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Diffstat (limited to 'tinyusb/hw/bsp/msp430/family.c')
-rwxr-xr-x | tinyusb/hw/bsp/msp430/family.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/tinyusb/hw/bsp/msp430/family.c b/tinyusb/hw/bsp/msp430/family.c new file mode 100755 index 00000000..4b8ae393 --- /dev/null +++ b/tinyusb/hw/bsp/msp430/family.c @@ -0,0 +1,218 @@ +/* + * 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. + */ + +#include "bsp/board.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 |