circuitpython/ports/esp8266/uart.c
robert-hh 8804993d0f esp8266/machine_uart: Implement uart.flush() and uart.txdone().
uart.flush()

flush() will wait until all characters but the last one have been sent.
It returns while the last character is sent. If needed, the calling
code has to add one character wait time. To avoid a permanent lock,
a timeout applies depending on the size of the FIFO and the baud rate.

ret = uart.txdone()

ret is True if no transfer is in progress. It returns already True when
the last byte of a transfer is sent.
ret is False otherwise.
2022-08-31 00:18:27 +10:00

332 lines
11 KiB
C

/******************************************************************************
* Copyright 2013-2014 Espressif Systems (Wuxi)
*
* FileName: uart.c
*
* Description: Two UART mode configration and interrupt handler.
* Check your hardware connection while use this mode.
*
* Modification history:
* 2014/3/12, v1.0 create this file.
*******************************************************************************/
#include "ets_sys.h"
#include "osapi.h"
#include "uart.h"
#include "osapi.h"
#include "uart_register.h"
#include "etshal.h"
#include "c_types.h"
#include "user_interface.h"
#include "esp_mphal.h"
// seems that this is missing in the Espressif SDK
#define FUNC_U0RXD 0
#define UART_REPL UART0
// UartDev is defined and initialized in rom code.
extern UartDevice UartDev;
// the uart to which OS messages go; -1 to disable
static int uart_os = UART_OS;
#if MICROPY_REPL_EVENT_DRIVEN
static os_event_t uart_evt_queue[16];
#endif
// A small, static ring buffer for incoming chars
// This will only be populated if the UART is not attached to dupterm
uint8 uart_ringbuf_array[UART0_STATIC_RXBUF_LEN];
static ringbuf_t uart_ringbuf = {uart_ringbuf_array, sizeof(uart_ringbuf_array), 0, 0};
static void uart0_rx_intr_handler(void *para);
void soft_reset(void);
void mp_sched_keyboard_interrupt(void);
/******************************************************************************
* FunctionName : uart_config
* Description : Internal used function
* UART0 used for data TX/RX, RX buffer size is 0x100, interrupt enabled
* UART1 just used for debug output
* Parameters : uart_no, use UART0 or UART1 defined ahead
* Returns : NONE
*******************************************************************************/
static void ICACHE_FLASH_ATTR uart_config(uint8 uart_no) {
if (uart_no == UART1) {
PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_U1TXD_BK);
} else {
ETS_UART_INTR_ATTACH(uart0_rx_intr_handler, NULL);
PIN_PULLUP_DIS(PERIPHS_IO_MUX_U0TXD_U);
PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0TXD_U, FUNC_U0TXD);
PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0RXD_U, FUNC_U0RXD);
}
uart_div_modify(uart_no, UART_CLK_FREQ / (UartDev.baut_rate));
WRITE_PERI_REG(UART_CONF0(uart_no), UartDev.exist_parity
| UartDev.parity
| (UartDev.stop_bits << UART_STOP_BIT_NUM_S)
| (UartDev.data_bits << UART_BIT_NUM_S));
// clear rx and tx fifo,not ready
SET_PERI_REG_MASK(UART_CONF0(uart_no), UART_RXFIFO_RST | UART_TXFIFO_RST);
CLEAR_PERI_REG_MASK(UART_CONF0(uart_no), UART_RXFIFO_RST | UART_TXFIFO_RST);
if (uart_no == UART0) {
// set rx fifo trigger
WRITE_PERI_REG(UART_CONF1(uart_no),
((0x10 & UART_RXFIFO_FULL_THRHD) << UART_RXFIFO_FULL_THRHD_S) |
((0x10 & UART_RX_FLOW_THRHD) << UART_RX_FLOW_THRHD_S) |
UART_RX_FLOW_EN |
