From f4e5f016ac31aadb597e0b49f846638b41b306a2 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benpicco@googlemail.com>
Date: Tue, 28 Apr 2020 01:48:30 +0200
Subject: [PATCH] boards/samd21-xpro: enable DAC

samd21-xpro exposes PA02 on the EXT3 pin header, so we can enable
the DAC
---
 boards/samd21-xpro/Makefile.features     | 1 +
 boards/samd21-xpro/include/periph_conf.h | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/boards/samd21-xpro/Makefile.features b/boards/samd21-xpro/Makefile.features
index 27a8b83bb7..e24a5fcae4 100644
--- a/boards/samd21-xpro/Makefile.features
+++ b/boards/samd21-xpro/Makefile.features
@@ -3,6 +3,7 @@ CPU_MODEL = samd21j18a
 
 # Put defined MCU peripherals here (in alphabetical order)
 FEATURES_PROVIDED += periph_adc
+FEATURES_PROVIDED += periph_dac
 FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_pwm
 FEATURES_PROVIDED += periph_rtc
diff --git a/boards/samd21-xpro/include/periph_conf.h b/boards/samd21-xpro/include/periph_conf.h
index 33e30efa36..5db595e851 100644
--- a/boards/samd21-xpro/include/periph_conf.h
+++ b/boards/samd21-xpro/include/periph_conf.h
@@ -347,6 +347,15 @@ static const adc_conf_chan_t adc_channels[] = {
 #define ADC_NUMOF                           ARRAY_SIZE(adc_channels)
 /** @} */
 
+/**
+ * @name DAC configuration
+ * @{
+ */
+#define DAC_CLOCK           SAM0_GCLK_1MHZ
+                            /* use Vcc as reference voltage */
+#define DAC_VREF            DAC_CTRLB_REFSEL_AVCC
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif