i.MX31: Interrupt Controller

Implement the Freescale i.MX31 advanced vectored interrupt controller, at least
to the extent it is used by Linux 3.x

Vectors are not implemented.

Signed-off-by: Philip O'Sullivan <philipo@ok-labs.com>
Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 408 insertions, 0 deletions

diff --git a/hw/imx_avic.c b/hw/imx_avic.c
new file mode 100644
index 0000000..25f47f3
--- /dev/null
+++ b/hw/imx_avic.c
@@ -0,0 +1,408 @@
+/*
+ * 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 licenced 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 "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,
+                             target_phys_addr_t 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, target_phys_addr_t 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",
+                (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)