Commit e5050143 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull more i2c updates from Wolfram Sang:
 "A small update pull request from I2C.

  This adds one comment to a change we did in this merge window to
  handle lockdep better, and pulls in a branch which should have been in
  4.8 already improving DT support for I2C"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  gpio: pca953x: add a comment explaining the need for a lockdep subclass
  i2c: core: Add support for 'i2c-bus' subnode
  dt-bindings: i2c: Add support for 'i2c-bus' subnode
parents b41d037a b2edcdae
......@@ -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.
......
......@@ -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));
......
......@@ -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)
......
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