OVMS3-idf/components/driver/include/driver/uart.h
Alex Lisitsyn a952eb1a92 driver: add rs485 half duplex interface support to uart driver (fix indentation after review)
An existing UART driver does not support RS485 half duplex mode.
This task adds this functionality to ESP_IDF UART driver.
driver/uart.c/h: updated to add support of RS485 half duplex mode
examples/peripherals/uart_echo_rs485/main/rs485_example.c: added test example
components/driver/test/test_uart.c: added test of RS485 half duplex mode
docs/en/api-reference/peripherals/uart.rst: updated documentation
test_uart.c: suppress GCC warnings about discarded const qualifiers
uart.rst: remove sphinx warning - "Duplicate explicit target name"
simple change in uart.h file
update (test_uart.c) after rebase from master
update uart.rst, uart.c, rs485_example.c
Update example description in file Readme.md
update uart.c/h, uart.rst, test_uart.c according to review results
update uart.h (uart_set_rx_timeout() description
test_uart.c remove ignore tag
uart.c/h: fix param errors
test_uart.c: Remove GCC warning supress
uart.rst: fix the notes
rs485_example.c: fix output

The tests are completed using RS485 adapters hardware connected to two ESP32 WROVER KITs.

TW#13812
Closes https://github.com/espressif/esp-idf/pull/667
Closes https://github.com/espressif/esp-idf/pull/1006
2018-07-02 15:24:58 +02:00

799 lines
28 KiB
C

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef _DRIVER_UART_H_
#define _DRIVER_UART_H_
#ifdef __cplusplus
extern "C" {
#endif
#include "soc/uart_reg.h"
#include "soc/uart_struct.h"
#include "esp_err.h"
#include "esp_intr_alloc.h"
#include "driver/periph_ctrl.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "freertos/xtensa_api.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "freertos/ringbuf.h"
#include <esp_types.h>
#include "soc/uart_channel.h"
#define UART_FIFO_LEN (128) /*!< Length of the hardware FIFO buffers */
#define UART_INTR_MASK 0x1ff /*!< Mask of all UART interrupts */
#define UART_LINE_INV_MASK (0x3f << 19) /*!< TBD */
#define UART_BITRATE_MAX 5000000 /*!< Max bit rate supported by UART */
#define UART_PIN_NO_CHANGE (-1) /*!< Constant for uart_set_pin function which indicates that UART pin should not be changed */
#define UART_INVERSE_DISABLE (0x0) /*!< Disable UART signal inverse*/
#define UART_INVERSE_RXD (UART_RXD_INV_M) /*!< UART RXD input inverse*/
#define UART_INVERSE_CTS (UART_CTS_INV_M) /*!< UART CTS input inverse*/
#define UART_INVERSE_TXD (UART_TXD_INV_M) /*!< UART TXD output inverse*/
#define UART_INVERSE_RTS (UART_RTS_INV_M) /*!< UART RTS output inverse*/
/**
* @brief UART mode selection
*/
typedef enum {
UART_MODE_UART = 0x00, /*!< mode: regular UART mode*/
UART_MODE_RS485_HALF_DUPLEX = 0x01, /*!< mode: half duplex RS485 UART mode control by RTS pin */
UART_MODE_IRDA = 0x02, /*!< mode: IRDA UART mode*/
UART_MODE_RS485_COLLISION_DETECT = 0x03, /*!< mode: RS485 collision detection UART mode (used for test purposes)*/
UART_MODE_RS485_APP_CTRL = 0x04, /*!< mode: application control RS485 UART mode (used for test purposes)*/
} uart_mode_t;
/**
* @brief UART word length constants
*/
typedef enum {
UART_DATA_5_BITS = 0x0, /*!< word length: 5bits*/
UART_DATA_6_BITS = 0x1, /*!< word length: 6bits*/
UART_DATA_7_BITS = 0x2, /*!< word length: 7bits*/
