Re: [PATCH v3] fujitsu-laptop: Support touchpad toggle hotkey on Skylake-based models

From: Jonathan Woithe
Date: Tue Jun 28 2016 - 07:20:17 EST


On Tue, Jun 28, 2016 at 09:25:50AM +0200, Micha?? K??pie?? wrote:
> Haswell-based Fujitsu laptops (Lifebook E734/E744/E754) have a touchpad
> toggle hotkey (Fn+F4) which is handled transparently to the operating
> system: while an ACPI notification is sent to FUJ02B1 when Fn+F4 is
> pressed, touchpad state is properly toggled without any explicit support
> for this operation in fujitsu-laptop.
>
> Skylake-based models (Lifebook E736/E746/E756) also have that hotkey,
> but the touchpad is not toggled transparently to the operating system.
> When Fn+F4 is pressed, an ACPI notification is sent to FUJ02E3. A
> subsequent call to S000 (FUNC_RFKILL) can be used to determine whether
> the touchpad toggle hotkey was pressed so that an input event can be
> sent to userspace.
>
> Relevant ACPI code:
>
> Method (_L21, 0, NotSerialized)
> {
> ...
> If (AHKF)
> {
> Notify (\_SB.FEXT, 0x80)
> }
> ...
> }
>
> Method (S000, 3, Serialized)
> {
> Name (_T_0, Zero)
> Local0 = Zero
> While (One)
> {
> _T_0 = Arg0
> If (_T_0 == Zero)
> {
> Local0 |= 0x04000000
> Local0 |= 0x02000000
> Local0 |= 0x00020000
> Local0 |= 0x0200
> Local0 |= 0x0100
> Local0 |= 0x20
> }
> ElseIf (_T_0 == One)
> {
> ...
> If (AHKF & 0x08)
> {
> Local0 |= 0x04000000
> AHKF ^= 0x08
> }
> ...
> } ...
> Break
> }
> Return (Local0)
> }
>
> Pressing Fn+F4 raises GPE 0x21 and sets bit 3 in AHKF. This in turn
> results in bit 26 being set in the value returned by FUNC_RFKILL called
> with 1 as its first argument. On Skylake-based models, bit 26 is also
> set in the value returned by FUNC_RFKILL called with 0 as its first
> argument (this value is saved in fujitsu_hotkey->rfkill_supported upon
> module initialization), which suggests that this bit is set on models
> which do not handle touchpad toggling transparently to the operating
> system.
>
> Note that bit 3 is cleared in AHKF once FUNC_RFKILL is called with 1 as
> its first argument, which requires fujitsu-laptop to handle this hotkey
> in a different manner than the other, GIRB-based hotkeys: two input
> events (press and release) are immediately sent once Fn+F4 is pressed.
>
> Reported-and-tested-by: Jan-Marek Glogowski <glogow@xxxxxxxxxx>
> Signed-off-by: Micha?? K??pie?? <kernel@xxxxxxxxxx>

Thanks for the revision and your patience.

Acked-by: Jonathan Woithe <jwoithe@xxxxxxxxxx>

Regards
jonathan

> ---
>
> Changes from v2:
>
> - edited code comment so that it defines "some models" more precisely.
>
> Changes from v1:
>
> - added KEY_TOUCHPAD_TOGGLE to the FUJ02E3 input device's key bitmap,
>
> - added code comment.
>
> drivers/platform/x86/fujitsu-laptop.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
> index ce41bc3..36cd743 100644
> --- a/drivers/platform/x86/fujitsu-laptop.c
> +++ b/drivers/platform/x86/fujitsu-laptop.c
> @@ -856,6 +856,7 @@ static int acpi_fujitsu_hotkey_add(struct acpi_device *device)
> set_bit(fujitsu->keycode3, input->keybit);
> set_bit(fujitsu->keycode4, input->keybit);
> set_bit(fujitsu->keycode5, input->keybit);
> + set_bit(KEY_TOUCHPAD_TOGGLE, input->keybit);
> set_bit(KEY_UNKNOWN, input->keybit);
>
> error = input_register_device(input);
> @@ -1060,6 +1061,19 @@ static void acpi_fujitsu_hotkey_notify(struct acpi_device *device, u32 event)
> }
> }
>
> + /* On some models (first seen on the Skylake-based Lifebook
> + * E736/E746/E756), the touchpad toggle hotkey (Fn+F4) is
> + * handled in software; its state is queried using FUNC_RFKILL
> + */
> + if ((fujitsu_hotkey->rfkill_supported & BIT(26)) &&
> + (call_fext_func(FUNC_RFKILL, 0x1, 0x0, 0x0) & BIT(26))) {
> + keycode = KEY_TOUCHPAD_TOGGLE;
> + input_report_key(input, keycode, 1);
> + input_sync(input);
> + input_report_key(input, keycode, 0);
> + input_sync(input);
> + }
> +
> break;
> default:
> keycode = KEY_UNKNOWN;
> --
> 1.7.10.4

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