66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
/* Handles communication with a tty device. */
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#pragma once
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#include <common.h>
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#include <termios.h>
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#define TTY_DEV_PATH_LEN 128
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typedef struct
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{
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int fd; /* tty device file descriptor */
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struct termios ttysetold; /* previous termios settings */
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struct termios ttyset; /* current termios settings */
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char path[TTY_DEV_PATH_LEN]; /* tty device path */
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char data[BUFFER_LEN]; /* buffer for received data */
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} tty_t;
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/**
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* Opens the tty device and configures it.
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* The old device settings are saved.
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*
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* Returns:
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* - 0 on success
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* - negative errno value if an error occurred
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*/
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int tty_open(tty_t *tty_dev);
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/**
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* Closes the tty device connection.
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* Also applies the old device settings.
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*
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* Returns:
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* - 0 on success
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* - negative errno value if an error occurred
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*/
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int tty_close(tty_t *tty_dev);
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/**
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* Reads incoming data from tty device to tty data buffer.
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*
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* Returns:
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* - number of read bytes on success,
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* - negative errno value set by an error while reading
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*/
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int tty_read(tty_t *tty_dev);
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/**
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* Sends data from a buffer to tty device.
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*
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* Returns:
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* - number of sent bytes on success,
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* - negative errno value set by an error while sending
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*/
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int tty_write(tty_t *tty_dev, char *databuf, int datalen);
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/**
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* Converts POSIX speed_t to a baud rate.
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* The values of the constants for speed_t are not themselves portable.
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*/
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int speed_to_baud(speed_t speed);
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/**
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* Converts a numeric baud rate to a POSIX speed_t.
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*/
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speed_t baud_to_speed(int baud);
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