[ot] hw/riscv: add an IRQ wrapper

Signed-off-by: Emmanuel Blot <eblot@rivosinc.com>

Includes existing MIT licenced code (already published elsewhere)

Author: rivos-eblot

include/hw/riscv/ibex_irq.h

@@ -0,0 +1,69 @@
+/*
+ * QEMU lowRISC Ibex IRQ wrapper
+ *
+ * Copyright (c) 2022-2023 Rivos, Inc.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+#ifndef HW_RISCV_IBEX_IRQ_H
+#define HW_RISCV_IBEX_IRQ_H
+
+#include "qemu/osdep.h"
+#include "qom/object.h"
+#include "hw/irq.h"
+#include "hw/qdev-core.h"
+#include "hw/sysbus.h"
+
+
+/** Simple IRQ wrapper to limit propagation of no-change calls */
+typedef struct {
+    qemu_irq irq;
+    int level;
+} IbexIRQ;
+
+static inline bool ibex_irq_set(IbexIRQ *ibex_irq, int level)
+{
+    if (level != ibex_irq->level) {
+        ibex_irq->level = level;
+        qemu_set_irq(ibex_irq->irq, level);
+        return true;
+    }
+
+    return false;
+}
+
+static inline bool ibex_irq_raise(IbexIRQ *irq)
+{
+    return ibex_irq_set(irq, 1);
+}
+
+static inline bool ibex_irq_lower(IbexIRQ *irq)
+{
+    return ibex_irq_set(irq, 0);
+}
+
+static inline void ibex_qdev_init_irq(Object *obj, IbexIRQ *irq,
+                                      const char *name)
+{
+    irq->level = 0;
+    qdev_init_gpio_out_named(DEVICE(obj), &irq->irq, name, 1);
+}
+
+static inline void ibex_qdev_init_irqs(Object *obj, IbexIRQ *irqs,
+                                       const char *name, unsigned count)
+{
+    for (unsigned ix = 0; ix < count; ix++) {
+        irqs[ix].level = 0;
+        qdev_init_gpio_out_named(DEVICE(obj), &irqs[ix].irq, name, 1);
+    }
+}
+
+static inline void ibex_sysbus_init_irq(Object *obj, IbexIRQ *irq)
+{
+    irq->level = 0;
+    sysbus_init_irq(SYS_BUS_DEVICE(obj), &irq->irq);
+}
+
+#endif /* HW_RISCV_IBEX_IRQ_H */