Multiple onewire w1-gpio devices with kernel 4.14.71-ti-r80

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1

Dear all

I am trying to get multiple (currently 2) onewire (w1-gpio) devices running at the same time with two entries in the filesystem
/sys/bus/w1/devices/w1_bus_master1
/sys/bus/w1/devices/w1_bus_master2
and mapping to two pins (in my case pins P8.39 and P8.41). I am using a BeagleBone Green running Debian 9 with kernel 4.14.71-ti-r80.

Unfortunately, I could not get it working so far. The closest I got, is the device tree overlay file below (based on BB-W1-P9.12-00A0.dts from https://github.com/beagleboard/bb.org-overlays):
/*

2

Congratulations to you on that ;we were completely unable to get 1w working on 4.14. After upgrading to 4.19 and using the default 1w dtb, things worked perfectly. Unfortunately we only use a single device so I can’t say whether 4.19 will help you in this case.

Best regards,
Jim

3

The W1 bus is designed for one master and multiple slave devices → only one GPIO pin necessary. Unfortunately the kernel driver doesn’t support this.

Check out libpruw1 for advanced features, including a bus log function to monitor the line during operation.

Regards

4

    fragment@2 {
        target-path="/";
        __overlay__ {

            w1_1: onewire@0 {
                status = "okay";
                pinctrl-names = "default";
                pinctrl-0 = <&dallas_w1_pins_tx>;

                compatible = "w1-gpio";
                gpios = <
                  &gpio2 12 GPIO_ACTIVE_HIGH
                >;
            };

            w1_2: onewire@1 {
                status = "okay";
                pinctrl-names = "default";
                pinctrl-0 = <&dallas_w1_pins_rx>;

                compatible = "w1-gpio";
                gpios = <
                    &gpio2 10 GPIO_ACTIVE_HIGH
                >;
            };
        };
    };
};

You used the exact same name for both pinmux identifiers:
"dallas_w1_pins_rx"... give each a unique name..

(and use v4.19.x based kernel)..

Regards,