UART_DATA_8_BITS = 0x3, /*!< word length: 8bits*/
UART_DATA_BITS_MAX = 0x4,
} uart_word_length_t;
/**
* @brief UART stop bits number
*/
typedef enum {
UART_STOP_BITS_1 = 0x1, /*!< stop bit: 1bit*/
UART_STOP_BITS_1_5 = 0x2, /*!< stop bit: 1.5bits*/
UART_STOP_BITS_2 = 0x3, /*!< stop bit: 2bits*/
UART_STOP_BITS_MAX = 0x4,
} uart_stop_bits_t;
/**
* @brief UART peripheral number
*/
typedef enum {
UART_NUM_0 = 0x0, /*!< UART base address 0x3ff40000*/
UART_NUM_1 = 0x1, /*!< UART base address 0x3ff50000*/
UART_NUM_2 = 0x2, /*!< UART base address 0x3ff6e000*/
UART_NUM_MAX,
} uart_port_t;
/**
* @brief UART parity constants
*/
typedef enum {
UART_PARITY_DISABLE = 0x0, /*!< Disable UART parity*/
UART_PARITY_EVEN = 0x2, /*!< Enable UART even parity*/
UART_PARITY_ODD = 0x3 /*!< Enable UART odd parity*/
} uart_parity_t;
/**
* @brief UART hardware flow control modes
*/
typedef enum {
UART_HW_FLOWCTRL_DISABLE = 0x0, /*!< disable hardware flow control*/
UART_HW_FLOWCTRL_RTS = 0x1, /*!< enable RX hardware flow control (rts)*/
UART_HW_FLOWCTRL_CTS = 0x2, /*!< enable TX hardware flow control (cts)*/
UART_HW_FLOWCTRL_CTS_RTS = 0x3, /*!< enable hardware flow control*/
UART_HW_FLOWCTRL_MAX = 0x4,
} uart_hw_flowcontrol_t;
/**
* @brief UART configuration parameters for uart_param_config function
*/
typedef struct {
int baud_rate; /*!< UART baud rate*/
uart_word_length_t data_bits; /*!< UART byte size*/
uart_parity_t parity; /*!< UART parity mode*/
uart_stop_bits_t stop_bits; /*!< UART stop bits*/
uart_hw_flowcontrol_t flow_ctrl; /*!< UART HW flow control mode (cts/rts)*/
uint8_t rx_flow_ctrl_thresh; /*!< UART HW RTS threshold*/
bool use_ref_tick; /*!< Set to true if UART should be clocked from REF_TICK */
} uart_config_t;
/**
* @brief UART interrupt configuration parameters for uart_intr_config function
*/
typedef struct {
uint32_t intr_enable_mask; /*!< UART interrupt enable mask, choose from UART_XXXX_INT_ENA_M under UART_INT_ENA_REG(i), connect with bit-or operator*/
uint8_t rx_timeout_thresh; /*!< UART timeout interrupt threshold (unit: time of sending one byte)*/
uint8_t txfifo_empty_intr_thresh; /*!< UART TX empty interrupt threshold.*/
uint8_t rxfifo_full_thresh; /*!< UART RX full interrupt threshold.*/
} uart_intr_config_t;
/**
* @brief UART event types used in the ring buffer
*/
typedef enum {
UART_DATA, /*!< UART data event*/
UART_BREAK, /*!< UART break event*/
UART_BUFFER_FULL, /*!< UART RX buffer full event*/
UART_FIFO_OVF, /*!< UART FIFO overflow event*/
UART_FRAME_ERR, /*!< UART RX frame error event*/
UART_PARITY_ERR, /*!< UART RX parity event*/
UART_DATA_BREAK, /*!< UART TX data and break event*/
UART_PATTERN_DET, /*!< UART pattern detected */
UART_EVENT_MAX, /*!< UART event max index*/
} uart_event_type_t;
/**
* @brief Event structure used in UART event queue
*/
typedef struct {
uart_event_type_t type; /*!< UART event type */
size_t size; /*!< UART data size for UART_DATA event*/
} uart_event_t;
typedef intr_handle_t uart_isr_handle_t;
/**
* @brief Set UART data bits.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param data_bit UART data bits
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_word_length(uart_port_t uart_num, uart_word_length_t data_bit);
/**
* @brief Get UART data bits.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param data_bit Pointer to accept value of UART data bits.
