diff --git a/arch/arm/src/lpc17xx/lpc17_dac.c b/arch/arm/src/lpc17xx/lpc17_dac.c
index 4f9a9332c3..13ac212f6e 100644
--- a/arch/arm/src/lpc17xx/lpc17_dac.c
+++ b/arch/arm/src/lpc17xx/lpc17_dac.c
@@ -65,7 +65,7 @@
 #include "lpc17_pinconn.h"
 #include "lpc17_dac.h"
 
-#if defined(CONFIG_LPC17_DAC)
+#ifdef CONFIG_LPC17_DAC
 
 /****************************************************************************
  * Private Types
@@ -91,17 +91,17 @@ static int  dac_interrupt(int irq, void *context);
 
 static const struct dac_ops_s g_dacops =
 {
-    .ao_reset =dac_reset,
-    .ao_setup = dac_setup,
-    .ao_shutdown = dac_shutdown,
-    .ao_txint = dac_txint,
-    .ao_send = dac_send,
-    .ao_ioctl = dac_ioctl,
+  .ao_reset =dac_reset,
+  .ao_setup = dac_setup,
+  .ao_shutdown = dac_shutdown,
+  .ao_txint = dac_txint,
+  .ao_send = dac_send,
+  .ao_ioctl = dac_ioctl,
 };
 
 static struct dac_dev_s g_dacdev =
 {
-    .ad_ops = &g_dacops,
+  .ad_ops = &g_dacops,
 };
 
 /****************************************************************************
@@ -114,22 +114,21 @@ static struct dac_dev_s g_dacdev =
 
 static void dac_reset(FAR struct dac_dev_s *dev)
 {
-    irqstate_t flags;
-    uint32_t regval;
+  irqstate_t flags;
+  uint32_t regval;
     
-    flags = irqsave();
+  flags = irqsave();
 
-    regval  = getreg32(LPC17_SYSCON_PCLKSEL0);
-    regval &= ~SYSCON_PCLKSEL0_DAC_MASK;
-    regval |= (SYSCON_PCLKSEL_CCLK8 << SYSCON_PCLKSEL0_DAC_SHIFT);
-    putreg32(regval, LPC17_SYSCON_PCLKSEL0);
+  regval  = getreg32(LPC17_SYSCON_PCLKSEL0);
+  regval &= ~SYSCON_PCLKSEL0_DAC_MASK;
+  regval |= (SYSCON_PCLKSEL_CCLK8 << SYSCON_PCLKSEL0_DAC_SHIFT);
+  putreg32(regval, LPC17_SYSCON_PCLKSEL0);
 
-    //putreg32(DAC_CTRL_DBLBUFEN,LPC17_DAC_CTRL); ?
+  //putreg32(DAC_CTRL_DBLBUFEN,LPC17_DAC_CTRL); ?
 
-    lpc17_configgpio(GPIO_AOUT);
-    
-    irqrestore(flags);
+  lpc17_configgpio(GPIO_AOUT);
 
+  irqrestore(flags);
 }
 
 /* Configure the DAC. This method is called the first time that the DAC
@@ -140,7 +139,7 @@ static void dac_reset(FAR struct dac_dev_s *dev)
 
 static int  dac_setup(FAR struct dac_dev_s *dev)
 {
-    return OK;
+  return OK;
 }
 
 /* Disable the DAC.  This method is called when the DAC device is closed.
@@ -159,17 +158,17 @@ static void dac_txint(FAR struct dac_dev_s *dev, bool enable)
 
 static int  dac_send(FAR struct dac_dev_s *dev, FAR struct dac_msg_s *msg)
 {
-    putreg32((msg->am_data>>16)&0xfffff,LPC17_DAC_CR);
-    dac_txdone(&g_dacdev);
-    return 0;
+  putreg32((msg->am_data>>16)&0xfffff,LPC17_DAC_CR);
+  dac_txdone(&g_dacdev);
+  return 0;
 }
 
 /* All ioctl calls will be routed through this method */
 
 static int  dac_ioctl(FAR struct dac_dev_s *dev, int cmd, unsigned long arg)
 {
-    dbg("Fix me:Not Implemented\n");
-    return 0;
+  dbg("Fix me:Not Implemented\n");
+  return 0;
 }
 
 static int  dac_interrupt(int irq, void *context)
@@ -181,7 +180,7 @@ static int  dac_interrupt(int irq, void *context)
  ****************************************************************************/
 
