[PATCH 10/10] ARM: dts: Fix dm814x pinctrl address and mask

* Tony Lindgren [off-list ref] [151201 17:23]:

* Matthijs van Duin [off-list ref] [151201 17:15]:

quoted

On 2 December 2015 at 01:46, Tony Lindgren [off-list ref] wrote:

quoted

Ouch. We should probably have separate PIN_INPUT_3V3 and PIN_OUTPUT_3V3
dts macros that ensure that?

Can't we just keep bit 18 out of the function mask? The bootloader
should already have made sure all pins have bit 18 set (and bit 19 set
to correct values after ROM mucked them up, see advisory 2.1.88), so
all that needs to be done is avoid touching them.

Sounds good to me. And people who really want to override the mask can
do it in the board specifc dts file.

quoted

Are the power savings from disabling unnecessary inputs significant
enough to spend any headache on it?

Only for some battery powered devices, not in this case for sure.

And here's an updated version of this patch.

Regards,

Tony

8< ----------------------------
From: Tony Lindgren <tony@atomide.com>
Date: Tue, 1 Dec 2015 15:04:38 -0800
Subject: [PATCH] ARM: dts: Fix dm814x pinctrl address and mask

Otherwise pinctrl won't work. Because of silicon errata for some dm814x
versions, let's also keep bit 18 out of the function-mask and rely on
the bootloader configuration for bit 18  as suggested by
Matthijs van Duin [off-list ref].

Devices with that need to use bit 18 can override the function-mask in
the board specific dts file if really needed.

Signed-off-by: Tony Lindgren <tony@atomide.com>

--- a/arch/arm/boot/dts/dm814x.dtsi
+++ b/arch/arm/boot/dts/dm814x.dtsi

@@ -205,13 +205,21 @@
 					};
 				};
 
+				/*
+				 * Note that silicon revision 2.1 and older
+				 * require input enabled (bit 18 set) for all
+				 * 3.3V I/Os to avoid cumulative hardware damage.
+				 * For more info, see errata advisory 2.1.87.
+				 * We leave bit 18 out of function-mask and rely
+				 * on the bootloader for it.
+				 */
 				pincntl: pinmux at 800 {
 					compatible = "pinctrl-single";
-					reg = <0x800 0xc38>;
+					reg = <0x800 0x438>;
 					#address-cells = <1>;
 					#size-cells = <0>;
 					pinctrl-single,register-width = <32>;
-					pinctrl-single,function-mask = <0x300ff>;
+					pinctrl-single,function-mask = <0x307ff>;
 				};
 			};