mirror of
https://github.com/RIOT-OS/RIOT.git
synced 2025-01-18 12:52:44 +01:00
ddf19783d7
As suggested in PR#5899 add a routine uart_mode() that will setup data bits, stop bits and parity at runtime. uart.h provides a set of enums defining these settings and each platform will override them to specify values corresponding to its configuration registers. The idea behind the enums is to specify default settings i.e. 8N1 through the 0 value item. Invoking uart_mode(uart, 0, 0, 0) will setup 8N1 mode. Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
223 lines
6.8 KiB
C
223 lines
6.8 KiB
C
/*
|
|
* Copyright (C) 2014-2015 Freie Universität Berlin
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU Lesser
|
|
* General Public License v2.1. See the file LICENSE in the top level
|
|
* directory for more details.
|
|
*/
|
|
|
|
/**
|
|
* @defgroup drivers_periph_uart UART
|
|
* @ingroup drivers_periph
|
|
* @brief Low-level UART peripheral driver
|
|
*
|
|
* This is a basic UART (Universal Asynchronous Receiver Transmitter) interface
|
|
* to allow platform independent access to the MCU's serial communication
|
|
* abilities. This interface is intentionally designed to be as simple as
|
|
* possible, to allow for easy implementation and maximum portability. In RIOT
|
|
* we only use the common 8-N-1 format of the serial port (8 data bits, no
|
|
* parity bit, one stop bit).
|
|
*
|
|
* The simple interface provides capabilities to initialize the serial
|
|
* communication module, which automatically enables for receiving data, as well
|
|
* as writing data to the UART port, which means transmitting data. The UART
|
|
* device and the corresponding pins need to be mapped in
|
|
* `RIOT/boards/ * /include/periph_conf.h`. Furthermore you need to select the
|
|
* baudrate for initialization which is typically {9600, 19200, 38400, 57600,
|
|
* 115200} baud. Additionally you should register a callback function that is
|
|
* executed in interrupt context when data is being received. The driver will
|
|
* then read the received data byte, call the registered callback function and
|
|
* pass the received data to it via its argument. The interface enforces the
|
|
* receiving to be implemented in an interrupt driven mode. Thus, you never know
|
|
* how many bytes are going to be received and might want to handle that in your
|
|
* specific callback function. The transmit function can be implemented in any
|
|
* way.
|
|
*
|
|
* By default the @p UART_DEV(0) device of each board is initialized and mapped
|
|
* to STDIO in RIOT which is used for standard input/output functions like
|
|
* `printf()` or `puts()`.
|
|
*
|
|
* @{
|
|
*
|
|
* @file
|
|
* @brief Low-level UART peripheral driver interface definition
|
|
*
|
|
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
|
|
*/
|
|
|
|
#ifndef PERIPH_UART_H
|
|
#define PERIPH_UART_H
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
#include <limits.h>
|
|
|
|
#include "periph_cpu.h"
|
|
#include "periph_conf.h"
|
|
/* TODO: remove once all platforms are ported to this interface */
|
|
#include "periph/dev_enums.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* @brief Define default UART type identifier
|
|
*/
|
|
#ifndef HAVE_UART_T
|
|
typedef unsigned int uart_t;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Default UART undefined value
|
|
*/
|
|
#ifndef UART_UNDEF
|
|
#define UART_UNDEF (UINT_MAX)
|
|
#endif
|
|
|
|
/**
|
|
* @brief Default UART device access macro
|
|
*/
|
|
#ifndef UART_DEV
|
|
#define UART_DEV(x) (x)
|
|
#endif
|
|
|
|
/**
|
|
* @brief Signature for receive interrupt callback
|
|
*
|
|
* @param[in] arg context to the callback (optional)
|
|
* @param[in] data the byte that was received
|
|
*/
|
|
typedef void(*uart_rx_cb_t)(void *arg, uint8_t data);
|
|
|
|
/**
|
|
* @brief Interrupt context for a UART device
|
|
*/
|
|
#ifndef HAVE_UART_ISR_CTX_T
|
|
typedef struct {
