Hi,
I am using beaglebone black default kernel, here is its informations :
Linux arm 3.8.13-bone40 #1 SMP Fri Jan 31 10:36:05 UTC 2014 armv7l
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=13.10
DISTRIB_CODENAME=saucy
DISTRIB_DESCRIPTION="Ubuntu 13.10"
I modify devicetree as follow : in /boot/dtbs/
# generate the dts from the dtb
dtc -I dtb -O dts -o am335x-boneblack.dts am335x-boneblack.dtb
# modify the dts with a text editor :
i add after cape_eeprom3@57 ( in i2c3 lines i2c@4819c000)
ina219@40 {
compatible = "ti,ina219";
reg = <0x40>;
shunt-resistor = <100000>;
};
# generate the dtb from the modified dts
dtc -I dts -O dtb -o am335x-boneblack.dtb am335x-boneblack.dts
#reboot the beaglebone black to load the new device tree
#use sensors
ubuntu@arm:~$ sensors
am335x-bandgap-isa-0000
Adapter: ISA adapter
temp1: +53.0°C
ina219-i2c-1-40
Adapter: OMAP I2C adapter
in0: +0.03 V
in1: +4.94 V
power1: 12.74 W <- wrong value since not the good shunt resistor
value...
curr1: +2.56 A <- wrong value since not the good shunt resistor
value..
*Kancir Pierre*
pierre.kancir@xxxxxxxxx
LinkedIn <http://www.linkedin.com/pub/pierre-kancir/4b/a1a/32a> |
Viadeo<http://www.viadeo.com/fr/profile/pierre.kancir>
2014-04-08 15:50 GMT+02:00 Guenter Roeck <linux@xxxxxxxxxxxx>:
> On 04/08/2014 06:29 AM, Pierre Kancir wrote:
>
>> Hi,
>>
>> I am trying to use ina219 sensor (http://www.adafruit.com/products/904)
>> with linux kernel driver on beaglebone black.
>>
>> I want to use device tree overlay to use the sensor. I follow kernel
>> indications (
>> http://lxr.free-electrons.com/source/Documentation/
>> devicetree/bindings/i2c/ina2xx.txt)
>> and the sensor works as expected.
>>
>> But adafruit board use 0.1ohms and default driver value for shunt-resistor
>> is 10mOhms so return value are wrong.
>>
>> I want to modify value in device tree as indicated
>>
>> ina219@40 {
>> compatible = "ti,ina219";
>> reg = <0x40>;
>> shunt-resistor = <100000>;
>> };
>>
>> but changing shunt-resistor value does nothing. The sensor is always
>> create
>> with 10mOhms value
>>
>> ina2xx 1-0040: power monitor ina219 (Rshunt = 10000 uOhm)
>>
>> How can i change the shunt-resistor value to get the proper return?
>>
>>
> Good question. This functionality was added mid-2013. What is your kernel
> version ?
>
> Guenter
>
>
_______________________________________________
lm-sensors mailing list
lm-sensors@xxxxxxxxxxxxxx
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
