boards/nrf52840-mdk-dongle: configure RGB LED as PWM

boards/nrf52840-mdk-dongle/Kconfig

@@ -12,6 +12,7 @@ config BOARD_NRF52840_MDK_DONGLE
     default y
     select BOARD_COMMON_NRF52
     select CPU_MODEL_NRF52840XXAA
+    select HAS_PERIPH_PWM
     select HAS_PERIPH_UART
     select HAS_PERIPH_USBDEV
     select HAS_HIGHLEVEL_STDIO

boards/nrf52840-mdk-dongle/Makefile.dep

@@ -1,5 +1,6 @@
 ifneq (,$(filter saul_default,$(USEMODULE)))
   USEMODULE += saul_gpio
+  USEMODULE += saul_pwm
 endif
 
 include $(RIOTBOARD)/common/nrf52/bootloader_nrfutil.dep.mk

boards/nrf52840-mdk-dongle/Makefile.features

@@ -1,6 +1,7 @@
 CPU_MODEL = nrf52840xxaa
 
 # Put defined MCU peripherals here (in alphabetical order)
+FEATURES_PROVIDED += periph_pwm
 FEATURES_PROVIDED += periph_uart
 FEATURES_PROVIDED += periph_usbdev
 

boards/nrf52840-mdk-dongle/include/gpio_params.h

@@ -31,6 +31,7 @@ extern "C" {
  */
 static const  saul_gpio_params_t saul_gpio_params[] =
 {
+#ifndef MODULE_SAUL_PWM
     {
         .name  = "LED Red",
         .pin   = LED0_PIN,
@@ -49,6 +50,7 @@ static const  saul_gpio_params_t saul_gpio_params[] =
         .mode  = GPIO_OUT,
         .flags = (SAUL_GPIO_INVERTED | SAUL_GPIO_INIT_CLEAR),
     },
+#endif
     {
         .name  = "Reset",
         .pin   = BTN0_PIN,

boards/nrf52840-mdk-dongle/include/periph_conf.h

@@ -55,6 +55,20 @@ static const uart_conf_t uart_config[] = {
 #define UART_NUMOF          ARRAY_SIZE(uart_config)
 /** @} */
 
+/**
+ * @name   PWM configuration
+ *
+ * For the nRF52840-mdk-dongle board, the PWM0 module is set to drive the RGB LED.
+ * Other PWM outputs are not configured.
+ *
+ * @{
+ */
+static const pwm_conf_t pwm_config[] = {
+    { NRF_PWM0, { GPIO_PIN(0, 23), GPIO_PIN(0, 22), GPIO_PIN(0, 24) } }
+};
+#define PWM_NUMOF           ARRAY_SIZE(pwm_config)
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif

boards/nrf52840-mdk-dongle/include/pwm_params.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     boards_nrf52840-mdk-dongle
+ * @{
+ *
+ * @file
+ * @brief       Configuration of SAUL mapped PWM channels
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#ifndef PWM_PARAMS_H
+#define PWM_PARAMS_H
+
+#include "board.h"
+#include "saul/periph.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief    No individual LED that needs dimming
+ */
+#define SAUL_PWM_NO_DIMMER
+
+/**
+ * @brief    The on-board RGB LED
+ */
+static const saul_pwm_rgb_params_t saul_pwm_rgb_params[] =
+{
+    {
+        .name  = "RGB",
+        .channels = {
+            { PWM_DEV(0), 0, SAUL_PWM_INVERTED },
+            { PWM_DEV(0), 1, SAUL_PWM_INVERTED },
+            { PWM_DEV(0), 2, SAUL_PWM_INVERTED }
+        }
+    }
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PWM_PARAMS_H */
+/** @} */