drivers: pwm: sun4i: Improve support for A64 SoCs

The PWM controllers found in the Allwinner A64 and H5 SoCs are fully compatible to the PWM controllers found in the A13 and H3. Add new compatible strings for those SoCs to the binding document, so that they can be safely used, together with a fallback string (preferably "allwinner,sun5i-a13-pwm").

Signed-off-by Andre Przywara <[email protected]>

The PWM controllers found in the Allwinner A64 and H5 SoCs are fully compatible to the PWM controllers found in the A13 and H3. Add new compatible strings for those SoCs to the binding document, so that they can be safely used, together with a fallback string (preferably "allwinner,sun5i-a13-pwm").

Signed-off-by Andre Przywara <[email protected]>

---
 Documentation/devicetree/bindings/pwm/pwm-sun4i.txt | 2 ++
 1 file changed, 2 insertions(+)

The Allwinner A64 SoC features two PWM controllers, which are fully compatible to the one used in the A13 and H3 chips.
Add the respective device nodes (one for the "normal" PWM, the other for the one in the CPUS domain) and the pin their output is connected to.

On the A64 the "normal" PWM is muxed together with one of the MDIO pins used to communicate with the Ethernet PHY, so it won't be usable on many boards. But the Pinebook laptop uses this pin for controlling the LCD backlight.
The CPUS PWM pin however is routed to the "RPi2" header, at the same location as the PWM pin on the RaspberryPi.

The Allwinner A64 SoC features two PWM controllers, which are fully compatible to the one used in the A13 and H3 chips.
Add the respective device nodes (one for the "normal" PWM, the other for the one in the CPUS domain) and the pin their output is connected to. On the A64 the "normal" PWM is muxed together with one of the MDIO pins used to communicate with the Ethernet PHY, so it won't be usable on many boards. But the Pinebook laptop uses this pin for controlling the LCD backlight.

The CPUS PWM pin however is routed to the "RPi2" header, at the same location as the PWM pin on the RaspberryPi.

Signed-off-by Andre Przywara <[email protected]>

---
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 28 +++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi +28 -0

index d783d164b9c3..fda1783b1c86 100644
@@ -321,6 +321,11 @@
 				bias-pull-up;
 			};
 
+			pwm_pin: pwm_pin {
+				pins = "PD22";
+				function = "pwm";
+			};
+
 			rmii_pins: rmii_pins {
 				pins = "PD10", "PD11", "PD13", "PD14", "PD17",
 				       "PD18", "PD19", "PD20", "PD22", "PD23";

@@ -537,6 +542,15 @@
 			#interrupt-cells = <3>;
 		};
 
+		pwm: pwm at 1c21400 {
+			compatible = "allwinner,sun50i-a64-pwm",
+				     "allwinner,sun5i-a13-pwm";
+			reg = <0x01c21400 0x400>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		rtc: rtc at 1f00000 {
 			compatible = "allwinner,sun6i-a31-rtc";
 			reg = <0x01f00000 0x54>;

@@ -563,6 +577,15 @@
 			#reset-cells = <1>;
 		};
 
+		r_pwm: pwm at 1f03800 {
+			compatible = "allwinner,sun50i-a64-pwm",
+				     "allwinner,sun5i-a13-pwm";
+			reg = <0x01f03800 0x400>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		r_pio: pinctrl at 1f02c00 {
 			compatible = "allwinner,sun50i-a64-r-pinctrl";
 			reg = <0x01f02c00 0x400>;

@@ -578,6 +601,11 @@
 				pins = "PL0", "PL1";
 				function = "s_rsb";
 			};
+
+			r_pwm_pin: pwm {
+				pins = "PL10";
+				function = "s_pwm";
+			};
 		};
 
 		r_rsb: rsb at 1f03400 {

A rework addressing the comments. I dropped the H6 and the reset support for now, to simplify merging this series.

This series adds PWM support for new Allwinner SoCs. Actually the A64 PWM is fully compatible with the A13 and H3 PWM IP, so the driver does not need any additional code. But I use this opportunity to provide some cleanup.
Patch 1 removes a no longer used parameter from our per-SoC data structure, to simplify patch 2, which groups SoCs with a compatible PWM controller. Patch 3 adds the new compatible strings to the binding documentation (and just there, we expect to use "allwinner,sun5i-a13-pwm" as a fallback compatible string).
The final patch 4 adds the respective PWM nodes to the A64 .dtsi. This eventually does not enable the PWM on any new board at the moment, as the PWM pins are either not usable (muxed with Ethernet) or exposed on a header pin not dedicated to PWM. But the Pinebook (and Teres I) should be able to use the PWM for the LCD backlights, plus users can enable the R_PWM on their Pine64 boards, if they like.

Tested by manually enabling r_pwm on a Pine64-LTS.

Cheers,
Andre.

Andre Przywara (4):
pwm: sun4i: drop unused .has_rdy member
pwm: sun4i: simplify controller mapping
dt-bindings: pwm: sunxi: add new compatible strings
dts: sunxi: A64: Add PWM controllers

 .../devicetree/bindings/pwm/pwm-sun4i.txt          |  2 ++
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi      | 28 +++++++++++++++++++
 drivers/pwm/pwm-sun4i.c                            | 32 ++++++----------------
 3 files changed, 38 insertions(+), 24 deletions(-)