Re: ACPI SPI slave device

Re: ACPI SPI slave device

[Lukas Wunner]

[Cc: += Matthew Garrett, linux-spi]

Hi Leif,

On Wed, Mar 02, 2016 at 03:37:27PM +0100, Leif Liddy wrote:
> On Wed, Mar 2, 2016 at 2:07 PM, Leif Liddy <leif.linux@gmail.com> wrote:
> > On Wed, Mar 2, 2016 at 12:42 PM, Lukas Wunner <lukas@wunner.de> wrote:
> >> On Wed, Mar 02, 2016 at 04:13:16AM +0100, Leif Liddy wrote:
> >>> I'll post more tomorrow, need to evaluate the changes I made --but I
> >>> think the change that did it was changing this:
> >>>
> >>> Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
> >>> {
> >>>     If (!OSDW ())
> >>>     {
> >>>         Return (WBUF) /* \_SB_.PCI0.SPI1.WBUF */
> >>>     }
> >>>
> >>>     Return (ConcatenateResTemplate (RBUF, DBUF))
> >>> }
> >>>
> >>> to:
> >>>
> >>> Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
> >>> {
> >>>       Return (ConcatenateResTemplate (RBUF, DBUF))
> >>> }
> >>
> >> If that is true then the fix is to change the OS we're reporting to ACPI:
> >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/acpi/osl.c#n141
> >>
> >> We had trouble with this before:
> >> https://mjg59.dreamwidth.org/29954.html
> >>
> >> I've just grabbed the acpidump you've posted here:
> >> https://bugzilla.kernel.org/attachment.cgi?id=200961&action=edit
> >>
> >> I'll take a look at it hopefully this afternoon to see what they've
> >> changed in the OSDW method.
> >>
> > You're right, it's not evaluating the OSDW method properly. I tracked
> > it down to this single change:
> >
> > change this:
> >
> >       If (!OSDW ())
> >       {
> >           Return (UBUF) /* \_SB_.PCI0.SPI1.SPIT._CRS.UBUF */
> >       }
> >      Return (ABUF) /* \_SB_.PCI0.SPI1.SPIT._CRS.ABUF */
> > }
> >
> > to:
> >
> >      Return (UBUF) /* \_SB_.PCI0.SPI1.SPIT._CRS.UBUF */
> >
> This issue is more easily resolved by just changing !OSDW to OSDW for
> that method. The default behavior it seems is for Linux to identify
> itself as OSX, but there are a few methods where we don't want to
> identify as being OSX. I'll try and come up with a list of methods of
> where we don't want to identify as being OSX.

I'm not aware that it's possible to choose the OS per method.

I've compared the \_SB.PCI0._INI method (which sets \OSYS) and the
OSDW method (which returns true iff \OSYS == 0x2710 (Darwin))
between your MB8,1 and my MBP9,1 and nothing relevant has changed.


However after looking at the DSDT I can explain what's going on:

The standard way of describing resource settings is to let _CRS
return them.

The OS X way of describing resource settings is to let a _DSM
return them. If you disassemble AppleACPIPlatform.kext and search
for the label gDSM_GET_PROP_UUID, you'll find a UUID that looks
like this: a0b5b7c6-1318-441c-b0c9-fe695eaf949b. The kernel
extension invokes the _DSM with this UUID for every ACPI device
and merges the package it returns into the device's entry in the
I/O registry. The SPI driver on OS X then retrieves the settings
from the I/O registry.

If you boot OS X and invoke "ioreg -l | grep spiSclkPeriod"
you should see the value stored in this device's _DSM (0x0000007d).

Now the problem is, in the DSDT of your machine, the _CRS method
for the SPIT (spi-topcase) device returns a proper ResourceTemplate
for non-Darwin OSes (UBUF) and an *empty* ResourceTemplate for Darwin
(named ABUF). Conversely the device's _DSM returns zero for non-Darwin
OSes and the I/O registry package for Darwin. (Excerpt of the DSDT
included below for others following this thread.)

Further down in the DSDT, the exact same snafu is present for the
Bluetooth resource settings (BCM2E7C, apple-uart-blth). Perhaps
on this particular laptop it's better to not masquerade as Darwin
at all? On the other hand e.g. in SSDT5 it's apparent that without
masquerading as Darwin, the USB controller's _PS0 and _PS3 methods
are no-ops, so it looks like it cannot enter low power modes.
Quirking SPI and Bluetooth is probably the lesser evil.

I think you want to add a quirk to spi.c:acpi_spi_add_device()
which checks if acpi_dev_get_resources() returned nothing and
the HID of the acpi_device is APP000D: Search the namespace below
the acpi_device's handle for _CRS.UBUF (using acpi_get_handle()).
If this exists, call acpi_walk_resource_buffer() on it (with the
acpi_spi_add_resource callback). You need to somehow convert the
acpi_handle to an acpi_buffer, maybe that just involves filling in
acpi_buffer->pointer = acpi_handle and somehow determining the
length of the resource settings from the handle. Someone more
intimately familiar with the layout of the namespace in memory
should be able to answer this. Hopefully this will already get
you started, if not just ask questions.

