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support RTS/CTS hardware flow control

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This commit is contained in:
Bernhard Boser 2021-01-07 14:13:19 -08:00
parent 55c80754c7
commit c7dc5f2507
1 changed files with 51 additions and 8 deletions
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55
ports/nrf/common-hal/busio/UART.c
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@ -36,6 +36,7 @@
#include "supervisor/shared/translate.h"
#include "nrfx_uarte.h"
#include "nrf_gpio.h"
#include <string.h>
// expression to examine, and return value in case of failing
@ -98,10 +99,16 @@ static void uart_callback_irq (const nrfx_uarte_event_t * event, void * 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:
@ -137,8 +144,8 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
mp_float_t timeout, uint16_t receiver_buffer_size, byte* receiver_buffer,
bool sigint_enabled) {
if ((rts != NULL) || (cts != NULL) || (rs485_dir != NULL) || (rs485_invert)) {
mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
if ((rs485_dir != NULL) || (rs485_invert)) {
mp_raise_ValueError(translate("RS485 Not yet supported on this device"));
}
// Find a free UART peripheral.
@ -166,16 +173,18 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
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 = NRF_UARTE_PSEL_DISCONNECTED,
.pselrts = NRF_UARTE_PSEL_DISCONNECTED,
.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 = 7,
.hal_cfg = {
.hwfc = NRF_UARTE_HWFC_DISABLED,
.hwfc = hwfc ? NRF_UARTE_HWFC_ENABLED : NRF_UARTE_HWFC_DISABLED,
.parity = (parity == BUSIO_UART_PARITY_NONE) ? NRF_UARTE_PARITY_EXCLUDED : NRF_UARTE_PARITY_INCLUDED
}
};
@ -207,9 +216,25 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
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));
}
@ -223,8 +248,12 @@ void common_hal_busio_uart_deinit(busio_uart_obj_t *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_free(&self->ringbuf);
}
}
@ -237,6 +266,10 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
uint64_t start_ticks = supervisor_ticks_ms64();
if (len > ringbuf_capacity(&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;
@ -252,6 +285,16 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
// 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));
return rx_bytes;