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/*
* Copyright (c) 2015-2016, Texas Instruments Incorporated
* All rights reserved.
*
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* modification, are permitted provided that the following conditions
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*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Texas Instruments Incorporated nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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/*!*****************************************************************************
* @file UART.h
* @brief UART driver interface
*
* To use the UART driver, ensure that the correct driver library for your
* device is linked in and include this header file as follows:
* @code
* #include <ti/drivers/UART.h>
* @endcode
*
* This module serves as the main interface for applications. Its purpose
* is to redirect the UART APIs to specific driver implementations
* which are specified using a pointer to a #UART_FxnTable.
*
* # Overview #
* A UART is used to translate data between the chip and a serial port.
* The UART driver simplifies reading and writing to any of the UART
* peripherals on the board, with multiple modes of operation and performance.
* These include blocking, non-blocking, and polling, as well as text/binary
* mode, echo and return characters.
*
* The APIs in this driver serve as an interface to a typical RTOS
* application. The specific peripheral implementations are responsible for
* creating all the RTOS specific primitives to allow for thread-safe
* operation.
*
* # Usage #
*
* The UART driver interface provides device independent APIs, data types,
* and macros. The following code example opens a UART instance, reads
* a byte from the UART, and then writes the byte back to the UART.
*
* @code
* char input;
* UART_Handle uart;
* UART_Params uartParams;
*
* // Initialize the UART driver.
* UART_init();
*
* // Create a UART with data processing off.
* UART_Params_init(&uartParams);
* uartParams.writeDataMode = UART_DATA_BINARY;
* uartParams.readDataMode = UART_DATA_BINARY;
* uartParams.readReturnMode = UART_RETURN_FULL;
* uartParams.readEcho = UART_ECHO_OFF;
* uartParams.baudRate = 9600;
*
* // Open an instance of the UART drivers
* uart = UART_open(Board_UART0, &uartParams);
*
* if (uart == NULL) {
* // UART_open() failed
* while (1);
* }
*
* // Loop forever echoing
* while (1) {
* UART_read(uart, &input, 1);
* UART_write(uart, &input, 1);
* }
* @endcode
*
* Details for the example code above are described in the following
* subsections.
*
*
* ### UART Driver Configuration #
*
* In order to use the UART APIs, the application is required
* to provide device-specific UART configuration in the Board.c file.
* The UART driver interface defines a configuration data structure:
*
* @code
* typedef struct UART_Config_ {
* UART_FxnTable const *fxnTablePtr;
* void *object;
* void const *hwAttrs;
* } UART_Config;
* @endcode
*
* The application must declare an array of UART_Config elements, named
* UART_config[]. Each element of UART_config[] are populated with
* pointers to a device specific UART driver implementation's function
* table, driver object, and hardware attributes. The hardware attributes
* define properties such as the UART peripheral's base address, and
* the pins for RX and TX. Each element in UART_config[] corresponds to
* a UART instance, and none of the elements should have NULL pointers.
* There is no correlation between the index and the peripheral designation
* (such as UART0 or UART1). For example, it is possible to use
* UART_config[0] for UART1.
*
* You will need to check the device-specific UART driver implementation's
* header file for example configuration. Please also refer to the
* Board.c file of any of your examples to see the UART configuration.
*
* ### Initializing the UART Driver #
*
* UART_init() must be called before any other UART APIs. This function
* calls the device implementation's UART initialization function, for each
* element of UART_config[].
*
* ### Opening the UART Driver #
*
* Opening a UART requires four steps:
* 1. Create and initialize a UART_Params structure.
* 2. Fill in the desired parameters.
* 3. Call UART_open(), passing the index of the UART in the UART_config
* structure, and the address of the UART_Params structure. The
* UART instance is specified by the index in the UART_config structure.
* 4. Check that the UART handle returned by UART_open() is non-NULL,
* and save it. The handle will be used to read and write to the
* UART you just opened.
