I2c access in kernel space

Technical Support
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1

I have a i2c device which is connected to iMX6DL module, I am able to write data on it with the following command in terminal:

i2cset  -y 0 0x2c 0x00 0x05

I have wrote a character driver, I want to access this device in my driver and work with it, I could not find a article to describe how to use i2c in kernel space, How should I work with i2c in kernel space?

2

There are lots of material available on Internet You can start from here - I2C and SMBus Subsystem — The Linux Kernel documentation

3

thank you for your response, yes I saw that article and many others including some drivers.
In those articles there is a function called i2c_master_send. which I saw in all drivers used to send data to i2c bus. In this function there is a input structure called i2c_client. this structure must be filled to send data to i2c bus and device, but there is no describing or example that I could find to how to fill this structure. I assume if this structure filled correctly I am able to send data to my device on i2c0. Can you help me with i2c_client structure?

4

The struct i2c_client is described here.

5

I have reached to my goal with following code in my driver:

#define VOL1_CHIP_ADDRESS 0x2c
#define VOL1_DATA_ADDRESS 0

struct i2c_client *clientstr;
struct file * fp;

...

mm_segment_t oldfs;

oldfs = get_fs();
set_fs(KERNEL_DS);
fp = filp_open("/dev/i2c-0",O_RDWR,0);
clientstr = (struct i2c_client *)fp->private_data;
clientstr->addr=VOL1_CHIP_ADDRESS;
i2c_smbus_write_byte_data(clientstr,VOL1_DATA_ADDRESS,0x05);
filp_close(fp,NULL);
set_fs(oldfs);
6

Perfect. Thanks for the feedback.