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success, result will be put in (*data_bit)
*/
esp_err_t uart_get_word_length(uart_port_t uart_num, uart_word_length_t* data_bit);
/**
* @brief Set UART stop bits.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param stop_bits UART stop bits
*
* @return
* - ESP_OK Success
* - ESP_FAIL Fail
*/
esp_err_t uart_set_stop_bits(uart_port_t uart_num, uart_stop_bits_t stop_bits);
/**
* @brief Get UART stop bits.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param stop_bits Pointer to accept value of UART stop bits.
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success, result will be put in (*stop_bit)
*/
esp_err_t uart_get_stop_bits(uart_port_t uart_num, uart_stop_bits_t* stop_bits);
/**
* @brief Set UART parity mode.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param parity_mode the enum of uart parity configuration
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success
*/
esp_err_t uart_set_parity(uart_port_t uart_num, uart_parity_t parity_mode);
/**
* @brief Get UART parity mode.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param parity_mode Pointer to accept value of UART parity mode.
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success, result will be put in (*parity_mode)
*
*/
esp_err_t uart_get_parity(uart_port_t uart_num, uart_parity_t* parity_mode);
/**
* @brief Set UART baud rate.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param baudrate UART baud rate.
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success
*/
esp_err_t uart_set_baudrate(uart_port_t uart_num, uint32_t baudrate);
/**
* @brief Get UART baud rate.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param baudrate Pointer to accept value of UART baud rate
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success, result will be put in (*baudrate)
*
*/
esp_err_t uart_get_baudrate(uart_port_t uart_num, uint32_t* baudrate);
/**
* @brief Set UART line inverse mode
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param inverse_mask Choose the wires that need to be inverted.
* Inverse_mask should be chosen from
* UART_INVERSE_RXD / UART_INVERSE_TXD / UART_INVERSE_RTS / UART_INVERSE_CTS,
* combined with OR operation.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_line_inverse(uart_port_t uart_num, uint32_t inverse_mask);
/**
* @brief Set hardware flow control.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param flow_ctrl Hardware flow control mode
* @param rx_thresh Threshold of Hardware RX flow control (0 ~ UART_FIFO_LEN).
* Only when UART_HW_FLOWCTRL_RTS is set, will the rx_thresh value be set.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_hw_flow_ctrl(uart_port_t uart_num, uart_hw_flowcontrol_t flow_ctrl, uint8_t rx_thresh);
/**
* @brief Set software flow control.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param enable switch on or off
* @param rx_thresh_xon low water mark
* @param rx_thresh_xoff high water mark
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_sw_flow_ctrl(uart_port_t uart_num, bool enable, uint8_t rx_thresh_xon, uint8_t rx_thresh_xoff);
/**
* @brief Get hardware flow control mode
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param flow_ctrl Option for different flow control mode.
*
* @return
* - ESP_FAIL Parameter error
* - ESP_OK Success, result will be put in (*flow_ctrl)
*/
esp_err_t uart_get_hw_flow_ctrl(uart_port_t uart_num, uart_hw_flowcontrol_t* flow_ctrl);
/**
* @brief Clear UART interrupt status
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param clr_mask Bit mask of the interrupt status to be cleared.
* The bit mask should be composed from the fields of register UART_INT_CLR_REG.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_clear_intr_status(uart_port_t uart_num, uint32_t clr_mask);
/**
* @brief Set UART interrupt enable
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param enable_mask Bit mask of the enable bits.
* The bit mask should be composed from the fields of register UART_INT_ENA_REG.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_enable_intr_mask(uart_port_t uart_num, uint32_t enable_mask);
/**
* @brief Clear UART interrupt enable bits
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param disable_mask Bit mask of the disable bits.
* The bit mask should be composed from the fields of register UART_INT_ENA_REG.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_disable_intr_mask(uart_port_t uart_num, uint32_t disable_mask);
/**
* @brief Enable UART RX interrupt (RX_FULL & RX_TIMEOUT INTERRUPT)
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_enable_rx_intr(uart_port_t uart_num);
/**
* @brief Disable UART RX interrupt (RX_FULL & RX_TIMEOUT INTERRUPT)
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_disable_rx_intr(uart_port_t uart_num);
/**
* @brief Disable UART TX interrupt (TX_FULL & TX_TIMEOUT INTERRUPT)
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_disable_tx_intr(uart_port_t uart_num);
/**
* @brief Enable UART TX interrupt (TX_FULL & TX_TIMEOUT INTERRUPT)
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param enable 1: enable; 0: disable
* @param thresh Threshold of TX interrupt, 0 ~ UART_FIFO_LEN
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_enable_tx_intr(uart_port_t uart_num, int enable, int thresh);
/**
* @brief Register UART interrupt handler (ISR).