*
* Only one UART index can be used at a time; calling UART_open() a second
* time with the same index previosly passed to UART_open() will result in
* an error. You can, though, re-use the index if the instance is closed
* via UART_close().
* In the example code, Board_UART0 is passed to UART_open(). This macro
* is defined in the example's Board.h file.
*
*
* ### Modes of Operation #
*
* The UART driver can operate in blocking mode or callback mode, by
* setting the writeMode and readMode parameters passed to UART_open().
* If these parameters are not set, as in the example code, the UART
* driver defaults to blocking mode. Options for the writeMode and
* readMode parameters are #UART_MODE_BLOCKING and #UART_MODE_CALLBACK:
*
* - #UART_MODE_BLOCKING uses a semaphore to block while data is being sent.
* The context of calling UART_read() or UART_write() must be a Task when
* using #UART_MODE_BLOCKING. The UART_write() or UART_read() call
* will block until all data is sent or received, or the write timeout or
* read timeout expires, whichever happens first.
*
* - #UART_MODE_CALLBACK is non-blocking and UART_read() and UART_write()
* will return while data is being sent in the context of a hardware
* interrupt. When the read or write finishes, the UART driver will call
* the user's callback function. In some cases, the UART data transfer
* may have been canceled, or a newline may have been received, so the
* number of bytes sent/received are passed to the callback function. Your
* implementation of the callback function can use this imformation
* as needed. Since the user's callback may be called in the context of an
* ISR, the callback function must not make any RTOS blocking calls.
*
* The example sets the writeDataMode and readDataMode parameters to
* #UART_DATA_BINARY. Options for these parameters are #UART_DATA_BINARY
* and #UART_DATA_TEXT:
*
* - #UART_DATA_BINARY: The data is passed as is, without processing.
*
* - #UART_DATA_TEXT: Write actions add a carriage return before a
* newline character, and read actions replace a return with a newline.
* This effectively treats all device line endings as LF and all host
* PC line endings as CRLF.
*
* Other parameters set by the example are readReturnMode and readEcho.
* Options for the readReturnMode parameter are #UART_RETURN_FULL and
* #UART_RETURN_NEWLINE:
*
* - #UART_RETURN_FULL: The read action unblocks or returns when the buffer
* is full.
* - #UART_RETURN_NEWLINE: The read action unblocks or returns when a
* newline character if read, before the buffer is full.
*
* Options for the readEcho parameter are #UART_ECHO_OFF and #UART_ECHO_ON.
* This parameter determines whether the driver echoes data back to the
* UART. When echo is turned on, each character that is read by the target
* is written back, independent of any write operations. If data is
* received in the middle of a write and echo is turned on, the echoed
* characters will be mixed in with the write data.
*
* ### Reading and Writing data #
*
* The example code reads one byte frome the UART instance, and then writes
* one byte back to the same instance:
*
* @code
* UART_read(uart, &input, 1);
* UART_write(uart, &input, 1);
* @endcode
*
* The UART driver allows full duplex data transfers. Therefore, it is
* possible to call UART_read() and UART_write() at the same time (for
* either blocking or callback modes). It is not possible, however,
* to issue multiple concurrent operations in the same direction.
* For example, if one thread calls UART_read(uart0, buffer0...),
* any other thread attempting UART_read(uart0, buffer1...) will result in
* an error of UART_ERROR, until all the data from the first UART_read()
* has been transferred to buffer0. This applies to both blocking and
* and callback modes. So applications must either synchronize
* UART_read() (or UART_write()) calls that use the same UART handle, or
* check for the UART_ERROR return code indicating that a transfer is still
* ongoing.
*
* # Implementation #
*
* The UART driver interface module is joined (at link time) to an
* array of UART_Config data structures named *UART_config*.
