Re: [PATCH v4 2/3] Documentation: ABI: testing: mt6360: Add ADC sysfs guideline

Gene Chen
2020-09-18T07:22:01Z

Jonathan Cameron <jic23@kernel.org> 於 2020年9月18日 週五 上午1:43寫道：
>
> On Wed, 16 Sep 2020 01:36:08 +0800
> Gene Chen <gene.chen.richtek@gmail.com> wrote:
>
> > From: Gene Chen <gene_chen@richtek.com>
> >
> > Add ABI documentation for mt6360 ADC sysfs interfaces.
> >
> > Signed-off-by: Gene Chen <gene_chen@richtek.com>
> Would you consider using the proposed label attribute for channels?
>
> https://lore.kernel.org/linux-iio/20200916132115.81795-1-cristian.pop@analog.com/T/#u
>
> I'm hoping that will remove the need to have ext name used in the majority of
> cases and would like to know if it would work for you?
> It may not work for this particular case of course.
>
> Other comments inline.
>

because of ADC layout is fixed, I can't switch channel to specific
purpose for userspace.

> > ---
> > Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360 | 83 ++++++++++++++++++++++
> > 1 file changed, 83 insertions(+)
> > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360
> > new file mode 100644
> > index 0000000..4b1c270
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360
> > @@ -0,0 +1,83 @@
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_USBID_input
>
>
> The mixture of case is a bit ugly. Could we do
> in_voltage_usbin_input?
>

ACK

> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 USBID ADC which connected to connector ID pin.
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_VBUSDIV5_input
>
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 VBUS ADC with high accuracy
> > + Reading returns voltage in uV
>
> Why would we ever read the low accuracy version?
>
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_VBUSDIV2_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 VBUS ADC with low accuracy
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_VSYS_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 VSYS ADC
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_VBAT_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 VBAT ADC
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_current_IBUS_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 IBUS ADC
> > + Reading returns current in uA
> Given voltage and current are already clear from the channel type,
> could we avoid the repetition?
>
> in_current_bus_input perhaps?
>

ACK

> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_current_IBAT_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 IBAT ADC
> > + Reading returns current in uA
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_CHG_VDDP_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 CHG_VDDP ADC
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_temp_TEMP_JC_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 IC junction temperature
> > + Reading returns temperature in degree
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_VREF_TS_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 VREF_TS ADC
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_TS_input
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 TS ADC
> > + Reading returns voltage in uV
> > +
> > +What: /sys/bus/iio/devices/iio:deviceX/timestamp
> > +KernelVersion: 5.8.0
> > +Contact: gene_chen@richtek.com
> > +Description:
> > + Indicated MT6360 timestamp
> > + Reading returns current timestamp in ms
>
> That's an odd bit of ABI. Why would we want to read the current timestamp from
> sysfs? Timestamps in IIO also tend to be in nano seconds.
>
>
>
>

ACK, I will remove this.