Initial project setup

managed_components/espressif__tinyusb/hw/bsp/msp430/family.c

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+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+/* metadata:
+   manufacturer: Texas Instruments
+*/
+
+#include "bsp/board_api.h"
+#include "board.h"
+#include "msp430.h"
+
+//--------------------------------------------------------------------+
+// Forward USB interrupt events to TinyUSB IRQ Handler
+//--------------------------------------------------------------------+
+void __attribute__ ((interrupt(USB_UBM_VECTOR))) USB_UBM_ISR(void)
+{
+  tud_int_handler(0);
+}
+
+//--------------------------------------------------------------------+
+// MACRO TYPEDEF CONSTANT ENUM
+//--------------------------------------------------------------------+
+
+uint32_t cnt = 0;
+
+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.
+
+  // Initialize USB power and PLL.
+  USBKEYPID = USBKEY;
+
+  // VUSB enabled automatically.
+  // Wait two milliseconds to stabilize, per manual recommendation.
+  uint32_t ms_elapsed = board_millis();
+  do
+  {
+    while((board_millis() - ms_elapsed) < 2);
+  }while(!(USBPWRCTL & USBBGVBV));
+
+  // USB uses XT2 (4 MHz) directly. Enable the PLL.
+  USBPLLDIVB |= USBPLL_SETCLK_4_0;
+  USBPLLCTL |= (UPFDEN | UPLLEN);
+
+  // Wait until PLL locks. Check every 2ms, per manual.
+  ms_elapsed = board_millis();
+  do
+  {
+    USBPLLIR &= ~USBOOLIFG;
+    while((board_millis() - ms_elapsed) < 2);
+  }while(USBPLLIR & USBOOLIFG);
+
+  USBKEYPID = 0;
+}
+
+uint32_t wait = 0;
+
+void board_init(void)
+{
+  __bis_SR_register(GIE); // Enable interrupts.
+  SystemClock_Config();
+
+  // Enable basic I/O.
+  P1DIR |= LED_PIN; // LED output.
+  P1REN |= BUTTON_PIN; // Internal resistor enable.
+  P1OUT |= BUTTON_PIN; // Pullup.
+
+  // Enable the backchannel UART (115200)
+  P4DIR |= BIT5;
+  P4SEL |= (BIT5 | BIT4);
+
+  UCA1CTL1 |= (UCSSEL__SMCLK | UCSWRST); // Hold in reset, use SMCLK.
+  UCA1BRW = 4;
+  UCA1MCTL |= (UCBRF_3 | UCBRS_5 | UCOS16); // Overampling mode, 115200 baud.
+                                            // Copied from manual.
+  UCA1CTL1 &= ~UCSWRST;
+
+  // Set up USB pins.
+  USBKEYPID = USBKEY;
+  USBPHYCTL |= PUSEL; // Convert USB D+/D- pins to USB functionality.
+  USBKEYPID = 0;
+}
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  if(state)
+  {
+    LED_PORT |= LED_PIN;
+  }
+  else
+  {
+    LED_PORT &= ~LED_PIN;
+  }
+}
+
+uint32_t board_button_read(void)
+{
+  return ((P1IN & BIT1) >> 1) == BUTTON_STATE_ACTIVE;
+}
+
+int board_uart_read(uint8_t * buf, int len)
+{
+  for(int i = 0; i < len; i++)
+  {
+    // Wait until something to receive (cleared by reading buffer).
+    while(!(UCA1IFG & UCRXIFG));
+    buf[i] = UCA1RXBUF;
+  }
+
+  return len;
+}
+
+int board_uart_write(void const * buf, int len)
+{
+  const char * char_buf = (const char *) buf;
+
+  for(int i = 0; i < len; i++)
+  {
+    // Wait until TX buffer is empty (cleared by writing buffer).
+    while(!(UCA1IFG & UCTXIFG));
+    UCA1TXBUF = char_buf[i];
+  }
+
+  return len;
+}
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+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)
+{
+  uint32_t systick_mirror;
+
+  // 32-bit update is not atomic on MSP430. We can read the bottom 16-bits,
+  // an interrupt occurs, updates _all_ 32 bits, and then we return a
+  // garbage value. And I've seen it happen!
+  TA0CCTL0 &= ~CCIE;
+  systick_mirror = system_ticks;
+  TA0CCTL0 |= CCIE;
+
+  return systick_mirror;
+}
+#endif