* UART_config is implemented in the application with each entry being an
* instance of a UART peripheral. Each entry in *UART_config* contains a:
* - (UART_FxnTable *) to a set of functions that implement a UART peripheral
* - (void *) data object that is associated with the UART_FxnTable
* - (void *) hardware attributes that are associated with the UART_FxnTable
*
* The UART APIs are redirected to the device specific implementations
* using the UART_FxnTable pointer of the UART_config entry.
* In order to use device specific functions of the UART driver directly,
* link in the correct driver library for your device and include the
* device specific UART driver header file (which in turn includes UART.h).
* For example, for the MSP432 family of devices, you would include the
* following header file:
* @code
* #include <ti/drivers/uart/UARTMSP432.h>
* @endcode
*
* ### Stack Requirements #
* It is STRONGLY discouraged to perform UART_read() or UART_write()
* calls within the driver's own callback function when in
* #UART_MODE_CALLBACK mode. Doing so will incur additional task or system
* stack size requirements. See the peripheral implementations'
* documentation for stack size estimations. It is expected that the
* user perform their own stack and usage analysis when choosing to
* nest these calls.
*
*******************************************************************************
*/
#ifndef ti_drivers_UART__include
#define ti_drivers_UART__include
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stddef.h>
/**
* @defgroup UART_CONTROL UART_control command and status codes
* These UART macros are reservations for UART.h
* @{
*/
/*!
* Common UART_control command code reservation offset.
* UART driver implementations should offset command codes with
* UART_CMD_RESERVED growing positively
*
* Example implementation specific command codes:
* @code
* #define UARTXYZ_CMD_COMMAND0 UART_CMD_RESERVED + 0
* #define UARTXYZ_CMD_COMMAND1 UART_CMD_RESERVED + 1
* @endcode
*/
#define UART_CMD_RESERVED (32)
/*!
* Common UART_control status code reservation offset.
* UART driver implementations should offset status codes with
* UART_STATUS_RESERVED growing negatively.
*
* Example implementation specific status codes:
* @code
* #define UARTXYZ_STATUS_ERROR0 UART_STATUS_RESERVED - 0
* #define UARTXYZ_STATUS_ERROR1 UART_STATUS_RESERVED - 1
* #define UARTXYZ_STATUS_ERROR2 UART_STATUS_RESERVED - 2
* @endcode
*/
#define UART_STATUS_RESERVED (-32)
/**
* @defgroup UART_STATUS Status Codes
* UART_STATUS_* macros are general status codes returned by UART_control()
* @{
* @ingroup UART_CONTROL
*/
/*!
* @brief Successful status code returned by UART_control().
*
* UART_control() returns UART_STATUS_SUCCESS if the control code was executed
* successfully.
*/
#define UART_STATUS_SUCCESS (0)
/*!
* @brief Generic error status code returned by UART_control().
*
* UART_control() returns UART_STATUS_ERROR if the control code was not executed
* successfully.
*/
#define UART_STATUS_ERROR (-1)
/*!
* @brief An error status code returned by UART_control() for undefined
* command codes.
*
* UART_control() returns UART_STATUS_UNDEFINEDCMD if the control code is not
* recognized by the driver implementation.
*/
#define UART_STATUS_UNDEFINEDCMD (-2)
/** @}*/
/**
* @defgroup UART_CMD Command Codes
* UART_CMD_* macros are general command codes for UART_control(). Not all UART
* driver implementations support these command codes.
* @{
* @ingroup UART_CONTROL
*/
/*!
* @brief Command code used by UART_control() to read the next unsigned char.
*
* This command is used to read the next unsigned char from the UART's circular
* buffer without removing it. With this command code, @b arg is a pointer to an
* integer. @b *arg contains the next @c unsigned @c char read if data is
* present, else @b *arg is set to #UART_ERROR.
*/
#define UART_CMD_PEEK (0)
/*!
* @brief Command code used by UART_control() to determine if the read buffer
* is empty.
*
* This command is used to determine if there are any unsigned chars available
* to read from the UART's circular buffer using UART_read(). With this command
* code, @b arg is a pointer to a @c bool. @b *arg contains @c true if data is
* available, else @c false.
