[PATCH v2 1/2] mips: dts: Fix PIC32MZDA GPIO register definitions

John Robertson john.robertson at simiatec.com
Tue Sep 1 20:02:13 CEST 2020


GPIO state cannot be changed via the device tree (e.g. with gpio-hog) or
using the 'gpio' command from the console.

The root cause is a discrepancy between the driver and the device tree:
the driver code expects an absolute I/O address in the <reg> property,
while the device tree defines the address relative to a declaration in
the parent pinctrl node.

Changing the device tree to fix a driver issue would normally be wrong,
however:
- I have run the first version of U-Boot in which this driver appears
  (v2016.03) and the same problem exists, so this is not a regression;
- There is no code that references a parent device tree node that might
  suggest the intent of the author was to parse the DT as it exists now;
- The equivalent Linux PIC32 GPIO driver also uses absolute addresses
  for the GPIO <reg> property. This change brings the U-Boot DT more
  into line with Linux.

Additionally, the data sheet (Microchip ref. 60001361H) shows that the
register set to control a GPIO bank spans 0xE0 bytes, but the device
tree specified size is only 0x48 bytes.

Signed-off-by: John Robertson <john.robertson at simiatec.com>
---
Changes in v2
- Split patch
- Document change more fully

 arch/mips/dts/pic32mzda.dtsi | 45 ++++++++++++++++++------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/arch/mips/dts/pic32mzda.dtsi b/arch/mips/dts/pic32mzda.dtsi
index 4c8b7a9a0b..8f9b4cc50e 100644
--- a/arch/mips/dts/pic32mzda.dtsi
+++ b/arch/mips/dts/pic32mzda.dtsi
@@ -69,6 +69,8 @@
 	};
 
 	pinctrl: pinctrl at 1f801400 {
+		#address-cells = <1>;
+		#size-cells = <1>;
 		compatible = "microchip,pic32mzda-pinctrl";
 		reg = <0x1f801400 0x100>, /* in  */
 		      <0x1f801500 0x200>, /* out */
@@ -76,75 +78,72 @@
 		reg-names = "ppsin","ppsout","port";
 		status = "disabled";
 
-		ranges = <0 0x1f860000 0xa00>;
-		#address-cells = <1>;
-		#size-cells = <1>;
-		gpioA: gpio0 at 0 {
+		gpioA: gpio0 at 1f860000 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x000 0x48>;
+			reg = <0x1f860000 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioB: gpio1 at 100 {
+		gpioB: gpio1 at 1f860100 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x100 0x48>;
+			reg = <0x1f860100 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioC: gpio2 at 200 {
+		gpioC: gpio2 at 1f860200 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x200 0x48>;
+			reg = <0x1f860200 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioD: gpio3 at 300 {
+		gpioD: gpio3 at 1f860300 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x300 0x48>;
+			reg = <0x1f860300 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioE: gpio4 at 400 {
+		gpioE: gpio4 at 1f860400 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x400 0x48>;
+			reg = <0x1f860400 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioF: gpio5 at 500 {
+		gpioF: gpio5 at 1f860500 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x500 0x48>;
+			reg = <0x1f860500 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioG: gpio6 at 600 {
+		gpioG: gpio6 at 1f860600 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x600 0x48>;
+			reg = <0x1f860600 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioH: gpio7 at 700 {
+		gpioH: gpio7 at 1f860700 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x700 0x48>;
+			reg = <0x1f860700 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioJ: gpio8 at 800 {
+		gpioJ: gpio8 at 1f860800 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x800 0x48>;
+			reg = <0x1f860800 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
 
-		gpioK: gpio9 at 900 {
+		gpioK: gpio9 at 1f860900 {
 			compatible = "microchip,pic32mzda-gpio";
-			reg = <0x900 0x48>;
+			reg = <0x1f860900 0xe0>;
 			gpio-controller;
 			#gpio-cells = <2>;
 		};
-- 
2.28.0



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