UART

概述

通用异步收发传输器（Universal Asynchronous Receiver/Transmitter，通常称为UART）是一种异步收发传输器，提供了与外部设备进行全双工数据交换的灵活方式。 BL602共有2组UART口（UART0和UART1），通过配合DMA使用，可以实现高效的数据通信。

注解

需要注意的是gpio的pin脚作为uart功能使用时，选取的gpio pin脚对8取余不能相等，如gpio0和gpio8不能同时做为uart的引脚，uart更多资料请参考 BL602参考手册 , BL602参考手册的3.2.8 GPIO功能设定。

应用实例

串口实例： customer_app/peripheral/demo_uart 。

API参考

Header File

components/platform/hosal/include/hosal_uart.h

Functions

int hosal_uart_abr_get(hosal_uart_dev_t *uart, uint8_t mode)

Get auto baudrate on a UART interface.

Return

= 0 on success
EIO if an error occurred with any step

Parameters

uart: the UART interface
mode: auto baudrate detection mode(codeword 0x55 or start bit)

int hosal_uart_init(hosal_uart_dev_t *uart)

Initialises a UART interface.

Return

0 on success
EIO if an error occurred with any step

Parameters

uart: the interface which should be initialised

int hosal_uart_send(hosal_uart_dev_t *uart, const void *txbuf, uint32_t size)

Poll transmit data on a UART interface.

Return

> 0 on success
EIO if an error occurred with any step

Parameters

uart: the UART interface
txbuf: pointer to the start of data
size: number of bytes to transmit

int hosal_uart_receive(hosal_uart_dev_t *uart, void *data, uint32_t expect_size)

Poll receive data on a UART interface.

Return

> 0 number of bytes to receive
EIO if an error occurred with any step

Parameters

uart: the UART interface
rxbuf: pointer to the buffer which will store incoming data
expect_size: expect number of bytes to receive

int hosal_uart_ioctl(hosal_uart_dev_t *uart, int ctl, void *p_arg)

hal uart ioctl

Return

0 on success
EIO if an error occurred with any step

Parameters

uart: the UART interface
ctl: Control request
- HOSAL_UART_BAUD_SET : baud set, p_arg is baud
- HOSAL_UART_BAUD_GET : baud get, p_arg is baud's pointer
- HOSAL_UART_DATA_WIDTH_SET : set data width，p_arg is hosal_uart_data_width_t
- HOSAL_UART_DATA_WIDTH_GET : get data width，p_arg is hosal_uart_data_width_t's pointer
- HOSAL_UART_STOP_BITS_SET : set stop bits, p_arg is hosal_uart_stop_bits_t
- HOSAL_UART_STOP_BITS_GET : get stop bits, p_arg is hosal_uart_stop_bits_t's pointer
- HOSAL_UART_PARITY_SET : set parity, p_arg is hosal_uart_parity_t
- HOSAL_UART_PARITY_GET : get parity, p_arg is hosal_uart_parity_t's pointer
- HOSAL_UART_MODE_SET : UART mode set, p_arg is hosal_uart_mode_t
- HOSAL_UART_MODE_GET : UART mode get, p_arg is hosal_uart_mode_t's pointer
- HOSAL_UART_FLOWMODE_SET : UART flow mode set, p_arg is hosal_uart_flow_control_t
- HOSAL_UART_FLOWSTAT_GET : UART flow state get, p_arg is hosal_uart_flow_control_t's pointer
- HOSAL_UART_FREE_TXFIFO_GET : get uart free tx fifo size (bytes)
- HOSAL_UART_FREE_RXFIFO_GET : get uart free rx fifo size (bytes)
- HOSAL_UART_FLUSH : Wait for the send to complete
- HOSAL_UART_TX_TRIGGER_ON : UART TX trigger on
- HOSAL_UART_TX_TRIGGER_OFF : UART TX trigger off
- HOSAL_UART_DMA_CONFIG : p_arg is hosal_uart_dma_cfg_t's pointer
- HOSAL_UART_DMA_TX_START : UART DMA TX start trans p_arg is hosal_uart_dma_cfg_t's pointer
- HOSAL_UART_DMA_RX_START : UART DMA RX start trans p_arg is hosal_uart_dma_cfg_t's pointer
p_arg: parameter

int hosal_uart_callback_set(hosal_uart_dev_t *uart, int callback_type, hosal_uart_callback_t pfn_callback, void *arg)

hal uart callback set

Return

0 on success
EIO if an error occurred with any step

Parameters

uart: the UART interface
callback_type: callback type
- HOSAL_UART_TX_CALLBACK
- HOSAL_UART_RX_CALLBACK
- HOSAL_UART_TX_DMA_CALLBACK
- HOSAL_UART_RX_DMA_CALLBACK
pfn_callback: callback function
arg: callback function parameter

int hosal_uart_finalize(hosal_uart_dev_t *uart)

Deinitialises a UART interface.

Return

0 on success
EIO if an error occurred with any step

Parameters

uart: the interface which should be deinitialised

Structures

struct hosal_uart_dma_cfg_t

UART DMA configuration.

Public Members

uint8_t *dma_buf: UART DMA trans buffer When the transmission is TX, the address is the src address When the transmission is RX, the address is the dest address.

uint32_t dma_buf_size: UART DMA trans buffer size.

struct hosal_uart_config_t

UART configuration.