*/
#define UART_CMD_ISAVAILABLE (1)
/*!
* @brief Command code used by UART_control() to determine how many unsigned
* chars are in the read buffer.
*
* This command is used to determine how many @c unsigned @c chars are available
* to read from the UART's circular buffer using UART_read(). With this command
* code, @b arg is a pointer to an @a integer. @b *arg contains the number of
* @c unsigned @c chars available to read.
*/
#define UART_CMD_GETRXCOUNT (2)
/*!
* @brief Command code used by UART_control() to enable data receive by the
* UART.
*
* This command is used to enable the UART in such a way that it stores received
* unsigned chars into the circular buffer. For drivers that support power
* management, this typically means that the UART will set a power constraint
* while receive is enabled. UART_open() will always have this option
* enabled. With this command code, @b arg is @a don't @a care.
*/
#define UART_CMD_RXENABLE (3)
/*!
* @brief Command code used by UART_control() to disable data received by the
* UART.
*
* This command is used to disable the UART in such a way that ignores the data
* it receives. For drivers that support power management, this typically means
* that the driver will release any power constraints, to permit the system to
* enter low power modes. With this command code, @b arg is @a don't @a care.
*
* @warning A call to UART_read() does @b NOT re-enable receive.
*/
#define UART_CMD_RXDISABLE (4)
/** @}*/
/** @}*/
#define UART_ERROR (UART_STATUS_ERROR)
/*!
* @brief Wait forever define
*/
#define UART_WAIT_FOREVER (~(0U))
/*!
* @brief A handle that is returned from a UART_open() call.
*/
typedef struct UART_Config_ *UART_Handle;
/*!
* @brief The definition of a callback function used by the UART driver
* when used in #UART_MODE_CALLBACK
* The callback can occur in task or HWI context.
*
* @warning Making UART_read() or UART_write() calls within its own callback
* routines are STRONGLY discouraged as it will impact Task and
* System stack size requirements! See the documentation for the
* specific driver implementations for additional estimated stack
* requirements.
*
* @param UART_Handle UART_Handle
*
* @param buf Pointer to read/write buffer
*
* @param count Number of elements read/written
*/
typedef void (*UART_Callback) (UART_Handle handle, void *buf, size_t count);
/*!
* @brief UART mode settings
*
* This enum defines the read and write modes for the configured UART.
*/
typedef enum UART_Mode_ {
/*!
* Uses a semaphore to block while data is being sent. Context of the call
* must be a Task.
*/
UART_MODE_BLOCKING,
/*!
* Non-blocking and will return immediately. When UART_write() or
* UART_read() has finished, the callback function is called from either
* the caller's context or from an interrupt context.
*/
UART_MODE_CALLBACK
} UART_Mode;
/*!
* @brief UART return mode settings
*
* This enumeration defines the return modes for UART_read() and
* UART_readPolling(). This mode only functions when in #UART_DATA_TEXT mode.
*
* #UART_RETURN_FULL unblocks or performs a callback when the read buffer has
* been filled.
* #UART_RETURN_NEWLINE unblocks or performs a callback whenever a newline
* character has been received.
*
* UART operation | UART_RETURN_FULL | UART_RETURN_NEWLINE |
* -------------- | ---------------- | ------------------- |
* UART_read() | Returns when buffer is full | Returns when buffer is full or newline was read |
* UART_write() | Sends data as is | Sends data with an additional newline at the end |
*
* @pre UART driver must be used in #UART_DATA_TEXT mode.
*/
typedef enum UART_ReturnMode_ {
/*! Unblock/callback when buffer is full. */
UART_RETURN_FULL,
/*! Unblock/callback when newline character is received. */
UART_RETURN_NEWLINE
} UART_ReturnMode;
/*!
* @brief UART data mode settings
*
* This enumeration defines the data mode for reads and writes.
