linux-kernel - Re: [PATCH v2 07/15] Documentation: ABI: testing: mt6370: Add ADC sysfs guideline

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CABtFH5KsiDchvshPEEs2hejCWW3z+7RFUXuUBkpR-uiWqOMKyQ@mail.gmail.com>
Date:   Tue, 21 Jun 2022 10:42:53 +0800
From:   ChiaEn Wu <peterwu.pub@...il.com>
To:     Jonathan Cameron <jic23@...nel.org>
Cc:     lars@...afoo.de, matthias.bgg@...il.com,
        Lee Jones <lee.jones@...aro.org>,
        Daniel Thompson <daniel.thompson@...aro.org>,
        jingoohan1@...il.com, pavel@....cz, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, linux-iio@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linux-leds@...r.kernel.org,
        devicetree@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-usb@...r.kernel.org, linux-fbdev@...r.kernel.org,
        szunichen@...il.com, ChiaEn Wu <chiaen_wu@...htek.com>
Subject: Re: [PATCH v2 07/15] Documentation: ABI: testing: mt6370: Add ADC
 sysfs guideline

Hi Jonathan,

Thanks for your reply!

Jonathan Cameron <jic23@...nel.org> 於 2022年6月21日 週二 凌晨2:35寫道：

>
> On Mon, 20 Jun 2022 14:00:43 +0800
> ChiaEn Wu <peterwu.pub@...il.com> wrote:
>
> > Hi Jonathan,
> >
> > Thanks for your helpful comments, and I have some questions want to
> > ask you below.
> >
> > Jonathan Cameron <jic23@...nel.org> 於 2022年6月18日 週六 晚上11:39寫道：
> > >
> > > On Mon, 13 Jun 2022 19:11:38 +0800
> > > ChiaEn Wu <peterwu.pub@...il.com> wrote:
> > >
> > > > From: ChiaEn Wu <chiaen_wu@...htek.com>
> > > >
> > > > Add ABI documentation for mt6370 non-standard ADC sysfs interfaces.
> > > >
> > > > Signed-off-by: ChiaEn Wu <chiaen_wu@...htek.com>
> > > > ---
> > > >  .../ABI/testing/sysfs-bus-iio-adc-mt6370      | 36 +++++++++++++++++++
> > > >  1 file changed, 36 insertions(+)
> > > >  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mt6370
> > > >
> > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6370 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6370
> > > > new file mode 100644
> > > > index 000000000000..039b3381176a
> > > > --- /dev/null
> > > > +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6370
> > > > @@ -0,0 +1,36 @@
> > > > +What:                /sys/bus/iio/devices/iio:deviceX/in_voltage0_raw
> > >
> > > Unfortunately the kernel documentation build scripts do no support duplicating
> > > standard ABI for particular devices so as to provide more information.
> > > Hence you can't have anything in this file.
> > >
> >
> > I want to confirm with you again,
> > because my ABI file duplicates with standard sysfs-bus-iio (voltage,
> > current, and temperature channels),
> > Should I just remove this ABI file and modify the code of mt6370-adc
> > to meet your expectations??
>
> yes.

OK! I got it! I will refine the code in the next patch!

>
> >
> > >
> > > > +KernelVersion:       5.18
> > > > +Contact:     chiaen_wu@...htek.com
> > > > +Description:
> > > > +             Indicated MT6370 VBUS ADC with lower accuracy(+-75mA)
> > > Curious though, voltage with a mA accuracy range?
> >
> > Yes, this description is based on the data sheet.
>
> Weird :)

First, I want to apologize to you because I rechecked the datasheet
and asked the hardware engineer,
the conclusion is I wrote the wrong unit...
The correction is that the accuracy of vbusdiv5 is +-75"mV", not "mA",
and another one, vbusdiv2, is +-30mV.
I sincerely apologize for this mistake and for any inconvenience...

>
> >
> > > This scale should be presented directly to userspace anyway so no need
> > > for this doc.
> > >
> > > > +             higher measure range(1~22V)
> > > > +             Calculating with scale returns voltage in uV
> > >
> > > No. All channels return in mV. That's the ABI requirement as
> > > in sysfs-bus-iio and we cannot vary if for particular drivers.  If we did
> > > no generic tooling would work.
> >
> > Ok, I got it!
> >
> > >
> > > > +
> > > > +What:                /sys/bus/iio/devices/iio:deviceX/in_voltage1_raw
> > > > +KernelVersion:       5.18
> > > > +Contact:     chiaen_wu@...htek.com
> > > > +Description:
> > > > +             Indicated MT6370 VBUS ADC with higher accuracy(+-30mA)
> > > > +             lower measure range(1~9.76V)
> > > > +             Calculating with scale offset returns voltage in uV
> > > > +
> > > > +What:                /sys/bus/iio/devices/iio:deviceX/in_voltage4_raw
> > > > +KernelVersion:       5.18
> > > > +Contact:     chiaen_wu@...htek.com
> > > > +Description:
> > > > +             Indicated MT6370 TS_BAT ADC
> > > > +             Calculating with scale returns voltage in uV
> > > > +
> > > > +What:                /sys/bus/iio/devices/iio:deviceX/in_voltage7_raw
> > > > +KernelVersion:       5.18
> > > > +Contact:     chiaen_wu@...htek.com
> > > > +Description:
> > > > +             Indicated MT6370 CHG_VDDP ADC
> > > > +             Calculating with scale returns voltage in mV
> > > > +
> > > > +What:                /sys/bus/iio/devices/iio:deviceX/in_temp8_raw
> > > > +KernelVersion:       5.18
> > > > +Contact:     chiaen_wu@...htek.com
> > > > +Description:
> > > > +             Indicated MT6370 IC junction temperature
> > > > +             Calculating with scale and offset returns temperature in degree
> >
> > Shall I modify the scale of temperature to milli degrees in
> > mt6370-adc.c and remove this item??
>
> yes.
>
> Thanks,
>
> Jonathan
>
> >
> > >
> >
> > Best regards,
> > ChiaEn Wu
>

Best regards,
ChiaEn Wu