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

[Dan Scally <dan.scally@ideasonboard.com>]

On 25/11/2022 10:58, Laurent Pinchart wrote:
> 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 ?


I think that's what led_sysfs_disable() is for, though I haven't gotten 
far enough down that route to know that for sure.

>>> 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(-)