[Qemu-devel] [PATCH 3/9] PlatBus: Add Sysbus/Platform bridge device

[Alexander Graf <agraf@suse.de>]

We have to be able to plug our platform bus into an existing system somehow.
To achieve this, we add a sysbus <-> platbus bridge device that maps an
arbitrary number of IRQ lines to a self-contained linear platform IRQ range.

It also provides a memory region that is the parent region for all platform
devices that get created below this bus.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/platbus/bridge.c         | 64 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/platbus/bridge.h | 32 +++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 hw/platbus/bridge.c
 create mode 100644 include/hw/platbus/bridge.h

diff --git a/hw/platbus/bridge.c b/hw/platbus/bridge.c
new file mode 100644
index 0000000..356d254
--- /dev/null
+++ b/hw/platbus/bridge.c
@@ -0,0 +1,64 @@
+/*
+ * Sysbus to Platform bus bridge device
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * Authors: Alexander Graf,   <agraf@suse.de>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of  the GNU General  Public License as published by
+ * the Free Software Foundation;  either version 2 of the  License, or
+ * (at your option) any later version.
+ *
+ * This bridge device allows you to plug a platform bus into your existing
+ * system bus.
+ */
+
+#include "qemu-common.h"
+#include "hw/platbus/bridge.h"
+
+static void platbus_bridge_realize(DeviceState *dev, Error **errp)
+{
+    SysBusDevice *d = SYS_BUS_DEVICE(dev);
+    PlatBusBridgeState *s = PLATBUS_BRIDGE(dev);
+    int i;
+
+    /* Create platform bus */
+    qbus_create_inplace(&s->bus.parent_obj, TYPE_PLAT_BUS, dev, NULL);
+
+    /* Wire up all platbus IRQs to sysbus IRQs. */
+    for (i = 0; i < s->nr_irqs; i++) {
+        sysbus_init_irq(d, &s->bus.irqs[i]);
+        platbus_add_irq(&s->bus, i);
+    }
+
+    /* Advertise our platbus memory hole to sysbus. Through this a guest OS
+       can access platbus devices */
+    sysbus_init_mmio(d, &s->bus.mem);
+}
+
+static Property platbus_bridge_properties[] = {
+    DEFINE_PROP_UINT32("nr_irqs", PlatBusBridgeState, nr_irqs, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void serial_platbus_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    dc->props = platbus_bridge_properties;
+    dc->realize = platbus_bridge_realize;
+}
+
+static const TypeInfo platbus_bridge_type_info = {
+    .name = TYPE_PLATBUS_BRIDGE,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(PlatBusBridgeState),
+    .class_init    = serial_platbus_class_init,
+};
+
+static void platbus_bridge_register_types(void)
+{
+    type_register_static(&platbus_bridge_type_info);
+}
+
+type_init(platbus_bridge_register_types)
diff --git a/include/hw/platbus/bridge.h b/include/hw/platbus/bridge.h
new file mode 100644
index 0000000..4d31fcb
--- /dev/null
+++ b/include/hw/platbus/bridge.h
@@ -0,0 +1,32 @@
+/*
+ * Generic platform bus with dynamic IRQ and IO placement
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * Authors: Alexander Graf,   <agraf@suse.de>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of  the GNU General  Public License as published by
+ * the Free Software Foundation;  either version 2 of the  License, or
+ * (at your option) any later version.
+ */
+
+#ifndef QEMU_HW_PLATBUS_BRIDGE_H
+#define QEMU_HW_PLATBUS_BRIDGE_H
+
+#include "platbus.h"
+#include "hw/sysbus.h"
+
+#define TYPE_PLATBUS_BRIDGE "platbus-bridge"
+#define PLATBUS_BRIDGE(obj) OBJECT_CHECK(PlatBusBridgeState, (obj), TYPE_PLATBUS_BRIDGE)
+
+typedef struct PlatBusBridgeState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+    /*< public >*/
+
+    PlatBusState bus;
+    uint32_t nr_irqs;
+} PlatBusBridgeState;
+
+#endif /* !QEMU_HW_PLATBUS_BRIDGE_H */
-- 
1.8.1.4