 /****************************************************************************
- * Name: up_dacinitialize
+ * Name: lpc17_dacinitialize
  *
  * Description:
  *   Initialize the DAC
@@ -191,9 +190,10 @@ static int  dac_interrupt(int irq, void *context)
  *
  ****************************************************************************/
 
-FAR struct dac_dev_s *up_dacinitialize()
+FAR struct dac_dev_s *lpc17_dacinitialize(void)
 {
-    return &g_dacdev;
+  return &g_dacdev;
 }
-#endif
+
+#endif /* CONFIG_LPC17_DAC */
 
diff --git a/arch/arm/src/lpc17xx/lpc17_internal.h b/arch/arm/src/lpc17xx/lpc17_internal.h
index aa2ddc4899..107200e4d3 100755
--- a/arch/arm/src/lpc17xx/lpc17_internal.h
+++ b/arch/arm/src/lpc17xx/lpc17_internal.h
@@ -609,7 +609,7 @@ EXTERN int lpc17_ssp1cmddata(FAR struct spi_dev_s *dev, enum spi_dev_e devid, bo
 #endif
 
 /****************************************************************************
- * Name: ssp_flush
+ * Name: spi_flush
  *
  * Description:
  *   Flush and discard any words left in the RX fifo.  This can be called
@@ -756,6 +756,21 @@ EXTERN void lpc17_dmadump(DMA_HANDLE handle, const struct lpc17_dmaregs_s *regs,
 #endif
 #endif
 
+/****************************************************************************
+ * Name: lpc17_dacinitialize
+ *
+ * Description:
+ *   Initialize the DAC
+ *
+ * Returned Value:
+ *   Valid dac device structure reference on succcess; a NULL on failure
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_LPC17_DAC
+EXTERN FAR struct dac_dev_s *lpc17_dacinitialize(void);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }
diff --git a/arch/arm/src/stm32/chip/stm32f103ze_pinmap.h b/arch/arm/src/stm32/chip/stm32f103ze_pinmap.h
index 3caf54279a..8446a24725 100644
--- a/arch/arm/src/stm32/chip/stm32f103ze_pinmap.h
+++ b/arch/arm/src/stm32/chip/stm32f103ze_pinmap.h
@@ -48,6 +48,65 @@
 
 /* Alternate Pin Functions: */
 
+/* ADC */
+
+#define GPIO_ADC1_IN0       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC1_IN1       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC1_IN2       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC1_IN3       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC1_IN4       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN4)
+#define GPIO_ADC1_IN5       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN5)
+#define GPIO_ADC1_IN6       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN6)
+#define GPIO_ADC1_IN7       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN7)
+#define GPIO_ADC1_IN8       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTB|GPIO_PIN0)
+#define GPIO_ADC1_IN9       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTB|GPIO_PIN1)
+#define GPIO_ADC1_IN10      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC1_IN11      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC1_IN12      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC1_IN13      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN3)
+#define GPIO_ADC1_IN14      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN4)
+#define GPIO_ADC1_IN15      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN5)
+
+#define GPIO_ADC2_IN0       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC2_IN1       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC2_IN2       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC2_IN3       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC2_IN4       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN4)
+#define GPIO_ADC2_IN5       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN5)
+#define GPIO_ADC2_IN6       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN6)
+#define GPIO_ADC2_IN7       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN7)
+#define GPIO_ADC2_IN8       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTB|GPIO_PIN0)
+#define GPIO_ADC2_IN9       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTB|GPIO_PIN1)
+#define GPIO_ADC2_IN10      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC2_IN11      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC2_IN12      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC2_IN13      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN3)
+#define GPIO_ADC2_IN14      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN4)
+#define GPIO_ADC2_IN15      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN5)
+
+#define GPIO_ADC3_IN0       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC3_IN1       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC3_IN2       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC3_IN3       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC3_IN4       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN6)
+#define GPIO_ADC3_IN5       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN7)
+#define GPIO_ADC3_IN6       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN8)
+#define GPIO_ADC3_IN7       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN9)
+#define GPIO_ADC3_IN8       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN10)
+#define GPIO_ADC3_IN10      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC3_IN11      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC3_IN12      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC3_IN13      (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTC|GPIO_PIN3)
+
+/* DAC - "Once the DAC channelx is enabled, the corresponding GPIO pin
+ * (PA4 or PA5) is automatically connected to the analog converter output
+ * (DAC_OUTx). In order to avoid parasitic consumption, the PA4 or PA5 pin
+ * should first be configured to analog (AIN)."
+ */
+
+#define GPIO_DAC_OUT1       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PORTF|GPIO_PIN10)
+#define GPIO_DAC_OUT2       (GPIO_ALT|GPIO_CNF_ANALOGIN|GPIO_MODE_INPUT|GPIO_PIN10)
+
 /* TIMERS */
 
