Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Philippe CORNU <philippe.cornu@st.com>
Cc:     Archit Taneja <architt@codeaurora.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        David Airlie <airlied@linux.ie>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Yannick FERTRE <yannick.fertre@st.com>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        Alexandre TORGUE <alexandre.torgue@st.com>
Subject: Re: [PATCH 1/2] dt-bindings/display/bridge: sii902x: add optional power supplies
Date:   Thu, 19 Apr 2018 14:09:52 +0300
Message-ID: <1733412.i2Wslp7VkI@avalon>
Organization: Ideas on Board Oy
In-Reply-To: <e709e4f7-2266-f99f-5864-5a8c037dbdc2@st.com>
References: <20180410051927.8268-1-philippe.cornu@st.com> <20599695.GSkeUvMnvx@avalon> <e709e4f7-2266-f99f-5864-5a8c037dbdc2@st.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Philippe,

On Thursday, 19 April 2018 12:31:15 EEST Philippe CORNU wrote:
> On 04/19/2018 10:11 AM, Laurent Pinchart wrote:
> > On Tuesday, 10 April 2018 08:19:26 EEST Philippe Cornu wrote:
> > 
> >> Add the 3 optional power supplies using the exact description
> >> found in the document named
> >> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)".
> >>
> >> Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
> >> ---
> >> 
> >>   Documentation/devicetree/bindings/display/bridge/sii902x.txt | 3 +++
> >>   1 file changed, 3 insertions(+)
> >>
> >> diff --git
> >> a/Documentation/devicetree/bindings/display/bridge/sii902x.txt
> >> b/Documentation/devicetree/bindings/display/bridge/sii902x.txt index
> >> 56a3e68ccb80..cf53678fe574 100644
> >> --- a/Documentation/devicetree/bindings/display/bridge/sii902x.txt
> >> +++ b/Documentation/devicetree/bindings/display/bridge/sii902x.txt
> >> @@ -8,6 +8,9 @@ Optional properties:
> >>   	- interrupts-extended or interrupt-parent + interrupts: describe
> >>   	  the interrupt line used to inform the host about hotplug events.
> >>   	- reset-gpios: OF device-tree gpio specification for RST_N pin.
> >> +	- iovcc-supply: I/O supply voltage (1.8V or 3.3V, host-dependent).
> >> +	- avcc12-supply: TMDS analog supply voltage (1.2V).
> >> +	- cvcc12-supply: Digital core supply voltage (1.2V).
> > 
> > It seems that the AVCC12 and CVCC12 power supplies are usually derived
> > from the same source. How about starting with one DT property for both,
> > and adding a second one later if needed ?
> 
> Well, I do not know what is the best. Here I took the description from 
> the documentation, and to allow all possible board configurations, I 
> added these supplies as "optional" properties: if there is only one 1v2 
> regulator on the board, the dt will contain only avcc12 or cvcc12 and 
> everything will work fine (we will have a dummy regulator for the 
> missing optional 1v2 reg), if both regulators are there for any reasons 
> (stability, noise, whatever...) then both entries will be in the dt.
> 
> If you confirm you prefer a single 1v2 supply (named for instance 
> "vcc12-supply") then I will do :-)

Please see https://lists.freedesktop.org/archives/dri-devel/2018-April/
172400.html (and the messages that lead to it) and https://
lists.freedesktop.org/archives/dri-devel/2018-March/170763.html.

> >>   Optional subnodes:
> >>   	- video input: this subnode can contain a video input port node

-- 
Regards,

Laurent Pinchart