Talk to I2C devices via SysFS or C api

Software
1

Hi, i’ve connected my i2c bus to a number of devices. i’ve run the following commands in an attempt to communicate with them.

$ ldto enable i2c-ao
$ i2cdetect -l
i2c-1   i2c             Meson I2C adapter                       I2C adapter
i2c-0   i2c             DesignWare HDMI                         I2C adapter
$ i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x08-0x77.
Continue? [Y/n] 
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         08 -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --
$ echo realtime_clock 0x68 > /sys/bus/i2c/devices/i2c-1/new-device

However, i’m stuck on how to communicate with the device either through sysfs or some other api? Is there a C api or some other sysfs file im supposed to write to?

Thanks

2

You can use i2cget and i2cset to send sample read and write.

For C, use the kernel interface IOCTLs.

3

Can you give an example of how to use i2cset and i2cget?

I tried to use

i2cget 1  0x08 0x08
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will read from device file /dev/i2c-1, chip address 0x08, data address
0x08, using read word data.
Continue? [Y/n] y
Error: Read failed