More STM32 DAC driver logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4186 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 236 insertions, 12 deletions

diff --git a/nuttx/arch/arm/src/stm32/stm32_dac.c b/nuttx/arch/arm/src/stm32/stm32_dac.c
index a7d46707c..09cdb76f1 100644
--- a/nuttx/arch/arm/src/stm32/stm32_dac.c
+++ b/nuttx/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 */
 
@@ -78,8 +77,32 @@
 #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
  ****************************************************************************/
@@ -110,16 +138,79 @@ 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 =
+{
+  .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_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
  *
  * Description:
@@ -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.
  *
  ****************************************************************************/
 
@@ -256,6 +356,82 @@ static int  dac_ioctl(FAR struct dac_dev_s *dev, int cmd, unsigned long arg)
 }
 
 /****************************************************************************
+ * 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 */