i2c

I'm embedding some driver into a Linux kernel when I get this error (I'm adding the device in the board file and registering it): error: 'kxtf9_get_slave_descr' undeclared here (not in a function) I located the function above in a driver file struct ext_slave_descr *kxtf9_get_slave_descr(void) { return &kxtf9_descr; } EXPORT_SYMBOL(kxtf9_get_slave_descr); Shouldn't it made "visible" by EXPORT_SYMBOL? The C file containing the code above has no header file (I didn't write it, I just found it here and I'm implementing. They say it's tested so I assume an header is not needed? The rest of the

How to make a character device for i2c device, with open, close, ioctl etc. functions? I was looking for information about it last two weeks and couldn't find anything working. I found some information in Essential Linux Device Drivers, but it was written for 2.6 kernel, and i use 3.4.79 (i'm trying to write this driver for cubieboard2 on cubian distr) so this book has many deprecated functions, i tried to write my driver like there, but it still don't work (give me kernel errors while i'm truing to cat character device). Can anyone explain me what to do with it, or at least give me a working

I am trying to understand I2C client drivers. As per my understanding before registering I2C driver we have to define i2c_device_id table and device tree compatible table. I have following doubts. Could please help me to understand. 1) The definition of i2c_device_id structure contains two members ( name , driver_data ). The 1st member ( name ) is used to define the device name which will be used during driver binding, what is the use of the 2nd member ( driver_data ). 2) Driver binding will happen based on i2c_device_id table or device tree compatible string. Thanks in advance. 1) The