gpiowrite.c

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/* gpiowrite.c - gpiowrite */

#include <xinu.h>

/*------------------------------------------------------------------------
 *  gpiowrite  -  Write value of gpio pins
 *------------------------------------------------------------------------
 */
devcall gpiowrite(
      struct dentry *devptr,    /* Entry in device switch table */
      char *value,          /* Pointer to 32-bit buffer */
      int32 pinmask         /* Pins to be written written   */
    )
{
    struct gpio_csreg *csrptr;  /* Pointer to GPIO CSRs     */
    uint32 val;         /* Value to be written      */

    csrptr = (struct gpio_csreg *)(devptr->dvcsr);
    val = * (uint32 *)value;

    /* Set bits that should become one */

    csrptr->set_data = pinmask & val;   

    /* Clear bits that should become zero */

    csrptr->clear_data = pinmask & ~val;

    return OK;
}