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authorJean Delvare <khali@linux-fr.org>2011-01-10 22:11:23 +0100
committerJean Delvare <khali@endymion.delvare>2011-01-10 22:11:23 +0100
commit0cc43a1806f078f7fd414850d8f1f1761696e4af (patch)
tree2278fca3af95002a867fa72b34e4ca97ccf5489f
parentaf5a60baaee66e2f891dbb9a8519ca28ab7da7cd (diff)
i2c: Constify i2c_client where possible
Helper functions for I2C and SMBus transactions don't modify the i2c_client that is passed to them, so it can be marked const. Signed-off-by: Jean Delvare <khali@linux-fr.org>
-rw-r--r--drivers/i2c/i2c-core.c29
-rw-r--r--drivers/rtc/rtc-ds1307.c12
-rw-r--r--include/linux/i2c.h27
3 files changed, 37 insertions, 31 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6b4cc567645b..c7db6980e3a3 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1362,7 +1362,7 @@ EXPORT_SYMBOL(i2c_transfer);
*
* Returns negative errno, or else the number of bytes written.
*/
-int i2c_master_send(struct i2c_client *client, const char *buf, int count)
+int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
{
int ret;
struct i2c_adapter *adap = client->adapter;
@@ -1389,7 +1389,7 @@ EXPORT_SYMBOL(i2c_master_send);
*
* Returns negative errno, or else the number of bytes read.
*/
-int i2c_master_recv(struct i2c_client *client, char *buf, int count)
+int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
{
struct i2c_adapter *adap = client->adapter;
struct i2c_msg msg;
@@ -1679,7 +1679,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
* This executes the SMBus "receive byte" protocol, returning negative errno
* else the byte received from the device.
*/
-s32 i2c_smbus_read_byte(struct i2c_client *client)
+s32 i2c_smbus_read_byte(const struct i2c_client *client)
{
union i2c_smbus_data data;
int status;
@@ -1699,7 +1699,7 @@ EXPORT_SYMBOL(i2c_smbus_read_byte);
* This executes the SMBus "send byte" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
+s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
{
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
@@ -1714,7 +1714,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte);
* This executes the SMBus "read byte" protocol, returning negative errno
* else a data byte received from the device.
*/
-s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
+s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
int status;
@@ -1735,7 +1735,8 @@ EXPORT_SYMBOL(i2c_smbus_read_byte_data);
* This executes the SMBus "write byte" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
+s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command,
+ u8 value)
{
union i2c_smbus_data data;
data.byte = value;
@@ -1753,7 +1754,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte_data);
* This executes the SMBus "read word" protocol, returning negative errno
* else a 16-bit unsigned "word" received from the device.
*/
-s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
+s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
int status;
@@ -1774,7 +1775,8 @@ EXPORT_SYMBOL(i2c_smbus_read_word_data);
* This executes the SMBus "write word" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
+s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
+ u16 value)
{
union i2c_smbus_data data;
data.word = value;
@@ -1793,7 +1795,8 @@ EXPORT_SYMBOL(i2c_smbus_write_word_data);
* 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)
+s32 i2c_smbus_process_call(const struct i2c_client *client, u8 command,
+ u16 value)
{
union i2c_smbus_data data;
int status;
@@ -1821,7 +1824,7 @@ EXPORT_SYMBOL(i2c_smbus_process_call);
* support this; its emulation through I2C messaging relies on a specific
* mechanism (I2C_M_RECV_LEN) which may not be implemented.
*/
-s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command,
u8 *values)
{
union i2c_smbus_data data;
@@ -1848,7 +1851,7 @@ EXPORT_SYMBOL(i2c_smbus_read_block_data);
* This executes the SMBus "block write" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
union i2c_smbus_data data;
@@ -1864,7 +1867,7 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
EXPORT_SYMBOL(i2c_smbus_write_block_data);
/* Returns the number of read bytes */
-s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
union i2c_smbus_data data;
@@ -1884,7 +1887,7 @@ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
}
EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
-s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
union i2c_smbus_data data;
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index d827ce570a8c..0d559b6416dd 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -106,9 +106,9 @@ struct ds1307 {
struct i2c_client *client;
struct rtc_device *rtc;
struct work_struct work;
- s32 (*read_block_data)(struct i2c_client *client, u8 command,
+ s32 (*read_block_data)(const struct i2c_client *client, u8 command,
u8 length, u8 *values);
- s32 (*write_block_data)(struct i2c_client *client, u8 command,
+ s32 (*write_block_data)(const struct i2c_client *client, u8 command,
u8 length, const u8 *values);
};
@@ -158,8 +158,8 @@ MODULE_DEVICE_TABLE(i2c, ds1307_id);
#define BLOCK_DATA_MAX_TRIES 10
-static s32 ds1307_read_block_data_once(struct i2c_client *client, u8 command,
- u8 length, u8 *values)
+static s32 ds1307_read_block_data_once(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
{
s32 i, data;
@@ -172,7 +172,7 @@ static s32 ds1307_read_block_data_once(struct i2c_client *client, u8 command,
return i;
}
-static s32 ds1307_read_block_data(struct i2c_client *client, u8 command,
+static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
@@ -198,7 +198,7 @@ static s32 ds1307_read_block_data(struct i2c_client *client, u8 command,
return length;
}
-static s32 ds1307_write_block_data(struct i2c_client *client, u8 command,
+static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
u8 currvalues[I2C_SMBUS_BLOCK_MAX];
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 56cfe23ffb39..903576df88dc 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -57,9 +57,10 @@ struct i2c_board_info;
* transmit an arbitrary number of messages without interruption.
* @count must be be less than 64k since msg.len is u16.
*/
-extern int i2c_master_send(struct i2c_client *client, const char *buf,
+extern int i2c_master_send(const struct i2c_client *client, const char *buf,
+ int count);
+extern int i2c_master_recv(const struct i2c_client *client, char *buf,
int count);
-extern int i2c_master_recv(struct i2c_client *client, char *buf, int count);
/* Transfer num messages.
*/
@@ -78,23 +79,25 @@ extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
/* Now follow the 'nice' access routines. These also document the calling
conventions of i2c_smbus_xfer. */
-extern s32 i2c_smbus_read_byte(struct i2c_client *client);
-extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
-extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
-extern s32 i2c_smbus_write_byte_data(struct i2c_client *client,
+extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
+extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
+extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
+ u8 command);
+extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
u8 command, u8 value);
-extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command);
-extern s32 i2c_smbus_write_word_data(struct i2c_client *client,
+extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
+ u8 command);
+extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
u8 command, u16 value);
/* Returns the number of read bytes */
-extern s32 i2c_smbus_read_block_data(struct i2c_client *client,
+extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
u8 command, u8 *values);
-extern s32 i2c_smbus_write_block_data(struct i2c_client *client,
+extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
u8 command, u8 length, const u8 *values);
/* Returns the number of read bytes */
-extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
+extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
u8 command, u8 length, u8 *values);
-extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
+extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
u8 command, u8 length,
const u8 *values);
#endif /* I2C */