*
* In #UART_DATA_BINARY, data is passed as is, with no processing.
*
* In #UART_DATA_TEXT mode, the driver will examine the #UART_ReturnMode
* value, to determine whether or not to unblock/callback when a newline
* is received. Read actions replace a carriage return with a newline,
* and write actions add a carriage return before a newline. This
* effectively treats all device line endings as LF, and all host PC line
* endings as CRLF.
*/
typedef enum UART_DataMode_ {
UART_DATA_BINARY = 0, /*!< Data is not processed */
UART_DATA_TEXT = 1 /*!< Data is processed according to above */
} UART_DataMode;
/*!
* @brief UART echo settings
*
* This enumeration defines if the driver will echo data when uses in
* #UART_DATA_TEXT mode. This only applies to data received by the UART.
*
* #UART_ECHO_ON will echo back characters it received while in #UART_DATA_TEXT
* mode.
* #UART_ECHO_OFF will not echo back characters it received in #UART_DATA_TEXT
* mode.
*
* @pre UART driver must be used in #UART_DATA_TEXT mode.
*/
typedef enum UART_Echo_ {
UART_ECHO_OFF = 0, /*!< Data is not echoed */
UART_ECHO_ON = 1 /*!< Data is echoed */
} UART_Echo;
/*!
* @brief UART data length settings
*
* This enumeration defines the UART data lengths.
*/
typedef enum UART_LEN_ {
UART_LEN_5 = 0, /*!< Data length is 5 bits */
UART_LEN_6 = 1, /*!< Data length is 6 bits */
UART_LEN_7 = 2, /*!< Data length is 7 bits */
UART_LEN_8 = 3 /*!< Data length is 8 bits */
} UART_LEN;
/*!
* @brief UART stop bit settings
*
* This enumeration defines the UART stop bits.
*/
typedef enum UART_STOP_ {
UART_STOP_ONE = 0, /*!< One stop bit */
UART_STOP_TWO = 1 /*!< Two stop bits */
} UART_STOP;
/*!
* @brief UART parity type settings
*
* This enumeration defines the UART parity types.
*/
typedef enum UART_PAR_ {
UART_PAR_NONE = 0, /*!< No parity */
UART_PAR_EVEN = 1, /*!< Parity bit is even */
UART_PAR_ODD = 2, /*!< Parity bit is odd */
UART_PAR_ZERO = 3, /*!< Parity bit is always zero */
UART_PAR_ONE = 4 /*!< Parity bit is always one */
} UART_PAR;
/*!
* @brief UART Parameters
*
* UART parameters are used with the UART_open() call. Default values for
* these parameters are set using UART_Params_init().
*
* @sa UART_Params_init()
*/
typedef struct UART_Params_ {
UART_Mode readMode; /*!< Mode for all read calls */
UART_Mode writeMode; /*!< Mode for all write calls */
uint32_t readTimeout; /*!< Timeout for read calls in blocking mode. */
uint32_t writeTimeout; /*!< Timeout for write calls in blocking mode. */
UART_Callback readCallback; /*!< Pointer to read callback function for callback mode. */
UART_Callback writeCallback; /*!< Pointer to write callback function for callback mode. */
UART_ReturnMode readReturnMode; /*!< Receive return mode */
UART_DataMode readDataMode; /*!< Type of data being read */
UART_DataMode writeDataMode; /*!< Type of data being written */
UART_Echo readEcho; /*!< Echo received data back */
uint32_t baudRate; /*!< Baud rate for UART */
UART_LEN dataLength; /*!< Data length for UART */
UART_STOP stopBits; /*!< Stop bits for UART */
UART_PAR parityType; /*!< Parity bit type for UART */
void *custom; /*!< Custom argument used by driver implementation */
} UART_Params;
/*!
* @brief A function pointer to a driver specific implementation of
* UART_CloseFxn().
*/
typedef void (*UART_CloseFxn) (UART_Handle handle);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_ControlFxn().