HTH,

Lukas

-- cut here --

            Scope (\_SB.PCI0.SPI1)
            {
                Device (SPIT)
                {
                    Name (_HID, EisaId ("APP000D"))  // _HID: Hardware ID
                    Name (_CID, "apple-spi-topcase")  // _CID: Compatible ID
...
                    Method (_CRS, 0, Serialized)  // _CRS: Current Resource Settings
                    {
                        Name (UBUF, ResourceTemplate ()
                        {
                            SpiSerialBus (0x0000, PolarityLow, FourWireMode, 0x08,
                                ControllerInitiated, 0x007A1200, ClockPolarityLow,
                                ClockPhaseFirst, "\\_SB.PCI0.SPI1",
                                0x00, ResourceConsumer, ,
                                )
                            Interrupt (ResourceConsumer, Level, ActiveLow, Exclusive, ,, )
                            {
                                0x0000001E,
                            }
                        })
                        Name (ABUF, ResourceTemplate ()
                        {
                        })
                        If (LNot (OSDW ()))
                        {
                            Return (UBUF) /* \_SB_.PCI0.SPI1.SPIT._CRS.UBUF */
                        }

                        Return (ABUF) /* \_SB_.PCI0.SPI1.SPIT._CRS.ABUF */
                    }
...
                    Method (_DSM, 4, NotSerialized)  // _DSM: Device-Specific Method
                    {
                        If (OSDW ())
                        {
                            If (LEqual (Arg0, ToUUID ("a0b5b7c6-1318-441c-b0c9-fe695eaf949b")))
                            {
                                Store (Package (0x10)
                                    {
                                        "spiSclkPeriod", 
                                        Buffer (0x08)
                                        {
                                             0x7D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* }....... */
                                        }, 

                                        "spiWordSize", 
                                        Buffer (0x08)
                                        {
                                             0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "spiBitOrder", 
                                        Buffer (0x08)
                                        {
                                             0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "spiSPO", 
                                        Buffer (0x08)
                                        {
                                             0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "spiSPH", 
                                        Buffer (0x08)
                                        {
                                             0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "spiCSDelay", 
                                        Buffer (0x08)
                                        {
                                             0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "resetA2RUsec", 
                                        Buffer (0x08)
                                        {
                                             0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }, 

                                        "resetRecUsec", 
                                        Buffer (0x08)
                                        {
                                             0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* ........ */
                                        }
                                    }, Local0)
                                DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0))
                                Return (Local0)
                            }
                        }

                        Return (0x00)
                    }

Re: ACPI SPI slave device

[Matthew Garrett]

On Thu, Mar 03, 2016 at 12:47:40PM +0100, Lukas Wunner wrote:

> I think you want to add a quirk to spi.c:acpi_spi_add_device()
> which checks if acpi_dev_get_resources() returned nothing and
> the HID of the acpi_device is APP000D: Search the namespace below
> the acpi_device's handle for _CRS.UBUF (using acpi_get_handle()).
> If this exists, call acpi_walk_resource_buffer() on it (with the
> acpi_spi_add_resource callback). You need to somehow convert the
> acpi_handle to an acpi_buffer, maybe that just involves filling in
> acpi_buffer->pointer = acpi_handle and somehow determining the
> length of the resource settings from the handle. Someone more
> intimately familiar with the layout of the namespace in memory
> should be able to answer this. Hopefully this will already get
> you started, if not just ask questions.

If Apple are consistently using this mechanism to define resources, do 
we want to extend acpi_dev_get_resources to attempt to call the _DSM 
method as well?

-- 
Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org
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Re: ACPI SPI slave device

[Matthew Garrett]

Oh, sorry, I see - it's a little more complicated than that. Bleah. I 
still think we probably want to do this at the core level rather than 
having the driver special-case things based on the HID, but it's clearly 
going to need some knowledge of the device type to parse Apple's data 
into something consistent with the spec.

-- 
Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org
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Re: ACPI SPI slave device

[Lukas Wunner]

Hi Matthew,

On Thu, Mar 03, 2016 at 05:45:35PM +0000, Matthew Garrett wrote:
> On Thu, Mar 03, 2016 at 12:47:40PM +0100, Lukas Wunner wrote:
> 
> > I think you want to add a quirk to spi.c:acpi_spi_add_device()
> > which checks if acpi_dev_get_resources() returned nothing and
> > the HID of the acpi_device is APP000D: Search the namespace below
> > the acpi_device's handle for _CRS.UBUF (using acpi_get_handle()).
> > If this exists, call acpi_walk_resource_buffer() on it (with the
> > acpi_spi_add_resource callback). You need to somehow convert the
> > acpi_handle to an acpi_buffer, maybe that just involves filling in
> > acpi_buffer->pointer = acpi_handle and somehow determining the
> > length of the resource settings from the handle. Someone more
> > intimately familiar with the layout of the namespace in memory
> > should be able to answer this. Hopefully this will already get
> > you started, if not just ask questions.
> 
> If Apple are consistently using this mechanism to define resources, do 
> we want to extend acpi_dev_get_resources to attempt to call the _DSM 
> method as well?

What Apple is doing with their _DSM is functionally equivalent to the
_DSD (Device Specific Data) method in the ACPI spec. (Apple isn't using
_DSD at all.)

We could extend drivers/acpi/property.c:acpi_init_properties() to
check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
calling _DSD, call _DSM with Apple's UUID and populate adev->data
with that. Or add the properties to the existing data, if any.

Then whenever we feel the need we could just retrieve Apple's
properties with acpi_dev_get_property().

