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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2015 Daniel Campora
*
* 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 <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include "py/mpconfig.h"
#include MICROPY_HAL_H
#include "py/obj.h"
#include "py/runtime.h"
#include "py/objlist.h"
#include "py/stream.h"
#include "inc/hw_types.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_uart.h"
#include "rom_map.h"
#include "interrupt.h"
#include "prcm.h"
#include "uart.h"
#include "pybuart.h"
#include "pybioctl.h"
#include "pybsleep.h"
#include "mpexception.h"
#include "py/mpstate.h"
#include "osi.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.
///
/// UART objects can be created and initialised using:
///
/// from pyb import UART
///
/// uart = UART(0, 9600) # init with given baudrate
/// uart.init(9600, bits=8, stop=1, parity=None) # init with given parameters
///
/// Bits can be 5, 6, 7, 8, parity can be None, 0 (even), 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.readall() # 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
/******************************************************************************
DEFINE CONSTANTS
******************************************************************************/
#define PYBUART_TX_WAIT_MS 1
#define PYBUART_TX_MAX_TIMEOUT_MS 5
/******************************************************************************
DECLARE PRIVATE FUNCTIONS
******************************************************************************/
STATIC void uart_init (pyb_uart_obj_t *self);
STATIC bool uart_rx_wait (pyb_uart_obj_t *self, uint32_t timeout);
STATIC pyb_uart_obj_t* pyb_uart_add (pyb_uart_id_t uart_id);
STATIC pyb_uart_obj_t* pyb_uart_find (pyb_uart_id_t uart_id);
STATIC void UARTGenericIntHandler(uint32_t uart_id);
STATIC void UART0IntHandler(void);
STATIC void UART1IntHandler(void);
STATIC mp_obj_t pyb_uart_deinit(mp_obj_t self_in);
/******************************************************************************
DEFINE PRIVATE TYPES
******************************************************************************/
struct _pyb_uart_obj_t {
mp_obj_base_t base;
pyb_uart_id_t uart_id;
uint reg;
uint baudrate;
uint config;
uint flowcontrol;
byte *read_buf; // read buffer pointer
uint16_t timeout; // timeout waiting for first char
uint16_t timeout_char; // timeout waiting between chars
uint16_t read_buf_len; // len in chars; buf can hold len-1 chars
volatile uint16_t read_buf_head; // indexes first empty slot
uint16_t read_buf_tail; // indexes first full slot (not full if equals head)
bool enabled;
};
/******************************************************************************
DEFINE PUBLIC FUNCTIONS
******************************************************************************/
void uart_init0 (void) {
mp_obj_list_init(&MP_STATE_PORT(pyb_uart_list), 0);
}
// unregister all interrupt sources
void uart_deinit(void) {
for (int i = PYB_UART_0; i < PYB_NUM_UARTS; i++) {
pyb_uart_obj_t *self;
if ((self = pyb_uart_find (i))) {
pyb_uart_deinit(self);
}
}
}
bool uart_rx_any(pyb_uart_obj_t *self) {
return (self->read_buf_tail != self->read_buf_head || MAP_UARTCharsAvail(self->reg));
}
int uart_rx_char(pyb_uart_obj_t *self) {
if (self->read_buf_tail != self->read_buf_head) {
// buffering via IRQ
int data = self->read_buf[self->read_buf_tail];
self->read_buf_tail = (self->read_buf_tail + 1) % self->read_buf_len;
return data;
} else {
// no buffering
return MAP_UARTCharGetNonBlocking(self->reg);
}
}
bool uart_tx_char(pyb_uart_obj_t *self, int c) {
uint32_t timeout = 0;
while (!MAP_UARTCharPutNonBlocking(self->reg, c)) {
if (timeout++ > (PYBUART_TX_MAX_TIMEOUT_MS / PYBUART_TX_WAIT_MS)) {
return false;
}
HAL_Delay (PYBUART_TX_WAIT_MS);
}
return true;
}
bool uart_tx_strn(pyb_uart_obj_t *self, const char *str, uint len) {
for (const char *top = str + len; str < top; str++) {
if (!uart_tx_char(self, *str)) {
return false;
}
}
return true;
}
void uart_tx_strn_cooked(pyb_uart_obj_t *self, const char *str, uint len) {
for (const char *top = str + len; str < top; str++) {
if (*str == '\n') {
uart_tx_char(self, '\r');
}
uart_tx_char(self, *str);
}
}
/******************************************************************************
DEFINE PRIVATE FUNCTIONS
******************************************************************************/
// assumes init parameters have been set up correctly
