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-rw-r--r--Documentation/i2c/writing-clients8
-rw-r--r--drivers/i2c/i2c-core.c97
2 files changed, 57 insertions, 48 deletions
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index d4cd4126d1ad..ba5d1971f35f 100644
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -598,10 +598,10 @@ be added back later if needed:
u8 command, u8 length,
u8 *values)
-All these transactions return -1 on failure. The 'write' transactions
-return 0 on success; the 'read' transactions return the read value, except
-for read_block, which returns the number of values read. The block buffers
-need not be longer than 32 bytes.
+All these transactions return a negative errno value on failure. The 'write'
+transactions return 0 on success; the 'read' transactions return the read
+value, except for block transactions, which return the number of values
+read. The block buffers need not be longer than 32 bytes.
You can read the file `smbus-protocol' for more information about the
actual SMBus protocol.
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index bb5c215a24e0..937f1dcbf3d7 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -974,7 +974,7 @@ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
return ret;
} else {
dev_dbg(&adap->dev, "I2C level transfers not supported\n");
- return -ENOSYS;
+ return -EOPNOTSUPP;
}
}
EXPORT_SYMBOL(i2c_transfer);
@@ -1106,7 +1106,7 @@ int i2c_probe(struct i2c_adapter *adapter,
dev_warn(&adapter->dev, "SMBus Quick command not supported, "
"can't probe for chips\n");
- return -1;
+ return -EOPNOTSUPP;
}
/* Probe entries are done second, and are not affected by ignore
@@ -1298,7 +1298,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
if (rpec != cpec) {
pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
rpec, cpec);
- return -1;
+ return -EBADMSG;
}
return 0;
}
@@ -1313,11 +1313,12 @@ EXPORT_SYMBOL(i2c_smbus_write_quick);
s32 i2c_smbus_read_byte(struct i2c_client *client)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
- return -1;
- else
- return data.byte;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &data);
+ return (status < 0) ? status : data.byte;
}
EXPORT_SYMBOL(i2c_smbus_read_byte);
@@ -1331,11 +1332,12 @@ EXPORT_SYMBOL(i2c_smbus_write_byte);
s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
- return -1;
- else
- return data.byte;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+ return (status < 0) ? status : data.byte;
}
EXPORT_SYMBOL(i2c_smbus_read_byte_data);
@@ -1352,11 +1354,12 @@ EXPORT_SYMBOL(i2c_smbus_write_byte_data);
s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
- return -1;
- else
- return data.word;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_WORD_DATA, &data);
+ return (status < 0) ? status : data.word;
}
EXPORT_SYMBOL(i2c_smbus_read_word_data);
@@ -1390,11 +1393,13 @@ s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
u8 *values)
{
union i2c_smbus_data data;
+ int status;
- if (i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_BLOCK_DATA, &data))
- return -1;
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BLOCK_DATA, &data);
+ if (status)
+ return status;
memcpy(values, &data.block[1], data.block[0]);
return data.block[0];
@@ -1421,14 +1426,16 @@ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
union i2c_smbus_data data;
+ int status;
if (length > I2C_SMBUS_BLOCK_MAX)
length = I2C_SMBUS_BLOCK_MAX;
data.block[0] = length;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command,
- I2C_SMBUS_I2C_BLOCK_DATA,&data))
- return -1;
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_I2C_BLOCK_DATA, &data);
+ if (status < 0)
+ return status;
memcpy(values, &data.block[1], data.block[0]);
return data.block[0];
@@ -1469,6 +1476,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
};
int i;
u8 partial_pec = 0;
+ int status;
msgbuf0[0] = command;
switch(size) {
@@ -1518,10 +1526,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
} else {
msg[0].len = data->block[0] + 2;
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
- dev_err(&adapter->dev, "smbus_access called with "
- "invalid block write size (%d)\n",
- data->block[0]);
- return -1;
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
}
for (i = 1; i < msg[0].len; i++)
msgbuf0[i] = data->block[i-1];
@@ -1531,10 +1539,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
num = 2; /* Another special case */
read_write = I2C_SMBUS_READ;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
- dev_err(&adapter->dev, "%s called with invalid "
- "block proc call size (%d)\n", __func__,
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
data->block[0]);
- return -1;
+ return -EINVAL;
}
msg[0].len = data->block[0] + 2;
for (i = 1; i < msg[0].len; i++)
@@ -1549,19 +1557,18 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
} else {
msg[0].len = data->block[0] + 1;
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
- dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
- "invalid block write size (%d)\n",
- data->block[0]);
- return -1;
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
}
for (i = 1; i <= data->block[0]; i++)
msgbuf0[i] = data->block[i];
}
break;
default:
- dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
- size);
- return -1;
+ dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
+ return -EOPNOTSUPP;
}
i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
@@ -1579,13 +1586,15 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
msg[num-1].len++;
}
- if (i2c_transfer(adapter, msg, num) < 0)
- return -1;
+ status = i2c_transfer(adapter, msg, num);
+ if (status < 0)
+ return status;
/* Check PEC if last message is a read */
if (i && (msg[num-1].flags & I2C_M_RD)) {
- if (i2c_smbus_check_pec(partial_pec, &msg[num-1]) < 0)
- return -1;
+ status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
+ if (status < 0)
+ return status;
}
if (read_write == I2C_SMBUS_READ)
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