diff options
Diffstat (limited to 'Documentation/i2c/dev-interface')
| -rw-r--r-- | Documentation/i2c/dev-interface | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface index b849ad63658..9dd79123ddd 100644 --- a/Documentation/i2c/dev-interface +++ b/Documentation/i2c/dev-interface @@ -90,12 +90,15 @@ ioctl(file,I2C_SLAVE,long addr) ioctl(file,I2C_TENBIT,long select) Selects ten bit addresses if select not equals 0, selects normal 7 bit - addresses if select equals 0. Default 0. + addresses if select equals 0. Default 0. This request is only valid + if the adapter has I2C_FUNC_10BIT_ADDR. ioctl(file,I2C_PEC,long select) Selects SMBus PEC (packet error checking) generation and verification if select not equals 0, disables if select equals 0. Default 0. - Used only for SMBus transactions. + Used only for SMBus transactions. This request only has an effect if the + the adapter has I2C_FUNC_SMBUS_PEC; it is still safe if not, it just + doesn't have any effect. ioctl(file,I2C_FUNCS,unsigned long *funcs) Gets the adapter functionality and puts it in *funcs. @@ -103,8 +106,10 @@ ioctl(file,I2C_FUNCS,unsigned long *funcs) ioctl(file,I2C_RDWR,struct i2c_rdwr_ioctl_data *msgset) Do combined read/write transaction without stop in between. - The argument is a pointer to a struct i2c_rdwr_ioctl_data { + Only valid if the adapter has I2C_FUNC_I2C. The argument is + a pointer to a + struct i2c_rdwr_ioctl_data { struct i2c_msg *msgs; /* ptr to array of simple messages */ int nmsgs; /* number of messages to exchange */ } |