[PATCH v5 0/2] Add Apple SPI keyboard and trackpad driver

[PATCH v5 0/2] Add Apple SPI keyboard and trackpad driver

[Ronald Tschalär]

This changeset adds a driver for the SPI keyboard and trackpad on recent
MacBook's and MacBook Pro's. The driver has seen a fair amount of use
over the last 2 years (basically anybody running linux on these
machines), with only relatively small changes in the last year or so.
For those interested, the driver development has been hosted at
https://github.com/cb22/macbook12-spi-driver/ (as well as my clone at
https://github.com/roadrunner2/macbook12-spi-driver/).

The first patch fixes a problem during config.

The second patch contains the new applespi driver.

Changes in v5:
  Applied all feedback from review by Andy Shevchenko (applespi) and
  Andrzej Hajda (sil-sii8620), including:
  - (sil_sii8620) use 'if (IS_DEFINED(...))' instead of conditional
    compilation to handle RC_CORE being undefined
  - (applespi) a number of cleanups of leftovers from changes to earlier
    versions
  - (applespi) replace some bool flags with loop-end detection
  - (applespi) improve error reporting in a couple places
  The full set of changes to applespi can be viewed at
  https://github.com/roadrunner2/macbook12-spi-driver/ as individual
  commits daf60f8..36afd70 in the upstreaming-review branch.

Ronald Tschalär (2):
  drm/bridge: sil_sii8620: make remote control optional.
  Input: add Apple SPI keyboard and trackpad driver.

 drivers/gpu/drm/bridge/Kconfig          |    3 +-
 drivers/gpu/drm/bridge/sil-sii8620.c    |   10 +-
 drivers/input/keyboard/Kconfig          |   15 +
 drivers/input/keyboard/Makefile         |    1 +
 drivers/input/keyboard/applespi.c       | 1985 +++++++++++++++++++++++
 drivers/input/keyboard/applespi.h       |   29 +
 drivers/input/keyboard/applespi_trace.h |   94 ++
 7 files changed, 2132 insertions(+), 5 deletions(-)
 create mode 100644 drivers/input/keyboard/applespi.c
 create mode 100644 drivers/input/keyboard/applespi.h
 create mode 100644 drivers/input/keyboard/applespi_trace.h

-- 
2.20.1

[PATCH v5 1/2] drm/bridge: sil_sii8620: make remote control optional.

[Ronald Tschalär]

commit d6abe6df706c (drm/bridge: sil_sii8620: do not have a dependency
of RC_CORE) changed the driver to select both RC_CORE and INPUT.
However, this causes problems with other drivers, in particular an input
driver that depends on MFD_INTEL_LPSS_PCI (to be added in a separate
commit):

  drivers/clk/Kconfig:9:error: recursive dependency detected!
  drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
  drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
  drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
  drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
  drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
  drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
  drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
  drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK

According to the docs and general consensus, select should only be used
for non user-visible symbols, but both RC_CORE and INPUT are
user-visible. Furthermore almost all other references to INPUT
throughout the kernel config are depends, not selects. For this reason
the first part of this change reverts commit d6abe6df706c.

In order to address the original reason for commit d6abe6df706c, namely
that not all boards use the remote controller functionality and hence
should not need have to deal with RC_CORE, the second part of this
change now makes the remote control support in the driver optional and
contingent on RC_CORE being defined. And with this the hard dependency
on INPUT also goes away as that is only needed if RC_CORE is defined
(which in turn already depends on INPUT).

CC: Inki Dae <inki.dae@samsung.com>
CC: Andrzej Hajda <a.hajda@samsung.com>
CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
---
 drivers/gpu/drm/bridge/Kconfig       |  3 +--
 drivers/gpu/drm/bridge/sil-sii8620.c | 10 +++++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 2fee47b0d50b..9cf07105b73a 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -85,8 +85,7 @@ config DRM_SIL_SII8620
 	depends on OF
 	select DRM_KMS_HELPER
 	imply EXTCON
-	select INPUT
-	select RC_CORE
+	imply RC_CORE
 	help
 	  Silicon Image SII8620 HDMI/MHL bridge chip driver.
 
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index a6e8f4591e63..cff3131aae6c 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -1763,10 +1763,8 @@ static bool sii8620_rcp_consume(struct sii8620 *ctx, u8 scancode)
 
 	scancode &= MHL_RCP_KEY_ID_MASK;
 
-	if (!ctx->rc_dev) {
-		dev_dbg(ctx->dev, "RCP input device not initialized\n");
+	if (!IS_ENABLED(CONFIG_RC_CORE) || !ctx->rc_dev)
 		return false;
-	}
 
 	if (pressed)
 		rc_keydown(ctx->rc_dev, RC_PROTO_CEC, scancode, 0);
@@ -2103,6 +2101,9 @@ static void sii8620_init_rcp_input_dev(struct sii8620 *ctx)
 	struct rc_dev *rc_dev;
 	int ret;
 
+	if (!IS_ENABLED(CONFIG_RC_CORE))
+		return;
+
 	rc_dev = rc_allocate_device(RC_DRIVER_SCANCODE);
 	if (!rc_dev) {
 		dev_err(ctx->dev, "Failed to allocate RC device\n");
@@ -2217,6 +2218,9 @@ static void sii8620_detach(struct drm_bridge *bridge)
 {
 	struct sii8620 *ctx = bridge_to_sii8620(bridge);
 
+	if (!IS_ENABLED(CONFIG_RC_CORE))
+		return;
+
 	rc_unregister_device(ctx->rc_dev);
 }
 
-- 
2.20.1

Re: [PATCH v5 1/2] drm/bridge: sil_sii8620: make remote control optional.

