Merge tag 'v3.14.25' into backport/v3.14.24-ltsi-rc1+v3.14.25/snapshot-merge.wip

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / linux / i2c.h

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index d9c8dbd..b556e0a 100644 (file)
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -342,11 +342,25 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 }
 #endif /* I2C_BOARDINFO */
 
-/*
+/**
+ * struct i2c_algorithm - represent I2C transfer method
+ * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
+ *   defined by the msgs array, with num messages available to transfer via
+ *   the adapter specified by adap.
+ * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
+ *   is not present, then the bus layer will try and convert the SMBus calls
+ *   into I2C transfers instead.
+ * @functionality: Return the flags that this algorithm/adapter pair supports
+ *   from the I2C_FUNC_* flags.
+ *
  * The following structs are for those who like to implement new bus drivers:
  * i2c_algorithm is the interface to a class of hardware solutions which can
  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  * to name two of the most common.
+ *
+ * The return codes from the @master_xfer field should indicate the type of
+ * error code that occured during the transfer, as documented in the kernel
+ * Documentation file Documentation/i2c/fault-codes.
  */
 struct i2c_algorithm {
        /* If an adapter algorithm can't do I2C-level access, set master_xfer
@@ -473,6 +487,7 @@ void i2c_unlock_adapter(struct i2c_adapter *);
 #define I2C_CLASS_HWMON                (1<<0)  /* lm_sensors, ... */
 #define I2C_CLASS_DDC          (1<<3)  /* DDC bus on graphics adapters */
 #define I2C_CLASS_SPD          (1<<7)  /* Memory modules */
+#define I2C_CLASS_DEPRECATED   (1<<8)  /* Warn users that adapter will stop using classes */
 
 /* Internal numbers to terminate lists */
 #define I2C_CLIENT_END         0xfffeU