From 13fbb7c1a07562ebfd25391afff2607eeade9596 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Tue, 16 Mar 2021 11:50:05 +0100
Subject: [PATCH] cpu/sam0_common: add rtc_tamper_pin_mask()

---
 cpu/sam0_common/include/periph_cpu_common.h | 12 ++++++++++++
 cpu/sam0_common/periph/rtc_rtt.c            | 10 ++++++++++
 2 files changed, 22 insertions(+)

diff --git a/cpu/sam0_common/include/periph_cpu_common.h b/cpu/sam0_common/include/periph_cpu_common.h
index 9953d8aad6..39bd90840d 100644
--- a/cpu/sam0_common/include/periph_cpu_common.h
+++ b/cpu/sam0_common/include/periph_cpu_common.h
@@ -1153,6 +1153,18 @@ void rtc_tamper_enable(void);
  *          pin index inside the @ref rtc_tamper_pins array.
  */
 uint8_t rtc_get_tamper_event(void);
+
+/**
+ * @brief   Get the tamper event mask for a certain pin.
+ *          Can be used together with @ref rtc_get_tamper_event to
+ *          check which RTC  pin caused the tamper event.
+ *
+ * @param pin   Pin to query
+ *
+ * @return  Bit mask with the bit corresponding to @p pin set
+ *          0 if @p pin is no RTC tamper pin
+ */
+uint8_t rtc_tamper_pin_mask(gpio_t pin);
 /** @} */
 
 /**
diff --git a/cpu/sam0_common/periph/rtc_rtt.c b/cpu/sam0_common/periph/rtc_rtt.c
index 54c16ec734..407314c18c 100644
--- a/cpu/sam0_common/periph/rtc_rtt.c
+++ b/cpu/sam0_common/periph/rtc_rtt.c
@@ -394,6 +394,16 @@ uint8_t rtc_get_tamper_event(void)
 
     return ret & RTC_TAMPID_TAMPID_Msk;
 }
+
+uint8_t rtc_tamper_pin_mask(gpio_t pin)
+{
+    int idx = _rtc_pin(pin);
+    if (idx < 0) {
+        return 0;
+    }
+
+    return 1 << idx;
+}
 #endif /* RTC_NUM_OF_TAMPERS */
 
 void rtt_set_overflow_cb(rtt_cb_t cb, void *arg)