zephyr/include/console/tty.h

140 lines
4.1 KiB
C

/*
* Copyright (c) 2018 Linaro Limited
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_CONSOLE_TTY_H_
#define ZEPHYR_INCLUDE_CONSOLE_TTY_H_
#include <sys/types.h>
#include <zephyr/types.h>
#include <kernel.h>
#ifdef __cplusplus
extern "C" {
#endif
struct tty_serial {
const struct device *uart_dev;
struct k_sem rx_sem;
uint8_t *rx_ringbuf;
uint32_t rx_ringbuf_sz;
uint16_t rx_get, rx_put;
int32_t rx_timeout;
struct k_sem tx_sem;
uint8_t *tx_ringbuf;
uint32_t tx_ringbuf_sz;
uint16_t tx_get, tx_put;
int32_t tx_timeout;
};
/**
* @brief Initialize serial port object (classically known as tty).
*
* "tty" device provides support for buffered, interrupt-driven,
* timeout-controlled access to an underlying UART device. For
* completeness, it also support non-interrupt-driven, busy-polling
* access mode. After initialization, tty is in the "most conservative"
* unbuffered mode with infinite timeouts (this is guaranteed to work
* on any hardware). Users should configure buffers and timeouts as
* they need using functions tty_set_rx_buf(), tty_set_tx_buf(),
* tty_set_rx_timeout(), tty_set_tx_timeout().
*
* @param tty tty device structure to initialize
* @param uart_dev underlying UART device to use (should support
* interrupt-driven operation)
*
* @return 0 on success, error code (<0) otherwise
*/
int tty_init(struct tty_serial *tty, const struct device *uart_dev);
/**
* @brief Set receive timeout for tty device.
*
* Set timeout for getchar() operation. Default timeout after
* device initialization is SYS_FOREVER_MS.
*
* @param tty tty device structure
* @param timeout timeout in milliseconds, or 0, or SYS_FOREVER_MS.
*/
static inline void tty_set_rx_timeout(struct tty_serial *tty, int32_t timeout)
{
tty->rx_timeout = timeout;
}
/**
* @brief Set transmit timeout for tty device.
*
* Set timeout for putchar() operation, for a case when output buffer is full.
* Default timeout after device initialization is SYS_FOREVER_MS.
*
* @param tty tty device structure
* @param timeout timeout in milliseconds, or 0, or SYS_FOREVER_MS.
*/
static inline void tty_set_tx_timeout(struct tty_serial *tty, int32_t timeout)
{
tty->tx_timeout = timeout;
}
/**
* @brief Set receive buffer for tty device.
*
* Set receive buffer or switch to unbuffered operation for receive.
*
* @param tty tty device structure
* @param buf buffer, or NULL for unbuffered operation
* @param size buffer buffer size, 0 for unbuffered operation
* @return 0 on success, error code (<0) otherwise:
* EINVAL: unsupported buffer (size)
*/
int tty_set_rx_buf(struct tty_serial *tty, void *buf, size_t size);
/**
* @brief Set transmit buffer for tty device.
*
* Set transmit buffer or switch to unbuffered operation for transmit.
* Note that unbuffered mode is implicitly blocking, i.e. behaves as
* if tty_set_tx_timeout(SYS_FOREVER_MS) was set.
*
* @param tty tty device structure
* @param buf buffer, or NULL for unbuffered operation
* @param size buffer buffer size, 0 for unbuffered operation
* @return 0 on success, error code (<0) otherwise:
* EINVAL: unsupported buffer (size)
*/
int tty_set_tx_buf(struct tty_serial *tty, void *buf, size_t size);
/**
* @brief Read data from a tty device.
*
* @param tty tty device structure
* @param buf buffer to read data to
* @param size maximum number of bytes to read
* @return >0, number of actually read bytes (can be less than size param)
* =0, for EOF-like condition (e.g., break signaled)
* <0, in case of error (e.g. -EAGAIN if timeout expired). errno
* variable is also set.
*/
ssize_t tty_read(struct tty_serial *tty, void *buf, size_t size);
/**
* @brief Write data to tty device.
*
* @param tty tty device structure
* @param buf buffer containing data
* @param size maximum number of bytes to write
* @return =>0, number of actually written bytes (can be less than size param)
* <0, in case of error (e.g. -EAGAIN if timeout expired). errno
* variable is also set.
*/
ssize_t tty_write(struct tty_serial *tty, const void *buf, size_t size);
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_CONSOLE_TTY_H_ */