ARM: dts: armadillo800eva: Split LCD mux and gpio

Configuration of the lcd0 pinmux group and GPIO hog for the external GPIO mux are done using a single device node, causing the "output-high" property to be applied to both. This will fail for the pinmux group, but doesn't cause any harm, as the failure is ignored silently.

However, after "pinctrl: sh-pfc: propagate errors on group config", the failure will become fatal, leading to a broken display:

sh-pfc e6050000.pin-controller: pin_config_group_set op failed for group
102 sh-pfc e6050000.pin-controller: Error applying setting, reverse things back sh-pfc e6050000.pin-controller: failed to select default state

Move the GPIO hog to its own node to fix this.

Fixes ffd2f9a5afb730b9 ("ARM: shmobile: armadillo800eva dts: Add pinctrl

and gpio-hog for lcdc0") Signed-off-by: Geert Uytterhoeven <[email protected]>
---
This is a hard dependency for "pinctrl: sh-pfc: propagate errors on group config" (https://patchwork.kernel.org/patch/9186713/).

v2:
- Keep the GPIO hog, but move it to its own node, instead of using another level of subnodes. As the GPIO hog node is not referenced from a pinctrl-0 property, pinconf doesn't fail with "No pin or group provided in DT node".

---
 arch/arm/boot/dts/r8a7740-armadillo800eva.dts | 2 ++
 1 file changed, 2 insertions(+)

(quoted diff) +0 -0

b/arch/arm/boot/dts/r8a7740-armadillo800eva.dts index 297b1f10f7346a9f..8c85d3ee5f5e7bfd 100644

arch/arm/boot/dts/r8a7740-armadillo800eva.dts +2 -0

@@ -273,7 +273,9 @@
 	lcd0_pins: lcd0 {
 		groups = "lcd0_data24_0", "lcd0_lclk_1", "lcd0_sync";
 		function = "lcd0";
+	};
 
+	lcd0_mux {
 		/* DBGMD/LCDC0/FSIA MUX */
 		gpio-hog;
 		gpios = <176 0>;

Hi Geert,

Thank you for the patch.

Quoted 21 lines · On Thursday 01 Jun 2017 12:27:00 Geert Uytterhoeven wrote:

Configuration of the lcd0 pinmux group and GPIO hog for the external GPIO mux are done using a single device node, causing the "output-high" property to be applied to both. This will fail for the pinmux group, but doesn't cause any harm, as the failure is ignored silently.

However, after "pinctrl: sh-pfc: propagate errors on group config", the failure will become fatal, leading to a broken display:

sh-pfc e6050000.pin-controller: pin_config_group_set op failed for group
102 sh-pfc e6050000.pin-controller: Error applying setting, reverse things back sh-pfc e6050000.pin-controller: failed to select default state

Move the GPIO hog to its own node to fix this.

Fixes ffd2f9a5afb730b9 ("ARM: shmobile: armadillo800eva dts: Add pinctrl

and gpio-hog for lcdc0") Signed-off-by: Geert Uytterhoeven <[email protected]>
---
This is a hard dependency for "pinctrl: sh-pfc: propagate errors on group config" (https://patchwork.kernel.org/patch/9186713/).

Quoted 5 lines

v2:
- Keep the GPIO hog, but move it to its own node, instead of using another level of subnodes. As the GPIO hog node is not referenced from a pinctrl-0 property, pinconf doesn't fail with "No pin or group provided in DT node".

I like this approach better, it allows us to drive the output instead of pulling it up, without requiring a full implementation of output drive control in the pfc driver.

Acked-by Laurent Pinchart <[email protected]>