/* spicontrol.c - spicontrol */

#include 

/*------------------------------------------------------------------------
 * spicontrol  -  Control function for SPI device
 *------------------------------------------------------------------------
 */
devcall spicontrol (
        struct  dentry  *devptr,        /* Entry in device switch table */
        int32   func,                   /* Control function             */
        int32   arg1,                   /* Argument 1, if needed        */
        int32   arg2                    /* Argument 2, if needed        */
        )
{
        struct  spi_csreg *csrptr;      /* SPI control and status regs  */
        struct  spi_transfer *msg;      /* Message pointer              */
        int     i;                      /* For loop index               */

        /* Get the pointer to the SPI CSRs */

        csrptr = (struct spi_csreg *)devptr->dvcsr;

        /* Get the pointer to the message */

        msg = (struct spi_transfer *)arg1;

        switch(func) {

         /* This is a SPI transfer */

         case SPI_CTRL_TRANSFER:

                for(i = 0; i < msg->length; i++) {

                        /* Wait while the transmit register is not empty */

                        while((csrptr->ch[0].chstat & SPI_CHSTAT_TXS) == 0);

                        /* Send a byte */

                        csrptr->ch[0].chtx = msg->txbuf[i];

                        /* Wait until there is a byte in the receive register */

                        while((csrptr->ch[0].chstat & SPI_CHSTAT_RXS) == 0);

                        /* Read the byte from the receive register */

                        msg->rxbuf[i] = csrptr->ch[0].chrx;
                }

                /* End the transfer by changing CS level */

                csrptr->ch[0].chconf &= ~SPI_CHCONF_FORCE;
                csrptr->ch[0].chconf |= SPI_CHCONF_FORCE;

                break;
        }

        return OK;
}