/* 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_root_adapter(struct device *dev)
{
struct device *i2c;
struct i2c_adapter *i2c_root;
/*
* Walk up the device tree to find an i2c adapter, indicating
* that this is an i2c client device. Check all ancestors to
* handle mfd devices etc.
*/
for (i2c = dev; i2c; i2c = i2c->parent) {
if (i2c->type == &i2c_adapter_type)
break;
}
if (!i2c)
return NULL;
/* Continue up the tree to find the root i2c adapter */
i2c_root = to_i2c_adapter(i2c);
while (i2c_parent_is_i2c_adapter(i2c_root))
i2c_root = i2c_parent_is_i2c_adapter(i2c_root);
return i2c_root;
}