Zephyr API Documentation 3.7.99
A Scalable Open Source RTOS
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Data Structures | |
struct | uart_event_tx |
UART TX event data. More... | |
struct | uart_event_rx |
UART RX event data. More... | |
struct | uart_event_rx_buf |
UART RX buffer released event data. More... | |
struct | uart_event_rx_stop |
UART RX stopped data. More... | |
struct | uart_event |
Structure containing information about current event. More... | |
Typedefs | |
typedef void(* | uart_callback_t) (const struct device *dev, struct uart_event *evt, void *user_data) |
Define the application callback function signature for uart_callback_set() function. | |
Enumerations | |
enum | uart_event_type { UART_TX_DONE , UART_TX_ABORTED , UART_RX_RDY , UART_RX_BUF_REQUEST , UART_RX_BUF_RELEASED , UART_RX_DISABLED , UART_RX_STOPPED } |
Types of events passed to callback in UART_ASYNC_API. More... | |
Functions | |
static int | uart_callback_set (const struct device *dev, uart_callback_t callback, void *user_data) |
Set event handler function. | |
int | uart_tx (const struct device *dev, const uint8_t *buf, size_t len, int32_t timeout) |
Send given number of bytes from buffer through UART. | |
int | uart_tx_u16 (const struct device *dev, const uint16_t *buf, size_t len, int32_t timeout) |
Send given number of datum from buffer through UART. | |
int | uart_tx_abort (const struct device *dev) |
Abort current TX transmission. | |
int | uart_rx_enable (const struct device *dev, uint8_t *buf, size_t len, int32_t timeout) |
Start receiving data through UART. | |
int | uart_rx_enable_u16 (const struct device *dev, uint16_t *buf, size_t len, int32_t timeout) |
Start receiving wide data through UART. | |
static int | uart_rx_buf_rsp (const struct device *dev, uint8_t *buf, size_t len) |
Provide receive buffer in response to UART_RX_BUF_REQUEST event. | |
static int | uart_rx_buf_rsp_u16 (const struct device *dev, uint16_t *buf, size_t len) |
Provide wide data receive buffer in response to UART_RX_BUF_REQUEST event. | |
int | uart_rx_disable (const struct device *dev) |
Disable RX. | |
typedef void(* uart_callback_t) (const struct device *dev, struct uart_event *evt, void *user_data) |
#include <zephyr/drivers/uart.h>
Define the application callback function signature for uart_callback_set() function.
dev | UART device instance. |
evt | Pointer to uart_event instance. |
user_data | Pointer to data specified by user. |
enum uart_event_type |
#include <zephyr/drivers/uart.h>
Types of events passed to callback in UART_ASYNC_API.
Receiving:
Any time during reception UART_RX_STOPPED event can occur. if there is any data received, UART_RX_RDY event will be generated. It will be followed by UART_RX_BUF_RELEASED event for every buffer currently passed to driver and finally by UART_RX_DISABLED event.
Receiving can be disabled using uart_rx_disable, after calling that function, if there is any data received, UART_RX_RDY event will be generated. UART_RX_BUF_RELEASED event will be generated for every buffer currently passed to driver and finally UART_RX_DISABLED event will occur.
Transmitting:
Transmitting can be aborted using uart_tx_abort, after calling that function UART_TX_ABORTED event will be generated.
Enumerator | |
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UART_TX_DONE | Whole TX buffer was transmitted. |
UART_TX_ABORTED | Transmitting aborted due to timeout or uart_tx_abort call. When flow control is enabled, there is a possibility that TX transfer won't finish in the allotted time. Some data may have been transferred, information about it can be found in event data. |
UART_RX_RDY | Received data is ready for processing. This event is generated in the following cases:
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UART_RX_BUF_REQUEST | Driver requests next buffer for continuous reception. This event is triggered when receiving has started for a new buffer, i.e. it's time to provide a next buffer for a seamless switchover to it. For continuous reliable receiving, user should provide another RX buffer in response to this event, using uart_rx_buf_rsp function If uart_rx_buf_rsp is not called before current buffer is filled up, receiving will stop. |
UART_RX_BUF_RELEASED | Buffer is no longer used by UART driver. |
UART_RX_DISABLED | RX has been disabled and can be reenabled. This event is generated whenever receiver has been stopped, disabled or finished its operation and can be enabled again using uart_rx_enable |
UART_RX_STOPPED | RX has stopped due to external event. Reason is one of uart_rx_stop_reason. |
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inlinestatic |
#include <zephyr/drivers/uart.h>
Set event handler function.
