diff options
Diffstat (limited to 'Documentation/i2c/dev-interface')
| -rw-r--r-- | Documentation/i2c/dev-interface | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface index 09d6cda..b849ad6 100644 --- a/Documentation/i2c/dev-interface +++ b/Documentation/i2c/dev-interface @@ -14,9 +14,12 @@ C example ========= So let's say you want to access an i2c adapter from a C program. The -first thing to do is `#include <linux/i2c.h>" and "#include <linux/i2c-dev.h>. -Yes, I know, you should never include kernel header files, but until glibc -knows about i2c, there is not much choice. +first thing to do is "#include <linux/i2c-dev.h>". Please note that +there are two files named "i2c-dev.h" out there, one is distributed +with the Linux kernel and is meant to be included from kernel +driver code, the other one is distributed with lm_sensors and is +meant to be included from user-space programs. You obviously want +the second one here. Now, you have to decide which adapter you want to access. You should inspect /sys/class/i2c-dev/ to decide this. Adapter numbers are assigned @@ -78,7 +81,7 @@ Full interface description ========================== The following IOCTLs are defined and fully supported -(see also i2c-dev.h and i2c.h): +(see also i2c-dev.h): ioctl(file,I2C_SLAVE,long addr) Change slave address. The address is passed in the 7 lower bits of the @@ -97,10 +100,10 @@ ioctl(file,I2C_PEC,long select) ioctl(file,I2C_FUNCS,unsigned long *funcs) Gets the adapter functionality and puts it in *funcs. -ioctl(file,I2C_RDWR,struct i2c_ioctl_rdwr_data *msgset) +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_ioctl_rdwr_data { + 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 */ |
