64 /* * These provide synchronization in the presence of * multiple users of the i2c bus. When a device * driver wishes to perform transfers on the i2c * bus, the driver should acquire the bus. When * the driver is finished, it should release the * bus. * * This is provided by the back-end since a single * controller may present e.g. i2c and smbus views * of the same set of i2c wires. */