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Commit 596c88f4 authored by Prakash Mortha's avatar Prakash Mortha Committed by Jean Delvare
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i2c: Restore i2c_smbus_process_call function 



Restore the i2c_smbus_process_call() as one driver (for the
Micronas MAP5401) will need it soon.

[JD: Update documentation accordingly.]

Signed-off-by: default avatarPrakash Mortha <pmortha@escient.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent a10f9e7c

Documentation/i2c/smbus-protocol

+2 −2
Original line number Diff line number Diff line
@@ -109,8 +109,8 @@ specified through the Comm byte. 
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P





SMBus Process Call

==================

SMBus Process Call:  i2c_smbus_process_call()

=============================================



This command selects a device register (through the Comm byte), sends

16 bits of data to it, and reads 16 bits of data in return.

Documentation/i2c/writing-clients

+2 −2
Original line number Diff line number Diff line
@@ -606,6 +606,8 @@ SMBus communication 
  extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);

  extern s32 i2c_smbus_write_word_data(struct i2c_client * client,

                                       u8 command, u16 value);

  extern s32 i2c_smbus_process_call(struct i2c_client *client,

                                    u8 command, u16 value);

  extern s32 i2c_smbus_read_block_data(struct i2c_client * client,

                                       u8 command, u8 *values);

  extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
@@ -621,8 +623,6 @@ These ones were removed from i2c-core because they had no users, but could 
be added back later if needed:



  extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);

  extern s32 i2c_smbus_process_call(struct i2c_client * client,

                                    u8 command, u16 value);

  extern s32 i2c_smbus_block_process_call(struct i2c_client *client,

                                          u8 command, u8 length,

                                          u8 *values)

drivers/i2c/i2c-core.c

+22 −0
Original line number Diff line number Diff line
@@ -1687,6 +1687,28 @@ s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) 
}

EXPORT_SYMBOL(i2c_smbus_write_word_data);



/**

 * i2c_smbus_process_call - SMBus "process call" protocol

 * @client: Handle to slave device

 * @command: Byte interpreted by slave

 * @value: 16-bit "word" being written

 *

 * This executes the SMBus "process call" protocol, returning negative errno

 * else a 16-bit unsigned "word" received from the device.

 */

s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)

{

	union i2c_smbus_data data;

	int status;

	data.word = value;



	status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,

				I2C_SMBUS_WRITE, command,

				I2C_SMBUS_PROC_CALL, &data);

	return (status < 0) ? status : data.word;

}

EXPORT_SYMBOL(i2c_smbus_process_call);



/**

 * i2c_smbus_read_block_data - SMBus "block read" protocol

 * @client: Handle to slave device