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circuitpython/ports/nrf/common-hal/busio/UART.c

330 lines
11 KiB

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Ha Thach for Adafruit Industries
*
* 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.
*/
#include "shared-bindings/microcontroller/__init__.h"
#include "shared-bindings/busio/UART.h"
#include "lib/utils/interrupt_char.h"
#include "py/mpconfig.h"
#include "py/gc.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "supervisor/shared/translate.h"
#include "tick.h"
#include "nrfx_uarte.h"
#include <string.h>
// expression to examine, and return value in case of failing
#define _VERIFY_ERR(_exp) \
do {\
uint32_t _err = (_exp);\
if (NRFX_SUCCESS != _err ) {\
mp_raise_msg_varg(&mp_type_RuntimeError, translate("error = 0x%08lX"), _err);\
}\
}while(0)
static nrfx_uarte_t nrfx_uartes[] = {
#if NRFX_CHECK(NRFX_UARTE0_ENABLED)
NRFX_UARTE_INSTANCE(0),
#endif
#if NRFX_CHECK(NRFX_UARTE1_ENABLED)
NRFX_UARTE_INSTANCE(1),
#endif
};
static uint32_t get_nrf_baud (uint32_t baudrate) {
static const struct {
const uint32_t boundary;
nrf_uarte_baudrate_t uarte_baudraute;
} baudrate_map[] = {
{ 1200, NRF_UARTE_BAUDRATE_1200 },
{ 2400, NRF_UARTE_BAUDRATE_2400 },
{ 4800, NRF_UARTE_BAUDRATE_4800 },
{ 9600, NRF_UARTE_BAUDRATE_9600 },
{ 14400, NRF_UARTE_BAUDRATE_14400 },
{ 19200, NRF_UARTE_BAUDRATE_19200 },
{ 28800, NRF_UARTE_BAUDRATE_28800 },
{ 38400, NRF_UARTE_BAUDRATE_38400 },
{ 57600, NRF_UARTE_BAUDRATE_57600 },
{ 76800, NRF_UARTE_BAUDRATE_76800 },
{ 115200, NRF_UARTE_BAUDRATE_115200 },
{ 230400, NRF_UARTE_BAUDRATE_230400 },
{ 250000, NRF_UARTE_BAUDRATE_250000 },
{ 460800, NRF_UARTE_BAUDRATE_460800 },
{ 921600, NRF_UARTE_BAUDRATE_921600 },
{ 0, NRF_UARTE_BAUDRATE_1000000 },
};
size_t i = 0;
uint32_t boundary;
do {
boundary = baudrate_map[i].boundary;
if (baudrate <= boundary || boundary == 0) {
return baudrate_map[i].uarte_baudraute;
}
i++;
} while (true);
}
static void uart_callback_irq (const nrfx_uarte_event_t * event, void * context) {
busio_uart_obj_t* self = (busio_uart_obj_t*) context;
switch ( event->type ) {
case NRFX_UARTE_EVT_RX_DONE:
ringbuf_put_n(&self->rbuf, event->data.rxtx.p_data, event->data.rxtx.bytes);
// keep receiving
(void) nrfx_uarte_rx(self->uarte, &self->rx_char, 1);
break;
case NRFX_UARTE_EVT_TX_DONE:
// nothing to do
break;
case NRFX_UARTE_EVT_ERROR:
// Possible Error source is Overrun, Parity, Framing, Break
// uint32_t errsrc = event->data.error.error_mask;
ringbuf_put_n(&self->rbuf, event->data.error.rxtx.p_data, event->data.error.rxtx.bytes);
// Keep receiving
(void) nrfx_uarte_rx(self->uarte, &self->rx_char, 1);
break;
default:
break;
}
}
void uart_reset(void) {
for (size_t i = 0 ; i < MP_ARRAY_SIZE(nrfx_uartes); i++) {
nrfx_uarte_uninit(&nrfx_uartes[i]);
}
}
void common_hal_busio_uart_construct(busio_uart_obj_t *self,
const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
mp_float_t timeout, uint16_t receiver_buffer_size) {
if ((rts != NULL) || (cts != NULL) || (rs485_dir != NULL) || (rs485_invert)) {
mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
}
// Find a free UART peripheral.
self->uarte = NULL;
for (size_t i = 0 ; i < MP_ARRAY_SIZE(nrfx_uartes); i++) {
if ((nrfx_uartes[i].p_reg->ENABLE & UARTE_ENABLE_ENABLE_Msk) == 0) {
self->uarte = &nrfx_uartes[i];
break;
}
}
if (self->uarte == NULL) {
mp_raise_ValueError(translate("All UART peripherals are in use"));
}
if ( (tx == NULL) && (rx == NULL) ) {
mp_raise_ValueError(translate("tx and rx cannot both be None"));
}
if ( receiver_buffer_size == 0 ) {
mp_raise_ValueError(translate("Invalid buffer size"));
}
if ( parity == PARITY_ODD ) {
mp_raise_ValueError(translate("Odd parity is not supported"));
}
nrfx_uarte_config_t config = {
.pseltxd = (tx == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : tx->number,
.pselrxd = (rx == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : rx->number,
.pselcts = NRF_UARTE_PSEL_DISCONNECTED,
.pselrts = NRF_UARTE_PSEL_DISCONNECTED,
.p_context = self,
.baudrate = get_nrf_baud(baudrate),
.interrupt_priority = 7,
.hal_cfg = {
.hwfc = NRF_UARTE_HWFC_DISABLED,
.parity = (parity == PARITY_NONE) ? NRF_UARTE_PARITY_EXCLUDED : NRF_UARTE_PARITY_INCLUDED
}
};
_VERIFY_ERR(nrfx_uarte_init(self->uarte, &config, uart_callback_irq));
// Init buffer for rx
if ( rx != NULL ) {
// Initially allocate the UART's buffer in the long-lived part of the
// heap. UARTs are generally long-lived objects, but the "make long-
// lived" machinery is incapable of moving internal pointers like
// self->buffer, so do it manually. (However, as long as internal
// pointers like this are NOT moved, allocating the buffer
// in the long-lived pool is not strictly necessary)
// (This is a macro.)