 #if defined(CONFIG_STM32_TIM1_FULL_REMAP)
diff --git a/arch/arm/src/stm32/chip/stm32f40xxx_pinmap.h b/arch/arm/src/stm32/chip/stm32f40xxx_pinmap.h
index cd0dbd1960..50c49cdbc6 100644
--- a/arch/arm/src/stm32/chip/stm32f40xxx_pinmap.h
+++ b/arch/arm/src/stm32/chip/stm32f40xxx_pinmap.h
@@ -68,6 +68,58 @@
  * pins in this file.
  */
 
+/* ADC */
+
+#define GPIO_ADC1_IN0         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC1_IN1         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC1_IN2         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC1_IN3         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC1_IN4         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN4)
+#define GPIO_ADC1_IN5         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN5)
+#define GPIO_ADC1_IN6         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN6)
+#define GPIO_ADC1_IN7         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN7)
+#define GPIO_ADC1_IN8         (GPIO_ANALOG|GPIO_PORTB|GPIO_PIN0)
+#define GPIO_ADC1_IN9         (GPIO_ANALOG|GPIO_PORTB|GPIO_PIN1)
+#define GPIO_ADC1_IN10        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC1_IN11        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC1_IN12        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC1_IN13        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN3)
+#define GPIO_ADC1_IN14        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN4)
+#define GPIO_ADC1_IN15        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN5)
+
+#define GPIO_ADC2_IN0         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC2_IN1         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC2_IN2         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC2_IN3         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC2_IN4         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN4)
+#define GPIO_ADC2_IN5         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN5)
+#define GPIO_ADC2_IN6         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN6)
+#define GPIO_ADC2_IN7         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN7)
+#define GPIO_ADC2_IN8         (GPIO_ANALOG|GPIO_PORTB|GPIO_PIN0)
+#define GPIO_ADC2_IN9         (GPIO_ANALOG|GPIO_PORTB|GPIO_PIN1)
+#define GPIO_ADC2_IN10        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC2_IN11        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC2_IN12        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC2_IN13        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN3)
+#define GPIO_ADC2_IN14        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN4)
+#define GPIO_ADC2_IN15        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN5)
+
+#define GPIO_ADC3_IN0         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN0)
+#define GPIO_ADC3_IN1         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN1)
+#define GPIO_ADC3_IN2         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN2)
+#define GPIO_ADC3_IN3         (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN3)
+#define GPIO_ADC3_IN4         (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN6)
+#define GPIO_ADC3_IN5         (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN7)
+#define GPIO_ADC3_IN6         (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN8)
+#define GPIO_ADC3_IN7         (GPIO_ANALOG|GPIO_PORT |GPIO_PIN9)
+#define GPIO_ADC3_IN9         (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN3)
+#define GPIO_ADC3_IN10        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN0)
+#define GPIO_ADC3_IN11        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN1)
+#define GPIO_ADC3_IN12        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN2)
+#define GPIO_ADC3_IN13        (GPIO_ANALOG|GPIO_PORTC|GPIO_PIN3)
+#define GPIO_ADC3_IN14        (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN4)
+#define GPIO_ADC3_IN15        (GPIO_ANALOG|GPIO_PORTF|GPIO_PIN5)
+
 /* CAN */
 
