Initial commit of fifo and i2c routines
This commit is contained in:
Ørn E. Hansen
@@ -626,9 +626,9 @@ acsi_dma: // atari dma
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move.l d1,-(a7)
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lea MCF_PSC0_PSCTB_8BIT,a1 // ++ vr
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mchar move.l, 'D,'M','A,'\ ,(a1)
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mchar move.l, 'D','M','A','\'' ,(a1)
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//move.l #"DMA ",(a1)
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mchar move.l,'I,'N,'T,'!,(a1)
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mchar move.l,'I','N','T','!',(a1)
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// move.l #'INT!',(a1)
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lea 0xf0020110,a5 // fifo daten
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109
i2cspi_BaS_gcc/sources/fifo.c
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109
i2cspi_BaS_gcc/sources/fifo.c
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@@ -0,0 +1,109 @@
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/*
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* fifo.c
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*
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* A general implementation of a fifo buffer
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*
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*/
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#include <fifo.h>
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//This initializes the FIFO structure with the given buffer and size
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void fifo_init(fifo_t * f, char * buf, int size)
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{
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f->head = 0;
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f->tail = 0;
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f->size = size;
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f->buf = buf;
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}
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// Get one byte from the fifo buffer
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uint8_t fifo_get(fifo_t *f)
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{
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uint8_t ch = 0;
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if( f->tail != f->head && f->tail < f->size )
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{
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ch = f->buf[f->tail++];
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if( f->tail >= f->size )
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f->tail = 0;
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}
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return ch;
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}
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// Put one byte into the buffer
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void fifo_put(fifo_t *f, uint8_t byte)
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{
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if( f->head == f->tail || f->head >= f->size )
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return;
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f->buf[f->head] = byte;
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fifo_advance(f,&f->head);
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}
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void fifo_clear(fifo_t *f)
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{
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f->head = f->tail = 0;
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}
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int fifo_used(fifo_t *f)
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{
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if( f->head > f->tail )
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return (f->head - f->tail);
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return (f->size - f->tail + f->head);
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}
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int fifo_unused(fifo_t *f)
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{
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if( f->head > f->tail )
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return (f->size-f->head+f->tail);
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return (f->tail-f->head);
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}
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int fifo_full(fifo_t *f)
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{
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if( f->head+1 >= f->size )
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return (f->tail == 0);
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return (f->head+1 == f->tail);
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}
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int fifo_empty(fifo_t *f)
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{
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return (f->head == f->tail);
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}
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void fifo_advance(fifo_t *f, int *ix)
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{
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if( ++*ix > f->size )
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*ix=0;
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}
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//This reads at most nbytes bytes from the FIFO
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//The number of bytes read is returned
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int fifo_read(fifo_t *f, char *buf, int nbytes){
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int n = 0;
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while( n < nbytes && !fifo_empty(f) )
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{
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n++;
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*buf++ = f->buf[f->tail];
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fifo_advance(f,&f->tail);
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}
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return n;
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}
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//This writes up to nbytes bytes to the FIFO
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//If the head runs in to the tail, not all bytes are written
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//The number of bytes written is returned
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int fifo_write(fifo_t *f, const char *buf, int nbytes){
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int n = 0;
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while( n < nbytes && !fifo_full(f) )
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{
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f->buf[f->head] = *buf++;
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fifo_advance(f,&f->head);
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n++;
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}
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return n;
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}
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185
i2cspi_BaS_gcc/sources/i2c_firebee.c
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185
i2cspi_BaS_gcc/sources/i2c_firebee.c
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@@ -0,0 +1,185 @@
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/*
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* i2c.c
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*
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*/
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#include <MCF5475.h>
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#include <i2c_firebee.h>
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#include <fifo.h>
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static struct {
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uint8_t state;
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long delay;
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uint16_t len;
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fifo_t fifo;
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unsigned char *_buf;
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uint16_t device;
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} i2c_param;
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char local_buf[BUFSIZ];
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#define FIFO &i2c_param.fifo
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/*
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* I2Cinit: I2C initilazation as master
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*
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* Parameters: None.
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*
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* Return : None.
