Hi,
On 02-02-17 13:32, Mika Westerberg wrote:
On Thu, Feb 02, 2017 at 02:10:18PM +0200, Mika Westerberg wrote:
I do not have a copy of the patch in this thread but sounds like
something that might work.
Actually, I seem have a copy of that patch.
So you are saying that the device has a power GPIO in ACPI _CRS but it
should not be used for some reason?
Yes, it should not be used as it is controlled by the _PS0 and _PS3
functions. It is reserved for firmware use by setting a special
bit indicating this in the gpio pin's control register in the intel
cherrytrail gpio controller. So arguably it should not be in _CRS
at all, since the OS is supposed to not touch it, yet it is there:
Device (TCS4)
{
Name (_ADR, Zero) // _ADR: Address
Name (_HID, "MSSL1680") // _HID: Hardware ID
Name (_CID, "PNP1680") // _CID: Compatible ID
Name (_S0W, Zero) // _S0W: S0 Device Wake State
Name (_DDN, "MSSL1680") // _DDN: DOS Device Name
<snip>
Method (_PS3, 0, Serialized) // _PS3: Power State 3
{
If (^^^^GPO1.AVBL == One)
{
^^^^GPO1.TCTL = One
}
Sleep (0x78)
}
Method (_PS0, 0, Serialized) // _PS0: Power State 0
{
If (^^^^GPO1.AVBL == One)
{
^^^^GPO1.TCTL = One
}
Sleep (0x05)
If (^^^^GPO1.AVBL == One)
{
^^^^GPO1.TCTL = Zero
}
Sleep (0x1E)
If (^^^^GPO1.AVBL == One)
{
^^^^GPO1.TCTL = Zero
}
Sleep (0x78)
}
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Setti
{
Name (WBUF, ResourceTemplate ()
{
I2cSerialBusV2 (0x0040, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.PCI0.I2C6",
0x00, ResourceConsumer, , Exclusive,
)
GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestri
"\\_SB.GPO1", 0x00, ResourceConsumer, ,
)
{ // Pin list
0x0019
}
GpioInt (Edge, ActiveHigh, Shared, PullDefault, 0x0000,
"\\_SB.GPO1", 0x00, ResourceConsumer, ,
)
{ // Pin list
0x0013
}
})
Return (WBUF) /* \_SB_.PCI0.I2C6.TCS4._CRS.WBUF */
}
The setting of the special bit in the gpio control register leads to
drivers/pinctrl/intel/pinctrl-cherryview.c chv_gpio_request_enable()
returning -EBUSY, which in return makes gpiod_get_optional
return -EBUSY for this pin, rather then NULL (as we would like).
Regards,
Hans
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