At the start of an i2c transaction, the i2c bus searches its list of
children to identify which devices correspond to the address (or
broadcast). Now the I2CSlave device has a method "match" that
encapsulates the lookup behavior. This allows the behavior to be changed
to support devices, such as i2c muxes.
Tested: A BMC firmware was booted to userspace and i2c devices were
detected.
Signed-off-by: Patrick Venture <vent...@google.com>
Reviewed-by: Hao Wu <wuhao...@google.com>
---
hw/i2c/core.c | 23 +++++++++++++++++++----
include/hw/i2c/i2c.h | 11 +++++++++++
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index 21ec52ac5a..d03b0eea5c 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -118,10 +118,9 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int
recv)
QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
DeviceState *qdev = kid->child;
I2CSlave *candidate = I2C_SLAVE(qdev);
- if ((candidate->address == address) || (bus->broadcast)) {
- node = g_malloc(sizeof(struct I2CNode));
- node->elt = candidate;
- QLIST_INSERT_HEAD(&bus->current_devs, node, next);
+ sc = I2C_SLAVE_GET_CLASS(candidate);
+ if (sc->match_and_add(candidate, address, bus->broadcast,
+ &bus->current_devs)) {
if (!bus->broadcast) {
break;
}
@@ -290,12 +289,28 @@ I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char
*name, uint8_t addr)
return dev;
}
+static bool i2c_slave_match(I2CSlave *candidate, uint8_t address,
+ bool broadcast, I2CNodeList *current_devs)
+{
+ if ((candidate->address == address) || (broadcast)) {
+ I2CNode *node = g_malloc(sizeof(struct I2CNode));
+ node->elt = candidate;
+ QLIST_INSERT_HEAD(current_devs, node, next);
+ return true;
+ }
+
+ /* Not found and not broadcast. */
+ return false;
+}
+
static void i2c_slave_class_init(ObjectClass *klass, void *data)
{
DeviceClass *k = DEVICE_CLASS(klass);
+ I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
set_bit(DEVICE_CATEGORY_MISC, k->categories);
k->bus_type = TYPE_I2C_BUS;
device_class_set_props(k, i2c_props);
+ sc->match_and_add = i2c_slave_match;
}
static const TypeInfo i2c_slave_type_info = {
diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h
index 1f7c268c86..9b8b95ff4a 100644
--- a/include/hw/i2c/i2c.h
+++ b/include/hw/i2c/i2c.h
@@ -16,6 +16,7 @@ enum i2c_event {
I2C_NACK /* Masker NACKed a receive byte. */
};
+typedef struct I2CNodeList I2CNodeList;
#define TYPE_I2C_SLAVE "i2c-slave"
OBJECT_DECLARE_TYPE(I2CSlave, I2CSlaveClass,
@@ -39,6 +40,16 @@ struct I2CSlaveClass {
* return code is not used and should be zero.
*/
int (*event)(I2CSlave *s, enum i2c_event event);
+
+ /*
+ * Check if this device matches the address provided. Returns bool of
+ * true if it matches (or broadcast), and updates the device list, false
+ * otherwise.
+ *
+ * If broadcast is true, match should add the device and return true.
+ */
+ bool (*match_and_add)(I2CSlave *candidate, uint8_t address, bool broadcast,
+ I2CNodeList *current_devs);
};
struct I2CSlave {
--
2.31.1.295.g9ea45b61b8-goog
