Hi Hans,
On Thu, Apr 18, 2024, at 7:34 AM, Hans de Goede wrote:
> Hi Mark,
>
> On 4/18/24 1:57 AM, Mark Pearson wrote:
>> Hi Hans,
>>
>> On Wed, Apr 17, 2024, at 4:06 PM, Hans de Goede wrote:
>>> Hi Mark,
>>>
>>> On 4/17/24 9:39 PM, Hans de Goede wrote:
>>>> Hi Mark,
>>>>
>>>> Thank you for the new version of this series, overall this looks good,
>>>> one small remark below.
>>>>
>>>> On 4/17/24 7:31 PM, Mark Pearson wrote:
>>>>> Lenovo trackpoints are adding the ability to generate a doubletap event.
>>>>> This handles the doubletap event and sends the KEY_PROG1 event to
>>>>> userspace.
>>>>>
>>>>> Signed-off-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
>>>>> Signed-off-by: Vishnu Sankar <vishnuocv@xxxxxxxxx>
>>>>> ---
>>>>> Changes in v2:
>>>>> - Use KEY_PROG1 instead of KEY_DOUBLETAP as input maintainer doesn't
>>>>> want new un-specific key codes added.
>>>>> - Add doubletap to hotkey scan code table and use existing hotkey
>>>>> functionality.
>>>>> - Tested using evtest, and then gnome settings to configure a custom shortcut
>>>>> to launch an application.
>>>>>
>>>>> drivers/platform/x86/thinkpad_acpi.c | 18 ++++++++++++++++++
>>>>> 1 file changed, 18 insertions(+)
>>>>>
>>>>> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
>>>>> index 3b48d893280f..6d04d45e8d45 100644
>>>>> --- a/drivers/platform/x86/thinkpad_acpi.c
>>>>> +++ b/drivers/platform/x86/thinkpad_acpi.c
>>>>> @@ -232,6 +232,9 @@ enum tpacpi_hkey_event_t {
>>>>>
>>>>> /* Misc */
>>>>> TP_HKEY_EV_RFKILL_CHANGED = 0x7000, /* rfkill switch changed */
>>>>> +
>>>>> + /* Misc2 */
>>>>> + TP_HKEY_EV_TRACK_DOUBLETAP = 0x8036, /* trackpoint doubletap */
>>>>> };
>>>>>
>>>>> /****************************************************************************
>>>>> @@ -1786,6 +1789,7 @@ enum { /* hot key scan codes (derived from ACPI DSDT) */
>>>>> TP_ACPI_HOTKEYSCAN_NOTIFICATION_CENTER,
>>>>> TP_ACPI_HOTKEYSCAN_PICKUP_PHONE,
>>>>> TP_ACPI_HOTKEYSCAN_HANGUP_PHONE,
>>>>
>>>> I understand why you've done this but I think this needs a comment,
>>>> something like:
>>>>
>>>> /*
>>>> * For TP_HKEY_EV_TRACK_DOUBLETAP, unlike the codes above which map to:
>>>> * (hkey_event - 0x1300) + TP_ACPI_HOTKEYSCAN_EXTENDED_START, this is
>>>> * hardcoded for TP_HKEY_EV_TRACK_DOUBLETAP handling. Therefor this must
>>>> * always be the last entry (after any 0x1300-0x13ff entries).
>>>> */
>>>> + TP_ACPI_HOTKEYSCAN_DOUBLETAP,
>>>
>>> Ugh, actually this will not work becuuse we want hotkeyscancodes to be stable
>>> because these are userspace API since they can be remapped using hwdb so we
>>> cannot have the hotkeyscancode changing when new 0x1300-0x13ff range entries
>>> get added.
>>>
>>> So we need to either grow the table a lot and reserve a whole bunch of space
>>> for future 0x13xx - 0x13ff codes or maybe something like this:
>>>
>>> diff --git a/drivers/platform/x86/thinkpad_acpi.c
>>> b/drivers/platform/x86/thinkpad_acpi.c
>>> index 771aaa7ae4cf..af3279889ecc 100644
>>> --- a/drivers/platform/x86/thinkpad_acpi.c
>>> +++ b/drivers/platform/x86/thinkpad_acpi.c
>>> @@ -1742,7 +1742,12 @@ enum { /* hot key scan codes (derived from ACPI
>>> DSDT) */
>>> TP_ACPI_HOTKEYSCAN_VOLUMEDOWN,
>>> TP_ACPI_HOTKEYSCAN_MUTE,
>>> TP_ACPI_HOTKEYSCAN_THINKPAD,
>>> - TP_ACPI_HOTKEYSCAN_UNK1,
>>> + /*
>>> + * Note this gets send both on 0x1019 and on
>>> TP_HKEY_EV_TRACK_DOUBLETAP
>>> + * hotkey-events. 0x1019 events have never been seen on any actual hw
>>> + * and a scancode is needed for the special 0x8036 doubletap
>>> hotkey-event.
>>> + */
>>> + TP_ACPI_HOTKEYSCAN_DOUBLETAP,
>>> TP_ACPI_HOTKEYSCAN_UNK2,
>>> TP_ACPI_HOTKEYSCAN_UNK3,
>>> TP_ACPI_HOTKEYSCAN_UNK4,
>>>
>>> or just hardcode KEY_PROG1 like your previous patch does, but I'm not
>>> a fan of that because of loosing hwdb remapping functionality for this
>>> "key" then.
>>>
>>> Note I'm open to other suggestions.
>>>
>> Oh...I hadn't thought of that impact. That's not great :(
>>
>> I have an idea, but want to prototype it to see if it works out or not. Will update once I've had a chance to play with it.
>
> Thinking more about this I just realized that the input subsystem
> already has a mechanism for dealing with scancode ranges with
> (big) holes in them in the form of linux/input/sparse-keymap.h .
>
> I think that what needs to be done is convert the existing code
> to use sparse-keymap, keeping the mapping of the "MHKP"
> returned hkey codes to internal TP_ACPI_HOTKEYSCAN_* values
> for currently supported "MHKP" hkey codes for compatibility
> and then for new codes just directly map them in the sparse map
> aka the struct key_entry table. After converting the existing code
> to use sparse-keymap, then for the new events we would simply add:
>
>
> { KE_KEY, 0x131d, { KEY_VENDOR} }, /* Fn + N, system debug info */
> { KE_KEY, 0x8036, { KEY_PROG1 } }, /* Trackpoint doubletap */
>
> entries to the table without needing to define intermediate
> TP_ACPI_HOTKEYSCAN_* values for these.
>
Ah! I didn't know about sparse-keymap but it looks similar to what I was thinking and played with a bit last night. Agreed using existing infrastructure is better.
Only things I'd flag is that:
- It did look like it would be useful to identify keys that the driver handles (there aren't many but a few). Maybe one of the other key types can help handle that?
- There are also some keys that use the tpacpi_input_send_key_masked that might need some special consideration.
> I already have somewhat of a design for this in my head and I really
> believe this is the way forward as it uses existing kernel infra
> and it will avoid hitting this problem again when some other new
> "MHKP" hkey codes show up.
>
> I plan to start working on implementing conversion of the existing
> code to use sparse-keymap, which should result in a nice cleanup
> after lunch and I hope to have something for you to test no later
> then next Tuesday.
>
That would be amazing - do let me know if there is anything I can help with. Agreed this will help clean up a bunch of the keycode handling :)
Mark