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*/
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void I2C_Init()
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{
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i2c_param.fifo.buf = local_buf;
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i2c_param.fifo.size = BUFSIZ;
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i2c_param.delay = 133*10L; // We can safely ignore this
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i2c_param.len = 0;
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I2C_ioctl(0,0);
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}
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void __attribute__ ((interrupt)) I2C_InterruptHandler(void)
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{
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char ch;
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clear_bit(MCF_I2C_I2SR,MCF_I2C_I2SR_IIF);
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if( MCF_I2C_I2CR & MCF_I2C_I2CR_MSTA )
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{ // Masters of the known universe
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if( MCF_I2C_I2SR & MCF_I2C_I2SR_ICF )
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{
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switch( i2c_param.state )
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{
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case I2C_MXRX:
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if( fifo_used(&i2c_param.fifo)+1 == i2c_param.len ) {
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clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MSTA);
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i2c_param.state = I2C_READY;
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} else if( fifo_used(&i2c_param.fifo)+2 == i2c_param.len ) {
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set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_TXAK);
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i2c_param.state = I2C_READY;
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}
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fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
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break;
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case I2C_ADDR:
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if( fifo_empty(&i2c_param.fifo) )
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{
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i2c_param.state = I2C_MXRX;
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clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX); // Receive mode
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set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_RSTA);
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ch = MCF_I2C_I2DR; // Dummy read
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break;
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}
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case I2C_MXTX:
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if( fifo_empty(&i2c_param.fifo) || (MCF_I2C_I2SR&MCF_I2C_I2SR_RXAK) ) {
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clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MSTA);
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i2c_param.state = I2C_READY;
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} else
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MCF_I2C_I2DR = fifo_get(&i2c_param.fifo);
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break;
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}
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}
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} else { // Slave mode.
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int set;
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if( set = (MCF_I2C_I2SR & MCF_I2C_I2SR_IAL) )
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clear_bit(MCF_I2C_I2SR,MCF_I2C_I2SR_IAL);
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if( MCF_I2C_I2SR & MCF_I2C_I2SR_IAAS )
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{
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if( MCF_I2C_I2SR & MCF_I2C_I2SR_SRW )
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{
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set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
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fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
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} else {
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clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
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ch = MCF_I2C_I2DR;
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}
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} else if( !set ) {
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if( MCF_I2C_I2CR&MCF_I2C_I2CR_MTX )
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{
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if( MCF_I2C_I2SR&MCF_I2C_I2SR_RXAK )
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MCF_I2C_I2DR = fifo_get(&i2c_param.fifo);
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else {
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clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
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ch = MCF_I2C_I2DR;
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}
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} else {
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fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
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}
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}
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}
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}
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void I2C_send(unsigned short device, unsigned char *buf, unsigned short len)
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{
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if( len > i2c_param.fifo.size )
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return;
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i2c_param.len = len;
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fifo_clear(&i2c_param.fifo);
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if( device > 127 ) // Use I2C 10 bit address
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{
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fifo_put(FIFO,0b11110|((device>>5)&6)|I2C_WRITE);
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fifo_put(FIFO,device&255);
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} else
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fifo_put(FIFO,((device<<1)&0xFE)|I2C_WRITE);
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fifo_write(FIFO,buf,len);
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i2c_param.state = I2C_MXTX;
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}
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void I2C_receive(unsigned short device, unsigned char *buf, unsigned short len)
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{
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if( len > i2c_param.fifo.size )
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return;
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i2c_param.len = len;
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fifo_clear(FIFO);
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if( device > 127 ) // Use I2C 10 bit address
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{
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fifo_put(FIFO,0b11110|((device>>5)&6)|I2C_READ);
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fifo_put(FIFO,device&255);
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} else
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fifo_put(FIFO,((device<<1)&0xFE)|I2C_READ);
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i2c_param.state = I2C_ADDR;
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}
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int I2C_ioctl(unsigned int index, unsigned long val)
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{
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unsigned short len = val;
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uint8_t temp;
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// Set device as slave or
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switch( index )
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{
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case I2CTLINIT: // make me master
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/* set the frequency near 400KHz */
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MCF_I2C_I2FDR = MCF_I2C_I2FDR_IC(0x10);
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/* start the module */
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MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN | MCF_I2C_I2CR_IEN;
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/* if bit busy set, send a stop condition to slave module */
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if(MCF_I2C_I2SR & MCF_I2C_I2SR_IBB)
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{
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MCF_I2C_I2CR = 0; /* clear control register */
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MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN|MCF_I2C_I2CR_IEN|MCF_I2C_I2CR_MSTA; /* enable module & send a START condition */
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temp = MCF_I2C_I2DR; /* dummy read */
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MCF_I2C_I2SR = 0; /* clear status register */
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MCF_I2C_I2CR = 0; /* clear control register */
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MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN|MCF_I2C_I2CR_IEN; /* enable the module again */
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}
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i2c_param.state = I2C_READY;
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i2c_param._buf = 0;
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break;
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case I2CTLSBUF:
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i2c_param._buf = (char *)val;
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break;
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case I2CTLDEV:
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i2c_param.device = val;
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break;
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case I2CTLREAD:
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if( i2c_param._buf == 0 || i2c_param.device == 0 )
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return -1;
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I2C_receive(i2c_param.device,i2c_param._buf,len);
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break;
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case I2CTLWRITE:
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if( i2c_param._buf == 0 || i2c_param.device == 0 )
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return -1;
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I2C_send(i2c_param.device,i2c_param._buf,len);
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break;
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}
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}
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