[PATCH RFC v3 02/14] i2c: core: add xfer_v2() to i2c_algorithm structure

[Dmitry Guzman]

In struct i2c_algorithm, add xfer_v2() - a new method that is
similar to xfer() but accepts in addition pointer to struct
i2c_transfer_report and puts the detailed transfer report into it.

With this method, it case of a fault, it is possible to get not only
the error code, but also the number of messages and bytes transferred
before the fault. If there were read messages before the fault, the read
data may also be used by the client.

Signed-off-by: Dmitry Guzman <Dmitry.Guzman@xxxxxxxxxxxx>
---
 include/linux/i2c.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 6a847fc88d25..bf7dc12f7264 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -537,6 +537,8 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  *   into I2C transfers instead.
  * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context
  *   so e.g. PMICs can be accessed very late before shutdown. Optional.
+ * @xfer_v2: Same as @xfer, but provides detailed report in case of a fault.
+ *   Optional. If it is present, @xfer must be also present.
  * @functionality: Return the flags that this algorithm/adapter pair supports
  *   from the ``I2C_FUNC_*`` flags.
  * @reg_target: Register given client to local target mode of this adapter
@@ -582,6 +584,8 @@ struct i2c_algorithm {
 				 unsigned short flags, char read_write,
 				 u8 command, int size, union i2c_smbus_data *data);
 
+	int (*xfer_v2)(struct i2c_adapter *adap, struct i2c_msg *msgs,
+		       int num, struct i2c_transfer_report *report);
 	/* To determine what the adapter supports */
 	u32 (*functionality)(struct i2c_adapter *adap);
 

-- 
2.43.0