E.g. in the case of this SPI slave we need to fill in five values
of struct spi_device and we would add a quirk for APP000D which
retrieves each value via acpi_dev_get_property() instead of
acpi_dev_get_resources().

Alternatively we could evaluate the _DSM individually from the
quirk and obtain the values we need from the returned package.
But being able to get them with acpi_dev_get_property() might
be more generic, it's not unlikely that we need to retrieve
Apple's properties from other quirks as well.

The suggestion I made in my previous e-mail (to fetch UBUF) was
probably not so great in terms of maintainability since Apple
might change the name of the variable in a future version of the
DSDT, or on other machines.

Best regards,

Lukas

Re: ACPI SPI slave device

[Matthew Garrett]

On Thu, Mar 03, 2016 at 07:55:53PM +0100, Lukas Wunner wrote:

> We could extend drivers/acpi/property.c:acpi_init_properties() to
> check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
> calling _DSD, call _DSM with Apple's UUID and populate adev->data
> with that. Or add the properties to the existing data, if any.

Just do it unconditionally, it's cheap.

> E.g. in the case of this SPI slave we need to fill in five values
> of struct spi_device and we would add a quirk for APP000D which
> retrieves each value via acpi_dev_get_property() instead of
> acpi_dev_get_resources().

Mm. It'd be nice to avoid having to keep a list of Apple devices - some 
sort of mapping function might be easier, returning the values from _CRS 
if they're present or from _DSM/_DSD otherwise?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: ACPI SPI slave device

[Leif Liddy]

> We could extend drivers/acpi/property.c:acpi_init_properties() to
> check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
> calling _DSD, call _DSM with Apple's UUID and populate adev->data
> with that. Or add the properties to the existing data, if any.

Lukas, this a bit beyond my skill level at the moment. I'd like to
start with something with a bit easier, and then work my way up.

Here's how I gather things are supposed to work.

The references inside the _DSM method for SPIT device: {spiSclkPeriod,
spiWordSize, spiCSDelay....etc} are meant to be parsed out and used as
parameters to configure the SPI controller/protocol driver (or not
used at all).

**that's exactly what i2c-designware-platdrv.c does in configuring the
ss_hcnt, ssh_lcnt...etc parameters


SPI controllers are relatively simple devices and I'm just going to
assume that the default parameters used in spi-pxa2xx are sufficient
for now. **I can always manually adjust them later

My goal at the moment is just to be able to perform basic connectivity
testing with the slave device.
The first issue I ran into was that the IRQ assigned to the DMA
controller (dw_dmac) was wrong.

/proc/interrupts
20:    dw_dmac                            --by default, it's set to 20
21:     pxa2xx-spi.0

/proc/interrupts
21:     dw_dmac, pxa2xx-spi.0    --should be set to 21 and share IRQ
with spi controller


IRQ 21 is what is shown in the DSDT table for both the DMA and SPI
devices. I think because the DMA controller is called by its PCI ID
(dma/dw/pci.c)that's it's not checking ACPI for the IRQ value.


modprobe spi_pxa2xx_pci     --everything seems to come up fine

....
xxx pxa2xx.c setup() tx_thres: 160 tx_hi_thres: 224 rx_thres: 64
xxx pxa2xx.c setup() chip->enable_dma is 1
xxx pxa2xx.c setup() bits_per_word: 8 dma_burst_size: 1 dma_threshold: 1088
spi spi-APP000D:00: setup mode 0, 8 bits/w, 8000000 Hz max --> 0
pxa2xx-spi pxa2xx-spi.0: registered child spi-APP000D:00
....


I've modified spidev.c to bind to the APP000D slave device. However,
when I run spidev_test nothing gets received.

./spidev_test -D /dev/spidev0.0

spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 KHz)
RX | 00 00 00 00 00 00 00 00 00 00.......

**dmesg (prink statements) shows it running through the whole dma
transfer transfer process


I'm wondering what functions SIEN, SIST, and ISOL methods are meant to
perform on the SPIT device (in the DSDT table) --and how to use them.


Here's what I got so far:

.....................................................
static int spi_hid_probe(struct spi_device *spi)
{
        struct acpi_object_list input;
        union acpi_object param[1];
        acpi_status status;
        param[0].type = ACPI_TYPE_INTEGER;
        param[0].integer.value = 0x01;
        input.count = 1;
        input.pointer = param;

        status = acpi_evaluate_object(ACPI_HANDLE(&spi->dev), "SIEN",
&input, NULL);
        if (ACPI_FAILURE(status))
                printk("xxx mb81_spi_probe --ACPI_FAILURE\n");

        return 0;
}


static const struct acpi_device_id spi_hid_acpi_match[] = {
        { "APP000D", 0 },
        { },
};
...
...................................................

If I load & unload this test module --and then run spidev

./spidev_test -D /dev/spidev0.0  -v
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 KHz)
TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF F0 0D  | ......@....�..................�.
RX | 20 D0 00 00 00 00 04 00 A0 80 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00  | .�......��....................

It changed something....
It looks like SIEN is modifying the GPIO registers, but its function
isn't exactly clear.


Lukas, can you help me sort out what the purpose of these methods are
and how to use them?

