From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v2 1/4] dt-bindings: drm/bridge: adv7511: Add regulator bindings Date: Wed, 9 Nov 2016 19:34:32 -0600 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=UTF-8 Return-path: Received: from mail.kernel.org ([198.145.29.136]:35572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754268AbcKJBe5 (ORCPT ); Wed, 9 Nov 2016 20:34:57 -0500 In-Reply-To: Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Archit Taneja Cc: Laurent Pinchart , Andy Gross , linux-arm-msm , "devicetree@vger.kernel.org" On Fri, Oct 14, 2016 at 12:40 AM, Archit Taneja wrote: > 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? If they are really intended to be the same supply, then combining them is fine with me. Rob