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samd/samd_soc: Allow a board to configure the low-level MCU config.

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The board specific #defines will be moved to individual boards.
This commit is contained in:
Peter van der Burg 2021-05-21 10:02:01 +10:00 committed by Damien George
parent cd2223b8fe
commit 4c132614e1
2 changed files with 53 additions and 54 deletions
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95
ports/samd/samd_soc.c
View File

@ -1,6 +1,12 @@
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* This file initialises the USB (tinyUSB) and USART (SERCOM). Board USART settings
* are set in 'boards/<board>/mpconfigboard.h.
*
* IMPORTANT: Please refer to "I/O Multiplexing and Considerations" chapters
* in device datasheets for I/O Pin functions and assignments.
*
* The MIT License (MIT)
*
* Copyright (c) 2019 Damien P. George
@ -24,56 +30,53 @@
* THE SOFTWARE.
*/
#include "py/runtime.h"
#include "modmachine.h"
#include "samd_soc.h"
#include "tusb.h"
static void uart0_init(void) {
// "MP" macros defined in "boards/$(BOARD)/mpconfigboard.h"
mp_obj_t machine_uart_init(void) {
// Firstly, assign alternate function SERCOM PADs to GPIO pins.
PORT->Group[MP_PIN_GRP].PINCFG[MP_TX_PIN].bit.PMUXEN = 1; // Enable
PORT->Group[MP_PIN_GRP].PINCFG[MP_RX_PIN].bit.PMUXEN = 1; // Enable
PORT->Group[MP_PIN_GRP].PMUX[MP_PERIPHERAL_MUX].reg = MP_PORT_FUNC; // Sets PMUXE & PMUXO in 1 hit.
uint32_t rxpo = MP_RXPO_PAD; // 1=Pad1,3=Pad3 Rx data
uint32_t txpo = MP_TXPO_PAD; // 0=pad0,1=Pad2 Tx data
// Initialise the clocks
#if defined(MCU_SAMD21)
// SERCOM0, TX=PA06=PAD2, RX=PA07=PAD3, ALT-D
PORT->Group[0].PMUX[3].reg = 0x33;
PORT->Group[0].PINCFG[6].reg = 1;
PORT->Group[0].PINCFG[7].reg = 1;
PM->APBCMASK.bit.SERCOM0_ = 1;
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_ID_SERCOM0_CORE;
PM->APBCMASK.bit.MP_SERCOMx = 1; // Enable synchronous clock
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | MP_SERCOM_GCLK_ID_x_CORE; // Select multiplexer generic clock source and enable.
// Wait while it updates synchronously.
while (GCLK->STATUS.bit.SYNCBUSY) {
}
uint32_t rxpo = 3;
uint32_t txpo = 1;
#elif defined(MCU_SAMD51)
// SERCOM3, TX=PA17=PAD0, RX=PA16=PAD1, ALT-D
PORT->Group[0].PMUX[8].reg = 0x33;
PORT->Group[0].PINCFG[16].reg = 1;
PORT->Group[0].PINCFG[17].reg = 1;
// Use Generator 0 which is already enabled and switched to DFLL @ 48MHz
GCLK->PCHCTRL[SERCOM3_GCLK_ID_CORE].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK0;
MCLK->APBBMASK.bit.SERCOM3_ = 1;
uint32_t rxpo = 1;
uint32_t txpo = 2;
GCLK->PCHCTRL[MP_SERCOM_GCLK_ID_x_CORE].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK0;
MCLK->APBBMASK.bit.MP_SERCOMx = 1;
#endif
// Setup the Peripheral.
// Reset (clear) the peripheral registers.
while (USARTx->USART.SYNCBUSY.bit.SWRST) {
}
USARTx->USART.CTRLA.bit.SWRST = 1;
USARTx->USART.CTRLA.bit.SWRST = 1; // Reset all Registers, disable peripheral
while (USARTx->USART.SYNCBUSY.bit.SWRST) {
}
USARTx->USART.CTRLA.reg =
SERCOM_USART_CTRLA_DORD
| SERCOM_USART_CTRLA_RXPO(rxpo)
| SERCOM_USART_CTRLA_TXPO(txpo)
| SERCOM_USART_CTRLA_MODE(1)
// Set the register bits as needed
// (CMODE (async),CHSIZE (8),FORM (no parity),SBMODE (1 stop) already 0).
USARTx->USART.CTRLA.reg = // USARTx = SERCOMx set in "boards/$(BOARD)/mpconfigboard.h"
SERCOM_USART_CTRLA_DORD // Data order
| SERCOM_USART_CTRLA_RXPO(rxpo) // Set Pad#
| SERCOM_USART_CTRLA_TXPO(txpo) // Set Pad#
| SERCOM_USART_CTRLA_MODE(1) // USART with internal clock
;
USARTx->USART.CTRLB.reg = SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN;
USARTx->USART.CTRLB.reg = SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN; // Enable Rx & Tx
while (USARTx->USART.SYNCBUSY.bit.CTRLB) {
}
// Baud rate is clock dependant.
#if CPU_FREQ == 8000000
uint32_t baud = 50437; // 115200 baud; 65536*(1 - 16 * 115200/8e6)
#elif CPU_FREQ == 48000000
@ -81,12 +84,26 @@ static void uart0_init(void) {
#elif CPU_FREQ == 120000000
uint32_t baud = 64529; // 115200 baud; 65536*(1 - 16 * 115200/120e6)
#endif
USARTx->USART.BAUD.bit.BAUD = baud;
USARTx->USART.CTRLA.bit.ENABLE = 1;
USARTx->USART.BAUD.bit.BAUD = baud; // Set Baud
USARTx->USART.CTRLA.bit.ENABLE = 1; // Enable the peripheral
// Wait for the Registers to update.
while (USARTx->USART.SYNCBUSY.bit.ENABLE) {
}
return mp_const_none;
}
// Disconnect SERCOM from GPIO pins. (Can't SWRST, as that will totally kill USART).
mp_obj_t machine_uart_deinit(void) {
// Reset
printf("Disabling the Alt-Funct, releasing the USART pins for GPIO... \n");
PORT->Group[MP_PIN_GRP].PINCFG[MP_TX_PIN].bit.PMUXEN = 0; // Disable
PORT->Group[MP_PIN_GRP].PINCFG[MP_RX_PIN].bit.PMUXEN = 0; // Disable
return mp_const_none;
}
static void usb_init(void) {
// Init USB clock
#if defined(MCU_SAMD21)
@ -142,21 +159,15 @@ void samd_init(void) {
while (GCLK->STATUS.bit.SYNCBUSY) {
}
// Configure PA10 as output for LED
PORT->Group[0].DIRSET.reg = 1 << 10;
#elif defined(MCU_SAMD51)
GCLK->GENCTRL[1].reg = 1 << GCLK_GENCTRL_DIV_Pos | GCLK_GENCTRL_GENEN | GCLK_GENCTRL_SRC_DFLL;
while (GCLK->SYNCBUSY.bit.GENCTRL1) {
}
// Configure PA22 as output for LED
PORT->Group[0].DIRSET.reg = 1 << 22;
#endif
SysTick_Config(CPU_FREQ / 1000);
uart0_init();
machine_uart_init();
usb_init();
}

12
ports/samd/samd_soc.h
View File

@ -29,18 +29,6 @@
#include <stdint.h>
#include "sam.h"
#if defined(MCU_SAMD21)
#define CPU_FREQ (48000000)
#define USARTx SERCOM0
#elif defined(MCU_SAMD51)
#define CPU_FREQ (48000000)
#define USARTx SERCOM3
#endif
void samd_init(void);
void samd_main(void);