Archipelago » qemu

/*

 * i.MX31 Vectored Interrupt Controller

 *

 * Note this is NOT the PL192 provided by ARM, but

 * a custom implementation by Freescale.

 *

 * Copyright (c) 2008 OKL

 * Copyright (c) 2011 NICTA Pty Ltd

 * Originally written by Hans Jiang

 *

 * This code is licensed under the GPL version 2 or later.  See

 * the COPYING file in the top-level directory.

 *

 * TODO: implement vectors.

 */

#include "hw.h"

#include "sysbus.h"

#include "qemu/host-utils.h"

#define DEBUG_INT 1

#undef DEBUG_INT /* comment out for debugging */

#ifdef DEBUG_INT

#define DPRINTF(fmt, args...) \

do { printf("imx_avic: " fmt , ##args); } while (0)

#else

#define DPRINTF(fmt, args...) do {} while (0)

#endif

/*

 * Define to 1 for messages about attempts to

 * access unimplemented registers or similar.

 */

#define DEBUG_IMPLEMENTATION 1

#if DEBUG_IMPLEMENTATION

#  define IPRINTF(fmt, args...) \

    do  { fprintf(stderr, "imx_avic: " fmt, ##args); } while (0)

#else

#  define IPRINTF(fmt, args...) do {} while (0)

#endif

#define IMX_AVIC_NUM_IRQS 64

/* Interrupt Control Bits */

#define ABFLAG (1<<25)

#define ABFEN (1<<24)

#define NIDIS (1<<22) /* Normal Interrupt disable */

#define FIDIS (1<<21) /* Fast interrupt disable */

#define NIAD  (1<<20) /* Normal Interrupt Arbiter Rise ARM level */

#define FIAD  (1<<19) /* Fast Interrupt Arbiter Rise ARM level */

#define NM    (1<<18) /* Normal interrupt mode */

#define PRIO_PER_WORD (sizeof(uint32_t) * 8 / 4)

#define PRIO_WORDS (IMX_AVIC_NUM_IRQS/PRIO_PER_WORD)

typedef struct {

    SysBusDevice busdev;

    MemoryRegion iomem;

    uint64_t pending;

    uint64_t enabled;

    uint64_t is_fiq;

    uint32_t intcntl;

    uint32_t intmask;

    qemu_irq irq;

    qemu_irq fiq;

    uint32_t prio[PRIO_WORDS]; /* Priorities are 4-bits each */

} IMXAVICState;

static const VMStateDescription vmstate_imx_avic = {

    .name = "imx-avic",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_UINT64(pending, IMXAVICState),

        VMSTATE_UINT64(enabled, IMXAVICState),

        VMSTATE_UINT64(is_fiq, IMXAVICState),

        VMSTATE_UINT32(intcntl, IMXAVICState),

        VMSTATE_UINT32(intmask, IMXAVICState),

        VMSTATE_UINT32_ARRAY(prio, IMXAVICState, PRIO_WORDS),

        VMSTATE_END_OF_LIST()

    },

};

static inline int imx_avic_prio(IMXAVICState *s, int irq)

{

    uint32_t word = irq / PRIO_PER_WORD;

    uint32_t part = 4 * (irq % PRIO_PER_WORD);

    return 0xf & (s->prio[word] >> part);

}

static inline void imx_avic_set_prio(IMXAVICState *s, int irq, int prio)

{

    uint32_t word = irq / PRIO_PER_WORD;

    uint32_t part = 4 * (irq % PRIO_PER_WORD);

    uint32_t mask = ~(0xf << part);

    s->prio[word] &= mask;

    s->prio[word] |= prio << part;

}

/* Update interrupts.  */

static void imx_avic_update(IMXAVICState *s)

{

    int i;

    uint64_t new = s->pending & s->enabled;

    uint64_t flags;

    flags = new & s->is_fiq;

    qemu_set_irq(s->fiq, !!flags);

    flags = new & ~s->is_fiq;

    if (!flags || (s->intmask == 0x1f)) {

        qemu_set_irq(s->irq, !!flags);

        return;

    }

    /*

     * Take interrupt if there's a pending interrupt with

     * priority higher than the value of intmask

     */

    for (i = 0; i < IMX_AVIC_NUM_IRQS; i++) {

        if (flags & (1UL << i)) {

            if (imx_avic_prio(s, i) > s->intmask) {

                qemu_set_irq(s->irq, 1);

                return;

            }

        }

    }

    qemu_set_irq(s->irq, 0);

}

static void imx_avic_set_irq(void *opaque, int irq, int level)

