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-rw-r--r--hw/misc/imx7_src.c276
1 files changed, 276 insertions, 0 deletions
diff --git a/hw/misc/imx7_src.c b/hw/misc/imx7_src.c
new file mode 100644
index 0000000000..983251e86f
--- /dev/null
+++ b/hw/misc/imx7_src.c
@@ -0,0 +1,276 @@
+/*
+ * IMX7 System Reset Controller
+ *
+ * Copyright (c) 2023 Jean-Christophe Dubois <jcd@tribudubois.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "hw/misc/imx7_src.h"
+#include "migration/vmstate.h"
+#include "qemu/bitops.h"
+#include "qemu/log.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "target/arm/arm-powerctl.h"
+#include "hw/core/cpu.h"
+#include "hw/registerfields.h"
+
+#include "trace.h"
+
+static const char *imx7_src_reg_name(uint32_t reg)
+{
+    static char unknown[20];
+
+    switch (reg) {
+    case SRC_SCR:
+        return "SRC_SCR";
+    case SRC_A7RCR0:
+        return "SRC_A7RCR0";
+    case SRC_A7RCR1:
+        return "SRC_A7RCR1";
+    case SRC_M4RCR:
+        return "SRC_M4RCR";
+    case SRC_ERCR:
+        return "SRC_ERCR";
+    case SRC_HSICPHY_RCR:
+        return "SRC_HSICPHY_RCR";
+    case SRC_USBOPHY1_RCR:
+        return "SRC_USBOPHY1_RCR";
+    case SRC_USBOPHY2_RCR:
+        return "SRC_USBOPHY2_RCR";
+    case SRC_PCIEPHY_RCR:
+        return "SRC_PCIEPHY_RCR";
+    case SRC_SBMR1:
+        return "SRC_SBMR1";
+    case SRC_SRSR:
+        return "SRC_SRSR";
+    case SRC_SISR:
+        return "SRC_SISR";
+    case SRC_SIMR:
+        return "SRC_SIMR";
+    case SRC_SBMR2:
+        return "SRC_SBMR2";
+    case SRC_GPR1:
+        return "SRC_GPR1";
+    case SRC_GPR2:
+        return "SRC_GPR2";
+    case SRC_GPR3:
+        return "SRC_GPR3";
+    case SRC_GPR4:
+        return "SRC_GPR4";
+    case SRC_GPR5:
+        return "SRC_GPR5";
+    case SRC_GPR6:
+        return "SRC_GPR6";
+    case SRC_GPR7:
+        return "SRC_GPR7";
+    case SRC_GPR8:
+        return "SRC_GPR8";
+    case SRC_GPR9:
+        return "SRC_GPR9";
+    case SRC_GPR10:
+        return "SRC_GPR10";
+    default:
+        sprintf(unknown, "%u ?", reg);
+        return unknown;
+    }
+}
+
+static const VMStateDescription vmstate_imx7_src = {
+    .name = TYPE_IMX7_SRC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, IMX7SRCState, SRC_MAX),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void imx7_src_reset(DeviceState *dev)
+{
+    IMX7SRCState *s = IMX7_SRC(dev);
+
+    memset(s->regs, 0, sizeof(s->regs));
+
+    /* Set reset values */
+    s->regs[SRC_SCR] = 0xA0;
+    s->regs[SRC_SRSR] = 0x1;
+    s->regs[SRC_SIMR] = 0x1F;
+}
+
+static uint64_t imx7_src_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint32_t value = 0;
+    IMX7SRCState *s = (IMX7SRCState *)opaque;
+    uint32_t index = offset >> 2;
+
+    if (index < SRC_MAX) {
+        value = s->regs[index];
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX7_SRC, __func__, offset);
+    }
+
+    trace_imx7_src_read(imx7_src_reg_name(index), value);
+
+    return value;
+}
+
+
+/*
+ * The reset is asynchronous so we need to defer clearing the reset
+ * bit until the work is completed.