-----------------------------------------------------------------------------------------------

Method (SIEN, 1, Serialized)
                    {
                        If ((Arg0 <= 0x01))
                        {
                            If ((Arg0 == 0x01))
                            {
                                GP13 = 0x01
                                GD13 = 0x00
                            }
                            Else
                            {
                                GD13 = 0x01
                            }
                        }
                    }

                    Method (SIST, 0, Serialized)
                    {
                        Local0 = GD13 /* \GD13 */
                        If ((Local0 == 0x01))
                        {
                            Return (GL13) /* \GL13 */
                        }
                        Else
                        {
                            Return (GP13) /* \GP13 */
                        }
                    }
                }

                Method (ISOL, 1, Serialized)
                {
                    If ((Arg0 <= 0x01))
                    {
                        If ((Arg0 == 0x01))
                        {
                            GP87 = 0x01
                            GP88 = 0x00
                            GP89 = 0x00
                            GP90 = 0x00
                            GD87 = 0x00
                            GD88 = 0x00
                            GD89 = 0x01
                            GD90 = 0x00
                            GU87 = 0x01
                            GU88 = 0x01
                            GU89 = 0x01
                            GU90 = 0x01
                            Local0 = GP87 /* \GP87 */
                        }
                        Else
                        {
                            GU87 = 0x00
                            GU88 = 0x00
                            GU89 = 0x00
                            GU90 = 0x00
                            GP87 = 0x00
                            GP88 = 0x00
                            GP89 = 0x00
                            GP90 = 0x00
                            GD87 = 0x00
                            GD88 = 0x00
                            GD89 = 0x00
                            GD90 = 0x00
                            Local0 = GU87 /* \GU87 */
                        }

                        Return (0x00)
                    }

                    Return (0xFFFFFFFF)
                }
            }

-----------------------------------------------------------------------------------------------

Decoded DSDT table:
https://bugzilla.kernel.org/attachment.cgi?id=202141

On Thu, Mar 3, 2016 at 8:12 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Thu, Mar 03, 2016 at 07:55:53PM +0100, Lukas Wunner wrote:
>
>> We could extend drivers/acpi/property.c:acpi_init_properties() to
>> check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
>> calling _DSD, call _DSM with Apple's UUID and populate adev->data
>> with that. Or add the properties to the existing data, if any.
>
> Just do it unconditionally, it's cheap.
>
>> E.g. in the case of this SPI slave we need to fill in five values
>> of struct spi_device and we would add a quirk for APP000D which
>> retrieves each value via acpi_dev_get_property() instead of
>> acpi_dev_get_resources().
>
> Mm. It'd be nice to avoid having to keep a list of Apple devices - some
> sort of mapping function might be easier, returning the values from _CRS
> if they're present or from _DSM/_DSD otherwise?
>
> --
> Matthew Garrett | mjg59@srcf.ucam.org
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Re: ACPI SPI slave device

[Lukas Wunner]

Hi Leif,

I went through my collection of MacBook acpidumps and noticed that the
MacBookPro12,1 also uses SPI, the DSDT entries are identical (save for
some changes in the ISOL method and an additional UIST method). That's
the 13" 2015 MacBookPro model.

John Horan and Henrik Rydberg added support for that model's keyboard
and trackpad with:
d58069265c9d ("Input: bcm5974 - add support for the 2015 Macbook Pro")
a4a2c54560f2 ("HID: apple: Add support for the 2015 Macbook Pro")
efbd34702fb1 ("Input: bcm5974 - prepare for a new trackpad generation")

I'm wondering, if the keyboard and trackpad are working on the MBP12,1,
why aren't they working on the MB8,1? Adding John and Henrik to cc: in
the hope of clarifying this.


On Tue, Mar 08, 2016 at 03:40:14PM +0100, Leif Liddy wrote:
> > We could extend drivers/acpi/property.c:acpi_init_properties() to
> > check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
> > calling _DSD, call _DSM with Apple's UUID and populate adev->data
> > with that. Or add the properties to the existing data, if any.
> 
> Lukas, this a bit beyond my skill level at the moment. I'd like to
> start with something with a bit easier, and then work my way up.
> 
> Here's how I gather things are supposed to work.
> 
> The references inside the _DSM method for SPIT device: {spiSclkPeriod,
> spiWordSize, spiCSDelay....etc} are meant to be parsed out and used as
> parameters to configure the SPI controller/protocol driver (or not
> used at all).

Yes. Call the _DSM method and you'll get back a "package". Basically
that's a fancy ACPI term for a struct. You can then retrieve the values
out of that package.


> My goal at the moment is just to be able to perform basic connectivity
> testing with the slave device.
> The first issue I ran into was that the IRQ assigned to the DMA
> controller (dw_dmac) was wrong.
> 
> /proc/interrupts
> 20:    dw_dmac                            --by default, it's set to 20
> 21:     pxa2xx-spi.0
> 
> /proc/interrupts
> 21:     dw_dmac, pxa2xx-spi.0    --should be set to 21 and share IRQ
> with spi controller

Hm, according to DSDT the interrupt for APP000D should be 0x1E, i.e. 30.

I notice that the interrupt is specified in the device's ResourceTemplate
(_CRS.UBUF) but not in the package returned by the _DSM. If we need that
value then we cannot solve this by just parsing the values returned by the
_DSM. The only option we'd have is to retrieve that UBUF ResourceTemplate.


