From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v1 1/8] dt-bindings: phy-qcom-qmp: Add UFS PHY reset Date: Mon, 21 Jan 2019 18:21:37 -0600 Message-ID: <20190122002137.GA14435@bogus> References: <20190111230129.127037-1-evgreen@chromium.org> <20190111230129.127037-2-evgreen@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190111230129.127037-2-evgreen@chromium.org> Sender: linux-kernel-owner@vger.kernel.org Cc: Andy Gross , Kishon Vijay Abraham I , Can Guo , Douglas Anderson , Asutosh Das , Stephen Boyd , Vivek Gautam , Evan Green , devicetree@vger.kernel.org, Mark Rutland , linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On Fri, 11 Jan 2019 15:01:22 -0800, Evan Green wrote: > Add a required reset to the SDM845 UFS phy to express the PHY reset > bit inside the UFS controller register space. Before this change, this > reset was not expressed in the DT, and the driver utilized two different > callbacks (phy_init and phy_poweron) to implement a two-phase > initialization procedure that involved deasserting this reset between > init and poweron. This abused the two callbacks and diluted their > purpose. > > That scheme does not work as regulators cannot be turned off in > phy_poweroff because they were turned on in init, rather than poweron. > The net result is that regulators are left on in suspend that shouldn't > be. > > This new scheme gives the UFS reset to the PHY, so that it can fully > initialize itself in a single callback. We can then turn regulators on > during poweron and off during poweroff. > > Signed-off-by: Evan Green > --- > I realize I'm not supposed to add a required property after the fact, > but given that the UFS DT nodes that would use this binding are not > yet upstream (and this would be the first), I was hoping to squeak by. > > Documentation/devicetree/bindings/phy/qcom-qmp-phy.txt | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > Reviewed-by: Rob Herring