Messages in this thread | | | Subject | Re: [PATCH v2] ARM: dts: vfxxx: Add iio_hwmon node for ADC temperature channel | From | Guenter Roeck <> | Date | Sun, 14 Feb 2016 21:14:06 -0800 |
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On 02/14/2016 08:42 PM, maitysanchayan@gmail.com wrote: > Hello Shawn, > > On 16-02-14 16:33:49, Shawn Guo wrote: >> On Fri, Feb 12, 2016 at 05:53:00PM +0530, Sanchayan Maity wrote: >>> Add iio_hwmon node to expose the temperature channel on Vybrid as >>> hardware monitor device using the iio_hwmon driver. >>> >>> Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> >>> --- >>> >>> Hello, >>> >>> The first version of the patch was send quite a while ago. >>> https://lkml.org/lkml/2015/9/16/932 >>> >>> Shawn you had requested that hyphen rather than underscore should >>> be used in node name. I looked into that. >>> >>> The iio_hwmon driver calls hwmon_device register_with_groups inside >>> hwmon.c and this >>> http://lxr.free-electrons.com/source/drivers/hwmon/hwmon.c#L103 >>> >>> does not allow hyphen in hwmon name attribute. I was not aware of >>> this but while trying to test the change, the device probe failed >>> with EINVAL. I think we should stick to the existing use of the >>> bindings or we need to change the hwmon code as well along with the >>> existing device tree files and binding documentation. >> >> I disagree. >> >> If hyphen is invalid to be part of hwmon name attribute, the following >> code in iio_hwmon_probe() is plain wrong, because hyphen is very valid >> to be part of node names in device tree. >> >> if (dev->of_node && dev->of_node->name) >> name = dev->of_node->name; > > @Shawn > I agree with what you state here, however as you can see the hwmon_device_ > register_with_groups does check for hypen with strpbrk and returns EINVAL. > Changing to hyphen instead of currently present underscore in iio_hwmon > node name causes probe failure. > > If the node name needs to have hyphen, then the check for hyphen as an invalid > character in hwmon name attribute needs to be changed. I am CC'ing the hwmon > subsystem maintainers Jean Delvare ands Guenter Roeck as well as hwmon list to > check. > > @Jean & Guenter > Can you please comment if the change to hwmon_device_register_with_groups > to accept hyphen as a valid character in hwmon name attribute will be acceptable?
User space would not like the '-' and get confused.
We'll have to change the above code and replace '-' with '_' in the name if/when it is seen. Sorry, I didn't realize the problem when I wrote that code.
Guenter
> Sorry if this is sudden andfor bringing you late into the discussion Jean and > Guenter. > > Thanks & Regards, > Sanchayan. > >> >> Shawn >> >>> >>> Changes since v1: >>> 1. Expose ADC1 temperature channel as well >>> 2. Move the entry outside of the aips1 bus node >>> >>> Best Regards, >>> Sanchayan Maity. >>> --- >>> arch/arm/boot/dts/vfxxx.dtsi | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/arch/arm/boot/dts/vfxxx.dtsi b/arch/arm/boot/dts/vfxxx.dtsi >>> index a5f07e3..8ed8e47 100644 >>> --- a/arch/arm/boot/dts/vfxxx.dtsi >>> +++ b/arch/arm/boot/dts/vfxxx.dtsi >>> @@ -673,5 +673,10 @@ >>> status = "disabled"; >>> }; >>> }; >>> + >>> + iio_hwmon { >>> + compatible = "iio-hwmon"; >>> + io-channels = <&adc0 16>, <&adc1 16>; >>> + }; >>> }; >>> }; >>> -- >>> 2.7.1 >>> >>> >
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