*/
typedef int_fast16_t (*UART_ControlFxn) (UART_Handle handle, uint_fast16_t cmd, void *arg);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_InitFxn().
*/
typedef void (*UART_InitFxn) (UART_Handle handle);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_OpenFxn().
*/
typedef UART_Handle (*UART_OpenFxn) (UART_Handle handle, UART_Params *params);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_ReadFxn().
*/
typedef int_fast32_t (*UART_ReadFxn) (UART_Handle handle, void *buffer,
size_t size);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_ReadPollingFxn().
*/
typedef int_fast32_t (*UART_ReadPollingFxn) (UART_Handle handle, void *buffer,
size_t size);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_ReadCancelFxn().
*/
typedef void (*UART_ReadCancelFxn) (UART_Handle handle);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_WriteFxn().
*/
typedef int_fast32_t (*UART_WriteFxn) (UART_Handle handle, const void *buffer,
size_t size);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_WritePollingFxn().
*/
typedef int_fast32_t (*UART_WritePollingFxn) (UART_Handle handle,
const void *buffer, size_t size);
/*!
* @brief A function pointer to a driver specific implementation of
* UART_WriteCancelFxn().
*/
typedef void (*UART_WriteCancelFxn) (UART_Handle handle);
/*!
* @brief The definition of a UART function table that contains the
* required set of functions to control a specific UART driver
* implementation.
*/
typedef struct UART_FxnTable_ {
/*! Function to close the specified peripheral */
UART_CloseFxn closeFxn;
/*! Function to implementation specific control function */
UART_ControlFxn controlFxn;
/*! Function to initialize the given data object */
UART_InitFxn initFxn;
/*! Function to open the specified peripheral */
UART_OpenFxn openFxn;
/*! Function to read from the specified peripheral */
UART_ReadFxn readFxn;
/*! Function to read via polling from the specified peripheral */
UART_ReadPollingFxn readPollingFxn;
/*! Function to cancel a read from the specified peripheral */
UART_ReadCancelFxn readCancelFxn;
/*! Function to write from the specified peripheral */
UART_WriteFxn writeFxn;
/*! Function to write via polling from the specified peripheral */
UART_WritePollingFxn writePollingFxn;
/*! Function to cancel a write from the specified peripheral */
UART_WriteCancelFxn writeCancelFxn;
} UART_FxnTable;
/*!
* @brief UART Global configuration
*
* The UART_Config structure contains a set of pointers used to characterize
* the UART driver implementation.
*
* This structure needs to be defined before calling UART_init() and it must
* not be changed thereafter.
*
* @sa UART_init()
*/
typedef struct UART_Config_ {
/*! Pointer to a table of driver-specific implementations of UART APIs */
UART_FxnTable const *fxnTablePtr;
/*! Pointer to a driver specific data object */
void *object;
/*! Pointer to a driver specific hardware attributes structure */
void const *hwAttrs;
} UART_Config;
/*!
* @brief Function to close a UART peripheral specified by the UART handle
*
* @pre UART_open() has been called.
* @pre Ongoing asynchronous read or write have been canceled using
* UART_readCancel() or UART_writeCancel() respectively.
*
* @param handle A #UART_Handle returned from UART_open()
*
* @sa UART_open()
*/
extern void UART_close(UART_Handle handle);
/*!
* @brief Function performs implementation specific features on a given
* #UART_Handle.
*
* Commands for %UART_control() can originate from UART.h or from implementation
* specific UART*.h (_UARTCC26XX.h_, _UARTMSP432.h_, etc.. ) files.
* While commands from UART.h are API portable across driver implementations,
* not all implementations may support all these commands.
* Conversely, commands from driver implementation specific UART*.h files add
* unique driver capabilities but are not API portable across all UART driver
* implementations.
*
* Commands supported by UART.h follow a UART_CMD_\<cmd\> naming
* convention.<br>
* Commands supported by UART*.h follow a UART*_CMD_\<cmd\> naming
* convention.<br>
* Each control command defines @b arg differently. The types of @b arg are
* documented with each command.
