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circuitpython/ports/esp8266/uart.c

309 lines
10 KiB

/******************************************************************************
* 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
static byte uart_ringbuf_array[16];
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_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);
}
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_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 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();
}
// Task-based UART interface
#include "py/obj.h"
#include "lib/utils/pyexec.h"
#if MICROPY_REPL_EVENT_DRIVEN
void 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(&input_buf)) >= 0) {
if (c == mp_interrupt_char) {
mp_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