topic Re: Pin mux Issue with gpio7[6] in i.MX Processors

Pin mux Issue with gpio7[6]

akashgajjar — Mon, 17 Oct 2016 12:37:42 GMT

Hi all,

i have connected one sensor on i2c 4 imx7d sabre board, gpio7[6] is used for reset

purpose, when i make gpio value 0 by

echo 0 > /sys/class/gpio198/value

my i2c4_scl comes to ground state.

here's device tree data

                pinctrl_i2c4: i2c4grp {
                        fsl,pins = <
                                MX7D_PAD_I2C4_SDA__I2C4_SDA     0x4000007f
                                MX7D_PAD_I2C4_SCL__I2C4_SCL     0x4000007f
                                MX7D_PAD_ENET1_RGMII_TD0__GPIO7_IO6        0x4000007f
                        >;
                };

when i detect the device it shows,

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 i2c 4 clock is at ground state it is scanning the device on bus as shown above,

can you please suggest me what's wrong with this.

Regards,

Akash

Re: Pin mux Issue with gpio7[6]

igorpadykov — Tue, 18 Oct 2016 06:50:42 GMT

Hi Akash

seems low level is produced from sensor side, so one can check its pull resistors

and try to debug it with oscilloscope and probably temporarily cutting scl line.

Best regards
igor
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Re: Pin mux Issue with gpio7[6]

akashgajjar — Tue, 18 Oct 2016 09:26:06 GMT

HI igor,

This is sccb supported image sensor.

when i took out sensor device from the reset state this is happening.

can i access register of this device using i2c-tools from linux user-space?

Regards,

Akash

Re: Pin mux Issue with gpio7[6]

igorpadykov — Tue, 18 Oct 2016 23:35:39 GMT

could you try other sensor like ov5640, I believe line could be

hold by this specific sensor.

Best regards
igor

Re: Pin mux Issue with gpio7[6]

akashgajjar — Wed, 19 Oct 2016 11:52:37 GMT

Hi Igor,

imx7d i2c controller is capable to drive the sccb supported sensor?

because both device has same sccb interface in camera.

Regards,

Akash