driverusart

/*  *  libMD407, driver_usart.c  *  Drivrutiner för STDIN_FILENO, STDOUT_FILENO och STDERR_FILENO  */
#include   <libmd407.h>

/* Deklarationer av de funktioner som ingår, krävs för tabellen */

#define USART1	((USART *)	0x40011000)

#define BIT_UE		(1<<13)
#define BIT_TE		(1<<3)
#define	BIT_RE		(1<<2)
#define BIT_RXNE	(1<<5)
#define BIT_TXE		(1<<7)


typedef struct tag_usart{
	volatile unsigned short sr;
	volatile unsigned short Unused0;
	volatile unsigned short dr;
	volatile unsigned short Unused1;
	volatile unsigned short	brr;
	volatile unsigned short	Unused2;
	volatile unsigned short cr1;
	volatile unsigned short	Unused3;
	volatile unsigned short cr2;
	volatile unsigned short Unused4;
	volatile unsigned short cr3;
	volatile unsigned short Unused5;
	volatile unsigned short gtpr;
} USART;

char _tstchar( void ){
	if( (USART1->sr & BIT_RXNE ) == BIT_RXNE)
		return (char) USART1->dr;
	return 0;
}

char _outchar( char c ){
	while(( USART1->sr & BIT_TXE ) == 0);
	USART1->dr = (unsigned short) c;
}

static int usart_init( int initval ) {
	USART1->brr = 0x2D9;
	USART1->cr2 = 0;
	USART1->cr1 = BIT_UE | BIT_TE | BIT_RE;
}
static void usart_deinit( int deinitval) {
	USART1->brr = 0;
	USART1->cr2=0;
	USART1->cr1 = 0;
}
static int usart_write(char *ptr, int len){
	for(int i = 0; i < len; i++){
		_outchar(*ptr++);
	}
}
static int usart_read(char *ptr, int len){
	char c = 0;
	while(!c){
		c = _tstchar();
	}
	ptr = c;
	//return c;
}
static int usart_isatty(void){ return 1; }

DEV_DRIVER_DESC StdIn = {
	{"stdin"},
	usart_init,
	usart_deinit,
	0,
	usart_isatty,
	0,
	0,
	0,
	0,
	usart_read
};

DEV_DRIVER_DESC StdOut = {
	{"stdout"},
	0,
	0,
	0,
	usart_isatty,
	0,
	0,
	0,
	usart_write,
	0
};

DEV_DRIVER_DESC StdErr = {
	{"stderr"},
	0,
	0,
	0,
	usart_isatty,
	0,
	0,
	0,
	usart_write,
	0
};