Public Members

uint8_t uart_id: UART id.

uint8_t tx_pin: UART tx pin.

uint8_t rx_pin: UART rx pin.

uint8_t cts_pin: UART cts pin.

uint8_t rts_pin: UART rts pin.

uint32_t baud_rate: UART baud rate.

hosal_uart_data_width_t data_width: UART data width.

hosal_uart_parity_t parity: UART parity bit.

hosal_uart_stop_bits_t stop_bits: UART stop btis.

hosal_uart_flow_control_t flow_control: UART flow control.

hosal_uart_mode_t mode: UART int or pull mode.

struct hosal_uart_dev_t

UART device type.

Public Members

uint8_t port: UART port.

hosal_uart_config_t config: UART config.

hosal_uart_callback_t tx_cb: UART tx callback.

void *p_txarg: UART tx callback arg.

hosal_uart_callback_t rx_cb: UART rx callback.

void *p_rxarg: UART rx callback arg.

hosal_uart_callback_t txdma_cb: UART tx dma callback.

void *p_txdma_arg: UART tx dma callback arg.

hosal_uart_callback_t rxdma_cb: UART rx dma callback.

void *p_rxdma_arg: UART rx dma callback arg.

hosal_dma_chan_t dma_tx_chan: UART dma tx channel.

hosal_dma_chan_t dma_rx_chan: UART dma rx channel.

void *priv: UART private data.

Macros

HOSAL_UART_AUTOBAUD_0X55: UART auto baudrate detection using codeword 0x55.

HOSAL_UART_AUTOBAUD_STARTBIT: UART auto baudrate detection using start bit.

HOSAL_UART_TX_CALLBACK: UART tx idle interrupt callback.

HOSAL_UART_RX_CALLBACK: UART rx complete callback.

HOSAL_UART_TX_DMA_CALLBACK: UART tx DMA trans complete callback.

HOSAL_UART_RX_DMA_CALLBACK: UART rx DMA trans complete callback.

HOSAL_UART_BAUD_SET: UART baud set.

HOSAL_UART_BAUD_GET: UART baud get.

HOSAL_UART_DATA_WIDTH_SET: UART data width set.

HOSAL_UART_DATA_WIDTH_GET: UART data width get.

HOSAL_UART_STOP_BITS_SET: UART stop bits set.

HOSAL_UART_STOP_BITS_GET: UART stop bits get.

HOSAL_UART_FLOWMODE_SET: UART flow mode set.

HOSAL_UART_FLOWSTAT_GET: UART flow state get.

HOSAL_UART_PARITY_SET: UART flow mode set.

HOSAL_UART_PARITY_GET: UART flow state get.

HOSAL_UART_MODE_SET: UART mode set.

HOSAL_UART_MODE_GET: UART mode get.

HOSAL_UART_FREE_TXFIFO_GET: UART free tx fifo get.

HOSAL_UART_FREE_RXFIFO_GET: UART free rx fifo get.

HOSAL_UART_FLUSH: Wait for the send to complete.

HOSAL_UART_TX_TRIGGER_ON: UART TX trigger on.

HOSAL_UART_TX_TRIGGER_OFF: UART TX trigger off.

HOSAL_UART_DMA_TX_START: UART DMA TX start trans.

HOSAL_UART_DMA_RX_START: UART DMA RX start trans.

HOSAL_UART_CFG_DECL(cfg, id, tx, rx, baud)

define a UART default config

Parameters

cfg: config define
id: uart id
tx: uart tx pin
rx: uart rx pin
baud: uart baud

HOSAL_UART_DEV_DECL(dev, id, tx, rx, baud)

define a UART device

Parameters

dev: uart device
id: uart id
tx: uart tx pin
rx: uart rx pin
baud: uart baud

Type Definitions

typedef int (*hosal_uart_callback_t)(void *p_arg)

hosal uart callback

Return

0 : on success
EIO : if an error occurred with any step

Parameters

p_arg: Set the custom parameters specified when the callback function is set

Enumerations

enum hosal_uart_data_width_t

UART data width.

Values:

HOSAL_DATA_WIDTH_5BIT

HOSAL_DATA_WIDTH_6BIT

HOSAL_DATA_WIDTH_7BIT

HOSAL_DATA_WIDTH_8BIT

HOSAL_DATA_WIDTH_9BIT

enum hosal_uart_stop_bits_t

UART stop bits.

Values:

HOSAL_STOP_BITS_1 = 1

HOSAL_STOP_BITS_2 = 3

enum hosal_uart_flow_control_t

UART flow control.

Values:

HOSAL_FLOW_CONTROL_DISABLED

HOSAL_FLOW_CONTROL_RTS

HOSAL_FLOW_CONTROL_CTS

HOSAL_FLOW_CONTROL_CTS_RTS

enum hosal_uart_parity_t

UART parity.

Values:

HOSAL_NO_PARITY

HOSAL_ODD_PARITY

HOSAL_EVEN_PARITY

enum hosal_uart_mode_t

UART mode.

Values:

HOSAL_UART_MODE_POLL: UART poll mode (default mode)

HOSAL_UART_MODE_INT_TX: UART TX int mode.

HOSAL_UART_MODE_INT_RX: UART RX int mode.

HOSAL_UART_MODE_INT: UART TX and RX int mode.