cpu/nrfxx: simplify LFCLK source selection

Signed-off-by: Dylan Laduranty <dylan.laduranty@mesotic.com>

cpu/nrf51/cpu.c

@@ -25,6 +25,15 @@
 #include "periph/init.h"
 #include "stdio_base.h"
 
+/**
+ * @brief    LFCLK Clock selection configuration guard
+*/
+#if ((CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_RC)   && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_Xtal) && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_Synth))
+#error "LFCLK init: CLOCK_LFCLK has invalid value"
+#endif
+
 /**
  * @brief Initialize the CPU, set IRQ priorities
  */

cpu/nrf52/cpu.c

@@ -35,6 +35,15 @@ static bool ftpan_32(void);
 static bool ftpan_37(void);
 static bool ftpan_36(void);
 
+/**
+ * @brief    LFCLK Clock selection configuration guard
+*/
+#if ((CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_RC)   && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_Xtal) && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_Synth))
+#error "LFCLK init: CLOCK_LFCLK has invalid value"
+#endif
+
 /**
  * @brief   Initialize the CPU, set IRQ priorities
  */

cpu/nrf53/cpu.c

@@ -27,6 +27,15 @@
 #include "stdio_base.h"
 #include "board.h"
 
+/**
+ * @brief    LFCLK Clock selection configuration guard
+*/
+#if ((CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_LFRC) && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_LFXO) && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_LFSYNT))
+#error "LFCLK init: CLOCK_LFCLK has invalid value"
+#endif
+
 /**
  * @brief   Initialize the CPU, set IRQ priorities
  */

cpu/nrf5x_common/clock.c

@@ -23,23 +23,16 @@
 #include "nrf_clock.h"
 #include "periph_conf.h"
 
-/* make sure both clocks are configured */
+/* make HFCLK clock is configured */
 #ifndef CLOCK_HFCLK
 #error "Clock init: CLOCK_HFCLK is not defined by your board!"
 #endif
-#ifndef CLOCK_LFCLK
-#error "Clock init: CLOCK_LFCLK is not defined by your board!"
-#endif
 
 /* Add compatibility wrapper defines for nRF families with Cortex-M33 core */
 #ifdef NRF_CLOCK_S
 #define NRF_CLOCK NRF_CLOCK_S
 #endif
 
-#ifdef CLOCK_LFCLKSRC_SRC_LFRC
-#define CLOCK_LFCLKSRC_SRC_RC CLOCK_LFCLKSRC_SRC_LFRC
-#endif
-
 static unsigned _hfxo_requests = 0;
 
 void clock_init_hf(void)
@@ -92,17 +85,9 @@ void clock_start_lf(void)
         return;
     }
 
-#if (CLOCK_LFCLK == 0)
+    /* Select LFCLK source */
-    NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_RC);
+    NRF_CLOCK->LFCLKSRC = CLOCK_LFCLK;
-#elif (CLOCK_LFCLK == 1)
+
-    NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal);
-#elif (CLOCK_LFCLK == 2)
-    NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Synth);
-#elif (CLOCK_LFCLK == 3)
-    NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_LFXO);
-#else
-#error "LFCLK init: CLOCK_LFCLK has invalid value"
-#endif
     /* enable LF clock */
     NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
     NRF_CLOCK->TASKS_LFCLKSTART = 1;

cpu/nrf9160/cpu.c

@@ -25,6 +25,14 @@
 #include "periph/init.h"
 #include "stdio_base.h"
 
+/**
+ * @brief    LFCLK Clock selection configuration guard
+*/
+#if ((CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_LFRC) && \
+     (CLOCK_LFCLK != CLOCK_LFCLKSRC_SRC_LFXO))
+#error "LFCLK init: CLOCK_LFCLK has invalid value"
+#endif
+
 /**
  * @brief   Initialize the CPU, set IRQ priorities
  */