Since it is mandatory to set callback to use other asynchronous functions, it can be used to detect if the device supports asynchronous API. Remaining API does not have that detection.
dev | UART device instance. |
callback | Event handler. |
user_data | Data to pass to event handler function. |
0 | If successful. |
-ENOSYS | If not supported by the device. |
-ENOTSUP | If API not enabled. |
#include <zephyr/drivers/uart.h>
Provide receive buffer in response to UART_RX_BUF_REQUEST event.
Provide pointer to RX buffer, which will be used when current buffer is filled.
dev | UART device instance. |
buf | Pointer to receive buffer. |
len | Buffer length. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EBUSY | Next buffer already set. |
-EACCES | Receiver is already disabled (function called too late?). |
-errno | Other negative errno value in case of failure. |
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inlinestatic |
#include <zephyr/drivers/uart.h>
Provide wide data receive buffer in response to UART_RX_BUF_REQUEST event.
Provide pointer to RX buffer, which will be used when current buffer is filled.
dev | UART device instance. |
buf | Pointer to wide data receive buffer. |
len | Buffer length. |
0 | If successful. |
-ENOTSUP | If API is not enabled |
-EBUSY | Next buffer already set. |
-EACCES | Receiver is already disabled (function called too late?). |
-errno | Other negative errno value in case of failure. |
int uart_rx_disable | ( | const struct device * | dev | ) |
#include <zephyr/drivers/uart.h>
Disable RX.
UART_RX_BUF_RELEASED event will be generated for every buffer scheduled, after that UART_RX_DISABLED event will be generated. Additionally, if there is any pending received data, the UART_RX_RDY event for that data will be generated before the UART_RX_BUF_RELEASED events.
dev | UART device instance. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EFAULT | There is no active reception. |
-errno | Other negative errno value in case of failure. |
#include <zephyr/drivers/uart.h>
Start receiving data through UART.
Function sets given buffer as first buffer for receiving and returns immediately. After that event handler, set using uart_callback_set, is called with UART_RX_RDY or UART_RX_BUF_REQUEST events.
dev | UART device instance. |
buf | Pointer to receive buffer. |
len | Buffer length. |
timeout | Inactivity period after receiving at least a byte which triggers UART_RX_RDY event. Given in microseconds. SYS_FOREVER_US disables timeout. See uart_event_type for details. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EBUSY | RX already in progress. |
-errno | Other negative errno value in case of failure. |
#include <zephyr/drivers/uart.h>
Start receiving wide data through UART.
Function sets given buffer as first buffer for receiving and returns immediately. After that event handler, set using uart_callback_set, is called with UART_RX_RDY or UART_RX_BUF_REQUEST events.
dev | UART device instance. |
buf | Pointer to wide data receive buffer. |
len | Buffer length. |
timeout | Inactivity period after receiving at least a byte which triggers UART_RX_RDY event. Given in milliseconds. SYS_FOREVER_MS disables timeout. See uart_event_type for details. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EBUSY | RX already in progress. |
-errno | Other negative errno value in case of failure. |
#include <zephyr/drivers/uart.h>
Send given number of bytes from buffer through UART.
Function returns immediately and event handler, set using uart_callback_set, is called after transfer is finished.
dev | UART device instance. |
buf | Pointer to transmit buffer. |
len | Length of transmit buffer. |
timeout | Timeout in microseconds. Valid only if flow control is enabled. SYS_FOREVER_US disables timeout. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EBUSY | If There is already an ongoing transfer. |
-errno | Other negative errno value in case of failure. |
int uart_tx_abort | ( | const struct device * | dev | ) |
#include <zephyr/drivers/uart.h>
Abort current TX transmission.
UART_TX_DONE event will be generated with amount of data sent.
dev | UART device instance. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EFAULT | There is no active transmission. |
-errno | Other negative errno value in case of failure. |
#include <zephyr/drivers/uart.h>
Send given number of datum from buffer through UART.
Function returns immediately and event handler, set using uart_callback_set, is called after transfer is finished.
dev | UART device instance. |
buf | Pointer to wide data transmit buffer. |
len | Length of wide data transmit buffer. |
timeout | Timeout in milliseconds. Valid only if flow control is enabled. SYS_FOREVER_MS disables timeout. |
0 | If successful. |
-ENOTSUP | If API is not enabled. |
-EBUSY | If there is already an ongoing transfer. |
-errno | Other negative errno value in case of failure. |