0200, Neil Armstrong wrote:
> >> On reference boards and derivatives, the HDMI Logic is powered by an external
> >> 5V regulator.
> >> This regulator was set by the Vendor U-Boot, add optional support for it.
> >>
> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> >> ---
> >>  Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt | 4 ++++
> >>  1 file changed, 4 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> >> index 7f040ed..bf4a180 100644
> >> --- a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> >> +++ b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
> >> @@ -48,6 +48,10 @@ Required properties:
> >>    Documentation/devicetree/bindings/reset/reset.txt,
> >>    the reset-names should be "hdmitx_apb", "hdmitx", "hdmitx_phy"
> >>  
> >> +Optional properties:
> >> +- hdmi-supply: Optional phandle to an external 5V regulator to power the HDMI
> >> +  logic, as described in the file ../regulator/regulator.txt
> > 
> > 5V into a modern SoC sounds strange. Is this really for the chip or for 
> > 5V to the connector? The latter should be in the connector node.
> > 
> > Rob
> > 
> 
> Hi Rob,
> 
> The chip does not get the 5V but multiple derived voltages, but depends on the 5V regulator to
> enable this power supply for the connector and to the hdmi io bank.
> 
> So in my opinion it's not related to the connector but to the HDMI logic.

But you just said it is for the connector too.

In any case, if it is for the HDMI i/o, then

Acked-by: Rob Herring <robh@kernel.org>
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
index 7f040ed..bf4a180 100644
--- a/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
+++ b/Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.txt
@@ -48,6 +48,10 @@  Required properties:
   Documentation/devicetree/bindings/reset/reset.txt,
   the reset-names should be "hdmitx_apb", "hdmitx", "hdmitx_phy"
 
+Optional properties:
+- hdmi-supply: Optional phandle to an external 5V regulator to power the HDMI
+  logic, as described in the file ../regulator/regulator.txt
+
 Required nodes:
 
 The connections to the HDMI ports are modeled using the OF graph