extern int et61x251_i2c_write(struct et61x251_device*, u8 address, u8 value);
extern int et61x251_i2c_read(struct et61x251_device*, u8 address);
extern int et61x251_i2c_try_write(struct et61x251_device*,
extern int et61x251_i2c_write(struct et61x251_device*, u8 address, u8 value);
extern int et61x251_i2c_read(struct et61x251_device*, u8 address);
extern int et61x251_i2c_try_write(struct et61x251_device*,