uart.c File Reference

UART general purpose interface code for file system. More...

#include <termios.h>
#include <stdio.h>
#include <fcntl.h>
#include "bbbandroidHAL.h"

Macros
#define	MAX_PATH   50

Functions
static speed_t	baudrate (const int baudrate)
int	uartOpen (const uint8_t device, const uint32_t bdrate)
int	uartWrite (const int uartFD, const int length, const uint8_t *bytes)
int	uartRead (const int uartFD, const int length, uint8_t *bytes)
void	uartClose (const int uartFD)

Detailed Description

UART general purpose interface code for file system.

Author

Ankur Yadav (ankur.nosp@m.ayad.nosp@m.av@gm.nosp@m.ail..nosp@m.com)

Macro Definition Documentation

#define MAX_PATH   50

Maximum buffer for creating path using snprintf()

Function Documentation

static speed_t baudrate ( const int  baudrate )

static

This function takes input baudrate and returns its proper macro value using switch case.

Parameters

baudrate

a constant integer argument.

Returns

macro corresponding to baudrate if it is present in switch cases otherwise -1.

void uartClose

(

const int

uartFD

)

This function is used to close UART file descriptor.

Parameters

uartFD

a constant integer argument.

int uartOpen	(	const uint8_t	device,
		const uint32_t	bdrate
	)

This takes device number and baud rate as input and opens uart deivce with specified baud rate and returns the file descriptor. It internally uses baudrate() to get proper value using macro.

Parameters

device	a constant uint8_t argument.
bdrate	a constant uint8_t argument.

See Also

baudrate()

Returns

If successful then UART file descriptor is returned and if it fails then -1 is returned.

int uartRead	(	const int	uartFD,
		const int	length,
		uint8_t *	bytes
	)

This functions takes file descriptor, length of data bytes to be received and pointer to array to store the bytes received as input and reads data from UART using read system call.

Parameters

uartFD	a constant integer argument.
length	a constant integer argument.
bytes	a constant uint8_t pointer argument.

Returns

0 if successful and -1 if it fails.

int uartWrite	(	const int	uartFD,
		const int	length,
		const uint8_t *	bytes
	)

This function takes file descriptor, length of data bytes to be transferred and pointer to the array of bytes to be transferred as input and sends it using write system call.

Parameters

uartFD	a constant integer argument.
length	a constant integer argument.
bytes	a constant uint8_t pointer argument.

Returns

0 if successful and -1 if it fails.