[PATCH v7 20/22] hw/i3c: Add hotplug support

Jamin Lin
2026-02-25T02:13:35Z

This adds support for hotplugging in I3C.
Conceptually this can be thought of as an I3C target being physically
socketed onto a board.
It is then the target's responsibility to go through the hot-join and
DAA process so it can participate on the bus.

Signed-off-by: Joe Komlodi <komlodi@google.com>
Reviewed-by: Patrick Venture <venture@google.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
---
hw/i3c/core.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/hw/i3c/core.c b/hw/i3c/core.c
index 22e6e226a7..8a37099ce3 100644
--- a/hw/i3c/core.c
+++ b/hw/i3c/core.c
@@ -11,6 +11,7 @@
#include "qapi/error.h"
#include "trace.h"
#include "hw/i3c/i3c.h"
+#include "hw/core/hotplug.h"
#include "hw/core/qdev-properties.h"

/*
@@ -26,6 +27,17 @@ static const Property i3c_props[] = {
DEFINE_PROP_UINT64("pid", struct I3CTarget, pid, 0),
};

+static void i3c_realize(BusState *bus, Error **errp)
+{
+ qbus_set_bus_hotplug_handler(bus);
+}
+
+static void i3c_class_init(ObjectClass *klass, const void *data)
+{
+ BusClass *k = BUS_CLASS(klass);
+ k->realize = i3c_realize;
+}
+
I3CBus *i3c_init_bus(DeviceState *parent, const char *name)
{
return i3c_init_bus_type(TYPE_I3C_BUS, parent, name);
@@ -633,6 +645,11 @@ static const TypeInfo i3c_types[] = {
.parent = TYPE_BUS,
.instance_size = sizeof(I3CBus),
.class_size = sizeof(I3CBusClass),
+ .class_init = i3c_class_init,
+ .interfaces = (InterfaceInfo[]) {
+ { TYPE_HOTPLUG_HANDLER },
+ { }
+ }
},
{
.name = TYPE_I3C_TARGET,
--
2.43.0