[Andrzej Hajda]

On 15.04.2019 10:12, Ronald Tschalär wrote:
> commit d6abe6df706c (drm/bridge: sil_sii8620: do not have a dependency
> of RC_CORE) changed the driver to select both RC_CORE and INPUT.
> However, this causes problems with other drivers, in particular an input
> driver that depends on MFD_INTEL_LPSS_PCI (to be added in a separate
> commit):
>
>   drivers/clk/Kconfig:9:error: recursive dependency detected!
>   drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
>   drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
>   drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
>   drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
>   drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
>   drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
>   drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
>   drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK
>
> According to the docs and general consensus, select should only be used
> for non user-visible symbols, but both RC_CORE and INPUT are
> user-visible. Furthermore almost all other references to INPUT
> throughout the kernel config are depends, not selects. For this reason
> the first part of this change reverts commit d6abe6df706c.
>
> In order to address the original reason for commit d6abe6df706c, namely
> that not all boards use the remote controller functionality and hence
> should not need have to deal with RC_CORE, the second part of this
> change now makes the remote control support in the driver optional and
> contingent on RC_CORE being defined. And with this the hard dependency
> on INPUT also goes away as that is only needed if RC_CORE is defined
> (which in turn already depends on INPUT).
>
> CC: Inki Dae <inki.dae@samsung.com>
> CC: Andrzej Hajda <a.hajda@samsung.com>
> CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Signed-off-by: Ronald Tschalär <ronald@innovation.ch>


Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>


If there are no objections I will take it to drm-misc tomorrow.


 --
Regards
Andrzej

Re: [PATCH v5 1/2] drm/bridge: sil_sii8620: make remote control optional.

[Life is hard, and then you die]

  Hi Andrzej,

On Mon, Apr 15, 2019 at 10:58:09AM +0200, Andrzej Hajda wrote:
> On 15.04.2019 10:12, Ronald Tschalär wrote:
> > commit d6abe6df706c (drm/bridge: sil_sii8620: do not have a dependency
> > of RC_CORE) changed the driver to select both RC_CORE and INPUT.
> > However, this causes problems with other drivers, in particular an input
> > driver that depends on MFD_INTEL_LPSS_PCI (to be added in a separate
> > commit):
> >
> >   drivers/clk/Kconfig:9:error: recursive dependency detected!
> >   drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
> >   drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
> >   drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
> >   drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
> >   drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
> >   drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
> >   drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
> >   drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK
> >
> > According to the docs and general consensus, select should only be used
> > for non user-visible symbols, but both RC_CORE and INPUT are
> > user-visible. Furthermore almost all other references to INPUT
> > throughout the kernel config are depends, not selects. For this reason
> > the first part of this change reverts commit d6abe6df706c.
> >
> > In order to address the original reason for commit d6abe6df706c, namely
> > that not all boards use the remote controller functionality and hence
> > should not need have to deal with RC_CORE, the second part of this
> > change now makes the remote control support in the driver optional and
> > contingent on RC_CORE being defined. And with this the hard dependency
> > on INPUT also goes away as that is only needed if RC_CORE is defined
> > (which in turn already depends on INPUT).
> >
> > CC: Inki Dae <inki.dae@samsung.com>
> > CC: Andrzej Hajda <a.hajda@samsung.com>
> > CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
> 
> 
> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

Thanks for your reviews!

> If there are no objections I will take it to drm-misc tomorrow.

This brings us back to the discussion started in response to the first
version of my patch (see
https://lore.kernel.org/lkml/20190124082423.23139-1-ronald@innovation.ch/T/#m24f45fecd987a787a9554c8088f463fd10de2b00).
To recap: the problem is that the applespi patch depends on this patch
here, as make-config will break as described above otherwise. So if
this patch is submitted through drm-misc, then it's unclear to me how
to ensure that the two patches make it upstream in proper order,
unless the applespi patch is also upstreamed through drm-misc, or the
Kconfig for applespi is (temporarily) modified to not trigger the
config error and another patch is later submitted to fix the Kconfig
again (which seems somewhat ugly to me). Assuming that consensus is to
merge both patches through one tree, then it would seem that because
this patch here is relatively small that maybe it could be merged
through the input tree along with the applespi patch?


  Cheers,

  Ronald

Re: [PATCH v5 1/2] drm/bridge: sil_sii8620: make remote control optional.

[Andrzej Hajda]

On 16.04.2019 01:24, Life is hard, and then you die wrote:
>   Hi Andrzej,
>
> On Mon, Apr 15, 2019 at 10:58:09AM +0200, Andrzej Hajda wrote:
>> On 15.04.2019 10:12, Ronald Tschalär wrote:
>>> commit d6abe6df706c (drm/bridge: sil_sii8620: do not have a dependency
>>> of RC_CORE) changed the driver to select both RC_CORE and INPUT.
>>> However, this causes problems with other drivers, in particular an input
>>> driver that depends on MFD_INTEL_LPSS_PCI (to be added in a separate
>>> commit):
>>>
>>>   drivers/clk/Kconfig:9:error: recursive dependency detected!
>>>   drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
>>>   drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
>>>   drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
>>>   drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
>>>   drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
>>>   drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
>>>   drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
>>>   drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK
>>>
>>> According to the docs and general consensus, select should only be used
>>> for non user-visible symbols, but both RC_CORE and INPUT are
>>> user-visible. Furthermore almost all other references to INPUT
>>> throughout the kernel config are depends, not selects. For this reason
>>> the first part of this change reverts commit d6abe6df706c.
>>>
>>> In order to address the original reason for commit d6abe6df706c, namely
>>> that not all boards use the remote controller functionality and hence
>>> should not need have to deal with RC_CORE, the second part of this
>>> change now makes the remote control support in the driver optional and
>>> contingent on RC_CORE being defined. And with this the hard dependency
>>> on INPUT also goes away as that is only needed if RC_CORE is defined
>>> (which in turn already depends on INPUT).
>>>
>>> CC: Inki Dae <inki.dae@samsung.com>
>>> CC: Andrzej Hajda <a.hajda@samsung.com>
>>> CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>> CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>>> Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
>>
>> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
> Thanks for your reviews!
>
>> If there are no objections I will take it to drm-misc tomorrow.
> This brings us back to the discussion started in response to the first
> version of my patch (see
> https://lore.kernel.org/lkml/20190124082423.23139-1-ronald@innovation.ch/T/#m24f45fecd987a787a9554c8088f463fd10de2b00).
> To recap: the problem is that the applespi patch depends on this patch
> here, as make-config will break as described above otherwise. So if
> this patch is submitted through drm-misc, then it's unclear to me how
> to ensure that the two patches make it upstream in proper order,
> unless the applespi patch is also upstreamed through drm-misc, or the
> Kconfig for applespi is (temporarily) modified to not trigger the
> config error and another patch is later submitted to fix the Kconfig
> again (which seems somewhat ugly to me). Assuming that consensus is to
> merge both patches through one tree, then it would seem that because
> this patch here is relatively small that maybe it could be merged
> through the input tree along with the applespi patch?


