Merge #19887 #19898

19887: cpu/efm32/periph: add DAC support for EFM32 Series 1 (VDAC) r=aabadie a=gschorcht

### Contribution description

This PR provides a small change for `periph_dac` to support the VDACs of EFM32 Series 1 MCUs. It was tested with `sltb009a` board for which this PR includes the DAC configuration.

### Testing procedure

`tests/periph/dac` should work for the `sltb009a` board. I've tested it already.
```
BOARD=sltb009a make -j8 -C tests/periph/dac flash
```

### Issues/PRs references

Depends on PR #19886 

19898: tests/net/gcoap_fileserver: disable test on CI r=aabadie a=benpicco




Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
Co-authored-by: Benjamin Valentin <benjamin.valentin@ml-pa.com>

boards/sltb009a/Kconfig

@@ -13,6 +13,7 @@ config BOARD_SLTB009A
     select BOARD_COMMON_SILABS
     select CPU_MODEL_EFM32GG12B810F1024GM64
     select HAS_PERIPH_ADC
+    select HAS_PERIPH_DAC
     select HAS_PERIPH_I2C
     select HAS_PERIPH_RTC
     select HAS_PERIPH_RTT

boards/sltb009a/Makefile.features

@@ -4,6 +4,7 @@ CPU_MODEL = efm32gg12b810f1024gm64
 
 # Put defined MCU peripherals here (in alphabetical order)
 FEATURES_PROVIDED += periph_adc
+FEATURES_PROVIDED += periph_dac
 FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_rtc
 FEATURES_PROVIDED += periph_rtt

boards/sltb009a/include/periph_conf.h

@@ -80,6 +80,29 @@ static const adc_chan_conf_t adc_channel_config[] = {
 #define ADC_NUMOF           ARRAY_SIZE(adc_channel_config)
 /** @} */
 
+/**
+ * @name    DAC configuration
+ * @{
+ */
+static const dac_conf_t dac_config[] = {
+    {
+        .dev = VDAC0,
+        .ref = vdacRefAvdd,
+        .cmu = cmuClock_VDAC0,
+    },
+};
+
+static const dac_chan_conf_t dac_channel_config[] = {
+    {
+        .dev = 0,
+        .index = 0,
+    },
+};
+
+#define DAC_DEV_NUMOF       ARRAY_SIZE(dac_config)
+#define DAC_NUMOF           ARRAY_SIZE(dac_channel_config)
+/** @} */
+
 /**
  * @name    I2C configuration
  * @{

cpu/efm32/families/efm32gg12b/system.c

@@ -29,6 +29,7 @@
  ******************************************************************************/
 
 #include <stdint.h>
+#include "periph_conf.h"
 #include "em_device.h"
 
 /*******************************************************************************

cpu/efm32/include/periph_cpu.h

@@ -40,6 +40,8 @@
 #include "em_rtc.h"
 #if defined(_SILICON_LABS_32B_SERIES_0)
 #include "em_dac.h"
+#elif defined (_SILICON_LABS_32B_SERIES_1) || defined(_SILICON_LABS_32B_SERIES_2)
+#include "em_vdac.h"
 #endif
 
 #ifdef __cplusplus
@@ -90,6 +92,24 @@ typedef struct {
     uint8_t dev;            /**< device index */
     uint8_t index;          /**< channel index */
 } dac_chan_conf_t;
+
+#elif defined(VDAC_COUNT) && VDAC_COUNT > 0
+/**
+ * @brief   DAC device configuration (VDAC configuration of EFM32 Series 1)
+ */
+typedef struct {
+    VDAC_TypeDef *dev;      /**< DAC device used */
+    VDAC_Ref_TypeDef ref;   /**< DAC voltage reference */
+    CMU_Clock_TypeDef cmu;  /**< the device CMU channel */
+} dac_conf_t;
+
+/**
+ * @brief   DAC channel configuration (VDAC configuration of EFM32 Series 1)
+ */
+typedef struct {
+    uint8_t dev;            /**< device index */
+    uint8_t index;          /**< channel index */
+} dac_chan_conf_t;
 #endif
 
 /**

cpu/efm32/periph/dac.c

@@ -20,6 +20,7 @@
  */
 
 #include "cpu.h"
+#include "macros/units.h"
 
 #include "periph_conf.h"
 #include "periph/dac.h"
@@ -27,6 +28,23 @@
 #include "em_cmu.h"
 #if defined(DAC_COUNT) && DAC_COUNT > 0
 #include "em_dac.h"
+#elif defined(VDAC_COUNT) && VDAC_COUNT > 0
+#include "em_vdac.h"
+#endif
+
+/* DAC implementation can be used for VDAC by mapping the symbols */
+#if defined(VDAC_COUNT) && VDAC_COUNT > 0
+
+#define DAC_INIT_DEFAULT        VDAC_INIT_DEFAULT
+#define DAC_INITCHANNEL_DEFAULT VDAC_INITCHANNEL_DEFAULT
+
+#define DAC_Init_TypeDef        VDAC_Init_TypeDef
+#define DAC_InitChannel_TypeDef VDAC_InitChannel_TypeDef
+#define DAC_Reset               VDAC_Reset
+#define DAC_Init                VDAC_Init
+#define DAC_InitChannel         VDAC_InitChannel
+#define DAC_ChannelOutputSet    VDAC_ChannelOutputSet
+
 #endif
 
 int8_t dac_init(dac_t line)
@@ -45,7 +63,11 @@ int8_t dac_init(dac_t line)
     /* reset and initialize peripheral */
     DAC_Init_TypeDef init = DAC_INIT_DEFAULT;
 
+#if defined(VDAC_COUNT)
     init.reference = dac_config[dev].ref;
+    init.prescaler = VDAC_PrescaleCalc(MHZ(1000000), true, 0);
+#endif
+
     DAC_Reset(dac_config[dev].dev);
     DAC_Init(dac_config[dev].dev, &init);
 

tests/net/gcoap_fileserver/Makefile

@@ -21,10 +21,12 @@ USEMODULE += vfs_auto_format
 USEMODULE += hashes
 USEMODULE += shell_cmd_md5sum
 
+# This integration test uncovers a bug somwehere in our stack, but there
+# are currently no resources to debug it, so blacklist it to keep CI running
+TEST_ON_CI_BLACKLIST += all
+
 # automated test only works on native
-TEST_ON_CI_WHITELIST += native
-# FIXME: for some reason the test fails very often when built with clang
-TOOLCHAINS_BLACKLIST += llvm
+# TEST_ON_CI_WHITELIST += native
 
 # use small blocksize for test to increase chance for errors
 CFLAGS += -DCONFIG_NANOCOAP_BLOCKSIZE_DEFAULT=COAP_BLOCKSIZE_16