From f41b43e2634e895e2ef2db5bdd0b621d0940adf6 Mon Sep 17 00:00:00 2001
From: Francisco Molina <femolina@uc.cl>
Date: Wed, 17 Jun 2020 12:40:13 +0200
Subject: [PATCH] cpu/saml21: add unified rtt configuration

---
 boards/saml21-xpro/include/periph_conf.h |  3 ++-
 boards/samr30-xpro/include/periph_conf.h |  6 ++++--
 boards/samr34-xpro/include/periph_conf.h |  5 +++--
 cpu/saml21/include/periph_cpu.h          | 10 ++++++++++
 4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/boards/saml21-xpro/include/periph_conf.h b/boards/saml21-xpro/include/periph_conf.h
index 95a6fe7420..05575a275d 100644
--- a/boards/saml21-xpro/include/periph_conf.h
+++ b/boards/saml21-xpro/include/periph_conf.h
@@ -162,8 +162,9 @@ static const i2c_conf_t i2c_config[] = {
  * @name    RTT configuration
  * @{
  */
+#ifndef RTT_FREQUENCY
 #define RTT_FREQUENCY       (32768U)
-#define RTT_MAX_VALUE       (0xffffffffU)
+#endif
 /** @} */
 
 /**
diff --git a/boards/samr30-xpro/include/periph_conf.h b/boards/samr30-xpro/include/periph_conf.h
index d10bc71771..a64d0114cf 100644
--- a/boards/samr30-xpro/include/periph_conf.h
+++ b/boards/samr30-xpro/include/periph_conf.h
@@ -153,10 +153,12 @@ static const i2c_conf_t i2c_config[] = {
  * @name    RTT configuration
  * @{
  */
-#define RTT_FREQUENCY                           (32768U)
-#define RTT_MAX_VALUE                           (0xffffffffU)
+#ifndef RTT_FREQUENCY
+#define RTT_FREQUENCY       (32768U)
+#endif
 /** @} */
 
+
 /**
  * @name ADC Configuration
  * @{
diff --git a/boards/samr34-xpro/include/periph_conf.h b/boards/samr34-xpro/include/periph_conf.h
index 2489d7b0be..3a3ad94f3b 100644
--- a/boards/samr34-xpro/include/periph_conf.h
+++ b/boards/samr34-xpro/include/periph_conf.h
@@ -144,8 +144,9 @@ static const i2c_conf_t i2c_config[] = {
  * @name    RTT configuration
  * @{
  */
-#define RTT_FREQUENCY                           (32768U)
-#define RTT_MAX_VALUE                           (0xffffffffU)
+#ifndef RTT_FREQUENCY
+#define RTT_FREQUENCY       (32768U)
+#endif
 /** @} */
 
 /**
diff --git a/cpu/saml21/include/periph_cpu.h b/cpu/saml21/include/periph_cpu.h
index d7f0345026..cd08216811 100644
--- a/cpu/saml21/include/periph_cpu.h
+++ b/cpu/saml21/include/periph_cpu.h
@@ -73,6 +73,16 @@ typedef enum {
  */
 #define DAC_NUMOF           (2)
 
+/**
+ * @name    Real time counter configuration
+ * @{
+ */
+#define RTT_MAX_VALUE       (0xffffffff)
+#define RTT_CLOCK_FREQUENCY (32768U)                      /* in Hz */
+#define RTT_MIN_FREQUENCY   (RTT_CLOCK_FREQUENCY / 512U)  /* in Hz */
+#define RTT_MAX_FREQUENCY   (RTT_CLOCK_FREQUENCY)         /* in Hz */
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif