Re: [PATCH 0/3] platform/x86: int3472/discrete: Make it work with IPU6

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Fri, Nov 25, 2022 at 10:17:17AM +0000, Dan Scally wrote:
> Morning Hans - thanks for the set
> 
> On 24/11/2022 20:00, Hans de Goede wrote:
> > Hi All,
> >
> > Here is a small set of patches to make the int3472/discrete code
> > work with the sensor drivers bundled with the (unfortunately out of tree)
> > IPU6 driver.
> >
> > There are parts of the out of tree IPU6 code, like the sensor drivers,
> > which can be moved to the mainline and I do plan to work on this at some
> > point and then some of this might need to change. But for now the goal is
> > to make the out of tree driver work with standard mainline distro kernels
> > through e.g. dkms. Otherwise users need to run a patched kernel just for
> > a couple of small differences.
> >
> > This is basically a rewrite of this patch:
> > https://github.com/intel/ipu6-drivers/blob/master/patch/int3472-support-independent-clock-and-LED-gpios-5.17%2B.patch
> >
> > Wich users who want to use the IPU6 driver so far have had to manually
> > apply to their kernels which is quite inconvenient.
> >
> > This rewrite makes 2 significant changes:
> >
> > 1. Don't break things on IPU3 platforms
> >
> > 2. Instead of extending the int3472_sensor_configs[] quirks table for each
> > model which needs "clken" and "pled" GPIOs, do this based on matching
> > the ACPI HID of the ACPI device describing the sensor.
> >
> > The need for these GPIOs is a property of the specific sensor driver which
> > binds using this same HID, so by using this we avoid having to extend the
> > int3472_sensor_configs[] quirks table all the time.
> >
> > This allows roling back the behavior to at least use a clk-framework
> > clk instead of clken GPIO on a per sensor(-driver) basis as we mainline
> > the sensor drivers, assuming that the drivers are switched over to the
> > clk framework as part of their mainlining.
> >
> > A bigger question is what to do with the privacy-led GPIO on IPU3
> > we so far have turned the LED on/off at the same as te clock,
> > but at least on some IPU6 models this won't work, because they only
> > have a privacy-led GPIO and no clk_en GPIO (there is no sensor
> > clk-control at all on some models).
> 
> Ah how annoying, we hadn't come across any situations for IPU3 with a 
> privacy LED but no clock GPIO
> 
> > I think we should maybe move all models, including IPU3 based
> > models over to using a normal GPIO for controlling the privacy-led
> > to make things consistent.
> 
> I think they probably should be represented as LED devices then, and 
> have the media subsytem call some framework to find associated LEDs and 
> cycle them at power on time in the sensor drivers. I know there's the 
> v4l2_flash structure at the moment, but not sure if a privacy one exists.

The whole point of a privacy LED is to be controlled automatically (and
ideally without software intervention, but that's a different story).
Can the LED framework be used without having the LED exposed to
userspace ?

> > And likewise (eventually) completely drop the "clken" GPIO this
> > patch series introduces (with some sensors) and instead always model
> > this through the clk-framework.
> >
> > Regards,
> >
> > Hans
> >
> >
> > Hans de Goede (3):
> >    platform/x86: int3472/discrete: Refactor GPIO to sensor mapping
> >    platform/x86: int3472/discrete: Get the polarity from the _DSM entry
> >    platform/x86: int3472/discrete: Add support for sensor-drivers which
> >      expect clken + pled GPIOs
> >
> >   drivers/platform/x86/intel/int3472/common.h   |  2 +-
> >   drivers/platform/x86/intel/int3472/discrete.c | 92 ++++++++++++++++---
> >   2 files changed, 78 insertions(+), 16 deletions(-)

-- 
Regards,

Laurent Pinchart