circuitpython/ports/espressif/common-hal/busio/UART.c
2021-09-25 09:03:24 +05:30

360 lines
11 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020 Scott Shawcroft for Adafruit Industries LLC
*
* 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 "components/driver/include/driver/uart.h"
#include "mpconfigport.h"
#include "lib/utils/interrupt_char.h"
#include "py/gc.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "supervisor/shared/translate.h"
#include "supervisor/shared/tick.h"
uint8_t never_reset_uart_mask = 0;
void uart_reset(void) {
for (uart_port_t num = 0; num < UART_NUM_MAX; num++) {
// Ignore the UART used by the IDF.
#ifdef CONFIG_CONSOLE_UART_NUM
if (num == CONFIG_CONSOLE_UART_NUM) {
continue;
}
#endif
if (uart_is_driver_installed(num) && !(never_reset_uart_mask & 1 << num)) {
uart_driver_delete(num);
}
}
}
void common_hal_busio_uart_never_reset(busio_uart_obj_t *self) {
common_hal_never_reset_pin(self->rx_pin);
common_hal_never_reset_pin(self->tx_pin);
common_hal_never_reset_pin(self->rts_pin);
common_hal_never_reset_pin(self->cts_pin);
never_reset_uart_mask |= 1 << self->uart_num;
}
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) {
if (bits > 8) {
mp_raise_NotImplementedError(translate("bytes > 8 bits not supported"));
}
bool have_tx = tx != NULL;
bool have_rx = rx != NULL;
bool have_rts = rts != NULL;
bool have_cts = cts != NULL;
bool have_rs485_dir = rs485_dir != NULL;
if (!have_tx && !have_rx) {
mp_raise_ValueError(translate("tx and rx cannot both be None"));
}
// Filter for sane settings for RS485
if (have_rs485_dir) {
if (have_rts || have_cts) {
mp_raise_ValueError(translate("Cannot specify RTS or CTS in RS485 mode"));
}
} else if (rs485_invert) {
mp_raise_ValueError(translate("RS485 inversion specified when not in RS485 mode"));
}
self->timeout_ms = timeout * 1000;
self->uart_num = UART_NUM_MAX;
for (uart_port_t num = 0; num < UART_NUM_MAX; num++) {
if (!uart_is_driver_installed(num)) {
self->uart_num = num;
}
}
if (self->uart_num == UART_NUM_MAX) {
mp_raise_ValueError(translate("All UART peripherals are in use"));
}
uart_mode_t mode = UART_MODE_UART;
uart_hw_flowcontrol_t flow_control = UART_HW_FLOWCTRL_DISABLE;
if (have_rs485_dir) {
mode = UART_MODE_RS485_HALF_DUPLEX;
if (!rs485_invert) {
uart_set_line_inverse(self->uart_num, UART_SIGNAL_DTR_INV);
}
} else if (have_rts && have_cts) {
flow_control = UART_HW_FLOWCTRL_CTS_RTS;
} else if (have_rts) {
flow_control = UART_HW_FLOWCTRL_RTS;
} else if (have_rts) {
flow_control = UART_HW_FLOWCTRL_CTS;
}
if (receiver_buffer_size <= UART_FIFO_LEN) {
receiver_buffer_size = UART_FIFO_LEN + 8;
}
uint8_t rx_threshold = UART_FIFO_LEN - 8;
// Install the driver before we change the settings.
if (uart_driver_install(self->uart_num, receiver_buffer_size, 0, 0, NULL, 0) != ESP_OK ||
uart_set_mode(self->uart_num, mode) != ESP_OK) {
mp_raise_ValueError(translate("Could not initialize UART"));
}
uart_set_hw_flow_ctrl(self->uart_num, flow_control, rx_threshold);
// Set baud rate
common_hal_busio_uart_set_baudrate(self, baudrate);
uart_word_length_t word_length = UART_DATA_8_BITS;
switch (bits) {
// Shared bindings prevents data < 7 bits.
// case 5:
// word_length = UART_DATA_5_BITS;
// break;
// case 6:
// word_length = UART_DATA_6_BITS;
// break;
case 7:
word_length = UART_DATA_7_BITS;
break;
case 8:
word_length = UART_DATA_8_BITS;
break;
default:
// Won't hit this because shared-bindings limits to 7-9 bits. We error on 9 above.
break;
}
uart_set_word_length(self->uart_num, word_length);
uart_parity_t parity_mode = UART_PARITY_DISABLE;
switch (parity) {
case BUSIO_UART_PARITY_NONE:
parity_mode = UART_PARITY_DISABLE;
break;
case BUSIO_UART_PARITY_EVEN:
parity_mode = UART_PARITY_EVEN;
break;
case BUSIO_UART_PARITY_ODD:
parity_mode = UART_PARITY_ODD;
break;
default:
// Won't reach here because the input is an enum that is completely handled.
