| Message ID | 20201218171231.58794-2-cristian.pop@analog.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v4,1/3] dt-bindings: iio: dac: AD5766 yaml documentation | expand |
On Fri, 18 Dec 2020 19:12:30 +0200 Cristian Pop <cristian.pop@analog.com> wrote: > New interface is proposed for dither functionality. This future allows > composing an external signals to the selected output channel. > The dither signal can be turned on/off, scaled, inverted, or it can be > selected from different sources. > > Signed-off-by: Cristian Pop <cristian.pop@analog.com> Coming together nicely though a few more thoughts came to mind when reading this. Only significant one is whether we are better with decimal scaling than percentage scaling for consistency with channel scales etc? Jonathan > --- > Changelog v4: > - Change to "in_voltageY_dither_enable" > - Change scale to numbers + 100% for no scaling > - Possible dither source values: 0 - N0, 1 - N1 > .../ABI/testing/sysfs-bus-iio-dac-ad5766 | 36 +++++++++++++++++++ > 1 file changed, 36 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > new file mode 100644 > index 000000000000..72100edb88bb > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > @@ -0,0 +1,36 @@ > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_pwr in_voltageY_dither_en would be more consistent with existing ABI naming. > +KernelVersion: > +Contact: linux-iio@vger.kernel.org > +Description: > + Dither enable. Write 1 to enable dither or 0 to disable it. > + > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_invert > +KernelVersion: > +Contact: linux-iio@vger.kernel.org > +Description: > + Inverts the dither applied to the selected DAC channel. Dither is not > + inverted by default. Write "1" to invert dither. > + > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale_available > +KernelVersion: > +Contact: linux-iio@vger.kernel.org > +Description: > + Returns possible scalings available for the current channel: Given this one is self defining and may well get generalized to other devices I'd got with a description that doesn't provide values. Returns possible scalings as percentages. However, thinking more on this it's a bit inconsistent with other scale values we have which are given in decimal. Would "1 0.75 0.5 0.25" work as well here? > + "100 75 50 25" scaling. > + > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale > +KernelVersion: > +Contact: linux-iio@vger.kernel.org > +Description: > + Scales the dither before it is applied to the selected channel: > + 100 - No scaling > + 75 - 75% scaling > + 50 - 50% scaling > + 25 - 25% scaling As above, I'm don't really see an advantage in providing the values. Any userspace ought to cope with any (finding out what is there via _available). "Scales the dither before it is applied to the selected channel. 1 corresponds to no scaling". > + > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_source > +KernelVersion: Please fill in the expected kernel version. I'll fix it if this happens to merge near the change over in a cycle, but it's easier to fix something that is there than to add it from scratch :) > +Contact: linux-iio@vger.kernel.org > +Description: > + Selects dither source applied to the selected channel. Write "0" to > + select N0 source, write "1" to select N1 source.
On Tue, 29 Dec 2020 16:27:58 +0000 Jonathan Cameron <jic23@kernel.org> wrote: > On Fri, 18 Dec 2020 19:12:30 +0200 > Cristian Pop <cristian.pop@analog.com> wrote: > > > New interface is proposed for dither functionality. This future allows > > composing an external signals to the selected output channel. > > The dither signal can be turned on/off, scaled, inverted, or it can be > > selected from different sources. > > > > Signed-off-by: Cristian Pop <cristian.pop@analog.com> > Coming together nicely though a few more thoughts came to mind when reading > this. Only significant one is whether we are better with decimal scaling > than percentage scaling for consistency with channel scales etc? > > Jonathan > > > --- > > Changelog v4: > > - Change to "in_voltageY_dither_enable" > > - Change scale to numbers + 100% for no scaling > > - Possible dither source values: 0 - N0, 1 - N1 > > .../ABI/testing/sysfs-bus-iio-dac-ad5766 | 36 +++++++++++++++++++ > > 1 file changed, 36 insertions(+) > > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > > new file mode 100644 > > index 000000000000..72100edb88bb > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 > > @@ -0,0 +1,36 @@ > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_pwr > > in_voltageY_dither_en would be more consistent with existing ABI naming. Seems to be different in the code (dither_enable I think) so please sanity check this file carefully against the driver. Thanks, Jonathan > > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Dither enable. Write 1 to enable dither or 0 to disable it. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_invert > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Inverts the dither applied to the selected DAC channel. Dither is not > > + inverted by default. Write "1" to invert dither. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale_available > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Returns possible scalings available for the current channel: > > Given this one is self defining and may well get generalized to other devices I'd > got with a description that doesn't provide values. > > Returns possible scalings as percentages. > > However, thinking more on this it's a bit inconsistent with other scale values we have > which are given in decimal. Would "1 0.75 0.5 0.25" work as well here? > > > + "100 75 50 25" scaling. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Scales the dither before it is applied to the selected channel: > > + 100 - No scaling > > + 75 - 75% scaling > > + 50 - 50% scaling > > + 25 - 25% scaling > > As above, I'm don't really see an advantage in providing the values. Any userspace > ought to cope with any (finding out what is there via _available). > "Scales the dither before it is applied to the selected channel. 1 corresponds > to no scaling". > > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_source > > +KernelVersion: > > Please fill in the expected kernel version. I'll fix it if this happens to merge near > the change over in a cycle, but it's easier to fix something that is there > than to add it from scratch :) > > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Selects dither source applied to the selected channel. Write "0" to > > + select N0 source, write "1" to select N1 source. >
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 new file mode 100644 index 000000000000..72100edb88bb --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766 @@ -0,0 +1,36 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_pwr +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Dither enable. Write 1 to enable dither or 0 to disable it. + +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_invert +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Inverts the dither applied to the selected DAC channel. Dither is not + inverted by default. Write "1" to invert dither. + +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale_available +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Returns possible scalings available for the current channel: + "100 75 50 25" scaling. + +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_scale +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Scales the dither before it is applied to the selected channel: + 100 - No scaling + 75 - 75% scaling + 50 - 50% scaling + 25 - 25% scaling + +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_dither_source +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Selects dither source applied to the selected channel. Write "0" to + select N0 source, write "1" to select N1 source.
New interface is proposed for dither functionality. This future allows composing an external signals to the selected output channel. The dither signal can be turned on/off, scaled, inverted, or it can be selected from different sources. Signed-off-by: Cristian Pop <cristian.pop@analog.com> --- Changelog v4: - Change to "in_voltageY_dither_enable" - Change scale to numbers + 100% for no scaling - Possible dither source values: 0 - N0, 1 - N1 .../ABI/testing/sysfs-bus-iio-dac-ad5766 | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac-ad5766