+ */
+
+struct SRCSCRResetInfo {
+    IMX7SRCState *s;
+    uint32_t reset_bit;
+};
+
+static void imx7_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
+{
+    struct SRCSCRResetInfo *ri = data.host_ptr;
+    IMX7SRCState *s = ri->s;
+
+    assert(qemu_mutex_iothread_locked());
+
+    s->regs[SRC_A7RCR0] = deposit32(s->regs[SRC_A7RCR0], ri->reset_bit, 1, 0);
+
+    trace_imx7_src_write(imx7_src_reg_name(SRC_A7RCR0), s->regs[SRC_A7RCR0]);
+
+    g_free(ri);
+}
+
+static void imx7_defer_clear_reset_bit(uint32_t cpuid,
+                                       IMX7SRCState *s,
+                                       uint32_t reset_shift)
+{
+    struct SRCSCRResetInfo *ri;
+    CPUState *cpu = arm_get_cpu_by_id(cpuid);
+
+    if (!cpu) {
+        return;
+    }
+
+    ri = g_new(struct SRCSCRResetInfo, 1);
+    ri->s = s;
+    ri->reset_bit = reset_shift;
+
+    async_run_on_cpu(cpu, imx7_clear_reset_bit, RUN_ON_CPU_HOST_PTR(ri));
+}
+
+
+static void imx7_src_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMX7SRCState *s = (IMX7SRCState *)opaque;
+    uint32_t index = offset >> 2;
+    long unsigned int change_mask;
+    uint32_t current_value = value;
+
+    if (index >= SRC_MAX) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX7_SRC, __func__, offset);
+        return;
+    }
+
+    trace_imx7_src_write(imx7_src_reg_name(SRC_A7RCR0), s->regs[SRC_A7RCR0]);
+
+    change_mask = s->regs[index] ^ (uint32_t)current_value;
+
+    switch (index) {
+    case SRC_A7RCR0:
+        if (FIELD_EX32(change_mask, CORE0, RST)) {
+            arm_reset_cpu(0);
+            imx7_defer_clear_reset_bit(0, s, R_CORE0_RST_SHIFT);
+        }
+        if (FIELD_EX32(change_mask, CORE1, RST)) {
+            arm_reset_cpu(1);
+            imx7_defer_clear_reset_bit(1, s, R_CORE1_RST_SHIFT);
+        }
+        s->regs[index] = current_value;
+        break;
+    case SRC_A7RCR1:
+        /*
+         * On real hardware when the system reset controller starts a
+         * secondary CPU it runs through some boot ROM code which reads
+         * the SRC_GPRX registers controlling the start address and branches
+         * to it.
+         * Here we are taking a short cut and branching directly to the
+         * requested address (we don't want to run the boot ROM code inside
+         * QEMU)
+         */
+        if (FIELD_EX32(change_mask, CORE1, ENABLE)) {
+            if (FIELD_EX32(current_value, CORE1, ENABLE)) {
+                /* CORE 1 is brought up */
+                arm_set_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4],
+                               3, false);
+            } else {
+                /* CORE 1 is shut down */
+                arm_set_cpu_off(1);
+            }
+            /* We clear the reset bits as the processor changed state */
+            imx7_defer_clear_reset_bit(1, s, R_CORE1_RST_SHIFT);
+            clear_bit(R_CORE1_RST_SHIFT, &change_mask);
+        }
+        s->regs[index] = current_value;
+        break;
+    default:
+        s->regs[index] = current_value;
+        break;
+    }
+}
+
+static const struct MemoryRegionOps imx7_src_ops = {
+    .read = imx7_src_read,
+    .write = imx7_src_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        /*
+         * 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 imx7_src_realize(DeviceState *dev, Error **errp)
+{
+    IMX7SRCState *s = IMX7_SRC(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(dev), &imx7_src_ops, s,
+                          TYPE_IMX7_SRC, 0x1000);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+}
+
+static void imx7_src_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = imx7_src_realize;
+    dc->reset = imx7_src_reset;
+    dc->vmsd = &vmstate_imx7_src;
+    dc->desc = "i.MX6 System Reset Controller";
+}
+
+static const TypeInfo imx7_src_info = {
+    .name          = TYPE_IMX7_SRC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IMX7SRCState),
+    .class_init    = imx7_src_class_init,
+};
+
+static void imx7_src_register_types(void)
+{
+    type_register_static(&imx7_src_info);
+}
+
+type_init(imx7_src_register_types)