ARM: dts: stm32: add board pin documentation stm32mp135f-dk

Relate the devices defined in the device tree to the SoC ports and pins
and labels available on the board.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20260420204647.1713944-2-u.kleine-koenig@baylibre.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

diff --git a/arch/arm/boot/dts/st/stm32mp135f-dk.dts b/arch/arm/boot/dts/st/stm32mp135f-dk.dts
index 4d4cec8b86aca241cfd487e9b9f40b4d15c4d46f..6022e73f58afd67017ace83bcd1eea3f11ffe593 100644 (file)
--- a/arch/arm/boot/dts/st/stm32mp135f-dk.dts
+++ b/arch/arm/boot/dts/st/stm32mp135f-dk.dts
@@ -64,6 +64,7 @@
                compatible = "gpio-keys";
 
                button-user {
+                       /* GPIO on PA13 "User button 2 (B2)" */
                        label = "User-PA13";
                        linux,code = <BTN_1>;
                        gpios = <&gpioa 13 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
@@ -74,6 +75,7 @@
                compatible = "gpio-leds";
 
                led_blue: led-blue {
+                       /* GPIO on PA14 "User LED (LD3)" */
                        function = LED_FUNCTION_HEARTBEAT;
                        color = <LED_COLOR_ID_BLUE>;
                        gpios = <&gpioa 14 GPIO_ACTIVE_LOW>;
@@ -82,6 +84,7 @@
                };
 
                led-red {
+                       /* GPIO on PA13 "User LED (LD4)" */
                        function = LED_FUNCTION_STATUS;
                        color = <LED_COLOR_ID_RED>;
                        gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;
@@ -252,6 +255,7 @@
 
 &i2c1 {
        pinctrl-names = "default", "sleep";
+       /* SDA on PE8 = CN8.27, SCL on PD12 = CN8.28 */
        pinctrl-0 = <&i2c1_pins_a>;
        pinctrl-1 = <&i2c1_sleep_pins_a>;
        i2c-scl-rising-time-ns = <96>;
@@ -486,7 +490,10 @@
                status = "okay";
        };
        pwm {
-               /* PWM output on pin 7 of the expansion connector (CN8.7) using TIM3_CH4 func */
+               /*
+                * CH4 on PB1 = CN8.7;
+                * CH3 on PB0 = CN8.10 is possible (conflicting with usart1)
+                */
                pinctrl-0 = <&pwm3_pins_a>;
                pinctrl-1 = <&pwm3_sleep_pins_a>;
                pinctrl-names = "default", "sleep";
@@ -505,7 +512,10 @@
                status = "okay";
        };
        pwm {
-               /* PWM output on pin 31 of the expansion connector (CN8.31) using TIM4_CH2 func */
+               /*
+                * CH2 on PD13 = CN8.31;
+                * CH1 on PD12 = CN8.28 is possible (conflicting with &i2c1)
+                */
                pinctrl-0 = <&pwm4_pins_a>;
                pinctrl-1 = <&pwm4_sleep_pins_a>;
                pinctrl-names = "default", "sleep";
@@ -524,7 +534,12 @@
                status = "okay";
        };
        pwm {
-               /* PWM output on pin 32 of the expansion connector (CN8.32) using TIM8_CH3 func */
+               /*
+                * CH3 on PE5 = CN8.32
+                * CH1N on PA7 = CN8.36 is possible (conflicting with &usart1)
+                * CH2N on PB0 = CN8.10 is possible (conflicting with &usart1)
+                * CH3N on PB1 = CN8.7 is possible (conflicting with &timers3)
+                */
                pinctrl-0 = <&pwm8_pins_a>;
                pinctrl-1 = <&pwm8_sleep_pins_a>;
                pinctrl-names = "default", "sleep";
@@ -541,7 +556,7 @@
                status = "okay";
        };
        pwm {
-               /* PWM output on pin 33 of the expansion connector (CN8.33) using TIM14_CH1 func */
+               /* CH1 on PF9 = CN8.33 (alternatively on PA7 = CN8.36 (conflicting with &usart1)) */
                pinctrl-0 = <&pwm14_pins_a>;
                pinctrl-1 = <&pwm14_sleep_pins_a>;
                pinctrl-names = "default", "sleep";
@@ -553,6 +568,7 @@
 };
 
 &uart4 {
+       /* Accessible via micro USB ST-LINK USB (CN10) */
        pinctrl-names = "default", "sleep", "idle";
        pinctrl-0 = <&uart4_pins_a>;
        pinctrl-1 = <&uart4_sleep_pins_a>;
@@ -564,6 +580,7 @@
 
 &uart8 {
        pinctrl-names = "default", "sleep", "idle";
+       /* TX on PE1 = CN8.37, RX on PF9 = CN8.33 */
        pinctrl-0 = <&uart8_pins_a>;
        pinctrl-1 = <&uart8_sleep_pins_a>;
        pinctrl-2 = <&uart8_idle_pins_a>;
@@ -574,6 +591,7 @@
 
 &usart1 {
        pinctrl-names = "default", "sleep", "idle";
+       /* TX on PC0 = CN8.8, RX on PB0 = CN8.10, RTS on PC2 = CN8.11, CTS on PA7 = CN8.36 */
        pinctrl-0 = <&usart1_pins_a>;
        pinctrl-1 = <&usart1_sleep_pins_a>;
        pinctrl-2 = <&usart1_idle_pins_a>;
@@ -584,6 +602,7 @@
 /* Bluetooth */
 &usart2 {
        pinctrl-names = "default", "sleep", "idle";
+       /* TX on PH12, RX on PD15, RTS on PD4, CTS on PE11 */
        pinctrl-0 = <&usart2_pins_a>;
        pinctrl-1 = <&usart2_sleep_pins_a>;
        pinctrl-2 = <&usart2_idle_pins_a>;
@@ -613,6 +632,7 @@
 };
 
 &usbotg_hs {
+       /* USB Type-C DRP (CN7) */
        phys = <&usbphyc_port1 0>;
        phy-names = "usb2-phy";
        usb-role-switch;