*
* @note UART ISR handler will be attached to the same CPU core that this function is running on.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param fn Interrupt handler function.
* @param arg parameter for handler function
* @param intr_alloc_flags Flags used to allocate the interrupt. One or multiple (ORred)
* ESP_INTR_FLAG_* values. See esp_intr_alloc.h for more info.
* @param handle Pointer to return handle. If non-NULL, a handle for the interrupt will
* be returned here.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_isr_register(uart_port_t uart_num, void (*fn)(void*), void * arg, int intr_alloc_flags, uart_isr_handle_t *handle);
/**
* @brief Free UART interrupt handler registered by uart_isr_register. Must be called on the same core as
* uart_isr_register was called.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_isr_free(uart_port_t uart_num);
/**
* @brief Set UART pin number
*
* @note Internal signal can be output to multiple GPIO pads.
* Only one GPIO pad can connect with input signal.
*
* @note Instead of GPIO number a macro 'UART_PIN_NO_CHANGE' may be provided
to keep the currently allocated pin.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param tx_io_num UART TX pin GPIO number.
* @param rx_io_num UART RX pin GPIO number.
* @param rts_io_num UART RTS pin GPIO number.
* @param cts_io_num UART CTS pin GPIO number.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_pin(uart_port_t uart_num, int tx_io_num, int rx_io_num, int rts_io_num, int cts_io_num);
/**
* @brief Manually set the UART RTS pin level.
* @note UART must be configured with hardware flow control disabled.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param level 1: RTS output low (active); 0: RTS output high (block)
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_rts(uart_port_t uart_num, int level);
/**
* @brief Manually set the UART DTR pin level.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param level 1: DTR output low; 0: DTR output high
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_dtr(uart_port_t uart_num, int level);
/**
* @brief Set UART idle interval after tx FIFO is empty
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param idle_num idle interval after tx FIFO is empty(unit: the time it takes to send one bit
* under current baudrate)
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_set_tx_idle_num(uart_port_t uart_num, uint16_t idle_num);
/**
* @brief Set UART configuration parameters.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param uart_config UART parameter settings
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_param_config(uart_port_t uart_num, const uart_config_t *uart_config);
/**
* @brief Configure UART interrupts.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param intr_conf UART interrupt settings
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_intr_config(uart_port_t uart_num, const uart_intr_config_t *intr_conf);
/**
* @brief Install UART driver.
*
* UART ISR handler will be attached to the same CPU core that this function is running on.
*
* @note Rx_buffer_size should be greater than UART_FIFO_LEN. Tx_buffer_size should be either zero or greater than UART_FIFO_LEN.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param rx_buffer_size UART RX ring buffer size.
* @param tx_buffer_size UART TX ring buffer size.
* If set to zero, driver will not use TX buffer, TX function will block task until all data have been sent out.
* @param queue_size UART event queue size/depth.
* @param uart_queue UART event queue handle (out param). On success, a new queue handle is written here to provide
* access to UART events. If set to NULL, driver will not use an event queue.
* @param intr_alloc_flags Flags used to allocate the interrupt. One or multiple (ORred)
* ESP_INTR_FLAG_* values. See esp_intr_alloc.h for more info. Do not set ESP_INTR_FLAG_IRAM here
* (the driver's ISR handler is not located in IRAM)
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_driver_install(uart_port_t uart_num, int rx_buffer_size, int tx_buffer_size, int queue_size, QueueHandle_t* uart_queue, int intr_alloc_flags);
/**
* @brief Uninstall UART driver.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_driver_delete(uart_port_t uart_num);
/**
* @brief Wait until UART TX FIFO is empty.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param ticks_to_wait Timeout, count in RTOS ticks
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
* - ESP_ERR_TIMEOUT Timeout
*/
esp_err_t uart_wait_tx_done(uart_port_t uart_num, TickType_t ticks_to_wait);
/**
* @brief Send data to the UART port from a given buffer and length.
