MAX78000: ICC Implementation

This commit implements the Instruction Cache Controller
for the MAX78000

Signed-off-by: Jackson Donaldson <jcksn@duck.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20250704223239.248781-3-jcksn@duck.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/Kconfig

@@ -366,6 +366,7 @@ config ALLWINNER_R40
 config MAX78000_SOC
     bool
     select ARM_V7M
+    select MAX78000_ICC
 
 config RASPI
     bool

hw/misc/Kconfig

@@ -47,6 +47,9 @@ config A9SCU
 config ARM11SCU
     bool
 
+config MAX78000_ICC
+    bool
+
 config MOS6522
     bool
 

hw/misc/max78000_icc.c

@@ -0,0 +1,120 @@
+/*
+ * MAX78000 Instruction Cache
+ *
+ * Copyright (c) 2025 Jackson Donaldson <jcksn@duck.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "trace.h"
+#include "hw/irq.h"
+#include "migration/vmstate.h"
+#include "hw/misc/max78000_icc.h"
+
+
+static uint64_t max78000_icc_read(void *opaque, hwaddr addr,
+                                    unsigned int size)
+{
+    Max78000IccState *s = opaque;
+    switch (addr) {
+    case ICC_INFO:
+        return s->info;
+
+    case ICC_SZ:
+        return s->sz;
+
+    case ICC_CTRL:
+        return s->ctrl;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr);
+        return 0;
+
+    }
+}
+
+static void max78000_icc_write(void *opaque, hwaddr addr,
+                    uint64_t val64, unsigned int size)
+{
+    Max78000IccState *s = opaque;
+
+    switch (addr) {
+    case ICC_CTRL:
+        s->ctrl = 0x10000 | (val64 & 1);
+        break;
+
+    case ICC_INVALIDATE:
+        break;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr);
+        break;
+    }
+}
+
+static const MemoryRegionOps max78000_icc_ops = {
+    .read = max78000_icc_read,
+    .write = max78000_icc_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+};
+
+static const VMStateDescription max78000_icc_vmstate = {
+    .name = TYPE_MAX78000_ICC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT32(info, Max78000IccState),
+        VMSTATE_UINT32(sz, Max78000IccState),
+        VMSTATE_UINT32(ctrl, Max78000IccState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void max78000_icc_reset_hold(Object *obj, ResetType type)
+{
+    Max78000IccState *s = MAX78000_ICC(obj);
+    s->info = 0;
+    s->sz = 0x10000010;
+    s->ctrl = 0x10000;
+}
+
+static void max78000_icc_init(Object *obj)
+{
+    Max78000IccState *s = MAX78000_ICC(obj);
+
+    memory_region_init_io(&s->mmio, obj, &max78000_icc_ops, s,
+                        TYPE_MAX78000_ICC, 0x800);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static void max78000_icc_class_init(ObjectClass *klass, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
+
+    rc->phases.hold = max78000_icc_reset_hold;
+    dc->vmsd = &max78000_icc_vmstate;
+}
+
+static const TypeInfo max78000_icc_info = {
+    .name          = TYPE_MAX78000_ICC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(Max78000IccState),
+    .instance_init = max78000_icc_init,
+    .class_init    = max78000_icc_class_init,
+};
+
+static void max78000_icc_register_types(void)
+{
+    type_register_static(&max78000_icc_info);
+}
+
+type_init(max78000_icc_register_types)

hw/misc/meson.build

@@ -70,6 +70,7 @@ system_ss.add(when: 'CONFIG_IMX', if_true: files(
   'imx_ccm.c',
   'imx_rngc.c',
 ))
+system_ss.add(when: 'CONFIG_MAX78000_ICC', if_true: files('max78000_icc.c'))
 system_ss.add(when: 'CONFIG_NPCM7XX', if_true: files(
   'npcm_clk.c',
   'npcm_gcr.c',

include/hw/misc/max78000_icc.h

@@ -0,0 +1,33 @@
+/*
+ * MAX78000 Instruction Cache
+ *
+ * Copyright (c) 2025 Jackson Donaldson <jcksn@duck.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_MAX78000_ICC_H
+#define HW_MAX78000_ICC_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_MAX78000_ICC "max78000-icc"
+OBJECT_DECLARE_SIMPLE_TYPE(Max78000IccState, MAX78000_ICC)
+
+#define ICC_INFO       0x0
+#define ICC_SZ         0x4
+#define ICC_CTRL       0x100
+#define ICC_INVALIDATE 0x700
+
+struct Max78000IccState {
+    SysBusDevice parent_obj;
+
+    MemoryRegion mmio;
+
+    uint32_t info;
+    uint32_t sz;
+    uint32_t ctrl;
+};
+
+#endif