break;
}
uart_set_parity(self->uart_num, parity_mode);
// Stop is 1 or 2 always.
uart_stop_bits_t stop_bits = UART_STOP_BITS_1;
if (stop == 2) {
stop_bits = UART_STOP_BITS_2;
}
uart_set_stop_bits(self->uart_num, stop_bits);
self->tx_pin = NULL;
self->rx_pin = NULL;
self->rts_pin = NULL;
self->cts_pin = NULL;
int tx_num = -1;
int rx_num = -1;
int rts_num = -1;
int cts_num = -1;
if (have_tx) {
claim_pin(tx);
self->tx_pin = tx;
tx_num = tx->number;
}
if (have_rx) {
claim_pin(rx);
self->rx_pin = rx;
rx_num = rx->number;
}
if (have_rts) {
claim_pin(rts);
self->rts_pin = rts;
rts_num = rts->number;
}
if (have_cts) {
claim_pin(cts);
self->cts_pin = cts;
cts_num = cts->number;
}
if (have_rs485_dir) {
claim_pin(rs485_dir);
// RTS is used for RS485 direction.
self->rts_pin = rs485_dir;
rts_num = rs485_dir->number;
}
if (uart_set_pin(self->uart_num, tx_num, rx_num, rts_num, cts_num) != ESP_OK) {
mp_raise_ValueError(translate("Invalid pins"));
}
}
bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
return self->rx_pin == NULL && self->tx_pin == NULL;
}
void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
if (common_hal_busio_uart_deinited(self)) {
return;
}
uart_driver_delete(self->uart_num);
common_hal_reset_pin(self->rx_pin);
common_hal_reset_pin(self->tx_pin);
common_hal_reset_pin(self->rts_pin);
common_hal_reset_pin(self->cts_pin);
self->rx_pin = NULL;
self->tx_pin = NULL;
self->cts_pin = NULL;
self->rts_pin = NULL;
}
// Read characters.
size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
if (self->rx_pin == NULL) {
mp_raise_ValueError(translate("No RX pin"));
}
if (len == 0) {
// Nothing to read.
return 0;
}
size_t total_read = 0;
uint64_t start_ticks = supervisor_ticks_ms64();
// Busy-wait until timeout or until we've read enough chars.
while (supervisor_ticks_ms64() - start_ticks <= self->timeout_ms) {
// Read as many chars as we can right now, up to len.
size_t num_read = uart_read_bytes(self->uart_num, data, len, 0);
if (num_read < 0) {
break;
}
// Advance pointer in data buffer, and decrease how many chars left to read.
data += num_read;
len -= num_read;
total_read += num_read;
if (len == 0) {
// Don't need to read any more: data buf is full.
break;
}
if (num_read > 0) {
// Reset the timeout on every character read.
start_ticks = supervisor_ticks_ms64();
}
RUN_BACKGROUND_TASKS;
// Allow user to break out of a timeout with a KeyboardInterrupt.
if (mp_hal_is_interrupted()) {
break;
}
// If we are zero timeout, make sure we don't loop again (in the event
// we read in under 1ms)
if (self->timeout_ms == 0) {
break;
}
}
if (total_read == 0) {
*errcode = EAGAIN;
return MP_STREAM_ERROR;
}
return total_read;
}
// Write characters.
size_t common_hal_busio_uart_write(busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
if (self->tx_pin == NULL) {
mp_raise_ValueError(translate("No TX pin"));
}
size_t left_to_write = len;
while (left_to_write > 0) {
int count = uart_tx_chars(self->uart_num, (const char *)data, left_to_write);
if (count < 0) {
*errcode = MP_EAGAIN;
return MP_STREAM_ERROR;
}
left_to_write -= count;
data += count;
RUN_BACKGROUND_TASKS;
}
while (uart_wait_tx_done(self->uart_num, 0) == ESP_ERR_TIMEOUT) {
RUN_BACKGROUND_TASKS;
}
return len;
}
uint32_t common_hal_busio_uart_get_baudrate(busio_uart_obj_t *self) {
uint32_t baudrate;
uart_get_baudrate(self->uart_num, &baudrate);
return baudrate;
}
void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrate) {
if (baudrate > UART_BITRATE_MAX ||
uart_set_baudrate(self->uart_num, baudrate) != ESP_OK) {
mp_raise_ValueError(translate("Unsupported 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) {
size_t count;
uart_get_buffered_data_len(self->uart_num, &count);
return count;
}
void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
uart_flush(self->uart_num);
}
// True if there are no characters still to be written.
bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
if (self->tx_pin == NULL) {
return false;
}
return uart_wait_tx_done(self->uart_num, 0) != ESP_ERR_TIMEOUT;
}