Open1788 SDCard DMA works

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5805 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -4478,3 +4478,7 @@
 	  logic to extend directory clusters for the case of long file names
 	  but also include a few important general fixes (such as for storing
 	  32 bit FAT values) (2013-03-31).
+	* arch/arm/src/lpc17xx/lpc17_gdma.c and lpc17_sdcard.c:  SD card DMA
+	  is now functional.  Thre may be some issues with DMA from CPU SRAM
+	  which is apparently disabled in sleep mode; up_idle() always enters
+	  sleep mode (2013-03-31).

arch/arm/src/lpc17xx/lpc17_gpdma.c

@@ -247,6 +247,10 @@ void weak_function up_dmainitialize(void)
     {
       up_enable_irq(LPC17_IRQ_GPDMA);
     }
+
+  /* Enable the DMA controller (for little endian operation) */
+
+  putreg32(DMA_CONFIG_E, LPC17_DMA_CONFIG);
 }
 
 /****************************************************************************