#include "gic.h"

static gic_distributor_registers* gic_dregs;
static gic_cpu_interface_registers* gic_ifregs;

void gic_init(void) {
	gic_ifregs = (gic_cpu_interface_registers*)GIC_IFACE_BASE;
	gic_dregs = (gic_distributor_registers*)GIC_DIST_BASE;

	WRITE32(gic_ifregs->CCPMR, 0xFFFFu); /* Enable all interrupt priorities */
	WRITE32(gic_ifregs->CCTLR, CCTRL_ENABLE); /* Enable interrupt forwarding to this CPU */

	gic_distributor_registers* gic_dregs = (gic_distributor_registers*) GIC_DIST_BASE;
	WRITE32(gic_dregs->DCTLR, DCTRL_ENABLE); /* Enable the interrupt distributor */
}

void gic_enable_interrupt(uint16_t number) {
	/* Enable the interrupt */
	uint8_t reg = number / 32;
	uint8_t bit = number / 32;

	uint32_t reg_val = gic_dregs->DISENABLER[reg];
	reg_val |= (1u << bit);
	WRITE32(gic_dregs->DISENABLER[reg], reg_val);

	/* Forward interrupt to CPU Interface 8 */
	reg = number / 4;
	bit = (number % 4) * 8; /* Can result in bit 0, 8, 16 or 24 */
	reg_val = gic_dregs->DITARGETSR[reg];
	reg_val |= (1u << bit);
	WRITE32(gic_dregs->DITARGETSR[reg], reg_val);
}