ringbuf_alloc(&self->rbuf, receiver_buffer_size, true);
if ( !self->rbuf.buf ) {
nrfx_uarte_uninit(self->uarte);
mp_raise_msg(&mp_type_MemoryError, translate("Failed to allocate RX buffer"));
}
self->rx_pin_number = rx->number;
claim_pin(rx);
}
if ( tx != NULL ) {
self->tx_pin_number = tx->number;
claim_pin(tx);
} else {
self->tx_pin_number = NO_PIN;
}
self->baudrate = baudrate;
self->timeout_ms = timeout * 1000;
// Initial wait for incoming byte
_VERIFY_ERR(nrfx_uarte_rx(self->uarte, &self->rx_char, 1));
}
bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
return self->rx_pin_number == NO_PIN;
}
void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
if ( !common_hal_busio_uart_deinited(self) ) {
nrfx_uarte_uninit(self->uarte);
reset_pin_number(self->tx_pin_number);
reset_pin_number(self->rx_pin_number);
self->tx_pin_number = NO_PIN;
self->rx_pin_number = NO_PIN;
gc_free(self->rbuf.buf);
self->rbuf.size = 0;
self->rbuf.iput = self->rbuf.iget = 0;
}
}
// Read characters.
size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
if ( nrf_uarte_rx_pin_get(self->uarte->p_reg) == NRF_UARTE_PSEL_DISCONNECTED ) {
mp_raise_ValueError(translate("No RX pin"));
}
size_t rx_bytes = 0;
uint64_t start_ticks = supervisor_ticks_ms64();
// Wait for all bytes received or timeout
while ( (ringbuf_count(&self->rbuf) < len) && (supervisor_ticks_ms64() - start_ticks < self->timeout_ms) ) {
RUN_BACKGROUND_TASKS;
// Allow user to break out of a timeout with a KeyboardInterrupt.
if ( mp_hal_is_interrupted() ) {
return 0;
}
}
// prevent conflict with uart irq
NVIC_DisableIRQ(nrfx_get_irq_number(self->uarte->p_reg));
// copy received data
rx_bytes = ringbuf_count(&self->rbuf);
rx_bytes = MIN(rx_bytes, len);
for ( uint16_t i = 0; i < rx_bytes; i++ ) {
data[i] = ringbuf_get(&self->rbuf);
}
NVIC_EnableIRQ(nrfx_get_irq_number(self->uarte->p_reg));
return rx_bytes;
}
// Write characters.
size_t common_hal_busio_uart_write (busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
if ( nrf_uarte_tx_pin_get(self->uarte->p_reg) == NRF_UARTE_PSEL_DISCONNECTED ) {
mp_raise_ValueError(translate("No TX pin"));
}
if ( len == 0 ) return 0;
// EasyDMA can only access SRAM
uint8_t * tx_buf = (uint8_t*) data;
if ( !nrfx_is_in_ram(data) ) {
// TODO: If this is not too big, we could allocate it on the stack.
tx_buf = (uint8_t *) gc_alloc(len, false, false);
memcpy(tx_buf, data, len);
}
(*errcode) = nrfx_uarte_tx(self->uarte, tx_buf, len);
_VERIFY_ERR(*errcode);
(*errcode) = 0;
// Wait for write to complete.
while ( nrfx_uarte_tx_in_progress(self->uarte) ) {
RUN_BACKGROUND_TASKS;
}
if ( !nrfx_is_in_ram(data) ) {
gc_free(tx_buf);
}
return len;
}
uint32_t common_hal_busio_uart_get_baudrate(busio_uart_obj_t *self) {
return self->baudrate;
}
void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrate) {
self->baudrate = baudrate;
nrf_uarte_baudrate_set(self->uarte->p_reg, get_nrf_baud(baudrate));
}
mp_float_t common_hal_busio_uart_get_timeout(busio_uart_obj_t *self) {
return (mp_float_t) (self->timeout_ms / 1000.0f);
}
void common_hal_busio_uart_set_timeout(busio_uart_obj_t *self, mp_float_t timeout) {
self->timeout_ms = timeout * 1000;
}
uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
return ringbuf_count(&self->rbuf);
}
void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
// prevent conflict with uart irq
NVIC_DisableIRQ(nrfx_get_irq_number(self->uarte->p_reg));
ringbuf_clear(&self->rbuf);
NVIC_EnableIRQ(nrfx_get_irq_number(self->uarte->p_reg));
}
bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
return !nrfx_uarte_tx_in_progress(self->uarte);
}