UART Interface

UART Interface . More...

Topics
	Async UART API
	Interrupt-driven UART API
	Polling UART API

Data Structures
struct	uart_config
	UART controller configuration structure. More...

Enumerations
enum	uart_line_ctrl {   UART_LINE_CTRL_BAUD_RATE = BIT(0) , UART_LINE_CTRL_RTS = BIT(1) , UART_LINE_CTRL_DTR = BIT(2) , UART_LINE_CTRL_DCD = BIT(3) ,   UART_LINE_CTRL_DSR = BIT(4) }
	Line control signals. More...
enum	uart_rx_stop_reason {   UART_ERROR_OVERRUN = (1 << 0) , UART_ERROR_PARITY = (1 << 1) , UART_ERROR_FRAMING = (1 << 2) , UART_BREAK = (1 << 3) ,   UART_ERROR_COLLISION = (1 << 4) , UART_ERROR_NOISE = (1 << 5) }
	Reception stop reasons. More...
enum	uart_config_parity {   UART_CFG_PARITY_NONE , UART_CFG_PARITY_ODD , UART_CFG_PARITY_EVEN , UART_CFG_PARITY_MARK ,   UART_CFG_PARITY_SPACE }
	Parity modes. More...
enum	uart_config_stop_bits { UART_CFG_STOP_BITS_0_5 , UART_CFG_STOP_BITS_1 , UART_CFG_STOP_BITS_1_5 , UART_CFG_STOP_BITS_2 }
	Number of stop bits. More...
enum	uart_config_data_bits {   UART_CFG_DATA_BITS_5 , UART_CFG_DATA_BITS_6 , UART_CFG_DATA_BITS_7 , UART_CFG_DATA_BITS_8 ,   UART_CFG_DATA_BITS_9 }
	Number of data bits. More...
enum	uart_config_flow_control { UART_CFG_FLOW_CTRL_NONE , UART_CFG_FLOW_CTRL_RTS_CTS , UART_CFG_FLOW_CTRL_DTR_DSR , UART_CFG_FLOW_CTRL_RS485 }
	Hardware flow control options. More...

Functions
int	uart_err_check (const struct device *dev)
	Check whether an error was detected.
int	uart_configure (const struct device *dev, const struct uart_config *cfg)
	Set UART configuration.
int	uart_config_get (const struct device *dev, struct uart_config *cfg)
	Get UART configuration.
int	uart_line_ctrl_set (const struct device *dev, uint32_t ctrl, uint32_t val)
	Manipulate line control for UART.
int	uart_line_ctrl_get (const struct device *dev, uint32_t ctrl, uint32_t *val)
	Retrieve line control for UART.
int	uart_drv_cmd (const struct device *dev, uint32_t cmd, uint32_t p)
	Send extra command to driver.

Detailed Description

UART Interface .

Since

1.0

Version

1.0.0

Enumeration Type Documentation

uart_config_data_bits

enum uart_config_data_bits

#include <zephyr/drivers/uart.h>

Number of data bits.

Enumerator
UART_CFG_DATA_BITS_5	5 data bits
UART_CFG_DATA_BITS_6	6 data bits
UART_CFG_DATA_BITS_7	7 data bits
UART_CFG_DATA_BITS_8	8 data bits
UART_CFG_DATA_BITS_9	9 data bits

uart_config_flow_control

enum uart_config_flow_control

#include <zephyr/drivers/uart.h>

Hardware flow control options.

With flow control set to none, any operations related to flow control signals can be managed by user with uart_line_ctrl functions. In other cases, flow control is managed by hardware/driver.

Enumerator
UART_CFG_FLOW_CTRL_NONE	No flow control.
UART_CFG_FLOW_CTRL_RTS_CTS	RTS/CTS flow control.
UART_CFG_FLOW_CTRL_DTR_DSR	DTR/DSR flow control.
UART_CFG_FLOW_CTRL_RS485	RS485 flow control.

uart_config_parity

enum uart_config_parity

#include <zephyr/drivers/uart.h>

Parity modes.

Enumerator
UART_CFG_PARITY_NONE	No parity.
UART_CFG_PARITY_ODD	Odd parity.
UART_CFG_PARITY_EVEN	Even parity.
UART_CFG_PARITY_MARK	Mark parity.
UART_CFG_PARITY_SPACE	Space parity.

uart_config_stop_bits

enum uart_config_stop_bits

#include <zephyr/drivers/uart.h>

Number of stop bits.

