Re: [PATCH] HID: asus: Add support for the ASUS T101HA keyboard dock

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Hi Aleix,

On Fri, Dec 14, 2018 at 9:07 AM Aleix Roca Nonell <kernelrocks@gmail.com> wrote:
>
> Kind remminder ping :)

Hehe, I have seen the patch floating by and realized I would need more
than 2 minutes to answer it so it fell a little bit behind in my TODO
list.

Let's try to work on this now.

>
> I'm also adding my fellow Matthias in CC
>
> On Sat, Dec 01, 2018 at 08:01:53PM +0100, Aleix Roca Nonell wrote:
> > The ASUS T101HA keyboard dock generates HID events using the ASUS vendor
> > specific UsagePage 0xff31. In consequence, some multimedia keys such as
> > brightness up and down are not working with hid-generic.
> >
> > This commit adds the T101HA dock into the supported device list of the
> > hid-asus driver. It also prevents the dock's integrated touchpad to be
> > bound with hid-asus given that it is already working fine with
> > hid-multitouch.
> >
> > Signed-off-by: Aleix Roca Nonell <kernelrocks@gmail.com>
> > ---
> >
> > This is my very first kernel patch done in my free time (be aware of the
> > newbie!!) so please, let me know if I can improve anything and I will
> > happily do it :)
> >
> >  drivers/hid/hid-asus.c | 12 ++++++++++++
> >  drivers/hid/hid-ids.h  |  1 +
> >  2 files changed, 13 insertions(+)
> >
> > diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> > index ab8bd40a77ed..d8b55dca97c6 100644
> > --- a/drivers/hid/hid-asus.c
> > +++ b/drivers/hid/hid-asus.c
> > @@ -42,6 +42,7 @@ MODULE_AUTHOR("Frederik Wenigwieser <frederik.wenigwieser@gmail.com>");
> >  MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
> >
> >  #define T100_TPAD_INTF 2
> > +#define T101HA_TPAD_INTF 2
> >
> >  #define T100CHI_MOUSE_REPORT_ID 0x06
> >  #define FEATURE_REPORT_ID 0x0d
> > @@ -70,6 +71,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
> >  #define QUIRK_T100_KEYBOARD          BIT(6)
> >  #define QUIRK_T100CHI                        BIT(7)
> >  #define QUIRK_G752_KEYBOARD          BIT(8)
> > +#define QUIRK_T101HA_DOCK            BIT(9)
> >
> >  #define I2C_KEYBOARD_QUIRKS                  (QUIRK_FIX_NOTEBOOK_REPORT | \
> >                                                QUIRK_NO_INIT_REPORTS | \
> > @@ -649,6 +651,14 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
> >       int ret;
> >       struct asus_drvdata *drvdata;
> >
> > +     if (id->driver_data & QUIRK_T101HA_DOCK) {
> > +             struct usb_interface *intf = to_usb_interface(hdev->dev.parent);

I know the hid-asus driver already does this for the other devices,
but it would be nice not to. USB is part of the low level transport
and HID drivers should have no reasons to assume the USB driver is
used and that it will stay forever.

What I ask when we have such a case is to check on the report
descriptor to see if there is anything we could use in it (usually the
application) to skip this HID interface.

Besides that, there is not much more to say.

For having a look at the report descriptor, you can either use printk
in the kernel, or use hid-recorder as root in
https://gitlab.freedesktop.org/libevdev/hid-tools.

Cheers,
Benjamin

> > +
> > +             /* use hid-multitouch for T101HA touchpad */
> > +             if (intf->altsetting->desc.bInterfaceNumber == T101HA_TPAD_INTF)
> > +                     return -ENODEV;
> > +     }
> > +
> >       drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
> >       if (drvdata == NULL) {
> >               hid_err(hdev, "Can't alloc Asus descriptor\n");
> > @@ -830,6 +840,8 @@ static const struct hid_device_id asus_devices[] = {
> >       { HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
> >               USB_DEVICE_ID_ASUSTEK_T100TAF_KEYBOARD),
> >         QUIRK_T100_KEYBOARD | QUIRK_NO_CONSUMER_USAGES },
> > +     { HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
> > +             USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD), QUIRK_T101HA_DOCK },
> >       { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_ASUS_AK1D) },
> >       { HID_USB_DEVICE(USB_VENDOR_ID_TURBOX, USB_DEVICE_ID_ASUS_MD_5110) },
> >       { HID_USB_DEVICE(USB_VENDOR_ID_JESS, USB_DEVICE_ID_ASUS_MD_5112) },
> > diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> > index 4206428c0ba2..f1eee2778b70 100644
> > --- a/drivers/hid/hid-ids.h
> > +++ b/drivers/hid/hid-ids.h
> > @@ -184,6 +184,7 @@
> >  #define USB_DEVICE_ID_ASUSTEK_T100TA_KEYBOARD        0x17e0
> >  #define USB_DEVICE_ID_ASUSTEK_T100TAF_KEYBOARD       0x1807
> >  #define USB_DEVICE_ID_ASUSTEK_T100CHI_KEYBOARD       0x8502
> > +#define USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD        0x183d
> >  #define USB_DEVICE_ID_ASUSTEK_T304_KEYBOARD  0x184a
> >  #define USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD   0x8585
> >  #define USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD   0x0101
> > --
> > 2.19.2
> >