*
* See @ref UART_CMD "UART_control command codes" for command codes.
*
* See @ref UART_STATUS "UART_control return status codes" for status codes.
*
* @pre UART_open() has to be called.
*
* @param handle A UART handle returned from UART_open()
*
* @param cmd UART.h or UART*.h commands.
*
* @param arg An optional R/W (read/write) command argument
* accompanied with cmd
*
* @return Implementation specific return codes. Negative values indicate
* unsuccessful operations.
*
* @sa UART_open()
*/
extern int_fast16_t UART_control(UART_Handle handle, uint_fast16_t cmd, void *arg);
/*!
* @brief Function to initialize the UART module
*
* @pre The UART_config structure must exist and be persistent before this
* function can be called. This function must also be called before
* any other UART driver APIs.
*/
extern void UART_init(void);
/*!
* @brief Function to initialize a given UART peripheral
*
* Function to initialize a given UART peripheral specified by the
* particular index value.
*
* @pre UART_init() has been called
*
* @param index Logical peripheral number for the UART indexed into
* the UART_config table
*
* @param params Pointer to a parameter block. If NULL, default
* parameter values will be used. All the fields in
* this structure are RO (read-only).
*
* @return A #UART_Handle upon success. NULL if an error occurs, or if the
* indexed UART peripheral is already opened.
*
* @sa UART_init()
* @sa UART_close()
*/
extern UART_Handle UART_open(uint_least8_t index, UART_Params *params);
/*!
* @brief Function to initialize the UART_Params struct to its defaults
*
* @param params An pointer to UART_Params structure for
* initialization
*
* Defaults values are:
* readMode = UART_MODE_BLOCKING;
* writeMode = UART_MODE_BLOCKING;
* readTimeout = UART_WAIT_FOREVER;
* writeTimeout = UART_WAIT_FOREVER;
* readCallback = NULL;
* writeCallback = NULL;
* readReturnMode = UART_RETURN_NEWLINE;
* readDataMode = UART_DATA_TEXT;
* writeDataMode = UART_DATA_TEXT;
* readEcho = UART_ECHO_ON;
* baudRate = 115200;
* dataLength = UART_LEN_8;
* stopBits = UART_STOP_ONE;
* parityType = UART_PAR_NONE;
*/
extern void UART_Params_init(UART_Params *params);
/*!
* @brief Function that writes data to a UART with interrupts enabled.
*
* %UART_write() writes data from a memory buffer to the UART interface.
* The source is specified by \a buffer and the number of bytes to write
* is given by \a size.
*
* In #UART_MODE_BLOCKING, UART_write() blocks task execution until all
* the data in buffer has been written.
*
* In #UART_MODE_CALLBACK, %UART_write() does not block task execution.
* Instead, a callback function specified by UART_Params::writeCallback is
* called when the transfer is finished.
* The callback function can occur in the caller's task context or in a HWI or
* SWI context, depending on the device implementation.
* An unfinished asynchronous write operation must always be canceled using
* UART_writeCancel() before calling UART_close().
*
* %UART_write() is mutually exclusive to UART_writePolling(). For an opened
* UART peripheral, either UART_write() or UART_writePolling() can be used,
* but not both.
*
* @warning Do not call %UART_write() from its own callback function when in
* #UART_MODE_CALLBACK.
*
* @sa UART_writePolling()
*
* @param handle A #UART_Handle returned by UART_open()
*
* @param buffer A read-only pointer to buffer containing data to
* be written to the UART
*
* @param size The number of bytes in the buffer that should be written
* to the UART
*
* @return Returns the number of bytes that have been written to the UART.
* If an error occurs, #UART_ERROR is returned.
* In #UART_MODE_CALLBACK mode, the return value is always 0.
*/
extern int_fast32_t UART_write(UART_Handle handle, const void *buffer, size_t size);
/*!
