Re: ideapad_laptop tablet mode toggle detection

[Armin Wolf <W_Armin@gmx.de>]

Am 06.03.23 um 02:26 schrieb Armin Wolf:

> Am 05.03.23 um 23:59 schrieb Andrew Kallmeyer:
>
>> On Sun, Mar 5, 2023 at 1:40 PM Armin Wolf <W_Armin@gmx.de> wrote:
>>> Hi,
>>>
>>> could it be that bit 5 is set to disable the touchpad when the
>>> device switches
>>> to tablet mode? I suspect that the query handler does the following:
>>> 1. Notify VPC0 to disable the touchpad.
>>> 2. Notify ACPI WMI, which does submit the necessary scancode for
>>> switching to tablet mode.
>> I think you're right about this notification being for the touchpad,
>> although at least on my machine
>> there is no other touchpad switch. So this is identical for my machine
>> specifically. In this function
>> from the decompiled ACPI dump you can see VCP0 and WM00 notified:
>>
>> Method (_Q44, 0, NotSerialized)  // _Qxx: EC Query, xx=0x00-0xFF
>> {
>>     P80B = 0x44
>>     Notify (VPC0, 0x80) // Status Change
>>     WEID = 0xF4
>>     Notify (WM00, 0x80) // Status Change
>> }
>>
>> This WM00 device sounds like the WMI you're talking about, however I'm
>> getting those errors
>> about this device not existing in journalctl still. I was asking
>> before about how to create this
>> missing device but it's not clear to me if that is possible.
>>
>> kernel: ACPI BIOS Error (bug): Could not resolve symbol
>> [\_SB.PC00.LPCB.EC0._Q44.WM00], AE_NOT_FOUND
>>
>> I searched in my .dsl files from the acpidump and wasn't able to find
>> any of the 3 ideapad_wmi_ids
>> listed in the driver. Maybe you have an idea of how to interface with
>> this missing WM00 object though.
>
> I was combing through the ACPI DSDT table inside the acpidump you
> provided,
> and i found serveral PNP0C14 devices, which hold WMI methods, events
> and data.
>
> The WMI GUIDs are encoded inside the associated _WDG buffers, you
> should therefore
> only grep for parts of the GUIDs.
> For example: GUID 06129D99-6083-4164-81AD-F092F9D773A6 -> grep "0xF0,
> 0x92"
>
> When feeding the content of the buffers named WQxx to the bmfdec
> utility, i was able
> to extract a description of each WMI object.
>
> On of which (WMIY) is handling the "Lenovo Yoga Mode", which seems to
> handle the tablet
> mode transitions. The MOF data is:
>
> [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"),
> Description("Lenovo Yoga Mode Change Event"),
> guid("{06129D99-6083-4164-81AD-F092F9D773A6}")]
> class LENOVO_GSENSOR_EVENT : WMIEvent {
>   [key, read] string InstanceName;
>   [read] boolean Active;
>   [WmiDataId(1), read, Description("Lenovo Yoga Mode Change Event")]
> uint32 ModeDataVal;
> };
>
> [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"),
> Description("LENOVO_GSENSOR_DATA class"),
> guid("{09B0EE6E-C3FD-4243-8DA1-7911FF80BB8C}")]
> class LENOVO_GSENSOR_DATA {
>   [key, read] string InstanceName;
>   [read] boolean Active;
>
>   [WmiMethodId(1), Implemented, Description("Mode Data")] void
> GetUsageMode([out, Description("Mode Data")] uint32 Data);
>   [WmiMethodId(2), Implemented, Description("Get Xaxis Value")] void
> GetXaxisValue([out, Description("Get Xaxis Value")] uint32 Data);
>   [WmiMethodId(3), Implemented, Description("Get Yaxis Value")] void
> GetYaxisValue([out, Description("Get Yaxis Value")] uint32 Data);
>   [WmiMethodId(4), Implemented, Description("Get Zaxis Value")] void
> GetZaxisValue([out, Description("Get Zaxis Value")] uint32 Data);
>   [WmiMethodId(5), Implemented, Description("Base to Ground")] void
> GetAngle4Value([out, Description("Base to Ground")] uint32 Data);
>   [WmiMethodId(6), Implemented, Description("Screen to Ground")] void
> GetAngle5Value([out, Description("Screen to Ground")] uint32 Data);
>   [WmiMethodId(7), Implemented, Description("Screen to Base")] void
> GetAngle6Value([out, Description("Screen to Base")] uint32 Data);
> };
>
> While looking at _WED (used to get ModeDataVal) and WMAB (handles
> method calls on LENOVO_GSENSOR_DATA),
> i assume that  only the first method (GetUsageMode) is implemented,
> and that ModeDataVal is used to tell
> which value of LENOVO_GSENSOR_DATA has changed (hardwired to 1 on your
> device).
>
> Maybe you can write a wmi driver which handles both WMI objects, so
> that you can find out what the values
> returned by GetUsageMode mean. With a bit of luck, you can use this to
> implement tablet mode toggle detection.
>
> BTW, what is the name of your notebook model?
>
> Armin Wolf
>
Well, it turns out i totally forgot that there exists already a patch which adds support for this:
https://patchwork.kernel.org/project/platform-driver-x86/patch/20221004214332.35934-1-soyer@irl.hu/

Maybe you can get this patch into shape and submit it again?

Armin Wolf

>>> Could you provide the output of "acpidump"? Because i suspect that
>>> the virtual key handling
>>> is done using ACPI WMI, as many modern devices are using this
>>> approach. In this case, you
>>> could experiment with ideapad_wmi_notify(), and maybe take a look at
>>> ideapad_wmi_ids[].
>>>
>>> Armin Wolf
>> Here is the raw acpidump output:
>> https://la.ask.systems/temp/acpidump.out
>>
>> - Andrew