 #define GPIO_CAN1_RX_1        (GPIO_ALT|GPIO_AF9|GPIO_PORTA|GPIO_PIN11)
@@ -84,6 +136,15 @@
 #define GPIO_CAN2_TX_1        (GPIO_ALT|GPIO_AF9|GPIO_PORTB|GPIO_PIN13)
 #define GPIO_CAN2_TX_2        (GPIO_ALT|GPIO_AF9|GPIO_PORTB|GPIO_PIN6)
 
+/* DAC -" Once the DAC channelx is enabled, the corresponding GPIO pin
+ * (PA4 or PA5) is automatically connected to the analog converter output
+ * (DAC_OUTx). In order to avoid parasitic consumption, the PA4 or PA5 pin
+ * should first be configured to analog (AIN)".
+ */
+
+#define GPIO_DAC1_OUT          (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN4)
+#define GPIO_DAC2_OUT          (GPIO_ANALOG|GPIO_PORTA|GPIO_PIN5)
+
 /* Digital Camera Interface (DCMI) */
 
 #define GPIO_DCMI_D0_1        (GPIO_ALT|GPIO_AF13|GPIO_PORTA|GPIO_PIN9)
diff --git a/arch/arm/src/stm32/stm32_dac.c b/arch/arm/src/stm32/stm32_dac.c
index a7d46707c4..09cdb76f1c 100644
--- a/arch/arm/src/stm32/stm32_dac.c
+++ b/arch/arm/src/stm32/stm32_dac.c
@@ -61,9 +61,8 @@
 #ifdef CONFIG_DAC
 
 /****************************************************************************
- * Private Types
+ * Pre-processor Definitions
  ****************************************************************************/
-
 /* Configuration ************************************************************/
 /* Up to 2 DAC interfaces are supported */
 
@@ -77,9 +76,33 @@
 
 #if defined(CONFIG_STM32_DAC1) || defined(CONFIG_STM32_DAC2)
 
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* This structure represents the internal state of the single STM32 DAC block */
+
+struct stm32_dac_s
+{
+  uint8_t  init   : 1; /* True, the DAC block has been initialized */
+};
+
+/* This structure represents the internal state of one STM32 DAC channel */
+
+struct stm32_chan_s
+{
+  uint8_t  inuse  : 1; /* True, the driver is in use and not available */
+  uint8_t  intf;       /* DAC zero-based interface number (0 or 1) */
+};
+
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
+/* DAC Register access */
+
+static uint32_t dac_getreg(struct stm32_chan_s *chan, int offset);
+static void dac_putreg(struct stm32_chan_s *chan, int offset, uint32_t value);
+
 /* Interrupt handler */
 
 #ifdef CONFIG_STM32_STM32F40XX
@@ -96,6 +119,11 @@ static int  dac_send(FAR struct dac_dev_s *dev, FAR struct dac_msg_s *msg);
 static int  dac_ioctl(FAR struct dac_dev_s *dev, int cmd, unsigned long arg);
 static int  dac_interrupt(int irq, void *context);
 
+/* Initialization */
+
+static int  dac_chaninit(struct stm32_chan_s *chan);
+static int  dac_blockinit(void);
+
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -110,15 +138,78 @@ static const struct dac_ops_s g_dacops =
   .ao_ioctl    = dac_ioctl,
 };
 
-static struct dac_dev_s g_dacdev =
+#ifdef CONFIG_STM32_DAC1
+static struct stm32_chan_s g_dac1priv =
 {
-  .ad_ops = &g_dacops,
+  .intf       = 0;
+}
+
+static struct dac_dev_s g_dac1dev =
+{
+  .ad_ops  = &g_dacops,
+  .ad_priv = &g_dac1priv,
 };
+#endif
+
+#ifdef CONFIG_STM32_DAC2
+static struct stm32_chan_s g_dac2priv =
+{
+  .intf       = 1;
+}
+
+static struct dac_dev_s g_dac2dev =
+{
+  .ad_ops  = &g_dacops,
+  .ad_priv = &g_dac2priv,
+};
+#endif
+
+static struct stm32_dac_s g_dacblock; 
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: dac_getreg
+ *
+ * Description:
+ *   Read the value of an DAC register.
+ *
+ * Input Parameters:
+ *   chan - A reference to the DAC block status
+ *   offset - The offset to the register to read
+ *
+ * Returned Value:
+ *   The current contents of the specified register
+ *
+ ****************************************************************************/
+
+static uint32_t dac_getreg(struct stm32_chan_s *chan, int offset)
+{
+  return getreg32(chan->base + offset);
+}
+
+/****************************************************************************
+ * Name: dac_getreg
+ *
+ * Description:
+ *   Read the value of an DAC register.
+ *
+ * Input Parameters:
+ *   chan - A reference to the DAC block status
+ *   offset - The offset to the register to read
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void dac_putreg(struct stm32_chan_s *chan, int offset, uint32_t value)
+{
+  putreg32(value, chan->base + offset);
+}
+
 /****************************************************************************
  * Name: dac_interrupt
  *
@@ -129,6 +220,7 @@ static struct dac_dev_s g_dacdev =
  * Input Parameters:
  *
  * Returned Value:
+ *   OK
  *
  ****************************************************************************/
 