(0x02 & UART_RX_TOUT_THRHD) << UART_RX_TOUT_THRHD_S |
UART_RX_TOUT_EN);
SET_PERI_REG_MASK(UART_INT_ENA(uart_no), UART_RXFIFO_TOUT_INT_ENA |
UART_FRM_ERR_INT_ENA);
} else {
WRITE_PERI_REG(UART_CONF1(uart_no),
((UartDev.rcv_buff.TrigLvl & UART_RXFIFO_FULL_THRHD) << UART_RXFIFO_FULL_THRHD_S));
}
// clear all interrupt
WRITE_PERI_REG(UART_INT_CLR(uart_no), 0xffff);
// enable rx_interrupt
SET_PERI_REG_MASK(UART_INT_ENA(uart_no), UART_RXFIFO_FULL_INT_ENA);
}
/******************************************************************************
* FunctionName : uart1_tx_one_char
* Description : Internal used function
* Use uart1 interface to transfer one char
* Parameters : uint8 TxChar - character to tx
* Returns : OK
*******************************************************************************/
void uart_tx_one_char(uint8 uart, uint8 TxChar) {
while (true) {
uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) < 126) {
break;
}
}
WRITE_PERI_REG(UART_FIFO(uart), TxChar);
}
int uart_txdone(uint8 uart) {
uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) == 0) {
return true;
} else {
return false;
}
}
void uart_flush(uint8 uart) {
while (true) {
uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) == 0) {
break;
}
}
}
/******************************************************************************
* FunctionName : uart1_write_char
* Description : Internal used function
* Do some special deal while tx char is '\r' or '\n'
* Parameters : char c - character to tx
* Returns : NONE
*******************************************************************************/
static void ICACHE_FLASH_ATTR
uart_os_write_char(char c) {
if (uart_os == -1) {
return;
}
if (c == '\n') {
uart_tx_one_char(uart_os, '\r');
uart_tx_one_char(uart_os, '\n');
} else if (c == '\r') {
} else {
uart_tx_one_char(uart_os, c);
}
}
void ICACHE_FLASH_ATTR
uart_os_config(int uart) {
uart_os = uart;
}
/******************************************************************************
* FunctionName : uart0_rx_intr_handler
* Description : Internal used function
* UART0 interrupt handler, add self handle code inside
* Parameters : void *para - point to ETS_UART_INTR_ATTACH's arg
* Returns : NONE
*******************************************************************************/
static void uart0_rx_intr_handler(void *para) {
/* uart0 and uart1 intr combine togther, when interrupt occur, see reg 0x3ff20020, bit2, bit0 represents
* uart1 and uart0 respectively
*/
uint8 uart_no = UART_REPL;
if (UART_FRM_ERR_INT_ST == (READ_PERI_REG(UART_INT_ST(uart_no)) & UART_FRM_ERR_INT_ST)) {
// frame error
WRITE_PERI_REG(UART_INT_CLR(uart_no), UART_FRM_ERR_INT_CLR);
}
if (UART_RXFIFO_FULL_INT_ST == (READ_PERI_REG(UART_INT_ST(uart_no)) & UART_RXFIFO_FULL_INT_ST)) {
// fifo full
goto read_chars;
} else if (UART_RXFIFO_TOUT_INT_ST == (READ_PERI_REG(UART_INT_ST(uart_no)) & UART_RXFIFO_TOUT_INT_ST)) {
read_chars:
ETS_UART_INTR_DISABLE();
while (READ_PERI_REG(UART_STATUS(uart_no)) & (UART_RXFIFO_CNT << UART_RXFIFO_CNT_S)) {
uint8 RcvChar = READ_PERI_REG(UART_FIFO(uart_no)) & 0xff;
// For efficiency, when connected to dupterm we put incoming chars
// directly on stdin_ringbuf, rather than going via uart_ringbuf
if (uart_attached_to_dupterm) {
if (RcvChar == mp_interrupt_char) {
mp_sched_keyboard_interrupt();
} else {
ringbuf_put(&stdin_ringbuf, RcvChar);
}
} else {
ringbuf_put(&uart_ringbuf, RcvChar);
}
}