> IRQ 21 is what is shown in the DSDT table for both the DMA and SPI
> devices. I think because the DMA controller is called by its PCI ID
> (dma/dw/pci.c)that's it's not checking ACPI for the IRQ value.
> 
> modprobe spi_pxa2xx_pci     --everything seems to come up fine
> 
> ....
> xxx pxa2xx.c setup() tx_thres: 160 tx_hi_thres: 224 rx_thres: 64
> xxx pxa2xx.c setup() chip->enable_dma is 1
> xxx pxa2xx.c setup() bits_per_word: 8 dma_burst_size: 1 dma_threshold: 1088
> spi spi-APP000D:00: setup mode 0, 8 bits/w, 8000000 Hz max --> 0
> pxa2xx-spi pxa2xx-spi.0: registered child spi-APP000D:00
> ....
> 
> I've modified spidev.c to bind to the APP000D slave device. However,
> when I run spidev_test nothing gets received.
> 
> ./spidev_test -D /dev/spidev0.0
> 
> spi mode: 0x0
> bits per word: 8
> max speed: 500000 Hz (500 KHz)
> RX | 00 00 00 00 00 00 00 00 00 00.......
> 
> **dmesg (prink statements) shows it running through the whole dma
> transfer transfer process
> 
> I'm wondering what functions SIEN, SIST, and ISOL methods are meant to
> perform on the SPIT device (in the DSDT table) --and how to use them.

If you grep /System/Library/Extensions on OS X for these strings you'll
find the SPI drivers. Disassemble those and you'll find these methods are
called in the following functions:

ISOL gets called in AppleIntelLpssGspi.kext from
       AppleIntelLpssGspi::gpioConfig()
       AppleIntelLpssGspi::initGspiGpio()
SIEN gets called in AppleIntelLpssSpiController.kext from
       AppleIntelLpssSpiController::_setSPIBusDeviceEnable()
SIEN, SIST und UIST in the same kext from:
       AppleIntelLpssSpiController::getSpiDevices()

Apple often uses nonstandard ACPI methods like this for power management,
i.e. to power a chip up and down and query its status. SIEN takes one
argument which can be 1 or 0 and modifies GPIO pin 13. You'd need the
schematics of the mainboard to know what this pin is connected to but
this might be a power switch which powers the SPI controller up and down.
So the "EN" in "SIEN" might stand for "enable", which matches with the
function it's called from (_setSPIBusDeviceEnable). Likewise SIST returns
the status of GPIO pin 13 so the "ST" might stand for "status".

I don't know what ISOL does. "Isolation" maybe? This also modifies a few
GPIO registers. And UIST ist only present in the MBP12,1 DSDT, it returns
the status of GPIO pin 26.

HTH,

Lukas

> Here's what I got so far:
> 
> .....................................................
> static int spi_hid_probe(struct spi_device *spi)
> {
>         struct acpi_object_list input;
>         union acpi_object param[1];
>         acpi_status status;
>         param[0].type = ACPI_TYPE_INTEGER;
>         param[0].integer.value = 0x01;
>         input.count = 1;
>         input.pointer = param;
> 
>         status = acpi_evaluate_object(ACPI_HANDLE(&spi->dev), "SIEN",
> &input, NULL);
>         if (ACPI_FAILURE(status))
>                 printk("xxx mb81_spi_probe --ACPI_FAILURE\n");
> 
>         return 0;
> }
> 
> 
> static const struct acpi_device_id spi_hid_acpi_match[] = {
>         { "APP000D", 0 },
>         { },
> };
> ...
> ...................................................
> 
> If I load & unload this test module --and then run spidev
> 
> ./spidev_test -D /dev/spidev0.0  -v
> spi mode: 0x0
> bits per word: 8
> max speed: 500000 Hz (500 KHz)
> TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF
> FF FF FF FF FF FF FF FF F0 0D  | ......@....???..................???.
> RX | 20 D0 00 00 00 00 04 00 A0 80 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00  | .???......??????....................
> 
> It changed something....
> It looks like SIEN is modifying the GPIO registers, but its function
> isn't exactly clear.
> 
> 
> Lukas, can you help me sort out what the purpose of these methods are
> and how to use them?
> 
> -----------------------------------------------------------------------------------------------
> 
> Method (SIEN, 1, Serialized)
>                     {
>                         If ((Arg0 <= 0x01))
>                         {
>                             If ((Arg0 == 0x01))
>                             {
>                                 GP13 = 0x01
>                                 GD13 = 0x00
>                             }
>                             Else
>                             {
>                                 GD13 = 0x01
>                             }
>                         }
>                     }
> 
>                     Method (SIST, 0, Serialized)
>                     {
>                         Local0 = GD13 /* \GD13 */
>                         If ((Local0 == 0x01))
>                         {
>                             Return (GL13) /* \GL13 */
>                         }
>                         Else
>                         {
>                             Return (GP13) /* \GP13 */
>                         }
>                     }
>                 }
> 
>                 Method (ISOL, 1, Serialized)
>                 {
>                     If ((Arg0 <= 0x01))
>                     {
>                         If ((Arg0 == 0x01))
>                         {
>                             GP87 = 0x01
>                             GP88 = 0x00
>                             GP89 = 0x00
>                             GP90 = 0x00
>                             GD87 = 0x00
>                             GD88 = 0x00
>                             GD89 = 0x01
>                             GD90 = 0x00
>                             GU87 = 0x01
>                             GU88 = 0x01
>                             GU89 = 0x01
>                             GU90 = 0x01
>                             Local0 = GP87 /* \GP87 */
>                         }
>                         Else
>                         {
>                             GU87 = 0x00
>                             GU88 = 0x00
>                             GU89 = 0x00
>                             GU90 = 0x00
>                             GP87 = 0x00
>                             GP88 = 0x00
>                             GP89 = 0x00
>                             GP90 = 0x00
>                             GD87 = 0x00
>                             GD88 = 0x00
>                             GD89 = 0x00
>                             GD90 = 0x00
>                             Local0 = GU87 /* \GU87 */
>                         }
> 
>                         Return (0x00)
>                     }
> 
>                     Return (0xFFFFFFFF)
>                 }
>             }
> 
> -----------------------------------------------------------------------------------------------
> 
> Decoded DSDT table:
> https://bugzilla.kernel.org/attachment.cgi?id=202141
> 
> On Thu, Mar 3, 2016 at 8:12 PM, Matthew Garrett <mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org> wrote:
> > On Thu, Mar 03, 2016 at 07:55:53PM +0100, Lukas Wunner wrote:
> >
> >> We could extend drivers/acpi/property.c:acpi_init_properties() to
> >> check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
> >> calling _DSD, call _DSM with Apple's UUID and populate adev->data
> >> with that. Or add the properties to the existing data, if any.
> >
> > Just do it unconditionally, it's cheap.
> >
> >> E.g. in the case of this SPI slave we need to fill in five values
> >> of struct spi_device and we would add a quirk for APP000D which
> >> retrieves each value via acpi_dev_get_property() instead of
> >> acpi_dev_get_resources().
> >
> > Mm. It'd be nice to avoid having to keep a list of Apple devices - some
> > sort of mapping function might be easier, returning the values from _CRS
> > if they're present or from _DSM/_DSD otherwise?
> >
> > --
> > Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org
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Re: ACPI SPI slave device

