Re: [PATCH 1/1] Force ELAN06FA touchpad I2C bus freq to 100KHz

[R Ha <rha051117@xxxxxxxxx>]

Hello,

Thanks for reading my patch!

On Fri, Jan 3, 2025 at 3:33 AM Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> What are those "some devices" and "some controllers"?

The "Some Devices" are the Lenovo V15 G4 IRU, which I use, and
potentially the Lenovo V15 G4 AMN and Lenovo Ideapad Slim 3 15IAH8 as
well (based on issue reports from other users [1]).
The "Some Controllers" are the Designware I2C controller.

Sorry for not putting this in the commit message; I had tried to
follow the comments for the quirk I copied in Commit 7574c0db2e68c
("i2c: acpi: Force bus speed to 400KHz if a Silead touchscreen is
present"), which left them out.

On Fri, Jan 3, 2025 at 3:33 AM Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> Can you add the ACPI table snippet here too for reference?

I believe this is the correct snippet in my ACPI table (Again, V15 G4
IRU). Tried to edit it down as much as I could, hopefully this tells
everything. Please let me know how I should attach a longer snippet or
the full ACPI table if needed.
Scope (_SB.PC00.I2C1)
{
    [...]
    Device (TPD0)
    {
        [...]
        CreateWordField (SBFB, \_SB.PC00.I2C1.TPD0._Y53._ADR, BADR)
// _ADR: Address
        CreateDWordField (SBFB, \_SB.PC00.I2C1.TPD0._Y53._SPE, SPED)
// _SPE: Speed
        CreateWordField (SBFG, 0x17, INT1)
        CreateDWordField (SBFI, \_SB.PC00.I2C1.TPD0._Y54._INT, INT2)
// _INT: Interrupts
        Method (_INI, 0, NotSerialized)  // _INI: Initialize
        {
            If ((OSYS < 0x07DC))
            {
                SRXO (0x09080011, One)
            }

            INT1 = GNUM (0x09080011)
            INT2 = INUM (0x09080011)
            If ((TPTY == One))
            {
                _HID = "ELAN06FA"
                _SUB = "ELAN0001"
                BADR = 0x15
                HID2 = One
                Return (Zero)
            }
            [...]
        }

        Name (_HID, "XXXX0000")  // _HID: Hardware ID
        Name (_CID, "PNP0C50" /* HID Protocol Device (I2C bus) */)  //
_CID: Compatible ID
        Name (_SUB, "XXXX0000")  // _SUB: Subsystem ID
        Name (_S0W, 0x03)  // _S0W: S0 Device Wake State
        Method (_DSM, 4, Serialized)  // _DSM: Device-Specific Method
        {
            If ((Arg0 == HIDG))
            {
                Return (HIDD (Arg0, Arg1, Arg2, Arg3, HID2))
            }

            If ((Arg0 == TP7G))
            {
                Return (TP7D (Arg0, Arg1, Arg2, Arg3, SBFB, SBFG))
            }

            Return (Buffer (One)
            {
                 0x00                                             // .
            })
        }
        [...]
        Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
        {
            If ((OSYS < 0x07DC))
            {
                Return (SBFI) /* \_SB_.PC00.I2C1.TPD0.SBFI */
            }

            If ((TPDM == Zero))
            {
                Return (ConcatenateResTemplate (I2CM (I2CX, BADR, SPED), SBFG))
            }

            Return (ConcatenateResTemplate (I2CM (I2CX, BADR, SPED), SBFI))
        }
        [...]
    }
}

For comparison, the properties for a device that I think did set a
proper speed was like this:
If ((TPNP == 0xD64D))
{
    _HID = "GTCH7503"
    HID2 = One
    BADR = 0x10
    SPED = 0x000F4240
    Return (Zero)
}

[1]: https://bbs.archlinux.org/viewtopic.php?id=297092