1-wire on Udoo (imx6qdl)

[chiefwigms]

I'm trying to get 1-wire implemented on a Udoo Quad (i.mx6qdl), and have been searching through various examples on how to do it (Raspberry Pi/BeagleBone etc).  I added in kernel support for w1-gpio and w1-therm, but I'm not sure what syntax needs to be added into the device tree (linux_kernel/imx6qdl-udoo.dtsi at imx_3.14.28_1.0.0_ga_udoo · UDOOboard/linux_kernel · GitHub ).

I looked at the beaglebone implementation (BeagleBone Black 1-Wire Temperature with Debian 8 (Jessie), Kernel 4.1.x and No Capemgr ) and someone pointed me to a SAM9x5 implementation (arch/arm/boot/dts/at91sam9x5cm.dtsi - kernel/common.git - Git at Google ), but I'm still a bit confused (I'm new to kernels).

Any ideas?

Thanks!

Pete

[chiefwigms]

anyone?

[fabio_estevam]

Take a look at arch/arm/boot/dts/imx28-tx28.dts for a reference as to how describe the w1-gpio in device tree.

Regards,

Fabio Estevam

[chiefwigms]

So i think in that dts reference 1wire is disabled (I'm not sure)... For the Udoo - I picked GPIO133 (GPIO5_IO05), which from this diagram doesn't look like it would have too many conflicts with other functions.

I think this is correct for the dtsi file (again referencing the sam9x5 dtsi from above), but i'm not sure about the ?????????​ any ideas?

1wire {

    compatible = "w1-gpio";

    gpios = <&gpio5 5 GPIO_ACTIVE_HIGH>;

    linux,open-drain;

    pinctrl-names = "default";

    pinctrl-0 = <&pinctrl_1wire>;

    status = "okay";

};

1wire {

    pinctrl_1wire: 1wire-0 {

    fsl,pins = <MX6QDL_PAD_DISP0_DAT11__GPIO5_IO05  ?????????>;

};

[fabio_estevam]

You can put 0x1b0b0, which is the default value for the IOMUXC_SW_PAD_CTL_PAD_DISP0_DATA11 register.

[chiefwigms]

So I recompiled the 4.2 kernel with the following : imx6qdl-udoo.dtsi - Pastebin.com , with "Thermal family implementation" as well as "GPIO 1-wire busmaster" and /or "Freescale MXC 1-wire busmaster" (I tried just GPIO, just Freescale and both).

Neither of the combinations above showed the one wire device (I tried multiple devices that work on beaglebone black with a pullup resistor installed).. any tips?  doesn't seem like it should be this complicated.

[fabio_estevam]

You define GPIO5_IO05 twice, so this is likely causing you issues.

Try removing the following line from the external_hog:

MX6QDL_PAD_DISP0_DAT11__GPIO5_IO05              0x80000000  // pin 27