| Message ID | 20201016130726.1378666-11-jckuo@nvidia.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Tegra XHCI controller ELPG support | expand |
On 10/20/20 5:40 AM, Rob Herring wrote: > On Fri, Oct 16, 2020 at 09:07:20PM +0800, JC Kuo wrote: >> This commit describes the "nvidia,pmc" property for Tegra210 tegra-xusb >> PHY driver. It is a phandle and specifier referring to the Tegra210 >> pmc@7000e400 node. >> >> Signed-off-by: JC Kuo <jckuo@nvidia.com> >> --- >> v4: >> new change to document "nvidia,pmc" prop >> >> .../devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >> index 38c5fa21f435..ea559baeb546 100644 >> --- a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >> +++ b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >> @@ -54,6 +54,7 @@ For Tegra210: >> - avdd-pll-uerefe-supply: PLLE reference PLL power supply. Must supply 1.05 V. >> - dvdd-pex-pll-supply: PCIe/USB3 PLL power supply. Must supply 1.05 V. >> - hvdd-pex-pll-e-supply: High-voltage PLLE power supply. Must supply 1.8 V. >> +- nvidia,pmc: phandle and specifier referring to the Tegra210 pmc@7000e400 node. > > 'Tegra210 pmc@7000e400' is kind of specific. Going to update this for > every address and chip? > > If there's only one PMC, you can just find the compatible PMC node. Then > you don't need a DT update. > > Rob > Hi Rob, Thanks for your review and suggestion. Yes, there is only one PMC node. You mean I can retrieve the PMC node with the following code and if do do DT update is not required, right? np = of_find_compatible_node(NULL, NULL, "nvidia,tegra210-pmc"); JC
On 11/14/20 12:20 AM, Thierry Reding wrote: > On Mon, Oct 19, 2020 at 04:40:46PM -0500, Rob Herring wrote: >> On Fri, Oct 16, 2020 at 09:07:20PM +0800, JC Kuo wrote: >>> This commit describes the "nvidia,pmc" property for Tegra210 tegra-xusb >>> PHY driver. It is a phandle and specifier referring to the Tegra210 >>> pmc@7000e400 node. >>> >>> Signed-off-by: JC Kuo <jckuo@nvidia.com> >>> --- >>> v4: >>> new change to document "nvidia,pmc" prop >>> >>> .../devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >>> index 38c5fa21f435..ea559baeb546 100644 >>> --- a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >>> +++ b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt >>> @@ -54,6 +54,7 @@ For Tegra210: >>> - avdd-pll-uerefe-supply: PLLE reference PLL power supply. Must supply 1.05 V. >>> - dvdd-pex-pll-supply: PCIe/USB3 PLL power supply. Must supply 1.05 V. >>> - hvdd-pex-pll-e-supply: High-voltage PLLE power supply. Must supply 1.8 V. >>> +- nvidia,pmc: phandle and specifier referring to the Tegra210 pmc@7000e400 node. >> >> 'Tegra210 pmc@7000e400' is kind of specific. Going to update this for >> every address and chip? >> >> If there's only one PMC, you can just find the compatible PMC node. Then >> you don't need a DT update. > > I did advise against doing the lookup by compatible string because I > think it has a couple of downsides. On one hand it's going to create an > additional maintenance burden on the XUSB pad controller driver because > the PMC is usually not compatible between SoC versions, so for every new > SoC generation we'll have to add the PMC compatible string to the XUSB > pad controller driver. > > On the other hand, this is new functionality and we can easily gate that > on the existence of this phandle, so it doesn't impact DT backwards > compatibility. That also has the advantage of explicitly listing the > dependency between the PMC and the XUSB pad controller in DT, so if we > ever do get around to come up with an even better mechanism to resolve > these dependencies than deferred probe, we do have the data already > available. > > Thierry > Hi Thierry, Thanks for the ideas. I will stay with the adding "nvidia,pmc" phandle property implementation. As for the DT document change, I will modify it with below. nvidia,pmc: phandle and specifier referring to the Tegra210 PMC node. Thanks, JC
diff --git a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt index 38c5fa21f435..ea559baeb546 100644 --- a/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt +++ b/Documentation/devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt @@ -54,6 +54,7 @@ For Tegra210: - avdd-pll-uerefe-supply: PLLE reference PLL power supply. Must supply 1.05 V. - dvdd-pex-pll-supply: PCIe/USB3 PLL power supply. Must supply 1.05 V. - hvdd-pex-pll-e-supply: High-voltage PLLE power supply. Must supply 1.8 V. +- nvidia,pmc: phandle and specifier referring to the Tegra210 pmc@7000e400 node. For Tegra186: - avdd-pll-erefeut-supply: UPHY brick and reference clock as well as UTMI PHY
This commit describes the "nvidia,pmc" property for Tegra210 tegra-xusb PHY driver. It is a phandle and specifier referring to the Tegra210 pmc@7000e400 node. Signed-off-by: JC Kuo <jckuo@nvidia.com> --- v4: new change to document "nvidia,pmc" prop .../devicetree/bindings/phy/nvidia,tegra124-xusb-padctl.txt | 1 + 1 file changed, 1 insertion(+)