From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: Re: [PATCH v2 1/4] dt-bindings: drm/bridge: adv7511: Add regulator bindings Date: Fri, 14 Oct 2016 11:10:28 +0530 Message-ID: References: <1472640730-24326-1-git-send-email-architt@codeaurora.org> <737415023.GKbfqYIf4s@avalon> <57E8C2CB.9000806@codeaurora.org> <1527982.jPo8JkVTxZ@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1527982.jPo8JkVTxZ@avalon> Sender: linux-arm-msm-owner@vger.kernel.org To: Laurent Pinchart , robh@kernel.org Cc: andy.gross@linaro.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Rob, On 09/26/2016 01:42 PM, Laurent Pinchart wrote: > 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 ? Could you suggest us which way to go? Thanks, Archit > >>>> +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: > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project