*
* This function will not wait for enough space in TX FIFO. It will just fill the available TX FIFO and return when the FIFO is full.
* @note This function should only be used when UART TX buffer is not enabled.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param buffer data buffer address
* @param len data length to send
*
* @return
* - (-1) Parameter error
* - OTHERS (>=0) The number of bytes pushed to the TX FIFO
*/
int uart_tx_chars(uart_port_t uart_num, const char* buffer, uint32_t len);
/**
* @brief Send data to the UART port from a given buffer and length,
*
* If the UART driver's parameter 'tx_buffer_size' is set to zero:
* This function will not return until all the data have been sent out, or at least pushed into TX FIFO.
*
* Otherwise, if the 'tx_buffer_size' > 0, this function will return after copying all the data to tx ring buffer,
* UART ISR will then move data from the ring buffer to TX FIFO gradually.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param src data buffer address
* @param size data length to send
*
* @return
* - (-1) Parameter error
* - OTHERS (>=0) The number of bytes pushed to the TX FIFO
*/
int uart_write_bytes(uart_port_t uart_num, const char* src, size_t size);
/**
* @brief Send data to the UART port from a given buffer and length,
*
* If the UART driver's parameter 'tx_buffer_size' is set to zero:
* This function will not return until all the data and the break signal have been sent out.
* After all data is sent out, send a break signal.
*
* Otherwise, if the 'tx_buffer_size' > 0, this function will return after copying all the data to tx ring buffer,
* UART ISR will then move data from the ring buffer to TX FIFO gradually.
* After all data sent out, send a break signal.
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param src data buffer address
* @param size data length to send
* @param brk_len break signal duration(unit: the time it takes to send one bit at current baudrate)
*
* @return
* - (-1) Parameter error
* - OTHERS (>=0) The number of bytes pushed to the TX FIFO
*/
int uart_write_bytes_with_break(uart_port_t uart_num, const char* src, size_t size, int brk_len);
/**
* @brief UART read bytes from UART buffer
*
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
* @param buf pointer to the buffer.
* @param length data length
* @param ticks_to_wait sTimeout, count in RTOS ticks
*
* @return
* - (-1) Error
* - OTHERS (>=0) The number of bytes read from UART FIFO
*/
int uart_read_bytes(uart_port_t uart_num, uint8_t* buf, uint32_t length, TickType_t ticks_to_wait);
/**
* @brief Alias of uart_flush_input.
* UART ring buffer flush. This will discard all data in the UART RX buffer.
* @note Instead of waiting the data sent out, this function will clear UART rx buffer.
* In order to send all the data in tx FIFO, we can use uart_wait_tx_done function.
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_flush(uart_port_t uart_num);
/**
* @brief Clear input buffer, discard all the data is in the ring-buffer.
* @note In order to send all the data in tx FIFO, we can use uart_wait_tx_done function.
* @param uart_num UART_NUM_0, UART_NUM_1 or UART_NUM_2
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_flush_input(uart_port_t uart_num);
/**
* @brief UART get RX ring buffer cached data length
*
* @param uart_num UART port number.
* @param size Pointer of size_t to accept cached data length
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_get_buffered_data_len(uart_port_t uart_num, size_t* size);
/**
* @brief UART disable pattern detect function.
* Designed for applications like 'AT commands'.
* When the hardware detects a series of one same character, the interrupt will be triggered.
*
* @param uart_num UART port number.
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_disable_pattern_det_intr(uart_port_t uart_num);
/**
* @brief UART enable pattern detect function.
* Designed for applications like 'AT commands'.
* When the hardware detect a series of one same character, the interrupt will be triggered.
*
* @param uart_num UART port number.
* @param pattern_chr character of the pattern
* @param chr_num number of the character, 8bit value.
* @param chr_tout timeout of the interval between each pattern characters, 24bit value, unit is APB (80Mhz) clock cycle.
* When the duration is less than this value, it will not take this data as at_cmd char
* @param post_idle idle time after the last pattern character, 24bit value, unit is APB (80Mhz) clock cycle.