* @brief Function that writes data to a UART, polling the peripheral to
* wait until new data can be written. Usage of this API is mutually
* exclusive with usage of UART_write().
*
* This function initiates an operation to write data to a UART controller.
*
* UART_writePolling() will not return until all the data was written to the
* UART (or to its FIFO if applicable).
*
* @sa UART_write()
*
* @param handle A #UART_Handle returned by UART_open()
*
* @param buffer A read-only pointer to the buffer containing the data to
* be written to the UART
*
* @param size The number of bytes in the buffer that should be written
* to the UART
*
* @return Returns the number of bytes that have been written to the UART.
* If an error occurs, #UART_ERROR is returned.
*/
extern int_fast32_t UART_writePolling(UART_Handle handle, const void *buffer, size_t size);
/*!
* @brief Function that cancels a UART_write() function call.
*
* This function cancels an asynchronous UART_write() operation and is only
* applicable in #UART_MODE_CALLBACK.
* UART_writeCancel() calls the registered TX callback function no matter how many bytes
* were sent. It is the application's responsibility to check the count argument in
* the callback function and handle cases where only a subset of the bytes were sent.
*
* @param handle A #UART_Handle returned by UART_open()
*/
extern void UART_writeCancel(UART_Handle handle);
/*!
* @brief Function that reads data from a UART with interrupt enabled.
*
* %UART_read() reads data from a UART controller. The destination is specified
* by \a buffer and the number of bytes to read is given by \a size.
*
* In #UART_MODE_BLOCKING, %UART_read() blocks task execution until all
* the data in buffer has been read.
*
* In #UART_MODE_CALLBACK, %UART_read() does not block task execution.
* Instead, a callback function specified by UART_Params::readCallback
* is called when the transfer is finished.
* The callback function can occur in the caller's context or in HWI or SWI
* context, depending on the device-specific implementation.
* An unfinished asynchronous read operation must always be canceled using
* UART_readCancel() before calling UART_close().
*
* %UART_read() is mutually exclusive to UART_readPolling(). For an opened
* UART peripheral, either %UART_read() or UART_readPolling() can be used,
* but not both.
*
* @warning Do not call %UART_read() from its own callback function when in
* #UART_MODE_CALLBACK.
*
* @sa UART_readPolling()
*
* @param handle A #UART_Handle returned by UART_open()
*
* @param buffer A pointer to an empty buffer to which
* received data should be written
*
* @param size The number of bytes to be written into buffer
*
* @return Returns the number of bytes that have been read from the UART,
* #UART_ERROR on an error.
*/
extern int_fast32_t UART_read(UART_Handle handle, void *buffer, size_t size);
/*!
* @brief Function that reads data from a UART without interrupts. This API
* must be used mutually exclusive with UART_read().
*
* This function initiates an operation to read data from a UART peripheral.
*
* %UART_readPolling() will not return until size data was read to the UART.
*
* @sa UART_read()
*
* @param handle A #UART_Handle returned by UART_open()
*
* @param buffer A pointer to an empty buffer in which
* received data should be written to
*
* @param size The number of bytes to be written into buffer
*
* @return Returns the number of bytes that have been read from the UART,
* #UART_ERROR on an error.
*/
extern int_fast32_t UART_readPolling(UART_Handle handle, void *buffer, size_t size);
/*!
* @brief Function that cancels a UART_read() function call.
*
* This function cancels an asynchronous UART_read() operation and is only
* applicable in #UART_MODE_CALLBACK.
* UART_readCancel() calls the registered RX callback function no matter how many bytes
* were received. It is the application's responsibility to check the count argument in
* the callback function and handle cases where only a subset of the bytes were received.
*
* @param handle A #UART_Handle returned by UART_open()
*/
extern void UART_readCancel(UART_Handle handle);
#ifdef __cplusplus
}
#endif
#endif /* ti_drivers_UART__include */