euint8 if_spiSend(hwInterface *iface, euint8 outgoing)
{
euint8 incoming=0;
alt_u8 SD_Data=0,status;
/* Set the SSO bit (force chipselect) */
IOWR_ALTERA_AVALON_SPI_CONTROL(SPI_0_BASE, 0x400);
do{
status = IORD_ALTERA_AVALON_SPI_STATUS(SPI_0_BASE);//get status
}while (((status & ALTERA_AVALON_SPI_STATUS_TRDY_MSK) == 0 ) &&
(status & ALTERA_AVALON_SPI_STATUS_RRDY_MSK) == 0);
/* wait till transmit and ready ok */
IOWR_ALTERA_AVALON_SPI_TXDATA(SPI_0_BASE, outgoing);
/* Wait until the interface has finished transmitting */
do{status = IORD_ALTERA_AVALON_SPI_STATUS(SPI_0_BASE);}
while ((status & ALTERA_AVALON_SPI_STATUS_TMT_MSK) == 0);
/* reciver ready */
if (((status & 0x80) != 0) ){
SD_Data = IORD_ALTERA_AVALON_SPI_RXDATA(SPI_0_BASE);
}
else{
printf("\n no recive after transmit");
}
IOWR_ALTERA_AVALON_SPI_SLAVE_SEL(SPI_0_BASE, 1);
IOWR_ALTERA_AVALON_SPI_CONTROL(SPI_0_BASE, 0);
if( (status & 0x100) !=0)
printf("\n error in spi error in spi");
return (SD_Data);
}
void if_spiInit(hwInterface *iface)
{
euint8 i;
IOWR_ALTERA_AVALON_SPI_SLAVE_SEL(SPI_0_BASE, 1 );
printf("\n spi ini");
}
int alt_avalon_spi_command(alt_u32 base, alt_u32 slave,
alt_u32 write_length, const alt_u8 * write_data,
alt_u32 read_length, alt_u8 * read_data,
alt_u32 flags)
{
const alt_u8 * write_end = write_data + write_length;
alt_u8 * read_end = read_data + read_length;
alt_u32 write_zeros = read_length;
alt_u32 read_ignore = write_length;
alt_u32 status;
/* We must not send more than two bytes to the target before it has
* returned any as otherwise it will overflow. */
/* Unfortunately the hardware does not seem to work with credits > 1,
* leave it at 1 for now. */
alt_32 credits = 1;
/* Warning: this function is not currently safe if called in a multi-threaded
* environment, something above must perform locking to make it safe if more
* than one thread intends to use it.
*/
IOWR_ALTERA_AVALON_SPI_SLAVE_SEL(base, 1 << slave);
/* Set the SSO bit (force chipselect) only if the toggle flag is not set */
if ((flags & ALT_AVALON_SPI_COMMAND_TOGGLE_SS_N) == 0) {
IOWR_ALTERA_AVALON_SPI_CONTROL(base, ALTERA_AVALON_SPI_CONTROL_SSO_MSK);
}
/*
* Discard any stale data present in the RXDATA register, in case
* previous communication was interrupted and stale data was left
* behind.
*/
IORD_ALTERA_AVALON_SPI_RXDATA(base);
/* Keep clocking until all the data has been processed. */
for ( ; ; )
{
do
{
status = IORD_ALTERA_AVALON_SPI_STATUS(base);
}
while (((status & ALTERA_AVALON_SPI_STATUS_TRDY_MSK) == 0 || credits == 0) &&
(status & ALTERA_AVALON_SPI_STATUS_RRDY_MSK) == 0);
if ((status & ALTERA_AVALON_SPI_STATUS_TRDY_MSK) != 0 && credits > 0)
{
credits--;
if (write_data < write_end)
IOWR_ALTERA_AVALON_SPI_TXDATA(base, *write_data++);
else if (write_zeros > 0)
{
write_zeros--;
IOWR_ALTERA_AVALON_SPI_TXDATA(base, 0);
}
else
credits = -1024;
};
if ((status & ALTERA_AVALON_SPI_STATUS_RRDY_MSK) != 0)
{
alt_u32 rxdata = IORD_ALTERA_AVALON_SPI_RXDATA(base);
if (read_ignore > 0)
read_ignore--;
else
*read_data++ = (alt_u8)rxdata;
credits++;
if (read_ignore == 0 && read_data == read_end)
break;
}
}
/* Wait until the interface has finished transmitting */
do
{
status = IORD_ALTERA_AVALON_SPI_STATUS(base);
}
while ((status & ALTERA_AVALON_SPI_STATUS_TMT_MSK) == 0);
/* Clear SSO (release chipselect) unless the caller is going to
* keep using this chip
*/
if ((flags & ALT_AVALON_SPI_COMMAND_MERGE) == 0)
IOWR_ALTERA_AVALON_SPI_CONTROL(base, 0);
return read_length;
}