Oh, I have forgot. Please take it then via input tree.


Regards

Andrzej



>
>
>   Cheers,
>
>   Ronald
>
>
>

Re: [PATCH v5 1/2] drm/bridge: sil_sii8620: make remote control optional.

[Life is hard, and then you die]

  Hi Andrzej,

On Tue, Apr 16, 2019 at 07:56:31AM +0200, Andrzej Hajda wrote:
> On 16.04.2019 01:24, Life is hard, and then you die wrote:
> >   Hi Andrzej,
> >
> > On Mon, Apr 15, 2019 at 10:58:09AM +0200, Andrzej Hajda wrote:
> >> On 15.04.2019 10:12, Ronald Tschalär wrote:
> >>> commit d6abe6df706c (drm/bridge: sil_sii8620: do not have a dependency
> >>> of RC_CORE) changed the driver to select both RC_CORE and INPUT.
> >>> However, this causes problems with other drivers, in particular an input
> >>> driver that depends on MFD_INTEL_LPSS_PCI (to be added in a separate
> >>> commit):
> >>>
> >>>   drivers/clk/Kconfig:9:error: recursive dependency detected!
> >>>   drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
> >>>   drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
> >>>   drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
> >>>   drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
> >>>   drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
> >>>   drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
> >>>   drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
> >>>   drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK
> >>>
> >>> According to the docs and general consensus, select should only be used
> >>> for non user-visible symbols, but both RC_CORE and INPUT are
> >>> user-visible. Furthermore almost all other references to INPUT
> >>> throughout the kernel config are depends, not selects. For this reason
> >>> the first part of this change reverts commit d6abe6df706c.
> >>>
> >>> In order to address the original reason for commit d6abe6df706c, namely
> >>> that not all boards use the remote controller functionality and hence
> >>> should not need have to deal with RC_CORE, the second part of this
> >>> change now makes the remote control support in the driver optional and
> >>> contingent on RC_CORE being defined. And with this the hard dependency
> >>> on INPUT also goes away as that is only needed if RC_CORE is defined
> >>> (which in turn already depends on INPUT).
> >>>
> >>> CC: Inki Dae <inki.dae@samsung.com>
> >>> CC: Andrzej Hajda <a.hajda@samsung.com>
> >>> CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>> CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> >>> Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
> >>
> >> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
> > Thanks for your reviews!
> >
> >> If there are no objections I will take it to drm-misc tomorrow.
> > This brings us back to the discussion started in response to the first
> > version of my patch (see
> > https://lore.kernel.org/lkml/20190124082423.23139-1-ronald@innovation.ch/T/#m24f45fecd987a787a9554c8088f463fd10de2b00).
> > To recap: the problem is that the applespi patch depends on this patch
> > here, as make-config will break as described above otherwise. So if
> > this patch is submitted through drm-misc, then it's unclear to me how
> > to ensure that the two patches make it upstream in proper order,
> > unless the applespi patch is also upstreamed through drm-misc, or the
> > Kconfig for applespi is (temporarily) modified to not trigger the
> > config error and another patch is later submitted to fix the Kconfig
> > again (which seems somewhat ugly to me). Assuming that consensus is to
> > merge both patches through one tree, then it would seem that because
> > this patch here is relatively small that maybe it could be merged
> > through the input tree along with the applespi patch?
> 
> 
> Oh, I have forgot. Please take it then via input tree.

Thank you!


  Cheers,

  Ronald

[PATCH v5 2/2] Input: add Apple SPI keyboard and trackpad driver.

[Ronald Tschalär]

The keyboard and trackpad on recent MacBook's (since 8,1) and
MacBookPro's (13,* and 14,*) are attached to an SPI controller instead
of USB, as previously. The higher level protocol is not publicly
documented and hence has been reverse engineered. As a consequence there
are still a number of unknown fields and commands. However, the known
parts have been working well and received extensive testing and use.

In order for this driver to work, the proper SPI drivers need to be
loaded too; for MB8,1 these are spi_pxa2xx_platform and spi_pxa2xx_pci;
for all others they are spi_pxa2xx_platform and intel_lpss_pci. For this
reason enabling this driver in the config implies enabling the above
drivers.

