I2C clock not working in imx6ul

[chandraevolute]

Hi All,

we are using imx6ul based custom board with Linux version 3.14.38-6UL. We interfaced ST7036 LCD driver to i2c3. 

When we tried i2cdetect by giving ./i2cdetect -y 2 below is the output

root@imx6ulevk:/# ./i2cdetect -y 2
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

When we probed the SDA and SCL lines there is no clock pulse on SCL line. The SCL line is always High. 

How to resolve this

EDIT1:

Checked with imx6ul development board

root@imx6ulevk:/# ./i2cget 1 0x1e 0x1e c
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will read from device file /dev/i2c-1, chip address 0x1e, data address
0x1e, using write byte/read byte.
Continue? [Y/n] y
Warning - write failed
Error: Read failed

With Development board also it is not successful

[igorpadykov · Accepted solution]

Hi chandra

one can check if i2c module clock is not gated in CCM_CCGR registers and check

pinctrl_i2c settings, please use example in imx6ul-14x14-evk.dts
git.freescale.com/git/cgit.cgi/imx/linux-imx.git/tree/arch/arm/boot/dts/imx6ul-14x14-evk.dts?id=rel_imx_4.1.15_2.0.0_ga

Best regards
igor
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[chandraevolute]

thank you igor it worked