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-rw-r--r--hw/misc/stm32_rcc.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/hw/misc/stm32_rcc.c b/hw/misc/stm32_rcc.c
new file mode 100644
index 0000000000..26672b5b24
--- /dev/null
+++ b/hw/misc/stm32_rcc.c
@@ -0,0 +1,162 @@
+/*
+ * STM32 RCC (only reset and enable registers are implemented)
+ *
+ * Copyright (c) 2024 Román Cárdenas <rcardenas.rod@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "trace.h"
+#include "hw/irq.h"
+#include "migration/vmstate.h"
+#include "hw/misc/stm32_rcc.h"
+
+static void stm32_rcc_reset(DeviceState *dev)
+{
+    STM32RccState *s = STM32_RCC(dev);
+
+    for (int i = 0; i < STM32_RCC_NREGS; i++) {
+        s->regs[i] = 0;
+    }
+}
+
+static uint64_t stm32_rcc_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    STM32RccState *s = STM32_RCC(opaque);
+
+    uint32_t value = 0;
+    if (addr > STM32_RCC_DCKCFGR2) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%"HWADDR_PRIx"\n",
+                      __func__, addr);
+    } else {
+        value = s->regs[addr >> 2];
+    }
+    trace_stm32_rcc_read(addr, value);
+    return value;
+}
+
+static void stm32_rcc_write(void *opaque, hwaddr addr,
+                            uint64_t val64, unsigned int size)
+{
+    STM32RccState *s = STM32_RCC(opaque);
+    uint32_t value = val64;
+    uint32_t prev_value, new_value, irq_offset;
+
+    trace_stm32_rcc_write(value, addr);
+
+    if (addr > STM32_RCC_DCKCFGR2) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%"HWADDR_PRIx"\n",
+                      __func__, addr);
+        return;
+    }
+
+    switch (addr) {
+    case STM32_RCC_AHB1_RSTR...STM32_RCC_APB2_RSTR:
+        prev_value = s->regs[addr / 4];
+        s->regs[addr / 4] = value;
+
+        irq_offset = ((addr - STM32_RCC_AHB1_RSTR) / 4) * 32;
+        for (int i = 0; i < 32; i++) {
+            new_value = extract32(value, i, 1);
+            if (extract32(prev_value, i, 1) && !new_value) {
+                trace_stm32_rcc_pulse_reset(irq_offset + i, new_value);
+                qemu_set_irq(s->reset_irq[irq_offset + i], new_value);
+            }
+        }
+        return;
+    case STM32_RCC_AHB1_ENR...STM32_RCC_APB2_ENR:
+        prev_value = s->regs[addr / 4];
+        s->regs[addr / 4] = value;
+
+        irq_offset = ((addr - STM32_RCC_AHB1_ENR) / 4) * 32;
+        for (int i = 0; i < 32; i++) {
+            new_value = extract32(value, i, 1);
+            if (!extract32(prev_value, i, 1) && new_value) {
+                trace_stm32_rcc_pulse_enable(irq_offset + i, new_value);
+                qemu_set_irq(s->enable_irq[irq_offset + i], new_value);
+            }
+        }
+        return;
+    default:
+        qemu_log_mask(
+            LOG_UNIMP,
+            "%s: The RCC peripheral only supports enable and reset in QEMU\n",
+            __func__
+        );
+        s->regs[addr >> 2] = value;
+    }
+}
+
+static const MemoryRegionOps stm32_rcc_ops = {
+    .read = stm32_rcc_read,
+    .write = stm32_rcc_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void stm32_rcc_init(Object *obj)
+{
+    STM32RccState *s = STM32_RCC(obj);
+
+    memory_region_init_io(&s->mmio, obj, &stm32_rcc_ops, s,
+                          TYPE_STM32_RCC, STM32_RCC_PERIPHERAL_SIZE);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+
+    qdev_init_gpio_out(DEVICE(obj), s->reset_irq, STM32_RCC_NIRQS);
+    qdev_init_gpio_out(DEVICE(obj), s->enable_irq, STM32_RCC_NIRQS);
+
+    for (int i = 0; i < STM32_RCC_NIRQS; i++) {
+        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->reset_irq[i]);
+        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->enable_irq[i]);
+    }
+}
+
+static const VMStateDescription vmstate_stm32_rcc = {
+    .name = TYPE_STM32_RCC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, STM32RccState, STM32_RCC_NREGS),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void stm32_rcc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &vmstate_stm32_rcc;
+    device_class_set_legacy_reset(dc, stm32_rcc_reset);
+}
+
+static const TypeInfo stm32_rcc_info = {
+    .name          = TYPE_STM32_RCC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(STM32RccState),
+    .instance_init = stm32_rcc_init,
+    .class_init    = stm32_rcc_class_init,
+};
+
+static void stm32_rcc_register_types(void)
+{
+    type_register_static(&stm32_rcc_info);
+}
+
+type_init(stm32_rcc_register_types)