@@ -143,12 +235,15 @@ static int dac_interrupt(int irq, void *context)
  * Name: dac_reset
  *
  * Description:
- *   Reset the DAC device.  Called early to initialize the hardware. This
+ *   Reset the DAC channel.  Called early to initialize the hardware. This
  *   is called, before dac_setup() and on error conditions.
  *
+ *   NOTE:  DAC reset will reset both DAC channels!
+ *
  * Input Parameters:
  *
  * Returned Value:
+ *   None
  *
  ****************************************************************************/
 
@@ -156,11 +251,11 @@ static void dac_reset(FAR struct dac_dev_s *dev)
 {
   irqstate_t flags;
   uint32_t regval;
-    
-  flags = irqsave();
 
-# warning "Missing logic"
-    
+  flags   = irqsave();
+
+#warning "Missing logic"
+
   irqrestore(flags);
 }
 
@@ -176,6 +271,7 @@ static void dac_reset(FAR struct dac_dev_s *dev)
  * Input Parameters:
  *
  * Returned Value:
+ *   Zero on success; a negated errno value on failure.
  *
  ****************************************************************************/
 
@@ -195,6 +291,7 @@ static int dac_setup(FAR struct dac_dev_s *dev)
  * Input Parameters:
  *
  * Returned Value:
+ *   None
  *
  ****************************************************************************/
 
@@ -212,6 +309,7 @@ static void dac_shutdown(FAR struct dac_dev_s *dev)
  * Input Parameters:
  *
  * Returned Value:
+ *   None
  *
  ****************************************************************************/
 
@@ -229,6 +327,7 @@ static void dac_txint(FAR struct dac_dev_s *dev, bool enable)
  * Input Parameters:
  *
  * Returned Value:
+ *   Zero on success; a negated errno value on failure.
  *
  ****************************************************************************/
 
@@ -247,6 +346,7 @@ static int dac_send(FAR struct dac_dev_s *dev, FAR struct dac_msg_s *msg)
  * Input Parameters:
  *
  * Returned Value:
+ *   Zero on success; a negated errno value on failure.
  *
  ****************************************************************************/
 
@@ -255,6 +355,82 @@ static int  dac_ioctl(FAR struct dac_dev_s *dev, int cmd, unsigned long arg)
   return -ENOTTY;
 }
 