CC: Federico Lorenzi <federico@travelground.com>
CC: Lukas Wunner <lukas@wunner.de>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=99891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=108331
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
---
 drivers/input/keyboard/Kconfig          |   15 +
 drivers/input/keyboard/Makefile         |    1 +
 drivers/input/keyboard/applespi.c       | 1985 +++++++++++++++++++++++
 drivers/input/keyboard/applespi.h       |   29 +
 drivers/input/keyboard/applespi_trace.h |   94 ++
 5 files changed, 2124 insertions(+)
 create mode 100644 drivers/input/keyboard/applespi.c
 create mode 100644 drivers/input/keyboard/applespi.h
 create mode 100644 drivers/input/keyboard/applespi_trace.h

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index a878351f1643..d0a9e7fa2508 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -70,6 +70,21 @@ config KEYBOARD_AMIGA
 config ATARI_KBD_CORE
 	bool
 
+config KEYBOARD_APPLESPI
+	tristate "Apple SPI keyboard and trackpad"
+	depends on ACPI && EFI
+	depends on SPI
+	depends on X86 || COMPILE_TEST
+	imply SPI_PXA2XX
+	imply SPI_PXA2XX_PCI
+	imply MFD_INTEL_LPSS_PCI
+	help
+	  Say Y here if you are running Linux on any Apple MacBook8,1 or later,
+	  or any MacBookPro13,* or MacBookPro14,*.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called applespi.
+
 config KEYBOARD_ATARI
 	tristate "Atari keyboard"
 	depends on ATARI
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 182e92985dbf..9283fee2505a 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_KEYBOARD_ADP5520)		+= adp5520-keys.o
 obj-$(CONFIG_KEYBOARD_ADP5588)		+= adp5588-keys.o
 obj-$(CONFIG_KEYBOARD_ADP5589)		+= adp5589-keys.o
 obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
+obj-$(CONFIG_KEYBOARD_APPLESPI)		+= applespi.o
 obj-$(CONFIG_KEYBOARD_ATARI)		+= atakbd.o
 obj-$(CONFIG_KEYBOARD_ATKBD)		+= atkbd.o
 obj-$(CONFIG_KEYBOARD_BCM)		+= bcm-keypad.o
diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c
new file mode 100644
index 000000000000..5c3d7687e346
--- /dev/null
+++ b/drivers/input/keyboard/applespi.c
@@ -0,0 +1,1985 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MacBook (Pro) SPI keyboard and touchpad driver
+ *
+ * Copyright (c) 2015-2018 Federico Lorenzi
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ */
+
+/*
+ * The keyboard and touchpad controller on the MacBookAir6, MacBookPro12,
+ * MacBook8 and newer can be driven either by USB or SPI. However the USB
+ * pins are only connected on the MacBookAir6 and 7 and the MacBookPro12.
+ * All others need this driver. The interface is selected using ACPI methods:
+ *
+ * * UIEN ("USB Interface Enable"): If invoked with argument 1, disables SPI
+ *   and enables USB. If invoked with argument 0, disables USB.
+ * * UIST ("USB Interface Status"): Returns 1 if USB is enabled, 0 otherwise.
+ * * SIEN ("SPI Interface Enable"): If invoked with argument 1, disables USB
+ *   and enables SPI. If invoked with argument 0, disables SPI.
+ * * SIST ("SPI Interface Status"): Returns 1 if SPI is enabled, 0 otherwise.
+ * * ISOL: Resets the four GPIO pins used for SPI. Intended to be invoked with
+ *   argument 1, then once more with argument 0.
+ *
+ * UIEN and UIST are only provided on models where the USB pins are connected.
+ *
+ * SPI-based Protocol
+ * ------------------
+ *
+ * The device and driver exchange messages (struct message); each message is
+ * encapsulated in one or more packets (struct spi_packet). There are two types
+ * of exchanges: reads, and writes. A read is signaled by a GPE, upon which one
+ * message can be read from the device. A write exchange consists of writing a
+ * command message, immediately reading a short status packet, and then, upon
+ * receiving a GPE, reading the response message. Write exchanges cannot be
+ * interleaved, i.e. a new write exchange must not be started till the previous
+ * write exchange is complete. Whether a received message is part of a read or
+ * write exchange is indicated in the encapsulating packet's flags field.
+ *
+ * A single message may be too large to fit in a single packet (which has a
+ * fixed, 256-byte size). In that case it will be split over multiple,
+ * consecutive packets.
+ */
+
+#include <linux/acpi.h>
+#include <linux/crc16.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/efi.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/spi/spi.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#include <asm/barrier.h>
+#include <asm/unaligned.h>
+
+#define CREATE_TRACE_POINTS
+#include "applespi.h"
+#include "applespi_trace.h"
+
+#define APPLESPI_PACKET_SIZE	256
+#define APPLESPI_STATUS_SIZE	4
+
