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circuitpython/ports/stm32/machine_uart.c
Damien George 23d9c6a0fd stm32: Add initial support for STM32L0xx MCUs.
2019-07-05 17:24:59 +10:00

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2018 Damien P. George
*
* 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 <stdio.h>
#include <string.h>
#include <stdarg.h>
#include "py/runtime.h"
#include "py/stream.h"
#include "py/mperrno.h"
#include "py/mphal.h"
#include "lib/utils/interrupt_char.h"
#include "lib/utils/mpirq.h"
#include "uart.h"
#include "irq.h"
#include "pendsv.h"
/// \moduleref pyb
/// \class UART - duplex serial communication bus
///
/// UART implements the standard UART/USART duplex serial communications protocol. At
/// the physical level it consists of 2 lines: RX and TX. The unit of communication
/// is a character (not to be confused with a string character) which can be 8 or 9
/// bits wide.
///
/// UART objects can be created and initialised using:
///
/// from pyb import UART
///
/// uart = UART(1, 9600) # init with given baudrate
/// uart.init(9600, bits=8, parity=None, stop=1) # init with given parameters
///
/// Bits can be 8 or 9. Parity can be None, 0 (even) or 1 (odd). Stop can be 1 or 2.
///
/// A UART object acts like a stream object and reading and writing is done
/// using the standard stream methods:
///
/// uart.read(10) # read 10 characters, returns a bytes object
/// uart.read() # read all available characters
/// uart.readline() # read a line
/// uart.readinto(buf) # read and store into the given buffer
/// uart.write('abc') # write the 3 characters
///
/// Individual characters can be read/written using:
///
/// uart.readchar() # read 1 character and returns it as an integer
/// uart.writechar(42) # write 1 character
///
/// To check if there is anything to be read, use:
///
/// uart.any() # returns True if any characters waiting
typedef struct _pyb_uart_irq_map_t {
uint16_t irq_en;
uint16_t flag;
} pyb_uart_irq_map_t;
STATIC const pyb_uart_irq_map_t mp_irq_map[] = {
{ USART_CR1_IDLEIE, UART_FLAG_IDLE}, // RX idle
{ USART_CR1_PEIE, UART_FLAG_PE}, // parity error
{ USART_CR1_TXEIE, UART_FLAG_TXE}, // TX register empty
{ USART_CR1_TCIE, UART_FLAG_TC}, // TX complete
{ USART_CR1_RXNEIE, UART_FLAG_RXNE}, // RX register not empty
#if 0
// For now only IRQs selected by CR1 are supported
#if defined(STM32F4)
{ USART_CR2_LBDIE, UART_FLAG_LBD}, // LIN break detection
#else
{ USART_CR2_LBDIE, UART_FLAG_LBDF}, // LIN break detection
#endif
{ USART_CR3_CTSIE, UART_FLAG_CTS}, // CTS
#endif
};
// OR-ed IRQ flags which should not be touched by the user
STATIC const uint32_t mp_irq_reserved = UART_FLAG_RXNE;
// OR-ed IRQ flags which are allowed to be used by the user
STATIC const uint32_t mp_irq_allowed = UART_FLAG_IDLE;
STATIC mp_obj_t pyb_uart_irq(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
STATIC void pyb_uart_irq_config(pyb_uart_obj_t *self, bool enable) {
if (self->mp_irq_trigger) {
for (size_t entry = 0; entry < MP_ARRAY_SIZE(mp_irq_map); ++entry) {
if (mp_irq_map[entry].flag & mp_irq_reserved) {
continue;
}
if (mp_irq_map[entry].flag & self->mp_irq_trigger) {
if (enable) {
self->uartx->CR1 |= mp_irq_map[entry].irq_en;
} else {
self->uartx->CR1 &= ~mp_irq_map[entry].irq_en;
}
}
}
}
}
STATIC mp_uint_t pyb_uart_irq_trigger(mp_obj_t self_in, mp_uint_t new_trigger) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
pyb_uart_irq_config(self, false);
self->mp_irq_trigger = new_trigger;
pyb_uart_irq_config(self, true);
return 0;
}
STATIC mp_uint_t pyb_uart_irq_info(mp_obj_t self_in, mp_uint_t info_type) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (info_type == MP_IRQ_INFO_FLAGS) {
return self->mp_irq_flags;
} else if (info_type == MP_IRQ_INFO_TRIGGERS) {
return self->mp_irq_trigger;
}
return 0;
}
STATIC const mp_irq_methods_t pyb_uart_irq_methods = {
.init = pyb_uart_irq,
.trigger = pyb_uart_irq_trigger,
.info = pyb_uart_irq_info,
};
STATIC void pyb_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (!self->is_enabled) {
mp_printf(print, "UART(%u)", self->uart_id);
} else {
mp_int_t bits;
uint32_t cr1 = self->uartx->CR1;
#if defined(UART_CR1_M1)
if (cr1 & UART_CR1_M1) {
bits = 7;
} else if (cr1 & UART_CR1_M0) {
bits = 9;
} else {
