Re: [PATCH v6 2/2] iio: proximity: vl53l0x: add interrupt support

From: Rob Herring <robh@kernel.org>
To: Song Qiang <songqiang1304521@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald <pmeerw@pmeerw.net>,
	Mark Rutland <mark.rutland@arm.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Matt Ranostay <matt.ranostay@konsulko.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andreas Klinger <ak@it-klinger.de>,
	linux-iio@vger.kernel.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v6 2/2] iio: proximity: vl53l0x: add interrupt support
Date: Fri, 28 Sep 2018 18:52:13 -0500	[thread overview]
Message-ID: <CAL_JsqLpNiGdK9hWTGWZwgbgRr8DNF=XvKGUx=oS2jTJ61yhFg@mail.gmail.com> (raw)
In-Reply-To: <20180928093618.GA24536@Eros>

On Fri, Sep 28, 2018 at 4:36 AM Song Qiang <songqiang1304521@gmail.com> wrote:
>
> On Wed, Sep 26, 2018 at 05:46:18PM -0500, Rob Herring wrote:
> > On Sat, Sep 22, 2018 at 04:05:23PM +0100, Jonathan Cameron wrote:
> > > On Tue, 18 Sep 2018 16:24:22 +0800
> > > Song Qiang <songqiang1304521@gmail.com> wrote:
> > >
> > > > The first version of this driver issues a measuring request and polling
> > > > for a status register in the device for measuring completes.
> > > > vl53l0x support configuring GPIO1 on it to generate interrupt to
> > > > indicate that new measurement is ready. This patch adds support for
> > > > using this mechanisim to reduce cpu cost.
> > > >
> > > > Signed-off-by: Song Qiang <songqiang1304521@gmail.com>
> > > Hi Song.
> > >
> > > Looks correct in principal but a few things to tidy up before
> > > this is ready to apply.
> > >
> > > Also we have an unrelated change in here to check the devices ID.
> > > That should be in it's own patch.
> > >
> > > Thanks,
> > >
> > > Jonathan
> > > > ---
> > > >  .../bindings/iio/proximity/vl53l0x.txt        |  14 +-
> >
> > This should have been split with the complete binding in one patch
> > rather than piecemeal driver feature by feature.
> >
>
> Hi Rob,
>
> A few days ago when I was submitting this driver, I didn't do it very
> well, the function of this driver is limited. I added interrupt support
> the next day after you acked my first patch. I thought it's not polite
> to add something after someone acked that patch, so I send the interrupt
> support as a second patch. The first patch is merged to togreg now, but
> this doesn't. I don't know when can I add new functions to the code that
> just merged to togreg branch, could you offer some suggestions?

You just needed to state why you didn't add a ack. But really, just
don't send things except as RFC until they are "done".

What to do next depends on Jonathan and whether he wants a follow-up
patch or he will drop the first one.

> > > >  drivers/iio/proximity/vl53l0x-i2c.c           | 135 +++++++++++++++---
> > > >  2 files changed, 129 insertions(+), 20 deletions(-)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt
> > > > index ab9a9539fec4..40290f8dd70f 100644
> > > > --- a/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt
> > > > +++ b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt
> > > > @@ -4,9 +4,21 @@ Required properties:
> > > >   - compatible: must be "st,vl53l0x-i2c"
> >
> > Is there more than one interface on this device, such as SPI? If not,
> > then '-i2c' should be dropped.
> >
>
> Yes, there is a CCI(Camera Control Interface) for communication.

Isn't CCI just a subset of I2C? I should clarify my question is
whether there's more than 1 mutually exclusive control interface (as
many devices have control and data interfaces) where you could have 2
different drivers. A common example are devices with I2C and SPI
interfaces.

Rob