+#define PACKET_TYPE_READ	0x20
+#define PACKET_TYPE_WRITE	0x40
+#define PACKET_DEV_KEYB		0x01
+#define PACKET_DEV_TPAD		0x02
+#define PACKET_DEV_INFO		0xd0
+
+#define MAX_ROLLOVER		6
+
+#define MAX_FINGERS		11
+#define MAX_FINGER_ORIENTATION	16384
+#define MAX_PKTS_PER_MSG	2
+
+#define KBD_BL_LEVEL_MIN	32U
+#define KBD_BL_LEVEL_MAX	255U
+#define KBD_BL_LEVEL_SCALE	1000000U
+#define KBD_BL_LEVEL_ADJ	\
+	((KBD_BL_LEVEL_MAX - KBD_BL_LEVEL_MIN) * KBD_BL_LEVEL_SCALE / 255U)
+
+#define EFI_BL_LEVEL_NAME	L"KeyboardBacklightLevel"
+#define EFI_BL_LEVEL_GUID	EFI_GUID(0xa076d2af, 0x9678, 0x4386, 0x8b, 0x58, 0x1f, 0xc8, 0xef, 0x04, 0x16, 0x19)
+
+#define APPLE_FLAG_FKEY		0x01
+
+#define SPI_RW_CHG_DELAY_US	100	/* from experimentation, in µs */
+
+#define SYNAPTICS_VENDOR_ID	0x06cb
+
+static unsigned int fnmode = 1;
+module_param(fnmode, uint, 0644);
+MODULE_PARM_DESC(fnmode, "Mode of Fn key on Apple keyboards (0 = disabled, [1] = fkeyslast, 2 = fkeysfirst)");
+
+static unsigned int fnremap;
+module_param(fnremap, uint, 0644);
+MODULE_PARM_DESC(fnremap, "Remap Fn key ([0] = no-remap; 1 = left-ctrl, 2 = left-shift, 3 = left-alt, 4 = left-meta, 6 = right-shift, 7 = right-alt, 8 = right-meta)");
+
+static bool iso_layout;
+module_param(iso_layout, bool, 0644);
+MODULE_PARM_DESC(iso_layout, "Enable/Disable hardcoded ISO-layout of the keyboard. ([0] = disabled, 1 = enabled)");
+
+static char touchpad_dimensions[40];
+module_param_string(touchpad_dimensions, touchpad_dimensions,
+		    sizeof(touchpad_dimensions), 0444);
+MODULE_PARM_DESC(touchpad_dimensions, "The pixel dimensions of the touchpad, as XxY+W+H .");
+
+/**
+ * struct keyboard_protocol - keyboard message.
+ * message.type = 0x0110, message.length = 0x000a
+ *
+ * @unknown1:		unknown
+ * @modifiers:		bit-set of modifier/control keys pressed
+ * @unknown2:		unknown
+ * @keys_pressed:	the (non-modifier) keys currently pressed
+ * @fn_pressed:		whether the fn key is currently pressed
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct keyboard_protocol {
+	__u8			unknown1;
+	__u8			modifiers;
+	__u8			unknown2;
+	__u8			keys_pressed[MAX_ROLLOVER];
+	__u8			fn_pressed;
+	__le16			crc16;
+};
+
+/**
+ * struct tp_finger - single trackpad finger structure, le16-aligned
+ *
+ * @origin:		zero when switching track finger
+ * @abs_x:		absolute x coodinate
+ * @abs_y:		absolute y coodinate
+ * @rel_x:		relative x coodinate
+ * @rel_y:		relative y coodinate
+ * @tool_major:		tool area, major axis
+ * @tool_minor:		tool area, minor axis
+ * @orientation:	16384 when point, else 15 bit angle
+ * @touch_major:	touch area, major axis
+ * @touch_minor:	touch area, minor axis
+ * @unused:		zeros
+ * @pressure:		pressure on forcetouch touchpad
+ * @multi:		one finger: varies, more fingers: constant
+ * @crc16:		on last finger: crc over the whole message struct
+ *			(i.e. message header + this struct) minus the last
+ *			@crc16 field; unknown on all other fingers.
+ */
+struct tp_finger {
+	__le16 origin;
+	__le16 abs_x;
+	__le16 abs_y;
+	__le16 rel_x;
+	__le16 rel_y;
+	__le16 tool_major;
+	__le16 tool_minor;
+	__le16 orientation;
+	__le16 touch_major;
+	__le16 touch_minor;
+	__le16 unused[2];
+	__le16 pressure;
+	__le16 multi;
+	__le16 crc16;
+};
+
+/**
+ * struct touchpad_protocol - touchpad message.
+ * message.type = 0x0210
+ *
+ * @unknown1:		unknown
+ * @clicked:		1 if a button-click was detected, 0 otherwise
+ * @unknown2:		unknown
+ * @number_of_fingers:	the number of fingers being reported in @fingers
+ * @clicked2:		same as @clicked
+ * @unknown3:		unknown
+ * @fingers:		the data for each finger
+ */
+struct touchpad_protocol {
+	__u8			unknown1[1];
+	__u8			clicked;
+	__u8			unknown2[28];
+	__u8			number_of_fingers;
+	__u8			clicked2;
+	__u8			unknown3[16];
+	struct tp_finger	fingers[0];
+};
+
+/**
+ * struct command_protocol_tp_info - get touchpad info.
+ * message.type = 0x1020, message.length = 0x0000
+ *
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct command_protocol_tp_info {
+	__le16			crc16;
+};
+
+/**
+ * struct touchpad_info - touchpad info response.
+ * message.type = 0x1020, message.length = 0x006e
+ *
+ * @unknown1:		unknown
+ * @model_flags:	flags (vary by model number, but significance otherwise
+ *			unknown)
+ * @model_no:		the touchpad model number
+ * @unknown2:		unknown
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct touchpad_info_protocol {
+	__u8			unknown1[105];
+	__u8			model_flags;
+	__u8			model_no;
+	__u8			unknown2[3];
+	__le16			crc16;
+};
+
+/**
+ * struct command_protocol_mt_init - initialize multitouch.
+ * message.type = 0x0252, message.length = 0x0002
+ *
+ * @cmd:		value: 0x0102