STATIC void uart_init (pyb_uart_obj_t *self) {
uint uartPerh;
switch (self->uart_id) {
case PYB_UART_0:
self->reg = UARTA0_BASE;
uartPerh = PRCM_UARTA0;
MAP_UARTIntRegister(UARTA0_BASE, UART0IntHandler);
MAP_IntPrioritySet(INT_UARTA0, INT_PRIORITY_LVL_3);
break;
case PYB_UART_1:
self->reg = UARTA1_BASE;
uartPerh = PRCM_UARTA1;
MAP_UARTIntRegister(UARTA1_BASE, UART1IntHandler);
MAP_IntPrioritySet(INT_UARTA1, INT_PRIORITY_LVL_3);
break;
default:
return;
}
// Enable the peripheral clock
MAP_PRCMPeripheralClkEnable(uartPerh, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK);
// Reset the uart
MAP_PRCMPeripheralReset(uartPerh);
// Initialize the UART
MAP_UARTConfigSetExpClk(self->reg, MAP_PRCMPeripheralClockGet(uartPerh),
self->baudrate, self->config);
// Enbale the FIFO
MAP_UARTFIFOEnable(self->reg);
// Configure the FIFO interrupt levels
MAP_UARTFIFOLevelSet(self->reg, UART_FIFO_TX4_8, UART_FIFO_RX4_8);
// Configure the flow control mode
UARTFlowControlSet(self->reg, self->flowcontrol);
// Setup the RX interrupts
if (self->read_buf != NULL) {
MAP_UARTIntEnable(self->reg, UART_INT_RX | UART_INT_RT);
}
else {
MAP_UARTIntDisable(self->reg, UART_INT_RX | UART_INT_RT);
}
}
// Waits at most timeout milliseconds for at least 1 char to become ready for
// reading (from buf or for direct reading).
// Returns true if something available, false if not.
STATIC bool uart_rx_wait (pyb_uart_obj_t *self, uint32_t timeout) {
for (;;) {
if (uart_rx_any(self)) {
return true; // have at least 1 char ready for reading
}
if (timeout > 0) {
HAL_Delay (1);
timeout--;
}
else {
return false;
}
}
}
STATIC pyb_uart_obj_t* pyb_uart_add (pyb_uart_id_t uart_id) {
// create a new uart object
pyb_uart_obj_t *self = m_new_obj(pyb_uart_obj_t);
self->base.type = &pyb_uart_type;
self->uart_id = uart_id;
self->read_buf = NULL;
self->enabled = false;
// add it to the list
mp_obj_list_append(&MP_STATE_PORT(pyb_uart_list), self);
return self;
}
STATIC pyb_uart_obj_t* pyb_uart_find (pyb_uart_id_t uart_id) {
for (mp_uint_t i = 0; i < MP_STATE_PORT(pyb_uart_list).len; i++) {
pyb_uart_obj_t *self = (pyb_uart_obj_t *)MP_STATE_PORT(pyb_uart_list).items[i];
if (self->uart_id == uart_id) {
return self;
}
}
return NULL;
}
STATIC void UARTGenericIntHandler(uint32_t uart_id) {
pyb_uart_obj_t *self;
uint32_t status;
if ((self = pyb_uart_find(uart_id))) {
status = MAP_UARTIntStatus(self->reg, true);
// receive interrupt
if (status & (UART_INT_RX | UART_INT_RT)) {
MAP_UARTIntClear(self->reg, UART_INT_RX | UART_INT_RT);
while (UARTCharsAvail(self->reg)) {
int data = MAP_UARTCharGetNonBlocking(self->reg);
if (MICROPY_STDIO_UART == self->uart_id && data == user_interrupt_char) {
// raise exception when interrupts are finished
mpexception_keyboard_nlr_jump();
}
else if (self->read_buf_len != 0) {
uint16_t next_head = (self->read_buf_head + 1) % self->read_buf_len;
if (next_head != self->read_buf_tail) {
// only store data if room in buf
self->read_buf[self->read_buf_head] = data;
self->read_buf_head = next_head;
}
}
}
}
}
}
STATIC void UART0IntHandler(void) {
UARTGenericIntHandler(0);
}
STATIC void UART1IntHandler(void) {
UARTGenericIntHandler(1);
}
/******************************************************************************/
/* Micro Python bindings */
STATIC void pyb_uart_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_uart_obj_t *self = self_in;
if (!self->enabled) {
print(env, "<UART%u>", self->uart_id);
} else {
print(env, "<UART%u, baudrate=%u, bits=", self->uart_id, self->baudrate);
switch (self->config & UART_CONFIG_WLEN_MASK) {
case UART_CONFIG_WLEN_5:
print(env, "5");
break;
case UART_CONFIG_WLEN_6:
print(env, "6");
break;
case UART_CONFIG_WLEN_7:
print(env, "7");
break;
case UART_CONFIG_WLEN_8:
print(env, "8");
break;
default:
break;
}
if ((self->config & UART_CONFIG_PAR_MASK) == UART_CONFIG_PAR_NONE) {
print(env, ", parity=None");
} else {
print(env, ", parity=%u", (self->config & UART_CONFIG_PAR_MASK) == UART_CONFIG_PAR_EVEN ? 0 : 1);
}
print(env, ", stop=%u, timeout=%u, timeout_char=%u, read_buf_len=%u>",
(self->config & UART_CONFIG_STOP_MASK) == UART_CONFIG_STOP_ONE ? 1 : 2,
self->timeout, self->timeout_char, self->read_buf_len);
}
}
/// \method init(baudrate, bits=8, parity=None, stop=1, *, timeout=1000, timeout_char=0, read_buf_len=128)
///
/// 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.
