[1/4] hw/i2c: core: Add reset

Commit Message

Joe Komlodi Jan. 10, 2024, 9:26 p.m. UTC

It's possible for a reset to come in the middle of a transaction, which
causes the bus to be in an old state when a new transaction comes in.

Signed-off-by: Joe Komlodi <[e-mail]>
---
 hw/i2c/core.c        | 30 +++++++++++++++++++++++++-----
 include/hw/i2c/i2c.h |  6 +++++-
 2 files changed, 30 insertions(+), 6 deletions(-)

Patch

diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index 4cf30b2c86..def4f134d0 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -23,11 +23,31 @@  static Property i2c_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static const TypeInfo i2c_bus_info = {
-    .name = TYPE_I2C_BUS,
-    .parent = TYPE_BUS,
-    .instance_size = sizeof(I2CBus),
-};
+static void i2c_bus_enter_reset(Object *obj, ResetType type)
+{
+    I2CBus *bus = I2C_BUS(obj);
+    I2CNode *node, *next;
+
+    bus->broadcast = false;
+    QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
+        QLIST_REMOVE(node, next);
+        g_free(node);
+    }
+}
+
+static void i2c_bus_class_init(ObjectClass *klass, void *data)
+{
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
+    rc->phases.enter = i2c_bus_enter_reset;
+}
+
+ static const TypeInfo i2c_bus_info = {
+     .name = TYPE_I2C_BUS,
+     .parent = TYPE_BUS,
+     .instance_size = sizeof(I2CBus),
+     .class_size = sizeof(I2CBusClass),
+     .class_init = i2c_bus_class_init,
+ };
 
 static int i2c_bus_pre_save(void *opaque)
 {
diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h
index 2a3abacd1b..420868a269 100644
--- a/include/hw/i2c/i2c.h
+++ b/include/hw/i2c/i2c.h
@@ -64,7 +64,7 @@  struct I2CSlave {
 };
 
 #define TYPE_I2C_BUS "i2c-bus"
-OBJECT_DECLARE_SIMPLE_TYPE(I2CBus, I2C_BUS)
+OBJECT_DECLARE_TYPE(I2CBus, I2CBusClass, I2C_BUS)
 
 typedef struct I2CNode I2CNode;
 
@@ -83,6 +83,10 @@  struct I2CPendingMaster {
 typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList;
 typedef QSIMPLEQ_HEAD(I2CPendingMasters, I2CPendingMaster) I2CPendingMasters;
 
+struct I2CBusClass {
+    DeviceClass parent_class;
+};
+
 struct I2CBus {
     BusState qbus;
     I2CNodeList current_devs;