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authorDavid Daney <david.daney@cavium.com>2012-04-12 14:14:23 -0700
committerWolfram Sang <w.sang@pengutronix.de>2012-05-12 14:28:16 +0200
commitbc45449b1444611d68466ae7f45f235420d79019 (patch)
tree89be285b67ffb6d11a5db26cc34fbe7f3f621aaf /drivers/i2c/i2c-mux.c
parent5a3ecd5f9877b963a581ca5d4495a1a24dafc88c (diff)
downloadlinux-linaro-stable-bc45449b1444611d68466ae7f45f235420d79019.tar.gz
i2c/of: Automatically populate i2c mux busses from device tree data.
For 'normal' i2c bus drivers, we can call of_i2c_register_devices() and have the device tree framework automatically populate the bus with the devices specified in the device tree. This patch adds a common code to the i2c mux framework to have the mux sub-busses be populated by the of_i2c_register_devices() too. If the mux device has an of_node, we populate the sub-bus' of_node so that the subsequent call to of_i2c_register_devices() will find the corresponding devices. It seemed better to put this logic in i2c_add_mux_adapter() rather than the individual mux drivers, as they will all probably want to do the same thing. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Tested-by: Lars-Peter Clausen <lars@metafoo.de> [wsa: removed superfluous ret-variable and fixed a typo in a comment] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Diffstat (limited to 'drivers/i2c/i2c-mux.c')
-rw-r--r--drivers/i2c/i2c-mux.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 26ab31dd742b..1038c381aea5 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -24,6 +24,8 @@
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c-mux.h>
+#include <linux/of.h>
+#include <linux/of_i2c.h>
/* multiplexer per channel data */
struct i2c_mux_priv {
@@ -125,6 +127,25 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
priv->adap.algo_data = priv;
priv->adap.dev.parent = &parent->dev;
+ /*
+ * Try to populate the mux adapter's of_node, expands to
+ * nothing if !CONFIG_OF.
+ */
+ if (mux_dev->of_node) {
+ struct device_node *child;
+ u32 reg;
+
+ for_each_child_of_node(mux_dev->of_node, child) {
+ ret = of_property_read_u32(child, "reg", &reg);
+ if (ret)
+ continue;
+ if (chan_id == reg) {
+ priv->adap.dev.of_node = child;
+ break;
+ }
+ }
+ }
+
if (force_nr) {
priv->adap.nr = force_nr;
ret = i2c_add_numbered_adapter(&priv->adap);
@@ -142,6 +163,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
i2c_adapter_id(&priv->adap));
+ of_i2c_register_devices(&priv->adap);
+
return &priv->adap;
}
EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);