RE:Re: [PATCH v3 1/3] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy

RE:Re: [PATCH v3 1/3] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy

[Richard Zhu]

> -----Original Message-----
> From: Lucas Stach <l.stach@pengutronix.de>
> Sent: Friday, March 26, 2021 5:38 PM
> To: Richard Zhu <hongxing.zhu@nxp.com>; andrew.smirnov@gmail.com;
> shawnguo@kernel.org; kw@linux.com; bhelgaas@google.com;
> stefan@agner.ch; lorenzo.pieralisi@arm.com
> Cc: linux-pci@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
> kernel@pengutronix.de
> Subject: Re: [PATCH v3 1/3] dt-bindings: imx6q-pcie: add one regulator
> used to power up pcie phy
> Am Donnerstag, dem 25.03.2021 um 16:44 +0800 schrieb Richard Zhu:
> > Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> > In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
> > sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
> > the VREG_BYPASS bits of GPR registers should be cleared from default
> > value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
> > turned on.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > ---
> >  Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > index de4b2baf91e8..e6d1886144ce 100644
> > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > @@ -38,6 +38,9 @@ Optional properties:
> >    The regulator will be enabled when initializing the PCIe host and
> >    disabled either as part of the init process or when shutting down the
> >    host.
> > +- vph-supply: Should specify the regulator in charge of VPH one of
> > +the three
> > +  PCIe PHY powers. This regulator can be supplied by both 1.8v and
> > +3.3v voltage
> > +  supplies. Might be used to distinguish different HW board designs.
> 
> Please just get rid of the last sentence. All DT properties are used in one way
> or the other to distinguish different HW designs, so no need to mention this.
[Richard Zhu] Thanks, would remove the last sentence later.
> 
> Regards,
> Lucas