+static inline void
+i2c_lock_segment(struct i2c_adapter *adapter)
+{
+	i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
+}
+
+static inline int
+i2c_trylock_segment(struct i2c_adapter *adapter)
+{
+	return i2c_trylock_bus(adapter, I2C_LOCK_SEGMENT);
+}
+
+static inline void
+i2c_unlock_segment(struct i2c_adapter *adapter)
+{
+	i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
+}

I wonder if i2c_lock_segment() and i2c_lock_root_adapter() are really
more readable and convenient than i2c_lock_bus() with the flag. I think
the flags have speaking names, too.

Is that an idea to remove these functions altogether and start using
i2c_lock_bus()?