[Leif Liddy]

> I'm wondering, if the keyboard and trackpad are working on the MBP12,1,
> why aren't they working on the MB8,1?

this issue has been brought up before:
http://www.spinics.net/lists/linux-acpi/msg61848.html

It sounds like the MBP12,1 models have a way to access the
keyboard/trackpad via USB and SPI

OSX identifies the keyboard/trackpad on the MB8,1 as

"Product" = "Apple Internal Keyboard / Trackpad"
"ProductID" = 0x272

https://bugzilla.kernel.org/attachment.cgi?id=201111


**that is same device id as the MBP12,1 keyboard/trackpad, which is
referenced in a few kernel device drivers as:
USB_DEVICE_ID_APPLE_WELLSPRING9_ANSI    0x0272


OSX appears to be binding an HID driver to the slave device via an SPI
transport driver.

there's no SPI transport driver for linux (yet??)
https://www.kernel.org/doc/Documentation/hid/hid-transport.txt

In any case I'd still like to try and make some progress on this
--it's a good learning experience


DSDT shows the following (named gpio's???) being assigned to the SPI master

"gspi-pin-cs",
Buffer (0x08)
{
     0x57, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* W....... */
},

"gspi-pin-clk",
Buffer (0x08)
{
     0x58, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* X....... */
},

"gspi-pin-mosi",
Buffer (0x08)
{
     0x59, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* Y....... */
},

"gspi-pin-miso",
Buffer (0x08)
{
     0x5A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00   /* Z....... */
}

I'm trying to sort out what these values represent and how to use them.
My guess is that they function as gpio's, although this is not the
standard format of passing this sort of information.


The config I'm using for the controller in spi-pxa2xx.c is

 {       /* LPSS_LPT_SSP */
        .offset = 0x800,
        .reg_general = 0x08,
        .reg_ssp = 0x0c,
        .reg_cs_ctrl = 0x18,
        .reg_capabilities = -1,
 }


**presumably it should be finding the parameters for controlling the
device from these memory locations.
**ACPI ID of controller INT33C1 matches this config
**In any case I'm going to spend the next couple of weeks
deconstructing this driver...


> Hm, according to DSDT the interrupt for APP000D should be 0x1E, i.e. 30.

I was referring to that fact that the SPI controller and the DMA
controller (and I2C1 and UART0) all share the same
interrupt. If the two controllers don't share the same IRQ, then no
communication will occur between the two controllers

I ran some basic DMA tests to highlight this:
https://bugzilla.kernel.org/attachment.cgi?id=207871

I don't think I need to worry about about the IRQ of the slave device
just yet, I don't *believe* that comes into play when
using spidev + DMA + spidev_test.

**I've modified the DSDT tables so that UBUF is returned..

[   39.509846] xxx spi.c acpi_spi_add_resource :if
(acpi_dev_resource_interrupt(ares, 0, &r))
[   39.509849] xxx spi.c acpi_spi_add_resource spi->irq = r.start --is
equal to 30
[   39.509851] xxx spi.c acpi_spi_add_resource --start
[   39.509853] xxx spi.c spi->irq = 30
[   39.509856] xxx resource.c acpi_dev_get_resources acpi_dev_name=APP000D:00
[   39.509859] xxx resource.c acpi_handle is ffff8802650be000 returns
c.count 0...
[   39.509864] xxx spi.c acpi_spi_add_device :spi->max_speed_hz is 8000000


> If you grep /System/Library/Extensions on OS X for these strings you'll
> find the SPI drivers. Disassemble those and you'll find these methods are
> called in the following functions:

Thanks for sharing that...really useful!!!

