/* gic.h — GIC-400 (Generic Interrupt Controller) for Raspberry Pi 5
 * BCM2712 uses GIC-400 at 0xFF840000
 */

#ifndef GIC_H
#define GIC_H

#include <stdint.h>

/* GIC-400 base addresses (BCM2712) */
#define GICD_BASE   0xFF841000UL  /* Distributor */
#define GICC_BASE   0xFF842000UL  /* CPU interface */

/* GIC Distributor registers */
#define GICD_CTLR       (*(volatile uint32_t *)(GICD_BASE + 0x000))
#define GICD_TYPER      (*(volatile uint32_t *)(GICD_BASE + 0x004))
#define GICD_ISENABLER(n) (*(volatile uint32_t *)(GICD_BASE + 0x100 + 4 * (n)))
#define GICD_ICENABLER(n) (*(volatile uint32_t *)(GICD_BASE + 0x180 + 4 * (n)))
#define GICD_IPRIORITYR(n) (*(volatile uint32_t *)(GICD_BASE + 0x400 + 4 * (n)))
#define GICD_ITARGETSR(n)  (*(volatile uint32_t *)(GICD_BASE + 0x800 + 4 * (n)))
#define GICD_ICFGR(n)   (*(volatile uint32_t *)(GICD_BASE + 0xC00 + 4 * (n)))
#define GICD_ICACTIVER(n) (*(volatile uint32_t *)(GICD_BASE + 0x380 + 4 * (n)))

/* GIC CPU interface registers */
#define GICC_CTLR       (*(volatile uint32_t *)(GICC_BASE + 0x000))
#define GICC_PMR        (*(volatile uint32_t *)(GICC_BASE + 0x004))
#define GICC_IAR        (*(volatile uint32_t *)(GICC_BASE + 0x00C))
#define GICC_EOIR       (*(volatile uint32_t *)(GICC_BASE + 0x010))

/* IRQ numbers for BCM2712 */
#define IRQ_TIMER_CNTP  30  /* ARM Generic Timer PPI 14 → IRQ 30 (16+14) */
#define IRQ_UART0       33  /* PL011 UART0 SPI → IRQ 33 (32+1 → check BCM2712 TRM) */
#define IRQ_UART1       34  /* PL011 UART1 (mini UART) */

/* Special IRQ values from GICC_IAR */
#define GIC_IRQ_SPURIOUS 1023

/* Initialize GIC-400 */
void gic_init(void);

/* Enable an IRQ */
void gic_enable_irq(int irq);

/* Disable an IRQ */
void gic_disable_irq(int irq);

/* Acknowledge IRQ (returns IRQ number) */
int gic_acknowledge(void);

/* End of interrupt */
void gic_eoi(int irq);

#endif /* GIC_H */