pinctrl: phandle entries will be applied sequentially

Commit Message

Shawn Guo Oct. 10, 2013, 10:22 a.m. UTC

On Thu, Oct 10, 2013 at 11:08:40AM +0100, Russell King - ARM Linux wrote:
> On Thu, Oct 10, 2013 at 03:26:26PM +0800, Shawn Guo wrote:
> > However, my patch is talking about a different thing.  For example, we
> > have a device whose pinctrl-0 consists of two phandle entries that point
> > to pin configuration nodes foo and bar.
> > 
> > 	pinctrl-0 = <&foo &bar>;
> > 
> > 	foo {
> > 		...
> > 	};
> > 
> > 	bar {
> > 		...
> > 	};
> > 
> > My patch only wants to make it clear that the configuration specified by
> > node foo will be applied to pin controller first, and the configuration
> > defined in node bar will be applied after that.  When both nodes have
> > configuration for a pin, these two configs for the same pin go to two
> > different pinctrl_setting structures.  And these two pinctrl_settings
> > can not be applied accumulatedly but only sequentially.  That's what my
> > patch talks about.
> 
> I still say this is a potentially dangerous thing, and in my case of
> overriding the DAT3 pull-sense, it will cause the pin to glitch if
> nothing is connected to it.
> 
> So even if you do get this clarified, I am *not* happy to change my
> patch.

What about the solution suggested by Stephen, moving
MX6QDL_PAD_SD1_DAT3__SD1_DATA3 out from pinctrl_usdhc1_1 and having
additional nodes/phandle for DAT3 with different settings?


Shawn

Comments

Russell King - ARM Linux Oct. 10, 2013, 10:23 a.m. UTC | #1

On Thu, Oct 10, 2013 at 06:22:07PM +0800, Shawn Guo wrote:
> What about the solution suggested by Stephen, moving
> MX6QDL_PAD_SD1_DAT3__SD1_DATA3 out from pinctrl_usdhc1_1 and having
> additional nodes/phandle for DAT3 with different settings?
> 
> diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
> index 59154dc..fd52f4e 100644
> --- a/arch/arm/boot/dts/imx6qdl.dtsi
> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
> @@ -1157,7 +1157,6 @@
>                                                         MX6QDL_PAD_SD1_DAT0__SD1_DATA0 0x17059
>                                                         MX6QDL_PAD_SD1_DAT1__SD1_DATA1 0x17059
>                                                         MX6QDL_PAD_SD1_DAT2__SD1_DATA2 0x17059
> -                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x17059
>                                                         MX6QDL_PAD_NANDF_D0__SD1_DATA4 0x17059
>                                                         MX6QDL_PAD_NANDF_D1__SD1_DATA5 0x17059
>                                                         MX6QDL_PAD_NANDF_D2__SD1_DATA6 0x17059
> @@ -1165,6 +1164,18 @@
>                                                 >;
>                                         };
> 
> +                                       pinctrl_usdhc1_1_dat3: usdhc1dat3-1 {
> +                                               fsl,pins = <
> +                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x17059
> +                                               >;
> +                                       };
> +
> +                                       pinctrl_usdhc1_1_dat3cd: usdhc1dat3cd-1 {
> +                                               fsl,pins = <
> +                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x13059
> +                                               >;
> +                                       };
> 
> Then pinctrl-0 = <&pinctrl_usdhc1_1 &pinctrl_usdhc1_1_dat3> for existing
> boards, and <&pinctrl_usdhc1_1 &pinctrl_usdhc1_1_dat3cd> for boards that
> want to use DAT3 for card detection.

Yes, that avoids the issue entirely, and is a much better solution IMHO.

Patch

diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index 59154dc..fd52f4e 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -1157,7 +1157,6 @@ 
                                                        MX6QDL_PAD_SD1_DAT0__SD1_DATA0 0x17059
                                                        MX6QDL_PAD_SD1_DAT1__SD1_DATA1 0x17059
                                                        MX6QDL_PAD_SD1_DAT2__SD1_DATA2 0x17059
-                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x17059
                                                        MX6QDL_PAD_NANDF_D0__SD1_DATA4 0x17059
                                                        MX6QDL_PAD_NANDF_D1__SD1_DATA5 0x17059
                                                        MX6QDL_PAD_NANDF_D2__SD1_DATA6 0x17059
@@ -1165,6 +1164,18 @@ 
                                                >;
                                        };

+                                       pinctrl_usdhc1_1_dat3: usdhc1dat3-1 {
+                                               fsl,pins = <
+                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x17059
+                                               >;
+                                       };
+
+                                       pinctrl_usdhc1_1_dat3cd: usdhc1dat3cd-1 {
+                                               fsl,pins = <
+                                                       MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x13059
+                                               >;
+                                       };

Then pinctrl-0 = <&pinctrl_usdhc1_1 &pinctrl_usdhc1_1_dat3> for existing
boards, and <&pinctrl_usdhc1_1 &pinctrl_usdhc1_1_dat3cd> for boards that
want to use DAT3 for card detection.