{

    IMXAVICState *s = (IMXAVICState *)opaque;

    if (level) {

        DPRINTF("Raising IRQ %d, prio %d\n",

                irq, imx_avic_prio(s, irq));

        s->pending |= (1ULL << irq);

    } else {

        DPRINTF("Clearing IRQ %d, prio %d\n",

                irq, imx_avic_prio(s, irq));

        s->pending &= ~(1ULL << irq);

    }

    imx_avic_update(s);

}

static uint64_t imx_avic_read(void *opaque,

                             hwaddr offset, unsigned size)

{

    IMXAVICState *s = (IMXAVICState *)opaque;

    DPRINTF("read(offset = 0x%x)\n", offset >> 2);

    switch (offset >> 2) {

    case 0: /* INTCNTL */

        return s->intcntl;

    case 1: /* Normal Interrupt Mask Register, NIMASK */

        return s->intmask;

    case 2: /* Interrupt Enable Number Register, INTENNUM */

    case 3: /* Interrupt Disable Number Register, INTDISNUM */

        return 0;

    case 4: /* Interrupt Enabled Number Register High */

        return s->enabled >> 32;

    case 5: /* Interrupt Enabled Number Register Low */

        return s->enabled & 0xffffffffULL;

    case 6: /* Interrupt Type Register High */

        return s->is_fiq >> 32;

    case 7: /* Interrupt Type Register Low */

        return s->is_fiq & 0xffffffffULL;

    case 8: /* Normal Interrupt Priority Register 7 */

    case 9: /* Normal Interrupt Priority Register 6 */

    case 10:/* Normal Interrupt Priority Register 5 */

    case 11:/* Normal Interrupt Priority Register 4 */

    case 12:/* Normal Interrupt Priority Register 3 */

    case 13:/* Normal Interrupt Priority Register 2 */

    case 14:/* Normal Interrupt Priority Register 1 */

    case 15:/* Normal Interrupt Priority Register 0 */

        return s->prio[15-(offset>>2)];

    case 16: /* Normal interrupt vector and status register */

    {

        /*

         * This returns the highest priority

         * outstanding interrupt.  Where there is more than

         * one pending IRQ with the same priority,

         * take the highest numbered one.

         */

        uint64_t flags = s->pending & s->enabled & ~s->is_fiq;

        int i;

        int prio = -1;

        int irq = -1;

        for (i = 63; i >= 0; --i) {

            if (flags & (1ULL<<i)) {

                int irq_prio = imx_avic_prio(s, i);

                if (irq_prio > prio) {

                    irq = i;

                    prio = irq_prio;

                }

            }

        }

        if (irq >= 0) {

            imx_avic_set_irq(s, irq, 0);

            return irq << 16 | prio;

        }

        return 0xffffffffULL;

    }

    case 17:/* Fast Interrupt vector and status register */

    {

        uint64_t flags = s->pending & s->enabled & s->is_fiq;

        int i = ctz64(flags);

        if (i < 64) {

            imx_avic_set_irq(opaque, i, 0);

            return i;

        }

        return 0xffffffffULL;

    }

    case 18:/* Interrupt source register high */

        return s->pending >> 32;

    case 19:/* Interrupt source register low */

        return s->pending & 0xffffffffULL;

    case 20:/* Interrupt Force Register high */

    case 21:/* Interrupt Force Register low */

        return 0;

    case 22:/* Normal Interrupt Pending Register High */

        return (s->pending & s->enabled & ~s->is_fiq) >> 32;

    case 23:/* Normal Interrupt Pending Register Low */

        return (s->pending & s->enabled & ~s->is_fiq) & 0xffffffffULL;

    case 24: /* Fast Interrupt Pending Register High  */

        return (s->pending & s->enabled & s->is_fiq) >> 32;

    case 25: /* Fast Interrupt Pending Register Low  */

        return (s->pending & s->enabled & s->is_fiq) & 0xffffffffULL;

    case 0x40:            /* AVIC vector 0, use for WFI WAR */

        return 0x4;

    default:

        IPRINTF("imx_avic_read: Bad offset 0x%x\n", (int)offset);

        return 0;

    }

}

static void imx_avic_write(void *opaque, hwaddr offset,

                          uint64_t val, unsigned size)

{

    IMXAVICState *s = (IMXAVICState *)opaque;

    /* Vector Registers not yet supported */

    if (offset >= 0x100 && offset <= 0x2fc) {

        IPRINTF("imx_avic_write to vector register %d ignored\n",

                (unsigned int)((offset - 0x100) >> 2));

        return;