bits = 8;
}
#else
if (cr1 & USART_CR1_M) {
bits = 9;
} else {
bits = 8;
}
#endif
if (cr1 & USART_CR1_PCE) {
bits -= 1;
}
mp_printf(print, "UART(%u, baudrate=%u, bits=%u, parity=",
self->uart_id, uart_get_baudrate(self), bits);
if (!(cr1 & USART_CR1_PCE)) {
mp_print_str(print, "None");
} else if (!(cr1 & USART_CR1_PS)) {
mp_print_str(print, "0");
} else {
mp_print_str(print, "1");
}
uint32_t cr2 = self->uartx->CR2;
mp_printf(print, ", stop=%u, flow=",
((cr2 >> USART_CR2_STOP_Pos) & 3) == 0 ? 1 : 2);
uint32_t cr3 = self->uartx->CR3;
if (!(cr3 & (USART_CR3_CTSE | USART_CR3_RTSE))) {
mp_print_str(print, "0");
} else {
if (cr3 & USART_CR3_RTSE) {
mp_print_str(print, "RTS");
if (cr3 & USART_CR3_CTSE) {
mp_print_str(print, "|");
}
}
if (cr3 & USART_CR3_CTSE) {
mp_print_str(print, "CTS");
}
}
mp_printf(print, ", timeout=%u, timeout_char=%u, rxbuf=%u",
self->timeout, self->timeout_char,
self->read_buf_len == 0 ? 0 : self->read_buf_len - 1); // -1 to adjust for usable length of buffer
if (self->mp_irq_trigger != 0) {
mp_printf(print, "; irq=0x%x", self->mp_irq_trigger);
}
mp_print_str(print, ")");
}
}
/// \method init(baudrate, bits=8, parity=None, stop=1, *, timeout=1000, timeout_char=0, flow=0, read_buf_len=64)
///
/// Initialise the UART bus with the given parameters:
///
/// - `baudrate` is the clock rate.
/// - `bits` is the number of bits per byte, 7, 8 or 9.
/// - `parity` is the parity, `None`, 0 (even) or 1 (odd).
/// - `stop` is the number of stop bits, 1 or 2.
/// - `timeout` is the timeout in milliseconds to wait for the first character.
/// - `timeout_char` is the timeout in milliseconds to wait between characters.
/// - `flow` is RTS | CTS where RTS == 256, CTS == 512
/// - `read_buf_len` is the character length of the read buffer (0 to disable).
STATIC mp_obj_t pyb_uart_init_helper(pyb_uart_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 9600} },
{ MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_parity, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_PTR(&mp_const_none_obj)} },
{ MP_QSTR_stop, MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_flow, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = UART_HWCONTROL_NONE} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_timeout_char, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_rxbuf, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_read_buf_len, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} }, // legacy
};
// parse args
struct {
mp_arg_val_t baudrate, bits, parity, stop, flow, timeout, timeout_char, rxbuf, read_buf_len;
} args;
mp_arg_parse_all(n_args, pos_args, kw_args,
MP_ARRAY_SIZE(allowed_args), allowed_args, (mp_arg_val_t*)&args);
// static UARTs are used for internal purposes and shouldn't be reconfigured
if (self->is_static) {
mp_raise_ValueError("UART is static and can't be init'd");
}
// baudrate
uint32_t baudrate = args.baudrate.u_int;
// parity
uint32_t bits = args.bits.u_int;
uint32_t parity;
if (args.parity.u_obj == mp_const_none) {
parity = UART_PARITY_NONE;
} else {
mp_int_t p = mp_obj_get_int(args.parity.u_obj);
parity = (p & 1) ? UART_PARITY_ODD : UART_PARITY_EVEN;
bits += 1; // STs convention has bits including parity
}
// number of bits
if (bits == 8) {
bits = UART_WORDLENGTH_8B;
} else if (bits == 9) {
bits = UART_WORDLENGTH_9B;
#ifdef UART_WORDLENGTH_7B
} else if (bits == 7) {
bits = UART_WORDLENGTH_7B;
#endif
} else {
mp_raise_ValueError("unsupported combination of bits and parity");
}
// stop bits
uint32_t stop;
switch (args.stop.u_int) {
case 1: stop = UART_STOPBITS_1; break;
default: stop = UART_STOPBITS_2; break;
}
// flow control
uint32_t flow = args.flow.u_int;
// init UART (if it fails, it's because the port doesn't exist)
if (!uart_init(self, baudrate, bits, parity, stop, flow)) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%d) doesn't exist", self->uart_id));
}
// set timeout
self->timeout = args.timeout.u_int;
// set timeout_char
// make sure it is at least as long as a whole character (13 bits to be safe)
// minimum value is 2ms because sys-tick has a resolution of only 1ms
self->timeout_char = args.timeout_char.u_int;
uint32_t min_timeout_char = 13000 / baudrate + 2;
if (self->timeout_char < min_timeout_char) {
self->timeout_char = min_timeout_char;
}
// setup the read buffer
m_del(byte, self->read_buf, self->read_buf_len << self->char_width);
if (args.rxbuf.u_int >= 0) {
// rxbuf overrides legacy read_buf_len
args.read_buf_len.u_int = args.rxbuf.u_int;
}
if (args.read_buf_len.u_int <= 0) {
// no read buffer
uart_set_rxbuf(self, 0, NULL);
} else {
// read buffer using interrupts
size_t len = args.read_buf_len.u_int + 1; // +1 to adjust for usable length of buffer
uint8_t *buf = m_new(byte, len << self->char_width);
uart_set_rxbuf(self, len, buf);
}
// compute actual baudrate that was configured
uint32_t actual_baudrate = uart_get_baudrate(self);
// check we could set the baudrate within 5%
uint32_t baudrate_diff;
if (actual_baudrate > baudrate) {
baudrate_diff = actual_baudrate - baudrate;
} else {
baudrate_diff = baudrate - actual_baudrate;
}
if (20 * baudrate_diff > actual_baudrate) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "set baudrate %d is not within 5%% of desired value", actual_baudrate));
}
return mp_const_none;
}
/// \classmethod \constructor(bus, ...)
///
/// Construct a UART object on the given bus. `bus` can be 1-6, or 'XA', 'XB', 'YA', or 'YB'.
/// With no additional parameters, the UART object is created but not
/// initialised (it has the settings from the last initialisation of
/// the bus, if any). If extra arguments are given, the bus is initialised.
/// See `init` for parameters of initialisation.
///
/// The physical pins of the UART busses are:
///
/// - `UART(4)` is on `XA`: `(TX, RX) = (X1, X2) = (PA0, PA1)`
/// - `UART(1)` is on `XB`: `(TX, RX) = (X9, X10) = (PB6, PB7)`
/// - `UART(6)` is on `YA`: `(TX, RX) = (Y1, Y2) = (PC6, PC7)`
/// - `UART(3)` is on `YB`: `(TX, RX) = (Y9, Y10) = (PB10, PB11)`
/// - `UART(2)` is on: `(TX, RX) = (X3, X4) = (PA2, PA3)`
STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// check arguments
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
// work out port
int uart_id = 0;
if (mp_obj_is_str(args[0])) {
const char *port = mp_obj_str_get_str(args[0]);
if (0) {
#ifdef MICROPY_HW_UART1_NAME
} else if (strcmp(port, MICROPY_HW_UART1_NAME) == 0) {
uart_id = PYB_UART_1;
#endif
#ifdef MICROPY_HW_UART2_NAME
} else if (strcmp(port, MICROPY_HW_UART2_NAME) == 0) {
uart_id = PYB_UART_2;
#endif
#ifdef MICROPY_HW_UART3_NAME
} else if (strcmp(port, MICROPY_HW_UART3_NAME) == 0) {
uart_id = PYB_UART_3;
#endif
#ifdef MICROPY_HW_UART4_NAME
} else if (strcmp(port, MICROPY_HW_UART4_NAME) == 0) {
uart_id = PYB_UART_4;
#endif
#ifdef MICROPY_HW_UART5_NAME
} else if (strcmp(port, MICROPY_HW_UART5_NAME) == 0) {
uart_id = PYB_UART_5;
#endif
#ifdef MICROPY_HW_UART6_NAME
} else if (strcmp(port, MICROPY_HW_UART6_NAME) == 0) {
uart_id = PYB_UART_6;
#endif
#ifdef MICROPY_HW_UART7_NAME
} else if (strcmp(port, MICROPY_HW_UART7_NAME) == 0) {
uart_id = PYB_UART_7;
#endif
#ifdef MICROPY_HW_UART8_NAME
} else if (strcmp(port, MICROPY_HW_UART8_NAME) == 0) {
uart_id = PYB_UART_8;
#endif
#ifdef MICROPY_HW_UART9_NAME
} else if (strcmp(port, MICROPY_HW_UART9_NAME) == 0) {
uart_id = PYB_UART_9;
#endif
#ifdef MICROPY_HW_UART10_NAME
} else if (strcmp(port, MICROPY_HW_UART10_NAME) == 0) {
uart_id = PYB_UART_10;
#endif
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%s) doesn't exist", port));
}
} else {
uart_id = mp_obj_get_int(args[0]);
if (!uart_exists(uart_id)) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%d) doesn't exist", uart_id));
}
}
pyb_uart_obj_t *self;
if (MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1] == NULL) {
// create new UART object
self = m_new0(pyb_uart_obj_t, 1);
self->base.type = &pyb_uart_type;
self->uart_id = uart_id;
MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1] = self;
} else {
// reference existing UART object
self = MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1];
}
if (n_args > 1 || n_kw > 0) {
// start the peripheral
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
pyb_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
}
return MP_OBJ_FROM_PTR(self);
}
STATIC mp_obj_t pyb_uart_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
return pyb_uart_init_helper(MP_OBJ_TO_PTR(args[0]), n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_uart_init_obj, 1, pyb_uart_init);
/// \method deinit()
/// Turn off the UART bus.
