arch/nrf53: initial clock configuration

arch/arm/src/nrf53/Kconfig

@@ -87,3 +87,48 @@ config NRF53_UART1
 	select NRF53_UART
 
 endmenu # NRF53 Peripheral Selection
+
+menu "Clock Configuration"
+
+config NRF53_HFCLK_XTAL
+	bool "Enable HFCLK from external crystal"
+	default n
+	---help---
+		If the board includes an external high-frequency crystal, enable this
+		option to supply the HFCLK. If this option is disabled, the internal
+		oscillator will be used.
+		Note that the RADIO peripheral requires the HFCLK to be used.
+
+config NRF53_USE_LFCLK
+	bool "Enable LFCLK"
+	default n
+	---help---
+		Enable low-frequency clock.
+
+if NRF53_USE_LFCLK
+
+choice
+	prompt "LFCLK source"
+	default NRF53_LFCLK_XTAL
+
+config NRF53_LFCLK_XTAL
+	bool "External 32.768Khz crystal"
+
+config NRF53_LFCLK_RC
+	bool "Internal RC oscillator"
+
+config NRF53_LFCLK_SYNTH
+	bool "Synthesized from HFCLK"
+
+endchoice
+
+endif # NRF53_USE_LFCLK
+
+config NRF53_OSCILLATOR_LFXO
+	bool "Configure LFXO oscillator"
+	default y if NRF53_LFCLK_XTAL
+	depends on NRF53_APPCORE
+	---help---
+		Configure LFXO oscillator
+
+endmenu # Clock Configuration

arch/arm/src/nrf53/Make.defs

@@ -24,6 +24,10 @@ CHIP_CSRCS += nrf53_systick.c
 CHIP_CSRCS += nrf53_start.c nrf53_clockconfig.c nrf53_irq.c nrf53_utils.c
 CHIP_CSRCS += nrf53_allocateheap.c nrf53_lowputc.c nrf53_gpio.c
 
+ifeq ($(CONFIG_NRF53_APPCORE),y)
+CHIP_CSRCS += nrf53_oscconfig.c
+endif
+
 ifneq ($(CONFIG_ARCH_IDLE_CUSTOM),y)
 CHIP_CSRCS += nrf53_idle.c
 endif

arch/arm/src/nrf53/nrf53_clockconfig.c

@@ -32,6 +32,17 @@
 
 #include "arm_internal.h"
 #include "nrf53_clockconfig.h"
+#include "hardware/nrf53_clock.h"
+#include "hardware/nrf53_power.h"
+#include "hardware/nrf53_gpio.h"
+
+#ifdef CONFIG_NRF53_APPCORE
+#  include "nrf53_oscconfig.h"
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
 
 /****************************************************************************
  * Public Functions
@@ -50,5 +61,47 @@
 
 void nrf53_clockconfig(void)
 {
-  /* TODO */
+#ifdef CONFIG_NRF53_APPCORE
+  /* Configure oscillators */
+
+  nrf53_oscconfig();
+#endif
+
+#ifdef CONFIG_NRF53_HFCLK_XTAL
+  /* Initialize HFCLK crystal oscillator */
+
+  putreg32(0x0, NRF53_CLOCK_EVENTS_HFCLKSTARTED);
+  putreg32(0x1, NRF53_CLOCK_TASKS_HFCLKSTART);
+
+  while (!getreg32(NRF53_CLOCK_EVENTS_HFCLKSTARTED))
+    {
+      /* wait for external oscillator to start */
+    }
+#endif
+
+#ifdef CONFIG_NRF53_USE_LFCLK
+  /* Initialize LFCLK */
+
+#if defined(CONFIG_NRF53_LFCLK_XTAL)
+  putreg32(CLOCK_LFCLKSRC_SRC_LFXO, NRF53_CLOCK_LFCLKSRC);
+#elif defined(CONFIG_NRF53_LFCLK_SYNTH)
+  putreg32(CLOCK_LFCLKSRC_SRC_LFSYNT, NRF53_CLOCK_LFCLKSRC);
+#else
+  putreg32(CLOCK_LFCLKSRC_SRC_LFRC, NRF53_CLOCK_LFCLKSRC);
+#endif
+
+  /* Trigger LFCLK start */
+
+  putreg32(0x0, NRF53_CLOCK_EVENTS_LFCLKSTARTED);
+  putreg32(0x1, NRF53_CLOCK_TASKS_LFCLKSTART);
+
+  while (!getreg32(NRF53_CLOCK_EVENTS_LFCLKSTARTED))
+    {
+      /* Wait for LFCLK to be running */
+    }
+
+#if defined(CONFIG_NRF53_LFCLK_RC)
+  /* TODO: calibrate LFCLK RC oscillator */
+#endif
+#endif
 }

arch/arm/src/nrf53/nrf53_oscconfig.c

@@ -0,0 +1,75 @@
+/****************************************************************************
+ * arch/arm/src/nrf53/nrf53_oscconfig.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <arch/board/board.h>
+
+#include "arm_internal.h"
+#include "nrf53_oscconfig.h"
+#include "nrf53_gpio.h"
+#include "hardware/nrf53_osc.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_NRF53_NETCORE
+#  error Oscillators configuration availalbe only for the App core
+#endif
+
+/* LFXO pins */
+
+#define LFXO_XL1_GPIO_PIN  (GPIO_MCUSEL_PERIP | GPIO_PORT0 | GPIO_PIN(0))
+#define LFXO_XL2_GPIO_PIN  (GPIO_MCUSEL_PERIP | GPIO_PORT0 | GPIO_PIN(1))
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nrf53_oscconfig
+ ****************************************************************************/
+
+void nrf53_oscconfig(void)
+{
+#ifdef CONFIG_NRF53_OSCILLATOR_LFXO
+  /* Configure LFXO pins */
+
+  nrf53_gpio_config(LFXO_XL1_GPIO_PIN);
+  nrf53_gpio_config(LFXO_XL2_GPIO_PIN);
+
+  /* Configure internal capacitors for LFXO */
+
+  putreg32(BOARD_OSC_XOSC32KI_INTCAP, NRF53_OSC_XOSC32KI_INTCAP);
+#endif
+
+#ifdef CONFIG_NRF53_HFCLK_XTAL
+#  warning TODO: missing HFCLK XTAL oscillator config
+#endif
+}

arch/arm/src/nrf53/nrf53_oscconfig.h

@@ -0,0 +1,61 @@
+/****************************************************************************
+ * arch/arm/src/nrf53/nrf53_oscconfig.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_NRF53_NRF53_OSCCONFIG_H
+#define __ARCH_ARM_SRC_NRF53_NRF53_OSCCONFIG_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nrf53_oscconfig
+ ****************************************************************************/
+
+void nrf53_oscconfig(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_ARM_SRC_NRF53_NRF53_OSCCONFIG_H */

boards/arm/nrf53/nrf5340-dk/include/board.h

@@ -32,6 +32,8 @@
 #  include <nuttx/irq.h>
 #endif
 
+#include "hardware/nrf53_osc.h"
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -39,6 +41,7 @@
 /* Clocking *****************************************************************/
 
 #define BOARD_SYSTICK_CLOCK         (64000000)
+#define BOARD_OSC_XOSC32KI_INTCAP   (OSC_XOSC32KI_INTCAP_C7PF)
 
 /* LED definitions **********************************************************/