-Leif


On Wed, Mar 9, 2016 at 1:36 PM, Lukas Wunner <lukas-JFq808J9C/izQB+pC5nmwQ@public.gmane.org> wrote:
> Hi Leif,
>
> I went through my collection of MacBook acpidumps and noticed that the
> MacBookPro12,1 also uses SPI, the DSDT entries are identical (save for
> some changes in the ISOL method and an additional UIST method). That's
> the 13" 2015 MacBookPro model.
>
> John Horan and Henrik Rydberg added support for that model's keyboard
> and trackpad with:
> d58069265c9d ("Input: bcm5974 - add support for the 2015 Macbook Pro")
> a4a2c54560f2 ("HID: apple: Add support for the 2015 Macbook Pro")
> efbd34702fb1 ("Input: bcm5974 - prepare for a new trackpad generation")
>
> I'm wondering, if the keyboard and trackpad are working on the MBP12,1,
> why aren't they working on the MB8,1? Adding John and Henrik to cc: in
> the hope of clarifying this.
>
>
> On Tue, Mar 08, 2016 at 03:40:14PM +0100, Leif Liddy wrote:
>> > We could extend drivers/acpi/property.c:acpi_init_properties() to
>> > check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
>> > calling _DSD, call _DSM with Apple's UUID and populate adev->data
>> > with that. Or add the properties to the existing data, if any.
>>
>> Lukas, this a bit beyond my skill level at the moment. I'd like to
>> start with something with a bit easier, and then work my way up.
>>
>> Here's how I gather things are supposed to work.
>>
>> The references inside the _DSM method for SPIT device: {spiSclkPeriod,
>> spiWordSize, spiCSDelay....etc} are meant to be parsed out and used as
>> parameters to configure the SPI controller/protocol driver (or not
>> used at all).
>
> Yes. Call the _DSM method and you'll get back a "package". Basically
> that's a fancy ACPI term for a struct. You can then retrieve the values
> out of that package.
>
>
>> My goal at the moment is just to be able to perform basic connectivity
>> testing with the slave device.
>> The first issue I ran into was that the IRQ assigned to the DMA
>> controller (dw_dmac) was wrong.
>>
>> /proc/interrupts
>> 20:    dw_dmac                            --by default, it's set to 20
>> 21:     pxa2xx-spi.0
>>
>> /proc/interrupts
>> 21:     dw_dmac, pxa2xx-spi.0    --should be set to 21 and share IRQ
>> with spi controller
>
> Hm, according to DSDT the interrupt for APP000D should be 0x1E, i.e. 30.
>
> I notice that the interrupt is specified in the device's ResourceTemplate
> (_CRS.UBUF) but not in the package returned by the _DSM. If we need that
> value then we cannot solve this by just parsing the values returned by the
> _DSM. The only option we'd have is to retrieve that UBUF ResourceTemplate.
>
>
>> IRQ 21 is what is shown in the DSDT table for both the DMA and SPI
>> devices. I think because the DMA controller is called by its PCI ID
>> (dma/dw/pci.c)that's it's not checking ACPI for the IRQ value.
>>
>> modprobe spi_pxa2xx_pci     --everything seems to come up fine
>>
>> ....
>> xxx pxa2xx.c setup() tx_thres: 160 tx_hi_thres: 224 rx_thres: 64
>> xxx pxa2xx.c setup() chip->enable_dma is 1
>> xxx pxa2xx.c setup() bits_per_word: 8 dma_burst_size: 1 dma_threshold: 1088
>> spi spi-APP000D:00: setup mode 0, 8 bits/w, 8000000 Hz max --> 0
>> pxa2xx-spi pxa2xx-spi.0: registered child spi-APP000D:00
>> ....
>>
>> I've modified spidev.c to bind to the APP000D slave device. However,
>> when I run spidev_test nothing gets received.
>>
>> ./spidev_test -D /dev/spidev0.0
>>
>> spi mode: 0x0
>> bits per word: 8
>> max speed: 500000 Hz (500 KHz)
>> RX | 00 00 00 00 00 00 00 00 00 00.......
>>
>> **dmesg (prink statements) shows it running through the whole dma
>> transfer transfer process
>>
>> I'm wondering what functions SIEN, SIST, and ISOL methods are meant to
>> perform on the SPIT device (in the DSDT table) --and how to use them.
>
> If you grep /System/Library/Extensions on OS X for these strings you'll
> find the SPI drivers. Disassemble those and you'll find these methods are
> called in the following functions:
>
> ISOL gets called in AppleIntelLpssGspi.kext from
>        AppleIntelLpssGspi::gpioConfig()
>        AppleIntelLpssGspi::initGspiGpio()
> SIEN gets called in AppleIntelLpssSpiController.kext from
>        AppleIntelLpssSpiController::_setSPIBusDeviceEnable()
> SIEN, SIST und UIST in the same kext from:
>        AppleIntelLpssSpiController::getSpiDevices()
>
> Apple often uses nonstandard ACPI methods like this for power management,
> i.e. to power a chip up and down and query its status. SIEN takes one
> argument which can be 1 or 0 and modifies GPIO pin 13. You'd need the
> schematics of the mainboard to know what this pin is connected to but
> this might be a power switch which powers the SPI controller up and down.
> So the "EN" in "SIEN" might stand for "enable", which matches with the
> function it's called from (_setSPIBusDeviceEnable). Likewise SIST returns
> the status of GPIO pin 13 so the "ST" might stand for "status".
>
> I don't know what ISOL does. "Isolation" maybe? This also modifies a few
> GPIO registers. And UIST ist only present in the MBP12,1 DSDT, it returns
> the status of GPIO pin 26.
>
> HTH,
>
> Lukas
>
>> Here's what I got so far:
>>
>> .....................................................
>> static int spi_hid_probe(struct spi_device *spi)
>> {
>>         struct acpi_object_list input;
>>         union acpi_object param[1];
