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Initial commit of fifo and i2c routines

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This commit is contained in:
Ørn E. Hansen
2013-04-16 20:20:42 +00:00
parent efd01c2fa3
commit 57e3d242b8
3 changed files with 296 additions and 2 deletions
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185
i2cspi_BaS_gcc/sources/i2c_firebee.c Normal file
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/*
* i2c.c
*
*/
#include <MCF5475.h>
#include <i2c_firebee.h>
#include <fifo.h>
static struct {
uint8_t state;
long delay;
uint16_t len;
fifo_t fifo;
unsigned char *_buf;
uint16_t device;
} i2c_param;
char local_buf[BUFSIZ];
#define FIFO &i2c_param.fifo
/*
* I2Cinit: I2C initilazation as master
*
* Parameters: None.
*
* Return : None.
*/
void I2C_Init()
{
i2c_param.fifo.buf = local_buf;
i2c_param.fifo.size = BUFSIZ;
i2c_param.delay = 133*10L; // We can safely ignore this
i2c_param.len = 0;
I2C_ioctl(0,0);
}
void __attribute__ ((interrupt)) I2C_InterruptHandler(void)
{
char ch;
clear_bit(MCF_I2C_I2SR,MCF_I2C_I2SR_IIF);
if( MCF_I2C_I2CR & MCF_I2C_I2CR_MSTA )
{ // Masters of the known universe
if( MCF_I2C_I2SR & MCF_I2C_I2SR_ICF )
{
switch( i2c_param.state )
{
case I2C_MXRX:
if( fifo_used(&i2c_param.fifo)+1 == i2c_param.len ) {
clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MSTA);
i2c_param.state = I2C_READY;
} else if( fifo_used(&i2c_param.fifo)+2 == i2c_param.len ) {
set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_TXAK);
i2c_param.state = I2C_READY;
}
fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
break;
case I2C_ADDR:
if( fifo_empty(&i2c_param.fifo) )
{
i2c_param.state = I2C_MXRX;
clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX); // Receive mode
set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_RSTA);
ch = MCF_I2C_I2DR; // Dummy read
break;
}
case I2C_MXTX:
if( fifo_empty(&i2c_param.fifo) || (MCF_I2C_I2SR&MCF_I2C_I2SR_RXAK) ) {
clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MSTA);
i2c_param.state = I2C_READY;
} else
MCF_I2C_I2DR = fifo_get(&i2c_param.fifo);
break;
}
}
} else { // Slave mode.
int set;
if( set = (MCF_I2C_I2SR & MCF_I2C_I2SR_IAL) )
clear_bit(MCF_I2C_I2SR,MCF_I2C_I2SR_IAL);
if( MCF_I2C_I2SR & MCF_I2C_I2SR_IAAS )
{
if( MCF_I2C_I2SR & MCF_I2C_I2SR_SRW )
{
set_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
} else {
clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
ch = MCF_I2C_I2DR;
}
} else if( !set ) {
if( MCF_I2C_I2CR&MCF_I2C_I2CR_MTX )
{
if( MCF_I2C_I2SR&MCF_I2C_I2SR_RXAK )
MCF_I2C_I2DR = fifo_get(&i2c_param.fifo);
else {
clear_bit(MCF_I2C_I2CR,MCF_I2C_I2CR_MTX);
ch = MCF_I2C_I2DR;
}
} else {
fifo_put(&i2c_param.fifo,MCF_I2C_I2DR);
}
}
}
}
void I2C_send(unsigned short device, unsigned char *buf, unsigned short len)
{
if( len > i2c_param.fifo.size )
return;
i2c_param.len = len;
fifo_clear(&i2c_param.fifo);
if( device > 127 ) // Use I2C 10 bit address
{
fifo_put(FIFO,0b11110|((device>>5)&6)|I2C_WRITE);
fifo_put(FIFO,device&255);
} else
fifo_put(FIFO,((device<<1)&0xFE)|I2C_WRITE);
fifo_write(FIFO,buf,len);
i2c_param.state = I2C_MXTX;
}
void I2C_receive(unsigned short device, unsigned char *buf, unsigned short len)
{
if( len > i2c_param.fifo.size )
return;
i2c_param.len = len;
fifo_clear(FIFO);
if( device > 127 ) // Use I2C 10 bit address
{
fifo_put(FIFO,0b11110|((device>>5)&6)|I2C_READ);
fifo_put(FIFO,device&255);
} else
fifo_put(FIFO,((device<<1)&0xFE)|I2C_READ);
i2c_param.state = I2C_ADDR;
}
int I2C_ioctl(unsigned int index, unsigned long val)
{
unsigned short len = val;
uint8_t temp;
// Set device as slave or
switch( index )
{
case I2CTLINIT: // make me master
/* set the frequency near 400KHz */
MCF_I2C_I2FDR = MCF_I2C_I2FDR_IC(0x10);
/* start the module */
MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN | MCF_I2C_I2CR_IEN;
/* if bit busy set, send a stop condition to slave module */
if(MCF_I2C_I2SR & MCF_I2C_I2SR_IBB)
{
MCF_I2C_I2CR = 0; /* clear control register */
MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN|MCF_I2C_I2CR_IEN|MCF_I2C_I2CR_MSTA; /* enable module & send a START condition */
temp = MCF_I2C_I2DR; /* dummy read */
MCF_I2C_I2SR = 0; /* clear status register */
MCF_I2C_I2CR = 0; /* clear control register */
MCF_I2C_I2CR = MCF_I2C_I2CR_IIEN|MCF_I2C_I2CR_IEN; /* enable the module again */
}
i2c_param.state = I2C_READY;
i2c_param._buf = 0;
break;
case I2CTLSBUF:
i2c_param._buf = (char *)val;
break;
case I2CTLDEV:
i2c_param.device = val;
break;
case I2CTLREAD:
if( i2c_param._buf == 0 || i2c_param.device == 0 )
return -1;
I2C_receive(i2c_param.device,i2c_param._buf,len);
break;
case I2CTLWRITE:
if( i2c_param._buf == 0 || i2c_param.device == 0 )
return -1;
I2C_send(i2c_param.device,i2c_param._buf,len);
break;
}
}