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct command_protocol_mt_init {
+	__le16			cmd;
+	__le16			crc16;
+};
+
+/**
+ * struct command_protocol_capsl - toggle caps-lock led
+ * message.type = 0x0151, message.length = 0x0002
+ *
+ * @unknown:		value: 0x01 (length?)
+ * @led:		0 off, 2 on
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct command_protocol_capsl {
+	__u8			unknown;
+	__u8			led;
+	__le16			crc16;
+};
+
+/**
+ * struct command_protocol_bl - set keyboard backlight brightness
+ * message.type = 0xB051, message.length = 0x0006
+ *
+ * @const1:		value: 0x01B0
+ * @level:		the brightness level to set
+ * @const2:		value: 0x0001 (backlight off), 0x01F4 (backlight on)
+ * @crc16:		crc over the whole message struct (message header +
+ *			this struct) minus this @crc16 field
+ */
+struct command_protocol_bl {
+	__le16			const1;
+	__le16			level;
+	__le16			const2;
+	__le16			crc16;
+};
+
+/**
+ * struct message - a complete spi message.
+ *
+ * Each message begins with fixed header, followed by a message-type specific
+ * payload, and ends with a 16-bit crc. Because of the varying lengths of the
+ * payload, the crc is defined at the end of each payload struct, rather than
+ * in this struct.
+ *
+ * @type:	the message type
+ * @zero:	always 0
+ * @counter:	incremented on each message, rolls over after 255; there is a
+ *		separate counter for each message type.
+ * @rsp_buf_len:response buffer length (the exact nature of this field is quite
+ *		speculative). On a request/write this is often the same as
+ *		@length, though in some cases it has been seen to be much larger
+ *		(e.g. 0x400); on a response/read this the same as on the
+ *		request; for reads that are not responses it is 0.
+ * @length:	length of the remainder of the data in the whole message
+ *		structure (after re-assembly in case of being split over
+ *		multiple spi-packets), minus the trailing crc. The total size
+ *		of the message struct is therefore @length + 10.
+ */
+struct message {
+	__le16		type;
+	__u8		zero;
+	__u8		counter;
+	__le16		rsp_buf_len;
+	__le16		length;
+	union {
+		struct keyboard_protocol	keyboard;
+		struct touchpad_protocol	touchpad;
+		struct touchpad_info_protocol	tp_info;
+		struct command_protocol_tp_info	tp_info_command;
+		struct command_protocol_mt_init	init_mt_command;
+		struct command_protocol_capsl	capsl_command;
+		struct command_protocol_bl	bl_command;
+		__u8				data[0];
+	};
+};
+
+/* type + zero + counter + rsp_buf_len + length */
+#define MSG_HEADER_SIZE	8
+
+/**
+ * struct spi_packet - a complete spi packet; always 256 bytes. This carries
+ * the (parts of the) message in the data. But note that this does not
+ * necessarily contain a complete message, as in some cases (e.g. many
+ * fingers pressed) the message is split over multiple packets (see the
+ * @offset, @remaining, and @length fields). In general the data parts in
+ * spi_packet's are concatenated until @remaining is 0, and the result is an
+ * message.
+ *
+ * @flags:	0x40 = write (to device), 0x20 = read (from device); note that
+ *		the response to a write still has 0x40.
+ * @device:	1 = keyboard, 2 = touchpad
+ * @offset:	specifies the offset of this packet's data in the complete
+ *		message; i.e. > 0 indicates this is a continuation packet (in
+ *		the second packet for a message split over multiple packets
+ *		this would then be the same as the @length in the first packet)
+ * @remaining:	number of message bytes remaining in subsequents packets (in
+ *		the first packet of a message split over two packets this would
+ *		then be the same as the @length in the second packet)
+ * @length:	length of the valid data in the @data in this packet
+ * @data:	all or part of a message
+ * @crc16:	crc over this whole structure minus this @crc16 field. This
+ *		covers just this packet, even on multi-packet messages (in
+ *		contrast to the crc in the message).
+ */
+struct spi_packet {
+	__u8			flags;
+	__u8			device;
+	__le16			offset;
+	__le16			remaining;
+	__le16			length;
+	__u8			data[246];
+	__le16			crc16;
+};
+
+struct spi_settings {
+	u64	spi_cs_delay;		/* cs-to-clk delay in us */
+	u64	reset_a2r_usec;		/* active-to-receive delay? */
+	u64	reset_rec_usec;		/* ? (cur val: 10) */
+};
+
+/* this mimics struct drm_rect */
+struct applespi_tp_info {
+	int	x_min;
+	int	y_min;
+	int	x_max;
+	int	y_max;
+};
+
+struct applespi_data {
+	struct spi_device		*spi;
+	struct spi_settings		spi_settings;
+	struct input_dev		*keyboard_input_dev;
+	struct input_dev		*touchpad_input_dev;
+
+	u8				*tx_buffer;
+	u8				*tx_status;
+	u8				*rx_buffer;
+
+	u8				*msg_buf;
+	unsigned int			saved_msg_len;
+
+	struct applespi_tp_info		tp_info;
