[PATCH v4 2/2] drm/tiny: add driver for Apple Touch Bars in x86 Macs

[Aditya Garg]

> On 25 Feb 2025, at 2:34 PM, Aditya Garg <gargaditya08 at live.com> wrote:
> 
> 
> 
>> On 25 Feb 2025, at 1:27 PM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>> 
>> Hi
>> 
>> Am 24.02.25 um 17:58 schrieb Aditya Garg:
>> [...]
>>>> 
>>>> +config DRM_APPLETBDRM
>>>> +    tristate "DRM support for Apple Touch Bars"
>>>> +    depends on DRM && USB && MMU
>>>> +    select DRM_GEM_SHMEM_HELPER
>>>> +    select DRM_KMS_HELPER
>>>> +    select HID_APPLETB_BL
>>> Btw I have a doubt regarding this dependency. While hid-appletb-bl has made into the linux-next tree, it has still not been merged into Linus' tree, and neither the drm tree I assume. It potentially could cause issues?
>> 
>> Yes. We cannot merge this driver until we have this symbol in our tree. But that will happen sooner or later.
>> 
>> More problematic is that your driver selects HID_APPLETB_BL. From what I've seen, this symbol is user configurable, so the driver shouldn't select it. You need to use 'depends on' instead of 'select' here.
> 
> Looking at this again, maybe it should be selected. If you see the kernel config of TINYDRM_HX8357D, which is also in drm/tiny, it is selecting BACKLIGHT_CLASS_DEVICE.

To make things more clear, 

1. hid-appletb-bl is for the backlight of the touchbar. The DRM code remains separate.
2. hid-multitouch is to make the touchbar a touch screen. You can still use the driver without the touch functionality.