diff options
Diffstat (limited to 'drivers/i2c/i2c-mux.c')
| -rw-r--r-- | drivers/i2c/i2c-mux.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 1038c381aea..d94e0ce7827 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -88,9 +88,23 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap) return parent->algo->functionality(parent); } +/* Return all parent classes, merged */ +static unsigned int i2c_mux_parent_classes(struct i2c_adapter *parent) +{ + unsigned int class = 0; + + do { + class |= parent->class; + parent = i2c_parent_is_i2c_adapter(parent); + } while (parent); + + return class; +} + struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, struct device *mux_dev, void *mux_priv, u32 force_nr, u32 chan_id, + unsigned int class, int (*select) (struct i2c_adapter *, void *, u32), int (*deselect) (struct i2c_adapter *, @@ -127,6 +141,14 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, priv->adap.algo_data = priv; priv->adap.dev.parent = &parent->dev; + /* Sanity check on class */ + if (i2c_mux_parent_classes(parent) & class) + dev_err(&parent->dev, + "Segment %d behind mux can't share classes with ancestors\n", + chan_id); + else + priv->adap.class = class; + /* * Try to populate the mux adapter's of_node, expands to * nothing if !CONFIG_OF. |