+
+	u8				last_keys_pressed[MAX_ROLLOVER];
+	u8				last_keys_fn_pressed[MAX_ROLLOVER];
+	u8				last_fn_pressed;
+	struct input_mt_pos		pos[MAX_FINGERS];
+	int				slots[MAX_FINGERS];
+	int				gpe;
+	acpi_handle			sien;
+	acpi_handle			sist;
+
+	struct spi_transfer		dl_t;
+	struct spi_transfer		rd_t;
+	struct spi_message		rd_m;
+
+	struct spi_transfer		ww_t;
+	struct spi_transfer		wd_t;
+	struct spi_transfer		wr_t;
+	struct spi_transfer		st_t;
+	struct spi_message		wr_m;
+
+	bool				want_tp_info_cmd;
+	bool				want_mt_init_cmd;
+	bool				want_cl_led_on;
+	bool				have_cl_led_on;
+	unsigned int			want_bl_level;
+	unsigned int			have_bl_level;
+	unsigned int			cmd_msg_cntr;
+	/* lock to protect the above parameters and flags below */
+	spinlock_t			cmd_msg_lock;
+	bool				cmd_msg_queued;
+	enum applespi_evt_type		cmd_evt_type;
+
+	struct led_classdev		backlight_info;
+
+	bool				suspended;
+	bool				drain;
+	wait_queue_head_t		drain_complete;
+	bool				read_active;
+	bool				write_active;
+
+	struct work_struct		work;
+	struct touchpad_info_protocol	rcvd_tp_info;
+
+	struct dentry			*debugfs_root;
+	bool				debug_tp_dim;
+	char				tp_dim_val[40];
+	int				tp_dim_min_x;
+	int				tp_dim_max_x;
+	int				tp_dim_min_y;
+	int				tp_dim_max_y;
+};
+
+static const unsigned char applespi_scancodes[] = {
+	0, 0, 0, 0,
+	KEY_A, KEY_B, KEY_C, KEY_D, KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J,
+	KEY_K, KEY_L, KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T,
+	KEY_U, KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z,
+	KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
+	KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB, KEY_SPACE, KEY_MINUS,
+	KEY_EQUAL, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH, 0,
+	KEY_SEMICOLON, KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA, KEY_DOT, KEY_SLASH,
+	KEY_CAPSLOCK,
+	KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9,
+	KEY_F10, KEY_F11, KEY_F12, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	KEY_RIGHT, KEY_LEFT, KEY_DOWN, KEY_UP,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_102ND,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_RO, 0, KEY_YEN, 0, 0, 0, 0, 0,
+	0, KEY_KATAKANAHIRAGANA, KEY_MUHENKAN
+};
+
+/*
+ * This must have exactly as many entries as there are bits in
+ * struct keyboard_protocol.modifiers .
+ */
+static const unsigned char applespi_controlcodes[] = {
+	KEY_LEFTCTRL,
+	KEY_LEFTSHIFT,
+	KEY_LEFTALT,
+	KEY_LEFTMETA,
+	0,
+	KEY_RIGHTSHIFT,
+	KEY_RIGHTALT,
+	KEY_RIGHTMETA
+};
+
+struct applespi_key_translation {
+	u16 from;
+	u16 to;
+	u8 flags;
+};
+
+static const struct applespi_key_translation applespi_fn_codes[] = {
+	{ KEY_BACKSPACE, KEY_DELETE },
+	{ KEY_ENTER,	KEY_INSERT },
+	{ KEY_F1,	KEY_BRIGHTNESSDOWN,	APPLE_FLAG_FKEY },
+	{ KEY_F2,	KEY_BRIGHTNESSUP,	APPLE_FLAG_FKEY },
+	{ KEY_F3,	KEY_SCALE,		APPLE_FLAG_FKEY },
+	{ KEY_F4,	KEY_DASHBOARD,		APPLE_FLAG_FKEY },
+	{ KEY_F5,	KEY_KBDILLUMDOWN,	APPLE_FLAG_FKEY },
+	{ KEY_F6,	KEY_KBDILLUMUP,		APPLE_FLAG_FKEY },
+	{ KEY_F7,	KEY_PREVIOUSSONG,	APPLE_FLAG_FKEY },
+	{ KEY_F8,	KEY_PLAYPAUSE,		APPLE_FLAG_FKEY },
+	{ KEY_F9,	KEY_NEXTSONG,		APPLE_FLAG_FKEY },
+	{ KEY_F10,	KEY_MUTE,		APPLE_FLAG_FKEY },
+	{ KEY_F11,	KEY_VOLUMEDOWN,		APPLE_FLAG_FKEY },
+	{ KEY_F12,	KEY_VOLUMEUP,		APPLE_FLAG_FKEY },
+	{ KEY_RIGHT,	KEY_END },
+	{ KEY_LEFT,	KEY_HOME },
+	{ KEY_DOWN,	KEY_PAGEDOWN },
+	{ KEY_UP,	KEY_PAGEUP },
+	{ }
+};
+
+static const struct applespi_key_translation apple_iso_keyboard[] = {
+	{ KEY_GRAVE,	KEY_102ND },
+	{ KEY_102ND,	KEY_GRAVE },
+	{ }
+};
+
+struct applespi_tp_model_info {
+	u16			model;
+	struct applespi_tp_info	tp_info;
+};
+
+static const struct applespi_tp_model_info applespi_tp_models[] = {
+	{
+		.model = 0x04,	/* MB8 MB9 MB10 */
+		.tp_info = { -5087, -182, 5579, 6089 },
+	},
+	{
+		.model = 0x05,	/* MBP13,1 MBP13,2 MBP14,1 MBP14,2 */
+		.tp_info = { -6243, -170, 6749, 7685 },
+	},
+	{
+		.model = 0x06,	/* MBP13,3 MBP14,3 */
+		.tp_info = { -7456, -163, 7976, 9283 },
+	},
+	{}
+};
+
+typedef void (*applespi_trace_fun)(enum applespi_evt_type,
+				   enum applespi_pkt_type, u8 *, size_t);
+
+static applespi_trace_fun applespi_get_trace_fun(enum applespi_evt_type type)
+{
+	switch (type) {
+	case ET_CMD_TP_INI:
+		return trace_applespi_tp_ini_cmd;
+	case ET_CMD_BL:
+		return trace_applespi_backlight_cmd;
+	case ET_CMD_CL:
+		return trace_applespi_caps_lock_cmd;
+	case ET_RD_KEYB:
+		return trace_applespi_keyboard_data;
+	case ET_RD_TPAD:
+		return trace_applespi_touchpad_data;
+	case ET_RD_UNKN:
+		return trace_applespi_unknown_data;
+	default:
+		WARN_ONCE(1, "Unknown msg type %d", type);
+		return trace_applespi_unknown_data;