Enumerator
UART_CFG_STOP_BITS_0_5	0.5 stop bit
UART_CFG_STOP_BITS_1	1 stop bit
UART_CFG_STOP_BITS_1_5	1.5 stop bits
UART_CFG_STOP_BITS_2	2 stop bits

uart_line_ctrl

enum uart_line_ctrl

#include <zephyr/drivers/uart.h>

Line control signals.

Enumerator
UART_LINE_CTRL_BAUD_RATE	Baud rate.
UART_LINE_CTRL_RTS	Request To Send (RTS)
UART_LINE_CTRL_DTR	Data Terminal Ready (DTR)
UART_LINE_CTRL_DCD	Data Carrier Detect (DCD)
UART_LINE_CTRL_DSR	Data Set Ready (DSR)

uart_rx_stop_reason

enum uart_rx_stop_reason

#include <zephyr/drivers/uart.h>

Reception stop reasons.

Values that correspond to events or errors responsible for stopping receiving.

Enumerator
UART_ERROR_OVERRUN	Overrun error.
UART_ERROR_PARITY	Parity error.
UART_ERROR_FRAMING	Framing error.
UART_BREAK	Break interrupt. A break interrupt was received. This happens when the serial input is held at a logic '0' state for longer than the sum of start time + data bits + parity + stop bits.
UART_ERROR_COLLISION	Collision error. This error is raised when transmitted data does not match received data. Typically this is useful in scenarios where the TX and RX lines maybe connected together such as RS-485 half-duplex. This error is only valid on UARTs that support collision checking.
UART_ERROR_NOISE	Noise error.

Function Documentation

uart_config_get()

int uart_config_get	(	const struct device *	dev,
		struct uart_config *	cfg )

#include <zephyr/drivers/uart.h>

Get UART configuration.

Stores current UART configuration to *cfg, can be used to retrieve initial configuration after device was initialized using data from DTS.

Parameters

dev	UART device instance.
cfg	UART configuration structure.

Return values

0	If successful.
-errno	Negative errno code in case of failure.
-ENOSYS	If driver does not support getting current configuration.
-ENOTSUP	If API is not enabled.

uart_configure()

int uart_configure	(	const struct device *	dev,
		const struct uart_config *	cfg )

#include <zephyr/drivers/uart.h>

Set UART configuration.

Sets UART configuration using data from *cfg.

Parameters

dev	UART device instance.
cfg	UART configuration structure.

Return values

0	If successful.
-errno	Negative errno code in case of failure.
-ENOSYS	If configuration is not supported by device or driver does not support setting configuration in runtime.
-ENOTSUP	If API is not enabled.

uart_drv_cmd()

int uart_drv_cmd	(	const struct device *	dev,
		uint32_t	cmd,
		uint32_t	p )

#include <zephyr/drivers/uart.h>

Send extra command to driver.

Implementation and accepted commands are driver specific. Refer to the drivers for more information.

Parameters

dev	UART device instance.
cmd	Command to driver.
p	Parameter to the command.

Return values

0	If successful.
-ENOSYS	If this function is not implemented.
-ENOTSUP	If API is not enabled.
-errno	Other negative errno value in case of failure.

uart_err_check()

int uart_err_check

(

const struct device *

dev

)

#include <zephyr/drivers/uart.h>

Check whether an error was detected.

Parameters

dev	UART device instance.

Return values

0	If no error was detected.
err	Error flags as defined in uart_rx_stop_reason
-ENOSYS	If not implemented.

uart_line_ctrl_get()

int uart_line_ctrl_get	(	const struct device *	dev,
		uint32_t	ctrl,
		uint32_t *	val )

#include <zephyr/drivers/uart.h>

Retrieve line control for UART.

Parameters

dev	UART device instance.
ctrl	The line control to retrieve (see enum uart_line_ctrl).
val	Pointer to variable where to store the line control value.

Return values

0	If successful.
-ENOSYS	If this function is not implemented.
-ENOTSUP	If API is not enabled.
-errno	Other negative errno value in case of failure.

uart_line_ctrl_set()

int uart_line_ctrl_set	(	const struct device *	dev,
		uint32_t	ctrl,
		uint32_t	val )

#include <zephyr/drivers/uart.h>

Manipulate line control for UART.

Parameters

dev	UART device instance.
ctrl	The line control to manipulate (see enum uart_line_ctrl).
val	Value to set to the line control.

Return values

0	If successful.
-ENOSYS	If this function is not implemented.
-ENOTSUP	If API is not enabled.
-errno	Other negative errno value in case of failure.