>>         acpi_status status;
>>         param[0].type = ACPI_TYPE_INTEGER;
>>         param[0].integer.value = 0x01;
>>         input.count = 1;
>>         input.pointer = param;
>>
>>         status = acpi_evaluate_object(ACPI_HANDLE(&spi->dev), "SIEN",
>> &input, NULL);
>>         if (ACPI_FAILURE(status))
>>                 printk("xxx mb81_spi_probe --ACPI_FAILURE\n");
>>
>>         return 0;
>> }
>>
>>
>> static const struct acpi_device_id spi_hid_acpi_match[] = {
>>         { "APP000D", 0 },
>>         { },
>> };
>> ...
>> ...................................................
>>
>> If I load & unload this test module --and then run spidev
>>
>> ./spidev_test -D /dev/spidev0.0  -v
>> spi mode: 0x0
>> bits per word: 8
>> max speed: 500000 Hz (500 KHz)
>> TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF
>> FF FF FF FF FF FF FF FF F0 0D  | ......@....???..................???.
>> RX | 20 D0 00 00 00 00 04 00 A0 80 00 00 00 00 00 00 00 00 00 00 00 00
>> 00 00 00 00 00 00 00 00 00 00  | .???......??????....................
>>
>> It changed something....
>> It looks like SIEN is modifying the GPIO registers, but its function
>> isn't exactly clear.
>>
>>
>> Lukas, can you help me sort out what the purpose of these methods are
>> and how to use them?
>>
>> -----------------------------------------------------------------------------------------------
>>
>> Method (SIEN, 1, Serialized)
>>                     {
>>                         If ((Arg0 <= 0x01))
>>                         {
>>                             If ((Arg0 == 0x01))
>>                             {
>>                                 GP13 = 0x01
>>                                 GD13 = 0x00
>>                             }
>>                             Else
>>                             {
>>                                 GD13 = 0x01
>>                             }
>>                         }
>>                     }
>>
>>                     Method (SIST, 0, Serialized)
>>                     {
>>                         Local0 = GD13 /* \GD13 */
>>                         If ((Local0 == 0x01))
>>                         {
>>                             Return (GL13) /* \GL13 */
>>                         }
>>                         Else
>>                         {
>>                             Return (GP13) /* \GP13 */
>>                         }
>>                     }
>>                 }
>>
>>                 Method (ISOL, 1, Serialized)
>>                 {
>>                     If ((Arg0 <= 0x01))
>>                     {
>>                         If ((Arg0 == 0x01))
>>                         {
>>                             GP87 = 0x01
>>                             GP88 = 0x00
>>                             GP89 = 0x00
>>                             GP90 = 0x00
>>                             GD87 = 0x00
>>                             GD88 = 0x00
>>                             GD89 = 0x01
>>                             GD90 = 0x00
>>                             GU87 = 0x01
>>                             GU88 = 0x01
>>                             GU89 = 0x01
>>                             GU90 = 0x01
>>                             Local0 = GP87 /* \GP87 */
>>                         }
>>                         Else
>>                         {
>>                             GU87 = 0x00
>>                             GU88 = 0x00
>>                             GU89 = 0x00
>>                             GU90 = 0x00
>>                             GP87 = 0x00
>>                             GP88 = 0x00
>>                             GP89 = 0x00
>>                             GP90 = 0x00
>>                             GD87 = 0x00
>>                             GD88 = 0x00
>>                             GD89 = 0x00
>>                             GD90 = 0x00
>>                             Local0 = GU87 /* \GU87 */
>>                         }
>>
>>                         Return (0x00)
>>                     }
>>
>>                     Return (0xFFFFFFFF)
>>                 }
>>             }
>>
>> -----------------------------------------------------------------------------------------------
>>
>> Decoded DSDT table:
>> https://bugzilla.kernel.org/attachment.cgi?id=202141
>>
>> On Thu, Mar 3, 2016 at 8:12 PM, Matthew Garrett <mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org> wrote:
>> > On Thu, Mar 03, 2016 at 07:55:53PM +0100, Lukas Wunner wrote:
>> >
>> >> We could extend drivers/acpi/property.c:acpi_init_properties() to
>> >> check if dmi_match(DMI_BOARD_VENDOR, "Apple Inc."), and instead of
>> >> calling _DSD, call _DSM with Apple's UUID and populate adev->data
>> >> with that. Or add the properties to the existing data, if any.
>> >
>> > Just do it unconditionally, it's cheap.
>> >
>> >> E.g. in the case of this SPI slave we need to fill in five values
>> >> of struct spi_device and we would add a quirk for APP000D which
>> >> retrieves each value via acpi_dev_get_property() instead of
>> >> acpi_dev_get_resources().
>> >
>> > Mm. It'd be nice to avoid having to keep a list of Apple devices - some
>> > sort of mapping function might be easier, returning the values from _CRS
>> > if they're present or from _DSM/_DSD otherwise?
>> >
>> > --
>> > Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org
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