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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 23:09:41 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 23:09:41 +0300
commite5050143d67c80a8705d6fcf5f9972663a0f082e (patch)
tree4d5259c31bc07a1a99f6d6ed8dba4ef88485dd13 /drivers
parentb41d037a1fd32d6535a2eef877b10f8deefeaf70 (diff)
parentb2edcdae3d9a29b25f6c161a8711caa74ce49991 (diff)
downloadlinux-e5050143d67c80a8705d6fcf5f9972663a0f082e.tar.xz
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
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-pca953x.c16
-rw-r--r--drivers/i2c/i2c-core.c10
2 files changed, 24 insertions, 2 deletions
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)