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Ibutton - onewire W1 in imx6ul

Question asked by Juan Alfonso Reyes on Nov 16, 2017
Latest reply on Nov 21, 2017 by Juan Alfonso Reyes

Hi,

I am currently trying to connect an iButton to my imx6ul based board. This is the schematic:

ibutton schematicIn the device tree I have enabled the pin as onewire:

 

         onewire {
               compatible = "w1-gpio";
               gpios = <&gpio3 3 GPIO_ACTIVE_HIGH>;
               status = "okay";
               };

and configured the pin with:

         MX6UL_PAD_LCD_VSYNC__GPIO3_IO03         0x1a8b1



I also have enabled every 1wire driver in the kernel:

CONFIG_W1=y
CONFIG_W1_CON=y

#
# 1-wire Bus Masters
#
CONFIG_W1_MASTER_DS2490=y
CONFIG_W1_MASTER_DS2482=y
CONFIG_W1_MASTER_MXC=y
CONFIG_W1_MASTER_DS1WM=y
CONFIG_W1_MASTER_GPIO=y

#
# 1-wire Slaves
#
CONFIG_W1_SLAVE_THERM=y
CONFIG_W1_SLAVE_SMEM=y
CONFIG_W1_SLAVE_DS2408=y
CONFIG_W1_SLAVE_DS2408_READBACK=y
CONFIG_W1_SLAVE_DS2413=y
CONFIG_W1_SLAVE_DS2406=y
CONFIG_W1_SLAVE_DS2423=y
CONFIG_W1_SLAVE_DS2431=y
CONFIG_W1_SLAVE_DS2433=y
CONFIG_W1_SLAVE_DS2433_CRC=y
CONFIG_W1_SLAVE_DS2760=y
CONFIG_W1_SLAVE_DS2780=y
CONFIG_W1_SLAVE_DS2781=y
CONFIG_W1_SLAVE_DS28E04=y
CONFIG_W1_SLAVE_BQ27000=y

When I boot my board up I can see (my kernel does not use modules):

root@ep100:/# dmesg | grep w1
DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko
root@ep100:/# dmesg | grep Dallas
Driver for 1-wire Dallas network protocol.
root@ep100:/# ls /sys/bus/w1/devices/
w1_bus_master1

With an oscilloscope to see the pin behaviour I can ensure the pin is searching for devices:

Oscilloscope

 

But there is no new devices in /sys/bus/w1/devices/. ¿What am I doing wrong?

 

Thanks

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