+/****************************************************************************
+ * Name: dac_ioctl
+ *
+ * Description:
+ *   All ioctl calls will be routed through this method.
+ *
+ * Input Parameters:
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+static int dac_chaninit(struct stm32_chan_s *chan)
+{
+  /* Is the selected channel already in-use? */
+
+  if (chan->inuse)
+    {
+      /* Yes.. then return EBUSY */
+
+      return -EBUSY;
+    }
+
+  /* Mark the DAC channel "in-use" */
+
+  chan->inuse = 1;
+  return OK;
+}
+
+/****************************************************************************
+ * Name: dac_ioctl
+ *
+ * Description:
+ *   All ioctl calls will be routed through this method.
+ *
+ * Input Parameters:
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+static int dac_blockinit(void)
+{
+  irqstate_t flags;
+  uint32_t regval;
+
+  /* Has the DMA block already been initialized? */
+
+  if (g_dacblock.init)
+    {
+      /* Yes.. then return success  We only have to do this once */
+
+      return OK;
+    }
+
+  /* Put the entire DAC block in reset state */
+
+  flags   = irqsave();
+  regval  = getreg32(STM32_RCC_APB1RSTR);
+  regval |= RCC_APB1RSTR_DACRST
+  putreg32(regval, STM32_RCC_APB1RSTR);
+
+  /* Take the DAC out of reset state */
+
+  regval &= ~RCC_APB1RSTR_DACRST
+  putreg32(regval, STM32_RCC_APB1RSTR);
+  irqrestore(flags);
+
+  /* Mark the DAC block as initialized */
+
+  g_dacblock.init = 1;
+  return OK;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -263,19 +439,67 @@ static int  dac_ioctl(FAR struct dac_dev_s *dev, int cmd, unsigned long arg)
  * Name: stm32_dacinitialize
  *
  * Description:
- *   Initialize the DAC
+ *   Initialize the DAC.
  *
  * Input Parameters:
  *   intf - The DAC interface number.
  *
  * Returned Value:
- *   Valid dac device structure reference on succcess; a NULL on failure
+ *   Valid dac device structure reference on succcess; a NULL on failure.
+ *
+ * Assumptions:
+ *   1. Clock to the DAC block has enabled,
+ *   2. Board-specific logic has already configured 
  *
  ****************************************************************************/
 
 FAR struct dac_dev_s *stm32_dacinitialize(int intf)
 {
-  return &g_dacdev;
+  FAR struct dac_dev_s    *dev;
+  FAR struct stm32_chan_s *chan;
+  int ret;
+  
+#ifdef CONFIG_STM32_DAC1
+  if (intf == 1)
+    {
+      avdbg("DAC1 Selected\n");
+      dev = &g_dacdev1;
+    }
+  else
+#endif
+#ifdef CONFIG_STM32_DAC2
+  if (intf == 2)
+    {
+      avdbg("DAC2 Selected\n");
+      dev = &g_dac2dev;
+    }
+  else
+#endif
+    {
+      adbg("No such DAC interface: %d\n", intf);
+      return NULL;
+    }
+
+  /* Make sure that the DAC block has been initialized */
+
+  ret = dac_blockinit();
+  if (ret < 0)
+    {
+      adbg("Failed to initialize the DAC block: %d\n", ret);
+      return ret;
+    }
+
+  /* Configure the selected DAC channel */
+
+  chan = dev->ad_priv;
+  ret  = dac_chaninit(chan);
+  if (ret < 0)
+    {
+      adbg("Failed to initialize DAC channel %d: %d\n", intf, ret);
+      return ret;
+    }
+
+  return dev;
 }
 
 #endif /* CONFIG_STM32_DAC1 || CONFIG_STM32_DAC2 */
diff --git a/arch/arm/src/stm32/stm32f10xxx_rcc.c b/arch/arm/src/stm32/stm32f10xxx_rcc.c
index 07dda8a592..9976e4870c 100644
--- a/arch/arm/src/stm32/stm32f10xxx_rcc.c
+++ b/arch/arm/src/stm32/stm32f10xxx_rcc.c
@@ -298,7 +298,7 @@ static inline void rcc_enableapb1(void)
   regval |= RCC_APB1ENR_PWREN;
 #endif
 
-#if CONFIG_STM32_DAC
+#ifdefined (CONFIG_STM32_DAC1) || defined(CONFIG_STM32_DAC2)
   /* DAC interface clock enable */
 
   regval |= RCC_APB1ENR_DACEN;
diff --git a/arch/arm/src/stm32/stm32f40xxx_rcc.c b/arch/arm/src/stm32/stm32f40xxx_rcc.c
index e06a84d655..4b8a16790e 100644
--- a/arch/arm/src/stm32/stm32f40xxx_rcc.c
+++ b/arch/arm/src/stm32/stm32f40xxx_rcc.c
@@ -431,7 +431,7 @@ static inline void rcc_enableapb1(void)
 
   regval |= RCC_APB1ENR_PWREN;
 
-#if CONFIG_STM32_DAC
+#ifdefined (CONFIG_STM32_DAC1) || defined(CONFIG_STM32_DAC2)
   /* DAC interface clock enable */
 
   regval |= RCC_APB1ENR_DACEN;