|
|
uart_rx_cb_t rx_cb; /**< data received interrupt callback */
|
|
void *arg; /**< argument to both callback routines */
|
|
} uart_isr_ctx_t;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Possible UART return values
|
|
*/
|
|
enum {
|
|
UART_OK = 0, /**< everything in order */
|
|
UART_NODEV = -1, /**< invalid UART device given */
|
|
UART_NOBAUD = -2, /**< given baudrate is not applicable */
|
|
UART_INTERR = -3, /**< all other internal errors */
|
|
UART_NOMODE = -4 /**< given mode is not applicable */
|
|
};
|
|
|
|
/**
|
|
* @brief Definition of possible parity modes
|
|
*/
|
|
#ifndef HAVE_UART_PARITY_T
|
|
typedef enum {
|
|
UART_PARITY_NONE, /**< no parity */
|
|
UART_PARITY_EVEN, /**< even parity */
|
|
UART_PARITY_ODD, /**< odd parity */
|
|
UART_PARITY_MARK, /**< mark parity */
|
|
UART_PARITY_SPACE /**< space parity */
|
|
} uart_parity_t;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Definition of possible data bits lengths in a UART frame
|
|
*/
|
|
#ifndef HAVE_UART_DATA_BITS_T
|
|
typedef enum {
|
|
UART_DATA_BITS_5, /**< 5 data bits */
|
|
UART_DATA_BITS_6, /**< 6 data bits */
|
|
UART_DATA_BITS_7, /**< 7 data bits */
|
|
UART_DATA_BITS_8, /**< 8 data bits */
|
|
} uart_data_bits_t;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Definition of possible stop bits lengths in a UART frame
|
|
*/
|
|
#ifndef HAVE_UART_STOP_BITS_T
|
|
typedef enum {
|
|
UART_STOP_BITS_1, /**< 1 stop bit */
|
|
UART_STOP_BITS_2, /**< 2 stop bits */
|
|
} uart_stop_bits_t;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Initialize a given UART device
|
|
*
|
|
* The UART device will be initialized with the following configuration:
|
|
* - 8 data bits
|
|
* - no parity
|
|
* - 1 stop bit
|
|
* - baudrate as given
|
|
*
|
|
* If no callback parameter is given (rx_cb := NULL), the UART will be
|
|
* initialized in TX only mode.
|
|
*
|
|
* @param[in] uart UART device to initialize
|
|
* @param[in] baudrate desired baudrate in baud/s
|
|
* @param[in] rx_cb receive callback, executed in interrupt context once
|
|
* for every byte that is received (RX buffer filled),
|
|
* set to NULL for TX only mode
|
|
* @param[in] arg optional context passed to the callback functions
|
|
*
|
|
* @return UART_OK on success
|
|
* @return UART_NODEV on invalid UART device
|
|
* @return UART_NOBAUD on inapplicable baudrate
|
|
* @return UART_INTERR on other errors
|
|
*/
|
|
int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg);
|
|
|
|
/**
|
|
* @brief Setup parity, data and stop bits for a given UART device
|
|
*
|
|
* @param[in] uart UART device to initialize
|
|
* @param[in] data_bits number of data bits in a UART frame
|
|
* @param[in] parity parity mode
|
|
* @param[in] stop_bits number of stop bits in a UART frame
|
|
*
|
|
* @return UART_OK on success
|
|
* @return UART_NOMODE on other errors
|
|
*/
|
|
int uart_mode(uart_t uart, uart_data_bits_t data_bits, uart_parity_t parity,
|
|
uart_stop_bits_t stop_bits);
|
|
|
|
/**
|
|
* @brief Write data from the given buffer to the specified UART device
|
|
*
|
|
* This function is blocking, as it will only return after @p len bytes from the
|
|
* given buffer have been send. The way this data is send is up to the
|
|
* implementation: active waiting, interrupt driven, DMA, etc.
|
|
*
|
|
* @param[in] uart UART device to use for transmission
|
|
* @param[in] data data buffer to send
|
|
* @param[in] len number of bytes to send
|
|
*
|
|
*/
|
|
void uart_write(uart_t uart, const uint8_t *data, size_t len);
|
|
|
|
/**
|
|
* @brief Power on the given UART device
|
|
*
|
|
* @param[in] uart the UART device to power on
|
|
*/
|
|
void uart_poweron(uart_t uart);
|
|
|
|
/**
|
|
* @brief Power off the given UART device
|
|
*
|
|
* @param[in] uart the UART device to power off
|
|
*/
|
|
void uart_poweroff(uart_t uart);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* PERIPH_UART_H */
|
|
/** @} */
|