From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH v2 1/4] dt-bindings: drm/bridge: adv7511: Add regulator bindings Date: Mon, 26 Sep 2016 11:12:48 +0300 Message-ID: <1527982.jPo8JkVTxZ@avalon> References: <1472640730-24326-1-git-send-email-architt@codeaurora.org> <737415023.GKbfqYIf4s@avalon> <57E8C2CB.9000806@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <57E8C2CB.9000806@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org To: Archit Taneja Cc: andy.gross@linaro.org, linux-arm-msm@vger.kernel.org, robh@kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Archit, On Monday 26 Sep 2016 12:10:11 Archit Taneja wrote: > On 9/25/2016 10:58 PM, Laurent Pinchart wrote: > > On Friday 23 Sep 2016 14:50:27 Archit Taneja wrote: > >> Add the regulator supply properties needed by ADV7511 and ADV7533. The > >> regulator names are named after the pin names, except for DVDD_3V on > >> ADV7511, which is left v3p3 to have the same name as it's on ADV7533. > >> > >> ADV7511 has a BGVDD pin for which the voltage to be configured isn't > >> clear. This needs to be updated in the document later. > >> > >> The regulators are specified as optional properties since there can > >> be boards which have a fixed supply directly routed to the pins, and > >> these may not be modelled as regulator supplies. > >> > >> Cc: Rob Herring > >> Cc: devicetree@vger.kernel.org > >> Signed-off-by: Archit Taneja > >> --- > >> v2: > >> - Specify regulator supplies for ADV7511 too. > >> - Have separate supply entries for AVDD, DVDD, PVDD, A2VDD pins. > >> - Add additional BGVDD supply for ADV7511. > >> > >> .../devicetree/bindings/display/bridge/adi,adv7511.txt | 14 +++++++ > >> 1 file changed, 14 insertions(+) > >> > >> diff --git > >> a/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt > >> b/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt index > >> 6532a59..66e6bae 100644 > >> --- a/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt > >> +++ b/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt > >> > >> @@ -56,6 +56,20 @@ Optional properties: > >> - adi,disable-timing-generator: Only for ADV7533. Disables the internal > >> > >> timing generator. The chip will rely on the sync signals in the DSI data > >> lanes, rather than generate its own timings for HDMI output. > >> +- avdd-supply: A 1.8V supply that powers up the AVDD pin on the chip. > >> +- dvdd-supply: A 1.8V supply that powers up the DVDD pin on the chip. > >> +- pvdd-supply: A 1.8V supply that powers up the PVDD pin on the chip. > >> +- v3p3-supply: A 3.3V supply that powers up the pin called DVDD_3V on > >> + ADV7511 and V3P3 on ADV7533. > >> + > >> +ADV7511 specific supplies: > >> +- bgvdd-supply: Powers the BGVDD pin. The voltage isn't clear from > >> + available datasheets. > > > > It's a 1.8V supply. The ADV7511 hardware user's guide recommends tying it > > to the PVDD supply, so I'm not sure we need a separate supply in DT. > > Thanks for providing the info. I'll update it in the doc. > > > Similarly, the user's guide recommends supplying the AVDD, DVDD and PVDD > > pins with a single 1.8V LDO and three independent filters. We could thus > > possibly combine them into a single 1.8V supply. > > I'd originally specified only one AVDD supply for all the 1.8 V > supplies, but Rob had recommended using separate supplies for each pin. > > I guess it doesn't do much harm specifying separate supplies, a > board can just provide avdd-supply, and the rest would be assumed dummy. DT should use the same regulator phandle for all power supplies in that case, not specify a single one. > It could also help describe boards which may not have followed the > user guide's recommendation, but I agree that's probably a rare > scenario. > > Is it okay if we stick with multiple supplies as it is in this version? It seems overkill to me but I can live with that. I'd remove the bgvdd supply though. Rob, what's your opinion on this ? Is there a specific reason why you prefer splitting the 1.8V supply in one supply per pin, when the hardware user's guide recommend powering them from the same LDO ? > >> +ADV7533 specific supplies: > >> +- a2vdd-supply: 1.8V supply that powers up the A2VDD pin on the chip. > >> +- v1p2-supply: A supply that powers up the V1P2 pin on the chip. It can > >> be > >> + either 1.2V or 1.8V. > >> > >> Required nodes: -- Regards, Laurent Pinchart