Le 11/06/2024 à 13:43, Farouk Bouabid a écrit :
Allow the mux (if it's an I2C device) to have the same address as a child
device. This is useful when the mux can only use an I2C address that is
used by a child device because no other addresses are free to use.
eg. the mux can only use address 0x18 which is used by amc6821 connected
to the mux.
Signed-off-by: Farouk Bouabid <farouk.bouabid@xxxxxxxxx>
---
Hi,
2 nitpicks below.
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -334,7 +334,53 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
priv->adap.dev.parent = &parent->dev;
priv->adap.retries = parent->retries;
priv->adap.timeout = parent->timeout;
- priv->adap.quirks = parent->quirks;
+
+ struct i2c_adapter_quirks *quirks;
Should this be at the beginning of the function?
+ /*
+ * When creating the adapter, the node devices are checked for I2C address
+ * match with other devices on the parent adapter, among which is the mux itself.
+ * If a match is found the node device is not probed successfully.
+ * Allow the mux to have the same address as a child device by skipping this check.
+ */
+ if (muxc->share_addr_with_children) {
+ struct i2c_client *client = to_i2c_client(muxc->dev);
+
+ if (muxc->dev->type != &i2c_client_type)
+ dev_warn_once(muxc->dev, "Mux is not an I2C device\n");
+
+ quirks = devm_kzalloc(muxc->dev, sizeof(*quirks), GFP_KERNEL);
+ if (!quirks)
+ return -ENOMEM;
+
+ if (parent->quirks)
+ memcpy(quirks, parent->quirks, sizeof(*quirks));
+
+ quirks->flags |= I2C_AQ_SKIP_ADDR_CHECK;
+ quirks->skip_addr_in_parent = client->addr;
+ priv->adap.quirks = quirks;
+
+ } else if (parent->quirks &&
+ parent->quirks->flags & I2C_AQ_SKIP_ADDR_CHECK) {
+ /*
+ * Another I2C mux device can be a child of the Mule I2C mux.
+ * The former could probably not allow address conflict between
+ * its address and its own children addresses.
+ *
+ * For this purpose, do not propagate this flag unless
+ * share_addr_with_children is set.
+ */
+ quirks = devm_kzalloc(muxc->dev, sizeof(*quirks), GFP_KERNEL);
devm_kmemdup()? (not sure it is a win)
+ if (!quirks)
+ return -ENOMEM;
+
+ memcpy(quirks, parent->quirks, sizeof(*quirks));
+ quirks->flags &= ~I2C_AQ_SKIP_ADDR_CHECK;
+ priv->adap.quirks = quirks;
+
+ } else {
+ priv->adap.quirks = parent->quirks;
+ }
+
if (muxc->mux_locked)
priv->adap.lock_ops = &i2c_mux_lock_ops;
else
...
CJ
