[openwrt/openwrt] realtek: rtl930x: Define GPIO_SEL_CTRL pinmux node

[LEDE Commits]

robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/9c8d634646d5a4fc1931fce8ef26b75acd05ddbb

commit 9c8d634646d5a4fc1931fce8ef26b75acd05ddbb
Author: Sven Eckelmann <sven at narfation.org>
AuthorDate: Wed Aug 20 05:19:31 2025 +0200

    realtek: rtl930x: Define GPIO_SEL_CTRL pinmux node
    
    The pinmux-related registers on the RTL930X SoC family are spread across
    various non-consecutive registers. It might be tempting to modify them
    directly in a specific driver (SPI, LED, etc.), but this would cause issues
    with parallel, non-locked read-modify-write operations, which are required
    to update individual portions of these registers.
    
    Instead, it is better to use the devicetree pinctrl properties to define
    the correct configurations for the various operation modes.
    
    One important setting here is the LED Sync bit. This allows the LED
    controller to generate an additional positive edge on the `STCP`
    ("STore Clock Pin", also known as `RCLK`) of the LED shift register after
    the actual content has already been shifted in using the normal shift
    clock. The LED shift register is then expected to copy the content from the
    shift register section into the storage registers, which act as the actual
    LED output control. This functionality is available in, and commonly used
    with, the SNx4HC595 family of shift registers.
    
    To activate it, simply register it in the default state of the
    "realtek,rtl83xx-switch" node:
    
        &switch0 {
            pinctrl-names = "default";
            pinctrl-0 = <&pinmux_enable_led_sync>;
            ....
        };
    
    It would be nicer when this can be directly added to the led subnode. But
    for this to work, `realtek,rtl9300-leds` must first be an actual driver
    (known to the driver core).
    
    [1] https://www.ti.com/lit/ds/symlink/sn74hc595.pdf
    
    Suggested-by: Bevan Weiss <bevan.weiss at gmail.com>
    Signed-off-by: Sven Eckelmann <sven at narfation.org>
    Link: https://github.com/openwrt/openwrt/pull/19815
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 target/linux/realtek/dts/rtl930x.dtsi | 38 +++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/target/linux/realtek/dts/rtl930x.dtsi b/target/linux/realtek/dts/rtl930x.dtsi
index 02d8c47e7c..312cc77956 100644
--- a/target/linux/realtek/dts/rtl930x.dtsi
+++ b/target/linux/realtek/dts/rtl930x.dtsi
@@ -195,6 +195,44 @@
 		};
 	};
 
+	pinmux at 1b000200 {
+		compatible = "pinctrl-single";
+		reg = <0x1b000200 0x4>;
+
+		pinctrl-single,bit-per-mux;
+		pinctrl-single,register-width = <32>;
+		pinctrl-single,function-mask = <0x1>;
+		#pinctrl-cells = <2>;
+
+		/* Enable GPIO 19 */
+		pinmux_disable_led_sync: disable-led-sync {
+			pinctrl-single,bits = <0x0 0x0 0x800>;
+		};
+
+		pinmux_enable_led_sync: enable-led-sync {
+			pinctrl-single,bits = <0x0 0x800 0x800>;
+		};
+
+		/* Enable GPIO 18 */
+		pinmux_disable_usb_led: disable-usb-led {
+			pinctrl-single,bits = <0x0 0x0 0x400>;
+		};
+
+		pinmux_enable_usb_led: enable-usb-led {
+			pinctrl-single,bits = <0x0 0x400 0x400>;
+		};
+
+		/* Disable SLV SPI CS - freeing any associated GPIOs */
+		pinmux_disable_slv_spi_cs: disable-slv-spi-cs {
+			pinctrl-single,bits = <0x0 0x0 0x3E0>;
+		};
+
+		/* Disable SLV SPI SDO - freeing any associated GPIOs */
+		pinmux_disable_slv_spi_sdo: disable-slv-spi-sdo {
+			pinctrl-single,bits = <0x0 0x0 0x1F>;
+		};
+	};
+
 	pinmux at 1b00c600 {
 		compatible = "pinctrl-single";
 		reg = <0x1b00c600 0x4>;