diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt index f31b2ad1552b..5fa691e6f638 100644 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ b/Documentation/devicetree/bindings/i2c/i2c.txt @@ -32,6 +32,14 @@ wants to support one of the below features, it should adapt the bindings below. - clock-frequency frequency of bus clock in Hz. +- i2c-bus + For I2C adapters that have child nodes that are a mixture of both I2C + devices and non-I2C devices, the 'i2c-bus' subnode can be used for + populating I2C devices. If the 'i2c-bus' subnode is present, only + subnodes of this will be considered as I2C slaves. The properties, + '#address-cells' and '#size-cells' must be defined under this subnode + if present. + - i2c-scl-falling-time-ns Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C specification. diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index 45c8817d068c..e422568e14ad 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -794,6 +794,22 @@ static int pca953x_probe(struct i2c_client *client, } mutex_init(&chip->i2c_lock); + /* + * In case we have an i2c-mux controlled by a GPIO provided by an + * expander using the same driver higher on the device tree, read the + * i2c adapter nesting depth and use the retrieved value as lockdep + * subclass for chip->i2c_lock. + * + * REVISIT: This solution is not complete. It protects us from lockdep + * false positives when the expander controlling the i2c-mux is on + * a different level on the device tree, but not when it's on the same + * level on a different branch (in which case the subclass number + * would be the same). + * + * TODO: Once a correct solution is developed, a similar fix should be + * applied to all other i2c-controlled GPIO expanders (and potentially + * regmap-i2c). + */ lockdep_set_subclass(&chip->i2c_lock, i2c_adapter_depth(client->adapter)); diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 98fffa3a09f7..5ab67219f71e 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1680,7 +1680,7 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, static void of_i2c_register_devices(struct i2c_adapter *adap) { - struct device_node *node; + struct device_node *bus, *node; /* Only register child devices if the adapter has a node pointer set */ if (!adap->dev.of_node) @@ -1688,11 +1688,17 @@ static void of_i2c_register_devices(struct i2c_adapter *adap) dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); - for_each_available_child_of_node(adap->dev.of_node, node) { + bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); + if (!bus) + bus = of_node_get(adap->dev.of_node); + + for_each_available_child_of_node(bus, node) { if (of_node_test_and_set_flag(node, OF_POPULATED)) continue; of_i2c_register_device(adap, node); } + + of_node_put(bus); } static int of_dev_node_match(struct device *dev, void *data)