From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@linaro.org (Shawn Guo) Date: Tue, 20 Jan 2015 16:03:39 +0800 Subject: [PATCH 1/2] ARM: imx6sx-sdb: change default board as reva board In-Reply-To: References: <1421220998-3491-1-git-send-email-peter.chen@freescale.com> <1421220998-3491-2-git-send-email-peter.chen@freescale.com> <20150120073527.GT2766@dragon> <20150120063016.GD13645@shlinux2> Message-ID: <20150120080338.GW2766@dragon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jan 20, 2015 at 07:51:31AM +0000, Anson.Huang at freescale.com wrote: > > > > +&cpu0 { > > > > + operating-points = < > > > > + /* kHz uV */ > > > > + 996000 1250000 > > > > + 792000 1175000 > > > > + 396000 1075000 > > > > + >; > > > > + fsl,soc-operating-points = < > > > > + /* ARM kHz SOC uV */ > > > > + 996000 1175000 > > > > + 792000 1175000 > > > > + 396000 1175000 > > > > + >; > > > > > > I'm wondering why different revision of the board require a different > > > OPP settings. > > > > > > > Anson, do you know the reason? > > As i.MX6SX SDB Rev-B board uses PFuse 200 which has only one power supply for both > VDDARM_IN and VDDSOC_IN, so it needs VDDARM_IN equal VDDSOC_IN, currently > we set Rev-B board as default in imx6sx.dtsi, which uses same voltage for both > VDDARM_IN and VDDSOC_IN.The Rev-A board uses PFuze 100 which has separate power > supply for VDDARM_IN and VDDSOC_IN, so it can use different voltage on VDDARM_IN > and VDDSOC_IN according to datasheet. Thanks for the clarification, Anson. Peter, OPP is a CPU characteristic defined by data sheet, so we should define OPP according to data sheet in imx6sx.dtsi, and only overwrite the property in Rev-B dts per board/PMIC quirk. Also, please put the rationale why we need OPP quick on Rev-B into commit log. Shawn