STATIC mp_obj_t pyb_uart_deinit(mp_obj_t self_in) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
uart_deinit(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_deinit_obj, pyb_uart_deinit);
/// \method any()
/// Return `True` if any characters waiting, else `False`.
STATIC mp_obj_t pyb_uart_any(mp_obj_t self_in) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
return MP_OBJ_NEW_SMALL_INT(uart_rx_any(self));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_any_obj, pyb_uart_any);
/// \method writechar(char)
/// Write a single character on the bus. `char` is an integer to write.
/// Return value: `None`.
STATIC mp_obj_t pyb_uart_writechar(mp_obj_t self_in, mp_obj_t char_in) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
// get the character to write (might be 9 bits)
uint16_t data = mp_obj_get_int(char_in);
// write the character
int errcode;
if (uart_tx_wait(self, self->timeout)) {
uart_tx_data(self, &data, 1, &errcode);
} else {
errcode = MP_ETIMEDOUT;
}
if (errcode != 0) {
mp_raise_OSError(errcode);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_uart_writechar_obj, pyb_uart_writechar);
/// \method readchar()
/// Receive a single character on the bus.
/// Return value: The character read, as an integer. Returns -1 on timeout.
STATIC mp_obj_t pyb_uart_readchar(mp_obj_t self_in) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (uart_rx_wait(self, self->timeout)) {
return MP_OBJ_NEW_SMALL_INT(uart_rx_char(self));
} else {
// return -1 on timeout
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_readchar_obj, pyb_uart_readchar);
// uart.sendbreak()
STATIC mp_obj_t pyb_uart_sendbreak(mp_obj_t self_in) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
#if defined(STM32F0) || defined(STM32F7) || defined(STM32L0) || defined(STM32L4) || defined(STM32H7)
self->uartx->RQR = USART_RQR_SBKRQ; // write-only register
#else
self->uartx->CR1 |= USART_CR1_SBK;
#endif
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_sendbreak_obj, pyb_uart_sendbreak);
// irq(handler, trigger, hard)
STATIC mp_obj_t pyb_uart_irq(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
mp_arg_val_t args[MP_IRQ_ARG_INIT_NUM_ARGS];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_IRQ_ARG_INIT_NUM_ARGS, mp_irq_init_args, args);
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
if (self->mp_irq_obj == NULL) {
self->mp_irq_trigger = 0;
self->mp_irq_obj = mp_irq_new(&pyb_uart_irq_methods, MP_OBJ_FROM_PTR(self));
}
if (n_args > 1 || kw_args->used != 0) {
// Check the handler
mp_obj_t handler = args[MP_IRQ_ARG_INIT_handler].u_obj;
if (handler != mp_const_none && !mp_obj_is_callable(handler)) {
mp_raise_ValueError("handler must be None or callable");
}
// Check the trigger
mp_uint_t trigger = args[MP_IRQ_ARG_INIT_trigger].u_int;
mp_uint_t not_supported = trigger & ~mp_irq_allowed;
if (trigger != 0 && not_supported) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "trigger 0x%08x unsupported", not_supported));
}
// Reconfigure user IRQs
pyb_uart_irq_config(self, false);
self->mp_irq_obj->handler = handler;
self->mp_irq_obj->ishard = args[MP_IRQ_ARG_INIT_hard].u_bool;
self->mp_irq_trigger = trigger;
pyb_uart_irq_config(self, true);
}
return MP_OBJ_FROM_PTR(self->mp_irq_obj);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_uart_irq_obj, 1, pyb_uart_irq);
STATIC const mp_rom_map_elem_t pyb_uart_locals_dict_table[] = {
// instance methods
