Re: [PATCH 4/5] HID: apple-ibridge: Add Apple iBridge HID driver for T1 chip.

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: "Ronald Tschalär" <ronald@innovation.ch>
Cc: Jiri Kosina <jikos@kernel.org>,
	Benjamin Tissoires <benjamin.tissoires@redhat.com>,
	Jonathan Cameron <jic23@kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-input <linux-input@vger.kernel.org>,
	linux-iio <linux-iio@vger.kernel.org>
Subject: Re: [PATCH 4/5] HID: apple-ibridge: Add Apple iBridge HID driver for T1 chip.
Date: Mon, 1 Mar 2021 16:12:30 +0200	[thread overview]
Message-ID: <CAHp75Vd13nobdyiUbYoTbeoqG4rGP-Vfswcuuy3oYjXgTXzNSw@mail.gmail.com> (raw)
In-Reply-To: <20210228012643.69944-5-ronald@innovation.ch>

On Sun, Feb 28, 2021 at 3:30 AM Ronald Tschalär <ronald@innovation.ch> wrote:
>
> The iBridge device provides access to several devices, including:
> - the Touch Bar
> - the iSight webcam
> - the light sensor
> - the fingerprint sensor
>
> This driver provides the core support for managing the iBridge device
> and the access to the underlying devices. In particular, the
> functionality for the touch bar and light sensor is exposed via USB HID
> interfaces, and on devices with the T1 chip one of the HID devices is
> used for both functions. So this driver creates virtual HID devices, one
> per top-level report collection on each HID device (for a total of 3
> virtual HID devices). The sub-drivers then bind to these virtual HID
> devices.
>
> This way the Touch Bar and ALS drivers can be kept in their own modules,
> while at the same time making them look very much like as if they were
> connected to the real HID devices. And those drivers then work (mostly)
> without further changes on MacBooks with the T2 chip that don't need
> this driver.

Thanks for the contribution.
Before I'll do a full review, two concerns:
 - don't do ACPI drivers, please, in the new code. Use platform driver
infrastructure for that
 - dependencies (see below)

...

> +config HID_APPLE_IBRIDGE
> +       tristate "Apple iBridge"

> +       depends on ACPI
> +       depends on USB_HID

> +       depends on X86 || COMPILE_TEST

I haven't found anything ACPI specific there, so this should be rather

depends on (X86 && ACPI) || COMPILE_TEST

> +       imply HID_SENSOR_HUB
> +       imply HID_SENSOR_ALS
> +       help
> +         This module provides the core support for the Apple T1 chip found
> +         on 2016 and 2017 MacBookPro's, also known as the iBridge. The drivers
> +         for the Touch Bar (apple-touchbar) and light sensor (hid-sensor-hub
> +         and hid-sensor-als) need to be enabled separately.
> +
> +         To compile this driver as a module, choose M here: the
> +         module will be called apple-ibridge.

-- 
With Best Regards,
Andy Shevchenko