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

From: Jonathan Cameron <jic23@kernel.org>
To: ChiaEn Wu <peterwu.pub@gmail.com>
Cc: lars@metafoo.de, matthias.bgg@gmail.com, lee.jones@linaro.org,
	daniel.thompson@linaro.org, jingoohan1@gmail.com, pavel@ucw.cz,
	robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
	linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org,
	devicetree@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org,
	szunichen@gmail.com, ChiaEn Wu <chiaen_wu@richtek.com>
Subject: Re: [PATCH v2 07/15] Documentation: ABI: testing: mt6370: Add ADC sysfs guideline
Date: Sat, 18 Jun 2022 16:48:20 +0100	[thread overview]
Message-ID: <20220618164820.2eeb8ae8@jic23-huawei> (raw)
In-Reply-To: <20220613111146.25221-8-peterwu.pub@gmail.com>

On Mon, 13 Jun 2022 19:11:38 +0800
ChiaEn Wu <peterwu.pub@gmail.com> wrote:

> From: ChiaEn Wu <chiaen_wu@richtek.com>
> 
> Add ABI documentation for mt6370 non-standard ADC sysfs interfaces.
> 
> Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.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.

> +KernelVersion:	5.18
> +Contact:	chiaen_wu@richtek.com
> +Description:
> +		Indicated MT6370 VBUS ADC with lower accuracy(+-75mA)
Curious though, voltage with a mA accuracy range?
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.

> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_voltage1_raw
> +KernelVersion:	5.18
> +Contact:	chiaen_wu@richtek.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@richtek.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@richtek.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@richtek.com
> +Description:
> +		Indicated MT6370 IC junction temperature
> +		Calculating with scale and offset returns temperature in degree