Merge pull request #4814 from gebart/pr/kinetis-dac

cpu/kinetis_common: Add periph/dac implementation

boards/frdm-k64f/include/periph_conf.h

@@ -117,9 +117,17 @@ static const adc_conf_t adc_config[] = {
 /** @} */
 
 /**
-* @name PWM configuration
-* @{
-*/
+ * @name DAC configuration
+ * @{
+ */
+#define DAC_CONFIG {}
+#define DAC_NUMOF  0
+/** @} */
+
+/**
+ * @name PWM configuration
+ * @{
+ */
 #define PWM_NUMOF                    (1U)
 #define PWM_0_EN                     1
 #define PWM_MAX_CHANNELS             8

boards/mulle/Makefile.features

@@ -1,6 +1,7 @@
 # Put defined MCU peripherals here (in alphabetical order)
 FEATURES_PROVIDED += periph_adc
 FEATURES_PROVIDED += periph_cpuid
+FEATURES_PROVIDED += periph_dac
 FEATURES_PROVIDED += periph_gpio
 FEATURES_PROVIDED += periph_hwrng
 FEATURES_PROVIDED += periph_i2c

boards/mulle/include/periph_conf.h

@@ -135,7 +135,6 @@ extern "C"
 
 /** @} */
 
-
 /**
  * @name ADC configuration
  * @{
@@ -164,6 +163,18 @@ static const adc_conf_t adc_config[] = {
 #define ADC_NUMOF           (sizeof(adc_config) / sizeof(adc_config[0]))
 /** @} */
 
+/**
+ * @name DAC configuration
+ * @{
+ */
+
+#define DAC_CONFIG { \
+    { DAC0, (uint32_t volatile *)BITBAND_REGADDR(SIM->SCGC2, SIM_SCGC2_DAC0_SHIFT) }, \
+  }
+#define DAC_NUMOF 1
+
+/** @} */
+
 /**
  * @name PWM configuration
  * @{

boards/pba-d-01-kw2x/include/periph_conf.h

@@ -133,6 +133,14 @@ static const adc_conf_t adc_config[] = {
 #define ADC_NUMOF           (sizeof(adc_config) / sizeof(adc_config[0]))
 /** @} */
 
+/**
+ * @name DAC configuration
+ * @{
+ */
+#define DAC_CONFIG {}
+#define DAC_NUMOF  0
+/** @} */
+
 /**
  * @name PWM configuration
  * @{

cpu/kinetis_common/include/periph_cpu.h

@@ -148,6 +148,16 @@ typedef struct {
     uint8_t chan;           /**< ADC channel */
 } adc_conf_t;
 
+/**
+ * @brief   CPU specific DAC configuration
+ */
+typedef struct {
+    /** DAC device base pointer */
+    DAC_Type *dev;
+    /** Pointer to module clock gate bit in bitband region, use BITBAND_REGADDR() */
+    uint32_t volatile *clk_gate;
+} dac_conf_t;
+
 /**
  * @brief   CPU internal function for initializing PORTs
  *

cpu/kinetis_common/periph/dac.c

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2016 Eistec AB
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup     cpu_kinetis_common_dac
+ *
+ * @{
+ *
+ * @file
+ * @brief       Low-level DAC driver implementation
+ *
+ * This driver uses the 12-bit in-CPU DAC module. The 6-bit digital-to-analog
+ * converter inside the CMP module is _not_ used by this implementation.
+ *
+ * @author      Joakim Nohlgård <joakim.nohlgard@eistec.se>
+ *
+ * @}
+ */
+
+#include <stdint.h>
+
+#include "cpu.h"
+#include "periph/dac.h"
+#include "periph_conf.h"
+
+static const dac_conf_t dac_config[] = DAC_CONFIG;
+
+int8_t dac_init(dac_t line)
+{
+    DAC_Type *dac;
+    if ((unsigned int)line >= DAC_NUMOF) {
+        return -1;
+    }
+
+    dac = dac_config[line].dev;
+
+    /* Enable module clock */
+    *(dac_config[line].clk_gate) = 1;
+
+    /* Select VDDA as voltage reference */
+    dac->C0 = (DAC_C0_DACRFS_MASK);
+
+    /* Disable DMA and buffering */
+    dac->C1 = 0;
+    dac->C2 = 0;
+
+    /* Power on */
+    dac_poweron(line);
+
+    /* Set output value to zero */
+    dac_set(line, 0);
+    return 0;
+}
+
+void dac_set(dac_t line, uint16_t value)
+{
+    DAC_Type *dac;
+
+    if ((unsigned int)line >= DAC_NUMOF) {
+        return;
+    }
+
+    dac = dac_config[line].dev;
+
+    /* Scale to 12 bit */
+    value = value >> ((sizeof(value) * 8) - 12);
+
+    dac->DAT[0].DATH = ((value >> 8) & 0xff);
+    dac->DAT[0].DATL = (value & 0xff);
+}
+
+static inline void _dac_set_power(dac_t line, uint8_t value)
+{
+    DAC_Type *dac;
+
+    if ((unsigned int)line >= DAC_NUMOF) {
+        return;
+    }
+
+    dac = dac_config[line].dev;
+
+    BITBAND_REG8(dac->C0, DAC_C0_DACEN_SHIFT) = value;
+}
+
+void dac_poweron(dac_t line)
+{
+    _dac_set_power(line, 1);
+}
+
+void dac_poweroff(dac_t line)
+{
+    _dac_set_power(line, 0);
+}