// Clear pending FIFO interrupts
WRITE_PERI_REG(UART_INT_CLR(UART_REPL), UART_RXFIFO_TOUT_INT_CLR | UART_RXFIFO_FULL_INT_ST);
ETS_UART_INTR_ENABLE();
if (uart_attached_to_dupterm) {
mp_hal_signal_input();
}
}
}
// Waits at most timeout microseconds for at least 1 char to become ready for reading.
// Returns true if something available, false if not.
bool ICACHE_FLASH_ATTR uart_rx_wait(uint32_t timeout_us) {
uint32_t start = system_get_time();
for (;;) {
if (uart_ringbuf.iget != uart_ringbuf.iput) {
return true; // have at least 1 char ready for reading
}
if (system_get_time() - start >= timeout_us) {
return false; // timeout
}
ets_event_poll();
}
}
int uart_rx_any(uint8 uart) {
if (uart_ringbuf.iget != uart_ringbuf.iput) {
return true; // have at least 1 char ready for reading
}
return false;
}
int uart_tx_any_room(uint8 uart) {
uint32_t fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) >= 126) {
return false;
}
return true;
}
// Returns char from the input buffer, else -1 if buffer is empty.
int uart_rx_char(void) {
return ringbuf_get(&uart_ringbuf);
}
int uart_rx_one_char(uint8 uart_no) {
if (READ_PERI_REG(UART_STATUS(uart_no)) & (UART_RXFIFO_CNT << UART_RXFIFO_CNT_S)) {
return READ_PERI_REG(UART_FIFO(uart_no)) & 0xff;
}
return -1;
}
/******************************************************************************
* FunctionName : uart_init
* Description : user interface for init uart
* Parameters : UartBautRate uart0_br - uart0 bautrate
* UartBautRate uart1_br - uart1 bautrate
* Returns : NONE
*******************************************************************************/
void ICACHE_FLASH_ATTR uart_init(UartBautRate uart0_br, UartBautRate uart1_br) {
// rom use 74880 baut_rate, here reinitialize
UartDev.baut_rate = uart0_br;
uart_config(UART0);
UartDev.baut_rate = uart1_br;
uart_config(UART1);
ETS_UART_INTR_ENABLE();
// install handler for "os" messages
os_install_putc1((void *)uart_os_write_char);
}
void ICACHE_FLASH_ATTR uart_reattach() {
uart_init(UART_BIT_RATE_74880, UART_BIT_RATE_74880);
}
void ICACHE_FLASH_ATTR uart_setup(uint8 uart) {
ETS_UART_INTR_DISABLE();
uart_config(uart);
ETS_UART_INTR_ENABLE();
}
int ICACHE_FLASH_ATTR uart0_get_rxbuf_len(void) {
return uart_ringbuf.size;
}
void ICACHE_FLASH_ATTR uart0_set_rxbuf(uint8 *buf, int len) {
ETS_UART_INTR_DISABLE();
uart_ringbuf.buf = buf;
uart_ringbuf.size = len;
uart_ringbuf.iget = 0;
uart_ringbuf.iput = 0;
ETS_UART_INTR_ENABLE();
}
// Task-based UART interface
#include "py/obj.h"
#include "shared/runtime/pyexec.h"
#if MICROPY_REPL_EVENT_DRIVEN
void ICACHE_FLASH_ATTR uart_task_handler(os_event_t *evt) {
if (pyexec_repl_active) {
// TODO: Just returning here isn't exactly right.
// What really should be done is something like
// enquing delayed event to itself, for another
// chance to feed data to REPL. Otherwise, there
// can be situation when buffer has bunch of data,
// and sits unprocessed, because we consumed all
// processing signals like this.
return;
}
int c, ret = 0;
while ((c = ringbuf_get(&stdin_ringbuf)) >= 0) {
if (c == mp_interrupt_char) {
mp_sched_keyboard_interrupt();
}
ret = pyexec_event_repl_process_char(c);
if (ret & PYEXEC_FORCED_EXIT) {
break;
}
}
if (ret & PYEXEC_FORCED_EXIT) {
soft_reset();
}
}
void uart_task_init() {
system_os_task(uart_task_handler, UART_TASK_ID, uart_evt_queue, sizeof(uart_evt_queue) / sizeof(*uart_evt_queue));
}
#endif