* When the duration is less than this value, it will not take the previous data as the last at_cmd char
* @param pre_idle idle time before the first pattern character, 24bit value, unit is APB (80Mhz) clock cycle.
* When the duration is less than this value, it will not take this data as the first at_cmd char
*
* @return
* - ESP_OK Success
* - ESP_FAIL Parameter error
*/
esp_err_t uart_enable_pattern_det_intr(uart_port_t uart_num, char pattern_chr, uint8_t chr_num, int chr_tout, int post_idle, int pre_idle);
/**
* @brief Return the nearest detected pattern position in buffer.
* The positions of the detected pattern are saved in a queue,
* this function will dequeue the first pattern position and move the pointer to next pattern position.
* @note If the RX buffer is full and flow control is not enabled,
* the detected pattern may not be found in the rx buffer due to overflow.
*
* The following APIs will modify the pattern position info:
* uart_flush_input, uart_read_bytes, uart_driver_delete, uart_pop_pattern_pos
* It is the application's responsibility to ensure atomic access to the pattern queue and the rx data buffer
* when using pattern detect feature.
*
* @param uart_num UART port number
* @return
* - (-1) No pattern found for current index or parameter error
* - others the pattern position in rx buffer.
*/
int uart_pattern_pop_pos(uart_port_t uart_num);
/**
* @brief Return the nearest detected pattern position in buffer.
* The positions of the detected pattern are saved in a queue,
* This function do nothing to the queue.
* @note If the RX buffer is full and flow control is not enabled,
* the detected pattern may not be found in the rx buffer due to overflow.
*
* The following APIs will modify the pattern position info:
* uart_flush_input, uart_read_bytes, uart_driver_delete, uart_pop_pattern_pos
* It is the application's responsibility to ensure atomic access to the pattern queue and the rx data buffer
* when using pattern detect feature.
*
* @param uart_num UART port number
* @return
* - (-1) No pattern found for current index or parameter error
* - others the pattern position in rx buffer.
*/
int uart_pattern_get_pos(uart_port_t uart_num);
/**
* @brief Allocate a new memory with the given length to save record the detected pattern position in rx buffer.
* @param uart_num UART port number
* @param queue_length Max queue length for the detected pattern.
* If the queue length is not large enough, some pattern positions might be lost.
* Set this value to the maximum number of patterns that could be saved in data buffer at the same time.
* @return
* - ESP_ERR_NO_MEM No enough memory
* - ESP_ERR_INVALID_STATE Driver not installed
* - ESP_FAIL Parameter error
* - ESP_OK Success
*/
esp_err_t uart_pattern_queue_reset(uart_port_t uart_num, int queue_length);
/**
* @brief UART set communication mode
* @note This function must be executed after uart_driver_install(), when the driver object is initialized.
* @param uart_num Uart number to configure
* @param mode UART UART mode to set
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Parameter error
*/
esp_err_t uart_set_mode(uart_port_t uart_num, uart_mode_t mode);
/**
* @brief UART set threshold timeout for TOUT feature
*
* @param uart_num Uart number to configure
* @param tout_thresh This parameter defines timeout threshold in uart symbol periods. The maximum value of threshold is 126.
* tout_thresh = 1, defines TOUT interrupt timeout equal to transmission time of one symbol (~11 bit) on current baudrate.
* If the time is expired the UART_RXFIFO_TOUT_INT interrupt is triggered. If tout_thresh == 0,
* the TOUT feature is disabled.
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Parameter error
* - ESP_ERR_INVALID_STATE Driver is not installed
*/
esp_err_t uart_set_rx_timeout(uart_port_t uart_num, const uint8_t tout_thresh);
/**
* @brief Returns collision detection flag for RS485 mode
* Function returns the collision detection flag into variable pointed by collision_flag.
* *collision_flag = true, if collision detected else it is equal to false.
* This function should be executed when actual transmission is completed (after uart_write_bytes()).
*
* @param uart_num Uart number to configure
* @param collision_flag Pointer to variable of type bool to return collision flag.
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Parameter error
*/
esp_err_t uart_get_collision_flag(uart_port_t uart_num, bool* collision_flag);
#ifdef __cplusplus
}
#endif
#endif /*_DRIVER_UART_H_*/