From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Stach Subject: Re: [PATCH v8 1/6] ARM: imx6q: provide documentation for new fsl,pmic-stby-poweroff property Date: Fri, 27 Jul 2018 10:30:11 +0200 Message-ID: <1532680211.32306.36.camel@pengutronix.de> References: <20180726092220.17250-1-o.rempel@pengutronix.de> <20180726092220.17250-2-o.rempel@pengutronix.de> <84c1921c-922e-4b5d-b688-db89047fa1db@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Robin Gong , Oleksij Rempel , Shawn Guo , Mark Brown , "Rafael J. Wysocki" Cc: Mark Rutland , "devicetree@vger.kernel.org" , Michael Turquette , Stephen Boyd , "linux-kernel@vger.kernel.org" , Liam Girdwood , Rob Herring , dl-linux-imx , "kernel@pengutronix.de" , "A.s. Dong" , Fabio Estevam , Russell King , Andrew Morton , Leonard Crestez , "linux-clk@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org Hi Robin, Am Freitag, den 27.07.2018, 01:51 +0000 schrieb Robin Gong: [...] > > > > --- > > > >  Documentation/devicetree/bindings/clock/imx6q-clock.txt | 8 ++++++++ > > > >  1 file changed, 8 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/clock/imx6q-clock.txt > > > > b/Documentation/devicetree/bindings/clock/imx6q-clock.txt > > > > index a45ca67a9d5f..e1308346e00d 100644 > > > > --- a/Documentation/devicetree/bindings/clock/imx6q-clock.txt > > > > +++ b/Documentation/devicetree/bindings/clock/imx6q-clock.txt > > > > @@ -6,6 +6,14 @@ Required properties: > > > >  - interrupts: Should contain CCM interrupt > > > >  - #clock-cells: Should be <1> > > > > > > > > +Optional properties: > > > > +- fsl,pmic-stby-poweroff: Configure CCM to assert PMIC_STBY_REQ > > > > +signal > > > > +  on power off. > > > > +  Use this property if the SoC should be powered off by external > > > > +power > > > > +  management IC (PMIC) triggered via PMIC_STBY_REQ signal. > > > > > > PMIC_ON_REQ didn't connect to any pin of PMIC in your case? > > > > No. First, it was only one customer specific issue. After some research I found > > even publicly available boards (for example RioTboard) which has same/similar > > design. After seeing this in imx6 documentation as valid power off way, I have > > no doubts - there should be even more devices doin this in the wild. > > Not sure why the customer didn't follow reference design, since PMIC_ON_REQ can > provide power off/on feature by pressing ONOFF key which connected ONOFF > pin of i.mx6(ONOFF will toggle PMIC_ON_REQ to power off/on PMIC). The official > power off/on way (PMIC_ON_REQ) can also power off all power rails of PFUZE except > snvs as your patch did on PMIC_STBY_REQ.  PMIC_STBY_REQ is used to notify pmic > switch power mode (PFM/APS) or decrease voltage to save power in kernel suspend, > not power off....I am not sure if we need this patchset to 'workaround' the board issue. > Not all boards follow the reference design, that's a fact of life. Please look at the i.MX6Q reference manual. The sequence implemented in this patchset can be found as a valid way to power off the system in "60.4.3 Power mode transitions" "Normal ON to OFF with external PMIC", so there is hardly any way to argue that this is a board specific quirk. This is one of the Freescale/NXP recommended sequences to turn off the system. Regards, Lucas