From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751811AbcBOFOO (ORCPT ); Mon, 15 Feb 2016 00:14:14 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:43358 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbcBOFOM (ORCPT ); Mon, 15 Feb 2016 00:14:12 -0500 Subject: Re: [PATCH v2] ARM: dts: vfxxx: Add iio_hwmon node for ADC temperature channel To: maitysanchayan@gmail.com, Shawn Guo References: <20160214083349.GR6756@tiger> <20160215044214.GA5545@Sanchayan-Arch.toradex.int> Cc: stefan@agner.ch, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, jdelvare@suse.com, lm-sensors@lm-sensors.org From: Guenter Roeck Message-ID: <56C15E9E.3070802@roeck-us.net> Date: Sun, 14 Feb 2016 21:14:06 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160215044214.GA5545@Sanchayan-Arch.toradex.int> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >>> --- >>> >>> 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 >>> >>> >