/// - `flowcontrol` is the flow control mode, `None`, `UART.FLOW_TX`,
/// `UART.FLOW_RX', 'UART.FLOW_TXRX`.
/// - `timeout` is the timeout in milliseconds to wait for the first character.
/// - `timeout_char` is the timeout in milliseconds to wait between characters.
/// - `read_buf_len` is the character length of the read buffer (0 to disable).
STATIC const mp_arg_t pyb_uart_init_args[] = {
{ MP_QSTR_baudrate, MP_ARG_REQUIRED | MP_ARG_INT, },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_parity, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_flow, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_int = UART_FLOWCONTROL_NONE} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
{ MP_QSTR_timeout_char, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_read_buf_len, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 128} },
};
STATIC mp_obj_t pyb_uart_init_helper(pyb_uart_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(pyb_uart_init_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(pyb_uart_init_args), pyb_uart_init_args, args);
// set timeouts
self->timeout = args[5].u_int;
self->timeout_char = args[6].u_int;
// setup the read buffer
m_del(byte, self->read_buf, self->read_buf_len);
self->read_buf_head = 0;
self->read_buf_tail = 0;
if (args[7].u_int <= 0) {
// no read buffer
self->read_buf_len = 0;
self->read_buf = NULL;
}
else {
// read buffer using interrupts
self->read_buf_len = args[7].u_int;
self->read_buf = m_new(byte, args[7].u_int);
}
// get the baudrate
self->baudrate = args[0].u_int;
// set the UART configuration values
if (n_args > 1) {
switch (args[1].u_int) {
case 5:
self->config = UART_CONFIG_WLEN_5;
break;
case 6:
self->config = UART_CONFIG_WLEN_6;
break;
case 7:
self->config = UART_CONFIG_WLEN_7;
break;
case 8:
self->config = UART_CONFIG_WLEN_8;
break;
default:
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
break;
}
// Parity
if (args[2].u_obj == mp_const_none) {
self->config |= UART_CONFIG_PAR_NONE;
} else {
self->config |= ((mp_obj_get_int(args[2].u_obj) & 1) ? UART_CONFIG_PAR_ODD : UART_CONFIG_PAR_EVEN);
}
// Stop bits
self->config |= (args[3].u_int == 1 ? UART_CONFIG_STOP_ONE : UART_CONFIG_STOP_TWO);
// Flow control
self->flowcontrol = args[4].u_int;
}
else {
self->config = UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE;
self->flowcontrol = UART_FLOWCONTROL_NONE;
}
// initialize and enable the uart
uart_init (self);
self->enabled = true;
// register it with the sleep module
pybsleep_add ((const mp_obj_t)self, (WakeUpCB_t)uart_init);
return mp_const_none;
}
/// \classmethod \constructor(bus, ...)
///
/// Construct a UART object on the given bus id. `bus id` can be 0-1
/// 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).
/// When only the baud rate is given the UART object is created and
/// initialized with the default configuration of: 8 bit transfers,
/// 1 stop bit, no parity and flow control disabled.
/// See `init` for parameters of initialisation.
/// If extra arguments are given, the bus is initialised with these arguments
/// See `init` for parameters of initialisation.
