From 24a5bb7b1838dc4524dd353224e2aa09c22cac3b Mon Sep 17 00:00:00 2001 From: David Brownell Date: Mon, 14 Jul 2008 22:38:23 +0200 Subject: [PATCH] i2c-core: Return -Errno, not -1 More updates to the I2C stack's fault reporting: make the core stop returning "-1" (usually "-EPERM") for all faults. Instead, pass lower level fault code up the stack, or return some appropriate errno. This patch happens to touch almost exclusively SMBus calls. Signed-off-by: David Brownell Signed-off-by: Jean Delvare --- Documentation/i2c/writing-clients | 8 +-- drivers/i2c/i2c-core.c | 97 +++++++++++++++++-------------- 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)