From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752020AbcFWQmI (ORCPT ); Thu, 23 Jun 2016 12:42:08 -0400 Received: from mail-vk0-f48.google.com ([209.85.213.48]:36687 "EHLO mail-vk0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751674AbcFWQmF (ORCPT ); Thu, 23 Jun 2016 12:42:05 -0400 MIME-Version: 1.0 In-Reply-To: References: <1463415447-29903-1-git-send-email-hotran@apm.com> <1463415447-29903-2-git-send-email-hotran@apm.com> <20160523203044.GA17450@rob-hp-laptop> From: Hoan Tran Date: Thu, 23 Jun 2016 09:42:02 -0700 Message-ID: Subject: Re: [PATCH 1/3] Documentation: dtb: xgene: Add hwmon dts binding documentation To: Jassi Brar , Rob Herring Cc: Jean Delvare , Guenter Roeck , Jonathan Corbet , Ashwin Chaugule , Duc Dang , Loc Ho , linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, lkml , "linux-arm-kernel@lists.infradead.org" , Devicetree List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 7, 2016 at 11:05 AM, Hoan Tran wrote: > Hi Jassi, > > Thanks for your reply ! > > On Tue, Jun 7, 2016 at 10:20 AM, Jassi Brar wrote: >> On Tue, May 24, 2016 at 6:31 AM, Hoan Tran wrote: >>> Hi Rob, >>> >>> Thanks for your review ! >>> >>> On Mon, May 23, 2016 at 1:30 PM, Rob Herring wrote: >>>> >>>> On Mon, May 16, 2016 at 09:17:25AM -0700, Hoan Tran wrote: >>>> > This patch adds the APM X-Gene hwmon device tree node documentation. >>>> > >>>> > Signed-off-by: Hoan Tran >>>> > --- >>>> > .../devicetree/bindings/hwmon/apm-xgene-hwmon.txt | 14 ++++++++++++++ >>>> > 1 file changed, 14 insertions(+) >>>> > create mode 100644 Documentation/devicetree/bindings/hwmon/apm-xgene-hwmon.txt >>>> > >>>> > diff --git a/Documentation/devicetree/bindings/hwmon/apm-xgene-hwmon.txt b/Documentation/devicetree/bindings/hwmon/apm-xgene-hwmon.txt >>>> > new file mode 100644 >>>> > index 0000000..49a482e >>>> > --- /dev/null >>>> > +++ b/Documentation/devicetree/bindings/hwmon/apm-xgene-hwmon.txt >>>> > @@ -0,0 +1,14 @@ >>>> > +APM X-Gene hwmon driver >>>> > + >>>> > +Hwmon driver accesses sensors over the "SLIMpro" mailbox. >>>> >>>> DT bindings describe h/w, not driver data. >>> How about this description: "APM X-Gene SOC sensors are accessed over >>> the "SLIMpro" mailbox" ? >>>> I'm not sure this belongs in >>>> DT and perhaps the devices for the mailbox should be created by the >>>> mailbox driver. >>> I don't think the current mailbox supports it. >>>> >>>> > + >>>> > +Required properties : >>>> > + - compatible : should be "apm,xgene-slimpro-hwmon" >>>> > + - mboxes : use the label reference for the mailbox as the first parameter. >>>> > + The second parameter is the channel number. >>>> >>>> When do you expect this to be different mailbox numbers? >>> No, this number is not changed. This "mboxes" property is used and >>> required by mailbox.c when hwmon driver requests a mailbox channel >>> >> I think that's inaccurate. >> >> The h/w and the firmware combined is the "platform" from Linux POV. >> Channels are physical resources provided by a mailbox controller. >> Currently the firmware listens on Channel-7 but some future revision >> might switch to, say, Channel-9. Or say the same firmware on next >> revision of h/w may have to switch to Channel-3 because it has only 4 >> channels. So I see the mailbox channel number as a hardware property >> just like an IRQ (which very often change with SoC iterations). > > Agree about that. I suppose this number is not changed. But as you > said, the mailbox channel number can be changed based on SoC or > Firmware. It would be better if this channel number is specified > inside a DT node. > > Hi Rob, do you have any comments ? > > Thanks > Hoan > >> >> Cheers. Hi Rob, Do you have any comments on Jassi's reply ? If not, I'll send another version which included the binding document and DT node. Thanks Hoan