Re: [PATCH v8 3/3] HID: cp2112: Fwnode Support

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

On Mar 07 2023, Andy Shevchenko wrote:
> On Tue, Mar 07, 2023 at 03:48:52PM +0100, Benjamin Tissoires wrote:
> > On Mar 07 2023, Daniel Kaehn wrote:
> 
> ...
> 
> > So I can see that the device gets probed, and that all ACPI resources
> > are tried to get the IRQ.
> > Right now, I see that it's attempting to bind to the acpi resource in
> > acpi_dev_resource_interrupt() (in file drivers/acpi/resources.c), but
> > instead of having a ACPI_RESOURCE_TYPE_EXTENDED_IRQ I only get a
> > ACPI_RESOURCE_TYPE_GPIO for the GpioInt() definition in the _CRS method.
> > 
> > So I am missing the proper transition from GpioInt to IRQ in the acpi.
> 
> I'm not sure I understand what this means.
> 
> The Linux kernel takes either Interrupt() resource (which is
> IOxAPIC / GIC / etc) or GpioInt() (which is GPIO based).
> 
> In both cases I²C framework submits this into client's IRQ field.
> 

I finally managed to get past the retrieval of the GpioInt.

Turns out that the function acpi_get_gpiod() matches on the parent of
the gpio_chip (gc->parent), which means that, with the current code and
my SSDT, it matches on the HID CP2112 ACPI node, not the GPIO one.

For reference (with lots of boiler plate removed):

        Device (CP21) { // the USB-hid & CP2112 shared node
         Device (GPIO) {
            Name (_ADR, One)
            Name (_STA, 0x0F)

            Name (_DSD, Package () {
              ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
              Package () {
                Package () { "gpio-line-names", Package () {
                            "",
                            "",
                            "irq-rmi4",
                            "",
                            "power", // set to 1 with gpio-hog above
                            "",
                            "",
                            "",
                            ""}},
              }
            })
         }

  Scope (\_SB_.PCI0.USB0.RHUB.CP21.I2C)
  {
    Device (TPD0)
    {
      Name (_HID, "RMI40001")
      Name (_CID, "PNP0C50")
      Name (_STA, 0x0F)

      Name (SBFB, ResourceTemplate ()
      {
          I2cSerialBusV2 (0x00c, ControllerInitiated, 100000,
              AddressingMode7Bit, "\\_SB_.PCI0.USB0.RHUB.CP21.I2C",
              0x00, ResourceConsumer,, Exclusive,
              )
      })
      Name (SBFG, ResourceTemplate ()
      {
          GpioInt (Level, ActiveLow, Exclusive, PullDefault, 0x0000,
              "\\_SB_.PCI0.USB0.RHUB.CP21", 0x00, ResourceConsumer, ,
              )
              {   // Pin list
                  0x0002
              }
      })
---

But if I refer "\\_SB_.PCI0.USB0.RHUB.CP21.GPIO", the IRQ is never assigned.
With the parent (CP21), it works.

So I wonder if the cp2112 driver is correctly assigning the gc->parent
field.

Cheers,
Benjamin