linux-kernel - Re: Cherryview wake up events

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Date:   Mon, 19 Sep 2016 22:36:22 +0200
From:   Johannes Stezenbach <js@...21.net>
To:     Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:     linux-acpi@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: Cherryview wake up events

On Mon, Sep 19, 2016 at 02:56:19PM +0300, Mika Westerberg wrote:
> On Mon, Sep 19, 2016 at 01:21:17PM +0200, Johannes Stezenbach wrote:
> > 
> > The LID causes a gpio irq:
> >  158:          2          0          0          0  chv-gpio   43 ACPI:Event
> > 
> > However, neither LID nor power button can wake up the
> > device from "echo freeze >/sys/power/state".  :-(
> 
> The cherryview pinctrl driver does not (yet) support wake up events. It
> currently just sets IRQCHIP_SKIP_SET_WAKE for the irqchip.

OK, but shouldn't the wakeup usually be handled by ACPI?
Clearly I don't understand this.  I mean on the non-ACPI
embedded ARM systems I'm used to I need to enable specific
irqs as wakeup sources, but on ACPI, isn't SCI the implicit
wakeup irq?  Probably I'm just totally confused, so let
me ask another way, below.

> I can make you a test patch which adds support for wakes for the pinctrl
> driver if you like to test it out. However, that will happen most likely
> near end of the week as I have other things right now.

That would be great!


I found in the DSDT:

    Scope (_SB.GPO0)
    {
        Name (EVBF, Buffer (0x03) {})
        CreateByteField (EVBF, Zero, EVST)
        CreateByteField (EVBF, One, ELEN)
        CreateByteField (EVBF, 0x02, ENVT)
        Name (LIDZ, One)
        Method (_E4E, 0, Serialized)  // _Exx: Edge-Triggered GPE
        {
            Name (_T_0, Zero)  // _T_x: Emitted by ASL Compiler
            If (^^PCI0.I2C1.AVBL != One)
            {
                Return (Zero)
            }

            EVBF = ^^PCI0.I2C1.ENID /* \_SB_.PCI0.I2C1.ENID */
...
            _T_0 = ENVT /* \_SB_.GPO0.ENVT */
...
                ElseIf (_T_0 == 0xA9)
                {
                    Notify (PWRB, 0x80) // Status Change
                    Break
                }

and
        Device (GPO0)
        {
...
            Method (_AEI, 0, NotSerialized)  // _AEI: ACPI Event Interrupts
            {
                Name (WBUF, ResourceTemplate ()
                {
                    GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullUp, 0x0000,
                        "\\_SB.GPO0", 0x00, ResourceConsumer, ,
                        )
                        {   // Pin list
                            0x004E
                        }
                })
                If (OSID == One)
                {
                    Return (WBUF) /* \_SB_.GPO0._AEI.WBUF */
                }
            }

and OSID is a field in 
    OperationRegion (GNVS, SystemMemory, 0x7A158000, 0x0362)
which is inside what /proc/iomem lists as "ACPI no-volatile storage".
OSID is read a lot in the DSDT but never written to.
But calling \_SB.GPO0._AEI in acpidbg returns a buffer of size 25.

Now my question is, is this pin 0x004E the same as this
in /proc/interrupts which fires on LID event?

 158:          2          0          0          0  chv-gpio   43 ACPI:Event



The FADT has
            Control Method Power Button (V1) : 0
            Control Method Sleep Button (V1) : 1

PWRBTN_EN in PM1 is set.  But PWRBTN press causes thermal irq.

No SCI (irq 9) is ever generated, except by writing to the
BIOS_RLS bit in SMI_EN register (IO port 0x430).

GPE block addresses in FADT are 0.  GPE0a_EN register (IO 0x428)
is set to 0x6000 (TCO_EN + PME_B0_EN, but none of the GPIO enables).

Any advice how to continue?


Thanks,
Johannes