Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751788AbdFAKZe (ORCPT ); Thu, 1 Jun 2017 06:25:34 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:35914 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751475AbdFAKZc (ORCPT ); Thu, 1 Jun 2017 06:25:32 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170526110413.24836-1-enric.balletbo@collabora.com> From: Liam Breck Date: Thu, 1 Jun 2017 03:25:30 -0700 X-Google-Sender-Auth: 8olap3RpJey49XBzVTIwggSGVcM Message-ID: Subject: Re: [PATCH v3 1/4] dt-bindings: power: supply: add battery charge voltage/current To: Enric Balletbo Serra Cc: Enric Balletbo i Serra , Sebastian Reichel , linux-pm@vger.kernel.org, "devicetree@vger.kernel.org" , linux-kernel , Liam Breck Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4270 Lines: 111 Hi Enric, On Thu, Jun 1, 2017 at 1:18 AM, Enric Balletbo Serra wrote: > Hi Liam, > > 2017-06-01 9:01 GMT+02:00 Liam Breck : >> Hi Enric, >> >> On Sat, May 27, 2017 at 1:11 PM, Enric Balletbo Serra >> wrote: >>> Hi Liam, >>> >>> 2017-05-26 23:20 GMT+02:00 Liam Breck : >>>> Hi Enric, >>>> >>>> On Fri, May 26, 2017 at 4:04 AM, Enric Balletbo i Serra >>>> wrote: >>>>> Add charging voltage and current characteristics to the battery DT for >>>>> proper handling of the battery by fuel-gauge and charger chips. >>>>> >>>>> Signed-off-by: Enric Balletbo i Serra >>>>> --- >>>>> Changes since v2: >>>>> - Requested by Sebastian Reichel >>>>> - Move to its own patch and apply to simple-battery framework. >>>>> Changes since v1: >>>>> - Requested by Rob Herring >>>>> - Rename ti,charge-* to charge-* to be standard properties. >>>>> - Use unit suffixes as per bindings/property-units.txt >>>>> >>>>> Documentation/devicetree/bindings/power/supply/battery.txt | 4 ++++ >>>>> 1 file changed, 4 insertions(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt >>>>> index 63a7028..c87a439 100644 >>>>> --- a/Documentation/devicetree/bindings/power/supply/battery.txt >>>>> +++ b/Documentation/devicetree/bindings/power/supply/battery.txt >>>>> @@ -12,6 +12,8 @@ Optional Properties: >>>>> - voltage-min-design-microvolt: drained battery voltage >>>>> - energy-full-design-microwatt-hours: battery design energy >>>>> - charge-full-design-microamp-hours: battery design capacity >>>>> + - charge-voltage-microvolt: battery charging voltage >>>>> + - charge-current-microamp: battery charging current >>>> >>>> I think you mean constant-charge-* which is how you surface these >>>> properties in your tps65217_charger patch. >>>> >>> >>> Yes, to be strict this is constant-charge-* >> >> The DT battery node should carry static battery characteristics. So on >> reflection, I think you want >> >> constant-charge-current-max-microamp >> constant-charge-voltage-max-microvolt >> >> The charger or the user could then safely apply any value <= those. >> >> Thoughts? I'm curious to hear how your hw config requires constant-charge settings? > Hmm I see your point and I'm thinking now that actually this is not > what I wanted to do. What I wanted is set the charger voltage and the > current hence my first patchset was setting these properties in the > charger node not the battery. You could certainly support constant-charge-* params in the charger node. And it's easy to enable userspace to set these via sysfs. > Said that, I think that you have reason and what we want in battery > node is the current/voltage max values but we also need to implement a > mechanism to set the charging voltage/current from userspace or from > the DT for the charger. The charger should be able to set these values > and fail if, based in the battery specs, is not supported. The charger could default constant-charge-* to the battery node's max values. See also this discussion about similar issues. https://patchwork.kernel.org/patch/9625331/ > More thoughts? > >>>> I'll add these to v14 of my patchset which adds simple-battery >>>> support. Rob requested a single patch for this file. >>>> >>> >>> Ok, I'll send the tps charger series without this patch, so please, >>> include this patch in your series. >>> >>>> I've been waiting for feedback on v13.2 from Sebastian. If I don't >>>> hear from him within a few days, I'll post v14. >>>> >>>>> Batteries must be referenced by chargers and/or fuel-gauges >>>>> using a phandle. The phandle's property should be named >>>>> @@ -24,6 +26,8 @@ Example: >>>>> voltage-min-design-microvolt = <3200000>; >>>>> energy-full-design-microwatt-hours = <5290000>; >>>>> charge-full-design-microamp-hours = <1430000>; >>>>> + charge-voltage-microvolt = <4100000>; >>>>> + charge-current-microamp = <300000>; >>>>> }; >>>>> >>>>> charger: charger@11 { >>>>> -- >>>>> 2.9.3 >>>>>