    }

    DPRINTF("imx_avic_write(0x%x) = %x\n",

            (unsigned int)offset>>2, (unsigned int)val);

    switch (offset >> 2) {

    case 0: /* Interrupt Control Register, INTCNTL */

        s->intcntl = val & (ABFEN | NIDIS | FIDIS | NIAD | FIAD | NM);

        if (s->intcntl & ABFEN) {

            s->intcntl &= ~(val & ABFLAG);

        }

        break;

    case 1: /* Normal Interrupt Mask Register, NIMASK */

        s->intmask = val & 0x1f;

        break;

    case 2: /* Interrupt Enable Number Register, INTENNUM */

        DPRINTF("enable(%d)\n", (int)val);

        val &= 0x3f;

        s->enabled |= (1ULL << val);

        break;

    case 3: /* Interrupt Disable Number Register, INTDISNUM */

        DPRINTF("disable(%d)\n", (int)val);

        val &= 0x3f;

        s->enabled &= ~(1ULL << val);

        break;

    case 4: /* Interrupt Enable Number Register High */

        s->enabled = (s->enabled & 0xffffffffULL) | (val << 32);

        break;

    case 5: /* Interrupt Enable Number Register Low */

        s->enabled = (s->enabled & 0xffffffff00000000ULL) | val;

        break;

    case 6: /* Interrupt Type Register High */

        s->is_fiq = (s->is_fiq & 0xffffffffULL) | (val << 32);

        break;

    case 7: /* Interrupt Type Register Low */

        s->is_fiq = (s->is_fiq & 0xffffffff00000000ULL) | val;

        break;

    case 8: /* Normal Interrupt Priority Register 7 */

    case 9: /* Normal Interrupt Priority Register 6 */

    case 10:/* Normal Interrupt Priority Register 5 */

    case 11:/* Normal Interrupt Priority Register 4 */

    case 12:/* Normal Interrupt Priority Register 3 */

    case 13:/* Normal Interrupt Priority Register 2 */

    case 14:/* Normal Interrupt Priority Register 1 */

    case 15:/* Normal Interrupt Priority Register 0 */

        s->prio[15-(offset>>2)] = val;

        break;

        /* Read-only registers, writes ignored */

    case 16:/* Normal Interrupt Vector and Status register */

    case 17:/* Fast Interrupt vector and status register */

    case 18:/* Interrupt source register high */

    case 19:/* Interrupt source register low */

        return;

    case 20:/* Interrupt Force Register high */

        s->pending = (s->pending & 0xffffffffULL) | (val << 32);

        break;

    case 21:/* Interrupt Force Register low */

        s->pending = (s->pending & 0xffffffff00000000ULL) | val;

        break;

    case 22:/* Normal Interrupt Pending Register High */

    case 23:/* Normal Interrupt Pending Register Low */

    case 24: /* Fast Interrupt Pending Register High  */

    case 25: /* Fast Interrupt Pending Register Low  */

        return;

    default:

        IPRINTF("imx_avic_write: Bad offset %x\n", (int)offset);

    }

    imx_avic_update(s);

}

static const MemoryRegionOps imx_avic_ops = {

    .read = imx_avic_read,

    .write = imx_avic_write,

    .endianness = DEVICE_NATIVE_ENDIAN,

};

static void imx_avic_reset(DeviceState *dev)

{

    IMXAVICState *s = container_of(dev, IMXAVICState, busdev.qdev);

    s->pending = 0;

    s->enabled = 0;

    s->is_fiq = 0;

    s->intmask = 0x1f;

    s->intcntl = 0;

    memset(s->prio, 0, sizeof s->prio);

}

static int imx_avic_init(SysBusDevice *dev)

{

    IMXAVICState *s = FROM_SYSBUS(IMXAVICState, dev);;

    memory_region_init_io(&s->iomem, &imx_avic_ops, s, "imx_avic", 0x1000);

    sysbus_init_mmio(dev, &s->iomem);

    qdev_init_gpio_in(&dev->qdev, imx_avic_set_irq, IMX_AVIC_NUM_IRQS);

    sysbus_init_irq(dev, &s->irq);

    sysbus_init_irq(dev, &s->fiq);

    return 0;

}

static void imx_avic_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = imx_avic_init;

    dc->vmsd = &vmstate_imx_avic;

    dc->reset = imx_avic_reset;

    dc->desc = "i.MX Advanced Vector Interrupt Controller";

}

static const TypeInfo imx_avic_info = {

    .name = "imx_avic",

    .parent = TYPE_SYS_BUS_DEVICE,

    .instance_size = sizeof(IMXAVICState),

    .class_init = imx_avic_class_init,

};

static void imx_avic_register_types(void)

{

    type_register_static(&imx_avic_info);

}

type_init(imx_avic_register_types)