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

414 lines
14 KiB
C

/*
* 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 "shared/runtime/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/translate.h"
#include "nrfx_uarte.h"
#include "nrf_gpio.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 bool never_reset[NRFX_UARTE0_ENABLED + NRFX_UARTE1_ENABLED];
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 },
{ 31250, NRF_UARTE_BAUDRATE_31250 },
{ 38400, NRF_UARTE_BAUDRATE_38400 },
{ 56000, NRF_UARTE_BAUDRATE_56000 },
{ 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:
if (ringbuf_num_empty(&self->ringbuf) >= event->data.rxtx.bytes) {
ringbuf_put_n(&self->ringbuf, event->data.rxtx.p_data, event->data.rxtx.bytes);
// keep receiving
(void)nrfx_uarte_rx(self->uarte, &self->rx_char, 1);
} else {
// receive buffer full, suspend
self->rx_paused = true;
nrf_gpio_pin_write(self->rts_pin_number, true);
}
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->ringbuf, 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++) {
if (never_reset[i]) {
continue;
}
nrfx_uarte_uninit(&nrfx_uartes[i]);
}
}
void common_hal_busio_uart_never_reset(busio_uart_obj_t *self) {
// Don't never reset objects on the heap.
if (gc_alloc_possible() && gc_nbytes(self) > 0) {
return;
}
for (size_t i = 0; i < MP_ARRAY_SIZE(nrfx_uartes); i++) {
if (self->uarte == &nrfx_uartes[i]) {
never_reset[i] = true;
break;
}
}
never_reset_pin_number(self->tx_pin_number);
never_reset_pin_number(self->rx_pin_number);
}
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, busio_uart_parity_t parity, uint8_t stop,
mp_float_t timeout, uint16_t receiver_buffer_size, byte *receiver_buffer,
bool sigint_enabled) {
mp_arg_validate_int(bits, 8, MP_QSTR_bits);
if ((rs485_dir != NULL) || (rs485_invert)) {
mp_raise_NotImplementedError(translate("RS485"));
}
// 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"));
}
// shared-bindings checks that TX and RX are not both None, so we don't need to check here.
mp_arg_validate_int_min(receiver_buffer_size, 1, MP_QSTR_receiver_buffer_size);
if (parity == BUSIO_UART_PARITY_ODD) {
mp_raise_ValueError(translate("Odd parity is not supported"));
}
bool hwfc = rts != NULL || cts != NULL;
nrfx_uarte_config_t config = {
.pseltxd = (tx == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : tx->number,
.pselrxd = (rx == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : rx->number,
.pselcts = (cts == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : cts->number,
.pselrts = (rts == NULL) ? NRF_UARTE_PSEL_DISCONNECTED : rts->number,
.p_context = self,
.baudrate = get_nrf_baud(baudrate),
.interrupt_priority = NRFX_UARTE_DEFAULT_CONFIG_IRQ_PRIORITY,
.hal_cfg = {
.hwfc = hwfc ? NRF_UARTE_HWFC_ENABLED : NRF_UARTE_HWFC_DISABLED,
.parity = (parity == BUSIO_UART_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) {
// Use the provided buffer when given.
if (receiver_buffer != NULL) {
ringbuf_init(&self->ringbuf, receiver_buffer, receiver_buffer_size);
} else {
// 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)
if (!ringbuf_alloc(&self->ringbuf, receiver_buffer_size, true)) {
nrfx_uarte_uninit(self->uarte);
m_malloc_fail(receiver_buffer_size);
}
}
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;
}
if (rts != NULL) {
self->rts_pin_number = rts->number;
claim_pin(rts);
} else {
self->rts_pin_number = NO_PIN;
}
if (cts != NULL) {
self->cts_pin_number = cts->number;
claim_pin(cts);
} else {
self->cts_pin_number = NO_PIN;
}
self->baudrate = baudrate;
self->timeout_ms = timeout * 1000;
self->rx_paused = false;
// 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);
reset_pin_number(self->rts_pin_number);
reset_pin_number(self->cts_pin_number);
self->tx_pin_number = NO_PIN;
self->rx_pin_number = NO_PIN;
self->rts_pin_number = NO_PIN;
self->cts_pin_number = NO_PIN;
ringbuf_deinit(&self->ringbuf);
for (size_t i = 0; i < MP_ARRAY_SIZE(nrfx_uartes); i++) {
if (self->uarte == &nrfx_uartes[i]) {
never_reset[i] = false;
break;
}
}
}
}
// 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"));
}
uint64_t start_ticks = supervisor_ticks_ms64();
// check removed to reduce code size
/*
if (len > ringbuf_size(&self->ringbuf)) {
mp_raise_ValueError(translate("Reading >receiver_buffer_size bytes is not supported"));
}
*/
// Wait for all bytes received or timeout
while ((ringbuf_num_filled(&self->ringbuf) < 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 as much received data as available, up to len bytes.
size_t rx_bytes = ringbuf_get_n(&self->ringbuf, data, len);
// restart reader, if stopped
if (self->rx_paused) {
// the character that did not fit in ringbuf is in rx_char
ringbuf_put_n(&self->ringbuf, &self->rx_char, 1);
// keep receiving
(void)nrfx_uarte_rx(self->uarte, &self->rx_char, 1);
nrf_gpio_pin_write(self->rts_pin_number, false);
self->rx_paused = false;
}
NVIC_EnableIRQ(nrfx_get_irq_number(self->uarte->p_reg));
if (rx_bytes == 0) {
*errcode = EAGAIN;
return MP_STREAM_ERROR;
}
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)) {
// Allocate long strings on the heap.
if (len > 128 && gc_alloc_possible()) {
tx_buf = (uint8_t *)gc_alloc(len, false, false);
} else {
tx_buf = alloca(len);
}
memcpy(tx_buf, data, len);
}
// There is a small chance we're called recursively during debugging. In that case,
// a UART write might already be in progress so wait for it to complete.
while (nrfx_uarte_tx_in_progress(self->uarte)) {
RUN_BACKGROUND_TASKS;
}
(*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_alloc_possible() && gc_nbytes(tx_buf) > 0) {
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_num_filled(&self->ringbuf);
}
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->ringbuf);
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);
}