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_uart_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&pyb_uart_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_any), MP_ROM_PTR(&pyb_uart_any_obj) },
/// \method read([nbytes])
{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
/// \method readline()
{ MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj)},
/// \method readinto(buf[, nbytes])
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
/// \method write(buf)
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_irq), MP_ROM_PTR(&pyb_uart_irq_obj) },
{ MP_ROM_QSTR(MP_QSTR_writechar), MP_ROM_PTR(&pyb_uart_writechar_obj) },
{ MP_ROM_QSTR(MP_QSTR_readchar), MP_ROM_PTR(&pyb_uart_readchar_obj) },
{ MP_ROM_QSTR(MP_QSTR_sendbreak), MP_ROM_PTR(&pyb_uart_sendbreak_obj) },
// class constants
{ MP_ROM_QSTR(MP_QSTR_RTS), MP_ROM_INT(UART_HWCONTROL_RTS) },
{ MP_ROM_QSTR(MP_QSTR_CTS), MP_ROM_INT(UART_HWCONTROL_CTS) },
// IRQ flags
{ MP_ROM_QSTR(MP_QSTR_IRQ_RXIDLE), MP_ROM_INT(UART_FLAG_IDLE) },
};
STATIC MP_DEFINE_CONST_DICT(pyb_uart_locals_dict, pyb_uart_locals_dict_table);
STATIC mp_uint_t pyb_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
byte *buf = buf_in;
// check that size is a multiple of character width
if (size & self->char_width) {
*errcode = MP_EIO;
return MP_STREAM_ERROR;
}
// convert byte size to char size
size >>= self->char_width;
// make sure we want at least 1 char
if (size == 0) {
return 0;
}
// wait for first char to become available
if (!uart_rx_wait(self, self->timeout)) {
// return EAGAIN error to indicate non-blocking (then read() method returns None)
*errcode = MP_EAGAIN;
return MP_STREAM_ERROR;
}
// read the data
byte *orig_buf = buf;
for (;;) {
int data = uart_rx_char(self);
if (self->char_width == CHAR_WIDTH_9BIT) {
*(uint16_t*)buf = data;
buf += 2;
} else {
*buf++ = data;
}
if (--size == 0 || !uart_rx_wait(self, self->timeout_char)) {
// return number of bytes read
return buf - orig_buf;
}
}
}
STATIC mp_uint_t pyb_uart_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
const byte *buf = buf_in;
// check that size is a multiple of character width
if (size & self->char_width) {
*errcode = MP_EIO;
return MP_STREAM_ERROR;
}
// wait to be able to write the first character. EAGAIN causes write to return None
if (!uart_tx_wait(self, self->timeout)) {
*errcode = MP_EAGAIN;
return MP_STREAM_ERROR;
}
// write the data
size_t num_tx = uart_tx_data(self, buf, size >> self->char_width, errcode);
if (*errcode == 0 || *errcode == MP_ETIMEDOUT) {
// return number of bytes written, even if there was a timeout
return num_tx << self->char_width;
} else {
return MP_STREAM_ERROR;
}
}
STATIC mp_uint_t pyb_uart_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *errcode) {
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_uint_t ret;
if (request == MP_STREAM_POLL) {
uintptr_t flags = arg;
ret = 0;
if ((flags & MP_STREAM_POLL_RD) && uart_rx_any(self)) {
ret |= MP_STREAM_POLL_RD;
}
if ((flags & MP_STREAM_POLL_WR) && uart_tx_avail(self)) {
ret |= MP_STREAM_POLL_WR;
}
} else {
*errcode = MP_EINVAL;
ret = MP_STREAM_ERROR;
}
return ret;
}
STATIC const mp_stream_p_t uart_stream_p = {
.read = pyb_uart_read,
.write = pyb_uart_write,
.ioctl = pyb_uart_ioctl,
.is_text = false,
};
const mp_obj_type_t pyb_uart_type = {
{ &mp_type_type },
.name = MP_QSTR_UART,
.print = pyb_uart_print,
.make_new = pyb_uart_make_new,
.getiter = mp_identity_getiter,
.iternext = mp_stream_unbuffered_iter,
.protocol = &uart_stream_p,
.locals_dict = (mp_obj_dict_t*)&pyb_uart_locals_dict,
};
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