///
STATIC mp_obj_t pyb_uart_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
// check arguments
mp_arg_check_num(n_args, n_kw, 1, MP_ARRAY_SIZE(pyb_uart_init_args), true);
// work out the uart id
pyb_uart_id_t uart_id = mp_obj_get_int(args[0]);
if (uart_id < PYB_UART_0 || uart_id > PYB_UART_1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, mpexception_os_resource_not_avaliable));
}
// search for an object in the list
pyb_uart_obj_t *self;
if (!(self = pyb_uart_find(uart_id))) {
self = pyb_uart_add(uart_id);
}
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 self;
}
STATIC mp_obj_t pyb_uart_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
return pyb_uart_init_helper(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 = self_in;
uint uartPerh;
switch (self->uart_id) {
case PYB_UART_0:
uartPerh = PRCM_UARTA0;
break;
case PYB_UART_1:
uartPerh = PRCM_UARTA1;
break;
default:
return mp_const_none;
}
// unregister it with the sleep module
pybsleep_remove (self);
self->enabled = false;
MAP_UARTIntDisable(self->reg, UART_INT_RX | UART_INT_RT);
MAP_UARTIntClear(self->reg, UART_INT_RX | UART_INT_RT);
MAP_UARTIntUnregister(self->reg);
MAP_UARTDisable(self->reg);
MAP_PRCMPeripheralClkDisable(uartPerh, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_deinit_obj, pyb_uart_deinit);
/// \method delete()
/// Deinits the UART and removes its references so that it can be cleaned by the gc
STATIC mp_obj_t pyb_uart_delete(mp_obj_t self_in) {
pyb_uart_obj_t *self = self_in;
// deinit the peripheral
pyb_uart_deinit(self);
// remove it from the list
mp_obj_list_remove(&MP_STATE_PORT(pyb_uart_list), self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_delete_obj, pyb_uart_delete);
/// \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 = self_in;
if (uart_rx_any(self)) {
return mp_const_true;
} else {
return mp_const_false;
}
}
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 = self_in;
// get the character to write
uint8_t data = mp_obj_get_int(char_in);
// send the character
if (!uart_tx_char(self, data)) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ETIMEDOUT)));
}
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 = self_in;
if (uart_rx_wait(self, self->timeout)) {
return mp_obj_new_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);
STATIC const mp_map_elem_t pyb_uart_locals_dict_table[] = {
// instance methods
{ MP_OBJ_NEW_QSTR(MP_QSTR___del__), (mp_obj_t)&pyb_uart_delete_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_uart_init_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_uart_deinit_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_any), (mp_obj_t)&pyb_uart_any_obj },
/// \method read([nbytes])
{ MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&mp_stream_read_obj },
/// \method readall()
{ MP_OBJ_NEW_QSTR(MP_QSTR_readall), (mp_obj_t)&mp_stream_readall_obj },
/// \method readline()
{ MP_OBJ_NEW_QSTR(MP_QSTR_readline), (mp_obj_t)&mp_stream_unbuffered_readline_obj},
/// \method readinto(buf[, nbytes])
{ MP_OBJ_NEW_QSTR(MP_QSTR_readinto), (mp_obj_t)&mp_stream_readinto_obj },
/// \method write(buf)
{ MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&mp_stream_write_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_writechar), (mp_obj_t)&pyb_uart_writechar_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_readchar), (mp_obj_t)&pyb_uart_readchar_obj },
// class constants
{ MP_OBJ_NEW_QSTR(MP_QSTR_FLOW_NONE), MP_OBJ_NEW_SMALL_INT(UART_FLOWCONTROL_NONE) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_FLOW_TX), MP_OBJ_NEW_SMALL_INT(UART_FLOWCONTROL_TX) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_FLOW_RX), MP_OBJ_NEW_SMALL_INT(UART_FLOWCONTROL_RX) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_FLOW_TXRX), MP_OBJ_NEW_SMALL_INT(UART_FLOWCONTROL_TX | UART_FLOWCONTROL_RX) },
};
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 = self_in;
byte *buf = buf_in;
// 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)) {
// we can either return 0 to indicate EOF (then read() method returns b'')
// or return EAGAIN error to indicate non-blocking (then read() method returns None)
return 0;
}
// read the data
byte *orig_buf = buf;
for (;;) {
*buf++ = uart_rx_char(self);
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 = self_in;
const char *buf = buf_in;
// write the data
if (!uart_tx_strn(self, buf, size)) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ETIMEDOUT)));
}
return size;
}
STATIC mp_uint_t pyb_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint_t arg, int *errcode) {
pyb_uart_obj_t *self = self_in;
mp_uint_t ret;
if (request == MP_IOCTL_POLL) {
mp_uint_t flags = arg;
ret = 0;
if ((flags & MP_IOCTL_POLL_RD) && uart_rx_any(self)) {
ret |= MP_IOCTL_POLL_RD;
}
if ((flags & MP_IOCTL_POLL_WR) && MAP_UARTSpaceAvail(self->reg)) {
ret |= MP_IOCTL_POLL_WR;
}
} else {
*errcode = 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,
.iternext = mp_stream_unbuffered_iter,
.stream_p = &uart_stream_p,
.locals_dict = (mp_obj_t)&pyb_uart_locals_dict,
};