msp_exp430f5529lp: Implement enough functionality for board_test.

hw/bsp/msp_exp430f5529lp/msp_exp430f5529lp.c

@@ -36,15 +36,66 @@
 #define BUTTON_PIN            BIT1
 #define BUTTON_STATE_ACTIVE   1
 
-
 static void SystemClock_Config(void)
 {
+  WDTCTL = WDTPW + WDTHOLD; // Disable watchdog.
 
+  // Increase VCore to level 2- required for 16 MHz operation on this MCU.
+  PMMCTL0 = PMMPW + PMMCOREV_2;
+
+  UCSCTL3 = SELREF__XT2CLK; // FLL is fed by XT2.
+
+  // XT1 used for ACLK (default- not used in this demo)
+  P5SEL |= BIT4; // Required to enable XT1
+  // Loop until XT1 fault flag is cleared.
+  do
+  {
+    UCSCTL7 &= ~XT1LFOFFG;
+  }while(UCSCTL7 & XT1LFOFFG);
+
+  // XT2 is 4 MHz an external oscillator, use PLL to boost to 16 MHz.
+  P5SEL |= BIT2; // Required to enable XT2.
+  // Loop until XT2 fault flag is cleared
+  do
+  {
+    UCSCTL7 &= ~XT2OFFG;
+  }while(UCSCTL7 & XT2OFFG);
+
+  // Kickstart the DCO into the correct frequency range, otherwise a
+  // fault will occur.
+  // FIXME: DCORSEL_6 should work according to datasheet params, but generates
+  // a fault. I am not sure why it faults.
+  UCSCTL1 = DCORSEL_7;
+  UCSCTL2 = FLLD_2 + 3; // DCO freq = D * (N + 1) * (FLLREFCLK / n)
+                        // DCOCLKDIV freq = (N + 1) * (FLLREFCLK / n)
+                        // N = 3, D = 2, thus DCO freq = 32 MHz.
+
+  // MCLK configured for 16 MHz using XT2.
+  // SMCLK configured for 8 MHz using XT2.
+  UCSCTL4 |= SELM__DCOCLKDIV + SELS__DCOCLKDIV;
+  UCSCTL5 |= DIVM__16 + DIVS__2;
+
+  // Now wait till everything's stabilized.
+  do
+  {
+    UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);
+    SFRIFG1 &= ~OFIFG;
+  }while(SFRIFG1 & OFIFG);
+
+  // Configure Timer A to use SMCLK as a source. Count 1000 ticks at 1 MHz.
+  TA0CCTL0 |= CCIE;
+  TA0CCR0 = 999; // 1000 ticks.
+  TA0CTL |= TASSEL_2 + ID_3 + MC__UP; // Use SMCLK, divide by 8, start timer.
 }
 
 void board_init(void)
 {
   SystemClock_Config();
+  __bis_SR_register(GIE); // Enable interrupts.
+
+  P1DIR |= LED_PIN; // LED output.
+  P1REN |= BUTTON_PIN; // Internal resistor enable.
+  P1OUT |= BUTTON_PIN; // Pullup.
 }
 
 //--------------------------------------------------------------------+
@@ -53,12 +104,19 @@ void board_init(void)
 
 void board_led_write(bool state)
 {
-
+  if(state)
+  {
+    LED_PORT |= LED_PIN;
+  }
+  else
+  {
+    LED_PORT &= ~LED_PIN;
+  }
 }
 
 uint32_t board_button_read(void)
 {
-  return 0;
+  return (P1IN & BIT1);
 }
 
 #if CFG_TUSB_OS  == OPT_OS_NONE
@@ -66,6 +124,7 @@ volatile uint32_t system_ticks = 0;
 void __attribute__ ((interrupt(TIMER0_A0_VECTOR))) TIMER0_A0_ISR (void)
 {
   system_ticks++;
+  // TAxCCR0 CCIFG resets itself as soon as interrupt is invoked.
 }
 
 uint32_t board_millis(void)