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authorPrakash Mortha <pmortha@escient.com>2008-10-14 17:30:06 +0200
committerJean Delvare <khali@mahadeva.delvare>2008-10-14 17:30:06 +0200
commit596c88f4601e6245a15ea7619527674abbfdcf92 (patch)
treefb79f818844fb3109a702a5ac45f3f873fa5ad5b
parenta10f9e7caf8d3028d8fb1d4c3d590492cde3df3e (diff)
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: Prakash Mortha <pmortha@escient.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
-rw-r--r--Documentation/i2c/smbus-protocol4
-rw-r--r--Documentation/i2c/writing-clients4
-rw-r--r--drivers/i2c/i2c-core.c22
3 files changed, 26 insertions, 4 deletions
diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol
index 24bfb65da17..9df47441f0e 100644
--- a/Documentation/i2c/smbus-protocol
+++ b/Documentation/i2c/smbus-protocol
@@ -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.
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index 6b61b3a2e90..d73ee117a8c 100644
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -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)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 80ae12048e8..42e852d79ff 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1688,6 +1688,28 @@ 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
* @command: Byte interpreted by slave