EFM32: dma_config_t needs to be only 16-bits for now

1 files changed, 38 insertions, 37 deletions

diff --git a/nuttx/arch/arm/src/efm32/efm32_dma.h b/nuttx/arch/arm/src/efm32/efm32_dma.h
index a0bd5cc0c..ee3fb02aa 100644
--- a/nuttx/arch/arm/src/efm32/efm32_dma.h
+++ b/nuttx/arch/arm/src/efm32/efm32_dma.h
@@ -53,7 +53,8 @@
  * Pre-processor Definitions
  ************************************************************************************/
 
-/* Bit encoded input parameter to efm32_channel()
+/* Bit encoded input parameter to efm32_channel().  These encodings must fit in the
+ * an unsigned integer of type dma_config_t.
  *
  * Current limitations/assumptions in the encoding:
  *
@@ -76,9 +77,9 @@
 #  define EFM32_DMA_XFERSIZE_SHIFT_HWORD  (1 << EFM32_DMA_SOURCSEL_SHIFT)
 #  define EFM32_DMA_XFERSIZE_SHIFT_WORD   (2 << EFM32_DMA_SOURCSEL_SHIFT)
 
-#define EFM32_DMA_SINGLE_MASK            (1 << 12) /* Bit 12: Single or Buffer full request */
-#  define EFM32_DMA_SINGLE               (1 << 12) /*         1=Buffer full request */
-#  define EFM32_DMA_BUFFER_FULL          (0)       /*         0=Buffer full request */
+#define EFM32_DMA_SINGLE_MASK             (1 << 12) /* Bit 12: Single or Buffer full request */
+#  define EFM32_DMA_SINGLE                (1 << 12) /*         1=Buffer full request */
+#  define EFM32_DMA_BUFFER_FULL           (0)       /*         0=Buffer full request */
 
 /************************************************************************************
  * Public Types
@@ -132,9 +133,12 @@ struct efm32_dmaregs_s
 };
 #endif
 
-/* Type of 'config' argument passed to efm32_rxdmasetup() and efm32_txdmasetup */
+/* Type of 'config' argument passed to efm32_rxdmasetup() and efm32_txdmasetup.
+ * See EFM32_DMA_* encodings above.  If these encodings exceed 16-bits, then this
+ * should be changed to a uint32_t.
+ */
 
-typedef uint32_t dma_config_t;
+typedef uint16_t dma_config_t;
 
 /************************************************************************************
  * Public Data
@@ -155,16 +159,15 @@ extern "C"
  * Public Function Prototypes
  ************************************************************************************/
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmachannel
  *
  * Description:
- *   Allocate a DMA channel.  This function gives the caller mutually
- *   exclusive access to a DMA channel.
+ *   Allocate a DMA channel.  This function gives the caller mutually exclusive
+ *   access to a DMA channel.
  *
- *   If no DMA channel is available, then efm32_dmachannel() will wait
- *   until the holder of a channel relinquishes the channel by calling
- *   efm32_dmafree().
+ *   If no DMA channel is available, then efm32_dmachannel() will wait until the
+ *   holder of a channel relinquishes the channel by calling efm32_dmafree().
  *
  * Input parameters:
  *   None
@@ -173,22 +176,21 @@ extern "C"
  *   This function ALWAYS returns a non-NULL, void* DMA channel handle.
  *
  * Assumptions:
- *   - The caller can wait for a DMA channel to be freed if it is not
- *     available.
+ *   - The caller can wait for a DMA channel to be freed if it is not available.
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 DMA_HANDLE efm32_dmachannel(void);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmafree
  *
  * Description:
- *   Release a DMA channel.  If another thread is waiting for this DMA channel
- *   in a call to efm32_dmachannel, then this function will re-assign the
- *   DMA channel to that thread and wake it up.  NOTE:  The 'handle' used
- *   in this argument must NEVER be used again until efm32_dmachannel() is
- *   called again to re-gain access to the channel.
+ *   Release a DMA channel.  If another thread is waiting for this DMA channel in a
+ *   call to efm32_dmachannel, then this function will re-assign the DMA channel to
+ *   that thread and wake it up.  NOTE:  The 'handle' used in this argument must
+ *   NEVER be used again until efm32_dmachannel() is called again to re-gain access
+ *   to the channel.
  *
  * Returned Value:
  *   None
@@ -197,11 +199,11 @@ DMA_HANDLE efm32_dmachannel(void);
  *   - The caller holds the DMA channel.
  *   - There is no DMA in progress
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 void efm32_dmafree(DMA_HANDLE handle);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_rxdmasetup
  *
  * Description:
@@ -214,12 +216,12 @@ void efm32_dmafree(DMA_HANDLE handle);
  *            configured transfer size.
  *   config - Channel configuration selections
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 void efm32_rxdmasetup(DMA_HANDLE handle, uintptr_t paddr, uintptr_t maddr,
                       size_t nbytes, dma_config_t config);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_txdmasetup
  *
  * Description:
@@ -232,12 +234,12 @@ void efm32_rxdmasetup(DMA_HANDLE handle, uintptr_t paddr, uintptr_t maddr,
  *            configured transfer size.
  *   config - Channel configuration selections
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 void efm32_txdmasetup(DMA_HANDLE handle, uintptr_t paddr, uintptr_t maddr,
                       size_t nbytes, dma_config_t config);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmastart
  *
  * Description:
@@ -247,26 +249,25 @@ void efm32_txdmasetup(DMA_HANDLE handle, uintptr_t paddr, uintptr_t maddr,
  *   - DMA handle allocated by efm32_dmachannel()
  *   - No DMA in progress
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 void efm32_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmastop
  *
  * Description:
- *   Cancel the DMA.  After efm32_dmastop() is called, the DMA channel is
- *   reset and efm32_dmasetup() must be called before efm32_dmastart() can be
- *   called again
+ *   Cancel the DMA.  After efm32_dmastop() is called, the DMA channel is reset and
+ *   efm32_dmasetup() must be called before efm32_dmastart() can be  called again
  *
  * Assumptions:
  *   - DMA handle allocated by efm32_dmachannel()
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 void efm32_dmastop(DMA_HANDLE handle);
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmasample
  *
  * Description:
@@ -275,7 +276,7 @@ void efm32_dmastop(DMA_HANDLE handle);
  * Assumptions:
  *   - DMA handle allocated by efm32_dmachannel()
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 #ifdef CONFIG_DEBUG_DMA
 void efm32_dmasample(DMA_HANDLE handle, struct efm32_dmaregs_s *regs);
@@ -283,7 +284,7 @@ void efm32_dmasample(DMA_HANDLE handle, struct efm32_dmaregs_s *regs);
 #  define efm32_dmasample(handle,regs)
 #endif
 
-/****************************************************************************
+/************************************************************************************
  * Name: efm32_dmadump
  *
  * Description:
@@ -292,7 +293,7 @@ void efm32_dmasample(DMA_HANDLE handle, struct efm32_dmaregs_s *regs);
  * Assumptions:
  *   - DMA handle allocated by efm32_dmachannel()
  *
- ****************************************************************************/
+ ************************************************************************************/
 
 #ifdef CONFIG_DEBUG_DMA
 void efm32_dmadump(DMA_HANDLE handle, const struct efm32_dmaregs_s *regs,