1 files changed, 175 insertions, 0 deletions
diff --git a/hw/misc/imx8mp_ccm.c b/hw/misc/imx8mp_ccm.c
new file mode 100644
index 0000000..1a1c932
--- /dev/null
+++ b/hw/misc/imx8mp_ccm.c
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2025 Bernhard Beschow <shentey@gmail.com>
+ *
+ * i.MX 8M Plus CCM IP block emulation code
+ *
+ * Based on hw/misc/imx7_ccm.c
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+
+#include "hw/misc/imx8mp_ccm.h"
+#include "migration/vmstate.h"
+
+#include "trace.h"
+
+#define CKIH_FREQ 16000000 /* 16MHz crystal input */
+
+static void imx8mp_ccm_reset(DeviceState *dev)
+{
+    IMX8MPCCMState *s = IMX8MP_CCM(dev);
+
+    memset(s->ccm, 0, sizeof(s->ccm));
+}
+
+#define CCM_INDEX(offset)   (((offset) & ~(hwaddr)0xF) / sizeof(uint32_t))
+#define CCM_BITOP(offset)   ((offset) & (hwaddr)0xF)
+
+enum {
+    CCM_BITOP_NONE = 0x00,
+    CCM_BITOP_SET  = 0x04,
+    CCM_BITOP_CLR  = 0x08,
+    CCM_BITOP_TOG  = 0x0C,
+};
+
+static uint64_t imx8mp_set_clr_tog_read(void *opaque, hwaddr offset,
+                                        unsigned size)
+{
+    const uint32_t *mmio = opaque;
+
+    return mmio[CCM_INDEX(offset)];
+}
+
+static void imx8mp_set_clr_tog_write(void *opaque, hwaddr offset,
+                                     uint64_t value, unsigned size)
+{
+    const uint8_t  bitop = CCM_BITOP(offset);
+    const uint32_t index = CCM_INDEX(offset);
+    uint32_t *mmio = opaque;
+
+    switch (bitop) {
+    case CCM_BITOP_NONE:
+        mmio[index]  = value;
+        break;
+    case CCM_BITOP_SET:
+        mmio[index] |= value;
+        break;
+    case CCM_BITOP_CLR:
+        mmio[index] &= ~value;
+        break;
+    case CCM_BITOP_TOG:
+        mmio[index] ^= value;
+        break;
+    };
+}
+
+static const struct MemoryRegionOps imx8mp_set_clr_tog_ops = {
+    .read = imx8mp_set_clr_tog_read,
+    .write = imx8mp_set_clr_tog_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        /*
+         * Our device would not work correctly if the guest was doing
+         * unaligned access. This might not be a limitation on the real
+         * device but in practice there is no reason for a guest to access
+         * this device unaligned.
+         */
+        .min_access_size = 4,
+        .max_access_size = 4,
+        .unaligned = false,
+    },
+};
+
+static void imx8mp_ccm_init(Object *obj)
+{
+    SysBusDevice *sd = SYS_BUS_DEVICE(obj);
+    IMX8MPCCMState *s = IMX8MP_CCM(obj);
+
+    memory_region_init_io(&s->iomem,
+                          obj,
+                          &imx8mp_set_clr_tog_ops,
+                          s->ccm,
+                          TYPE_IMX8MP_CCM ".ccm",
+                          sizeof(s->ccm));
+
+    sysbus_init_mmio(sd, &s->iomem);
+}
+
+static const VMStateDescription imx8mp_ccm_vmstate = {
+    .name = TYPE_IMX8MP_CCM,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(ccm, IMX8MPCCMState, CCM_MAX),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static uint32_t imx8mp_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
+{
+    /*
+     * This function is "consumed" by GPT emulation code. Some clocks
+     * have fixed frequencies and we can provide requested frequency
+     * easily. However for CCM provided clocks (like IPG) each GPT
+     * timer can have its own clock root.
+     * This means we need additional information when calling this
+     * function to know the requester's identity.
+     */
+    uint32_t freq = 0;
+
+    switch (clock) {
+    case CLK_NONE:
+        break;
+    case CLK_32k:
+        freq = CKIL_FREQ;
+        break;
+    case CLK_HIGH:
+        freq = CKIH_FREQ;
+        break;
+    case CLK_IPG:
+    case CLK_IPG_HIGH:
+        /*
+         * For now we don't have a way to figure out the device this
+         * function is called for. Until then the IPG derived clocks
+         * are left unimplemented.
+         */
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Clock %d Not implemented\n",
+                      TYPE_IMX8MP_CCM, __func__, clock);
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: unsupported clock %d\n",
+                      TYPE_IMX8MP_CCM, __func__, clock);
+        break;
+    }
+
+    trace_ccm_clock_freq(clock, freq);
+
+    return freq;
+}
+
+static void imx8mp_ccm_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    IMXCCMClass *ccm = IMX_CCM_CLASS(klass);
+
+    device_class_set_legacy_reset(dc, imx8mp_ccm_reset);
+    dc->vmsd  = &imx8mp_ccm_vmstate;
+    dc->desc  = "i.MX 8M Plus Clock Control Module";
+
+    ccm->get_clock_frequency = imx8mp_ccm_get_clock_frequency;
+}
+
+static const TypeInfo imx8mp_ccm_types[] = {
+    {
+        .name          = TYPE_IMX8MP_CCM,
+        .parent        = TYPE_IMX_CCM,
+        .instance_size = sizeof(IMX8MPCCMState),
+        .instance_init = imx8mp_ccm_init,
+        .class_init    = imx8mp_ccm_class_init,
+    },
+};
+
+DEFINE_TYPES(imx8mp_ccm_types);