Update SAMA5D3x-EK board configuration to support on-board UART connections, LEDs, and push buttons

configs/sama5d3x-ek/include/board.h

@@ -145,17 +145,77 @@
 #define BOARD_FWS                  3
 
 /* LED definitions ******************************************************************/
+/* There are two LEDs on the SAMA5D3 series-CM board that can be controlled
+ * by software.  A  blue LED is controlled via GPIO pins.  A red LED normally
+ * provides an indication that power is supplied to the board but can also
+ * be controlled via software.
+ *
+ *   PE25.  This blue LED is pulled high and is illuminated by pulling PE25
+ *   low.
+ *
+ *   PE24.  The red LED is also pulled high but is driven by a transistor so
+ *   that it is illuminated when power is applied even if PE24 is not
+ *   configured as an output.  If PE24 is configured as an output, then the
+ *   LCD is illuminated by a low output.
+ */
 
-#define LED_STARTED       0
-#define LED_HEAPALLOCATE  1
-#define LED_IRQSENABLED   2
-#define LED_STACKCREATED  3
-#define LED_INIRQ         4
-#define LED_SIGNAL        5
-#define LED_ASSERTION     6
-#define LED_PANIC         7
+/* LED index values for use with sam_setled() */
+
+#define BOARD_BLUE        0
+#define BOARD_RED         1
+#define BOARD_NLEDS       2
+
+/* LED bits for use with sam_setleds() */
+
+#define BOARD_BLUE_BIT    (1 << BOARD_BLUE)
+#define BOARD_RED_BIT     (1 << BOARD_RED)
+
+
+/* These LEDs are not used by the board port unless CONFIG_ARCH_LEDS is
+ * defined.  In that case, the usage by the board port is defined in
+ * include/board.h and src/sam_leds.c. The LEDs are used to encode OS-related
+ * events as follows:
+ *
+ *      SYMBOL            Val    Meaning                     LED state
+ *                                                         Blue     Red
+ *      ----------------- ---   -----------------------  -------- --------   */
+#define LED_STARTED       0  /* NuttX has been started     OFF      OFF      */
+#define LED_HEAPALLOCATE  0  /* Heap has been allocated    OFF      OFF      */
+#define LED_IRQSENABLED   0  /* Interrupts enabled         OFF      OFF      */
+#define LED_STACKCREATED  1  /* Idle stack created         ON       OFF      */
+#define LED_INIRQ         2  /* In an interrupt              No change       */
+#define LED_SIGNAL        2  /* In a signal handler          No change       */
+#define LED_ASSERTION     2  /* An assertion failed          No change       */
+#define LED_PANIC         3  /* The system has crashed     OFF      Blinking */
+#undef  LED_IDLE             /* MCU is is sleep mode         Not used        */
+
+/* Thus if the blue LED is statically on, NuttX has successfully booted and
+ * is, apparently, running normmally.  If the red is flashing at
+ * approximately 2Hz, then a fatal error has been detected and the system
+ * has halted.
+ */
 
 /* Button definitions ***************************************************************/
+/* There are five push button switches on the SAMA5D3X-EK base board:
+ *
+ *   1. One Reset, board reset (BP1)
+ *   2. One Wake up, push button to bring the processor out of low power mode
+ *     (BP2)
+ *   3. One User momentary Push Button
+ *   4. One Disable CS Push Button
+ *
+ * Only the momentary push button is controllable by software (labeled
+ * "PB_USER1" on the board):
+ *
+ *   - PE27.  Pressing the switch connect PE27 to grounded.  Therefore, PE27
+ *     must be pulled high internally.  When the button is pressed the SAMA5
+ *     will sense "0" is on PE27.
+ */
+
+#define BUTTON_USER1      0
+#define NUM_BUTTONS       1
+
+#define BUTTON_USER1_BIT  (1 << BUTTON_USER1)
 
 /************************************************************************************
  * Public Data