/* gpiocontrol.c - gpiocontrol */

#include 

/*------------------------------------------------------------------------
 *  gpiocontrol  -  Control a gpio device pin settings
 *------------------------------------------------------------------------
 */
devcall gpiocontrol(
          struct dentry *devptr,        /* Entry in device switch table */
          int32  func,                  /* Function to perform          */
          int32  arg1,                  /* Argument 1 for request       */
          int32  arg2                   /* Argument 2 for request       */
        )
{
        struct gpio_csreg *csrptr;      /* Pointer ot the CSR for GPIO  */
        struct  gpiocblk  *gpioptr;     /* Pointer to the control block */

        csrptr = (struct gpio_csreg *)(devptr->dvcsr);
        gpioptr = &gpiotab[devptr->dvminor];

        /* Process the request */

        switch ( func ) {

        /* Enable output capability for pins in arg1 */

        case GPIO_OUTPUT_ENABLE:
                csrptr->oe &= (~arg1);
                return (devcall)OK;

        /* Disable output capability for pins in arg1 */

        case GPIO_OUTPUT_DISABLE:
                csrptr->oe |= arg1;
                return (devcall)OK;

        /* Register arg1 function pointer to be called from interrupt */

        case GPIO_REG_INT_HANDLER:
                gpioptr->gphookfn = (gpiointhook)arg1;
                return (devcall)OK;

        /* Configure debounce capability for pins in arg2 */

        case GPIO_DEB_SET_TIME:
                if(arg1 > 0)    {
                        csrptr->deb_time = (arg1-1) & 0xFF;
                        csrptr->deb_ena |= arg2;
                }
                else    {
                        csrptr->deb_ena &= (~arg2);
                }
                return (devcall)OK;

        /* Configure interrupt capability for pins in arg2 */

        case GPIO_INTERRUPT_CTL:

                /* No lines affected */

                if((arg1&GPIO_INT_ALL_LINES) == 0)      { 
                        return (devcall)SYSERR;
                }

                /* Disable lines and triggers */

                if((arg1&GPIO_INT_ALL_TRIG) == 0)       { 

                        /* Flags affect line 0 */

                        if((arg1&GPIO_INT_LINE0_EN) != 0) {
                                csrptr->irqclear0 = arg2;
                        }

                        /* Flags affect line 1 */

                        if((arg1&GPIO_INT_LINE1_EN) != 0) { 
                                csrptr->irqclear1 = arg2;
                        }
                        
                        /* Disable all triggers */

                        csrptr->rising &= (~arg2);
                        csrptr->falling &= (~arg2);
                        csrptr->level0 &= (~arg2);
                        csrptr->level1 &= (~arg2);

                        return (devcall)OK;
                }

                /* Enable lines and triggers */

                if((arg1&GPIO_INT_LINE0_EN) != 0)       { 
                                csrptr->irqset0 = arg2;
                }
                if((arg1&GPIO_INT_LINE1_EN) != 0)       { 
                                csrptr->irqset1 = arg2;
                }
                if((arg1&GPIO_INT_RISE_TRIG) != 0)      {
                        csrptr->rising |= arg2;
                }
                if((arg1&GPIO_INT_FALL_TRIG) != 0)      {
                        csrptr->falling |= arg2;
                }
                if((arg1&GPIO_INT_LVL0_TRIG) != 0)      {
                        csrptr->level0 |= arg2;
                }
                if((arg1&GPIO_INT_LVL1_TRIG) != 0)      {
                        csrptr->level1 |= arg2;
                }

                return (devcall)OK;

        /* Read input from a single pin arg1 */

        case GPIO_READ_PIN:
                arg2 = csrptr->datain & PIN_MASK(arg1);
                return (arg2>0);

        /* Write value arg2 to a single output pin arg1 */

        case GPIO_WRITE_PIN:
                if(arg2){
                        csrptr->set_data = PIN_MASK(arg1);
                }
                else    {
                        csrptr->clear_data = PIN_MASK(arg1);
                }
                return (devcall)OK;

        default:
                return (devcall)SYSERR;
        }
}