+	}
+}
+
+static void applespi_setup_read_txfrs(struct applespi_data *applespi)
+{
+	struct spi_message *msg = &applespi->rd_m;
+	struct spi_transfer *dl_t = &applespi->dl_t;
+	struct spi_transfer *rd_t = &applespi->rd_t;
+
+	memset(dl_t, 0, sizeof(*dl_t));
+	memset(rd_t, 0, sizeof(*rd_t));
+
+	dl_t->delay_usecs = applespi->spi_settings.spi_cs_delay;
+
+	rd_t->rx_buf = applespi->rx_buffer;
+	rd_t->len = APPLESPI_PACKET_SIZE;
+
+	spi_message_init(msg);
+	spi_message_add_tail(dl_t, msg);
+	spi_message_add_tail(rd_t, msg);
+}
+
+static void applespi_setup_write_txfrs(struct applespi_data *applespi)
+{
+	struct spi_message *msg = &applespi->wr_m;
+	struct spi_transfer *wt_t = &applespi->ww_t;
+	struct spi_transfer *dl_t = &applespi->wd_t;
+	struct spi_transfer *wr_t = &applespi->wr_t;
+	struct spi_transfer *st_t = &applespi->st_t;
+
+	memset(wt_t, 0, sizeof(*wt_t));
+	memset(dl_t, 0, sizeof(*dl_t));
+	memset(wr_t, 0, sizeof(*wr_t));
+	memset(st_t, 0, sizeof(*st_t));
+
+	/*
+	 * All we need here is a delay at the beginning of the message before
+	 * asserting cs. But the current spi API doesn't support this, so we
+	 * end up with an extra unnecessary (but harmless) cs assertion and
+	 * deassertion.
+	 */
+	wt_t->delay_usecs = SPI_RW_CHG_DELAY_US;
+	wt_t->cs_change = 1;
+
+	dl_t->delay_usecs = applespi->spi_settings.spi_cs_delay;
+
+	wr_t->tx_buf = applespi->tx_buffer;
+	wr_t->len = APPLESPI_PACKET_SIZE;
+	wr_t->delay_usecs = SPI_RW_CHG_DELAY_US;
+
+	st_t->rx_buf = applespi->tx_status;
+	st_t->len = APPLESPI_STATUS_SIZE;
+
+	spi_message_init(msg);
+	spi_message_add_tail(wt_t, msg);
+	spi_message_add_tail(dl_t, msg);
+	spi_message_add_tail(wr_t, msg);
+	spi_message_add_tail(st_t, msg);
+}
+
+static int applespi_async(struct applespi_data *applespi,
+			  struct spi_message *message, void (*complete)(void *))
+{
+	message->complete = complete;
+	message->context = applespi;
+
+	return spi_async(applespi->spi, message);
+}
+
+static inline bool applespi_check_write_status(struct applespi_data *applespi,
+					       int sts)
+{
+	static u8 status_ok[] = { 0xac, 0x27, 0x68, 0xd5 };
+
+	if (sts < 0) {
+		dev_warn(&applespi->spi->dev, "Error writing to device: %d\n",
+			 sts);
+		return false;
+	}
+
+	if (memcmp(applespi->tx_status, status_ok, APPLESPI_STATUS_SIZE)) {
+		dev_warn(&applespi->spi->dev, "Error writing to device: %*ph\n",
+			 APPLESPI_STATUS_SIZE, applespi->tx_status);
+		return false;
+	}
+
+	return true;
+}
+
+static int applespi_get_spi_settings(struct applespi_data *applespi)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&applespi->spi->dev);
+	const union acpi_object *o;
+	struct spi_settings *settings = &applespi->spi_settings;
+
+	if (!acpi_dev_get_property(adev, "spiCSDelay", ACPI_TYPE_BUFFER, &o))
+		settings->spi_cs_delay = *(u64 *)o->buffer.pointer;
+	else
+		dev_warn(&applespi->spi->dev,
+			 "Property spiCSDelay not found\n");
+
+	if (!acpi_dev_get_property(adev, "resetA2RUsec", ACPI_TYPE_BUFFER, &o))
+		settings->reset_a2r_usec = *(u64 *)o->buffer.pointer;
+	else
+		dev_warn(&applespi->spi->dev,
+			 "Property resetA2RUsec not found\n");
+
+	if (!acpi_dev_get_property(adev, "resetRecUsec", ACPI_TYPE_BUFFER, &o))
+		settings->reset_rec_usec = *(u64 *)o->buffer.pointer;
+	else
+		dev_warn(&applespi->spi->dev,
+			 "Property resetRecUsec not found\n");
+
+	dev_dbg(&applespi->spi->dev,
+		"SPI settings: spi_cs_delay=%llu reset_a2r_usec=%llu reset_rec_usec=%llu\n",
+		settings->spi_cs_delay, settings->reset_a2r_usec,
+		settings->reset_rec_usec);
+
+	return 0;
+}
+
+static int applespi_setup_spi(struct applespi_data *applespi)
+{
+	int sts;
+
+	sts = applespi_get_spi_settings(applespi);
+	if (sts)
+		return sts;
+
+	spin_lock_init(&applespi->cmd_msg_lock);
+	init_waitqueue_head(&applespi->drain_complete);
+
+	return 0;
+}
+
+static int applespi_enable_spi(struct applespi_data *applespi)
+{
+	acpi_status acpi_sts;
+	unsigned long long spi_status;
+
+	/* check if SPI is already enabled, so we can skip the delay below */
+	acpi_sts = acpi_evaluate_integer(applespi->sist, NULL, NULL,
+					 &spi_status);
+	if (ACPI_SUCCESS(acpi_sts) && spi_status)
+		return 0;
+
+	/* SIEN(1) will enable SPI communication */
+	acpi_sts = acpi_execute_simple_method(applespi->sien, NULL, 1);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev, "SIEN failed: %s\n",
+			acpi_format_exception(acpi_sts));
+		return -ENODEV;
+	}
+
+	/*
+	 * Allow the SPI interface to come up before returning. Without this
+	 * delay, the SPI commands to enable multitouch mode may not reach
+	 * the trackpad controller, causing pointer movement to break upon
+	 * resume from sleep.
+	 */
+	msleep(50);
+
+	return 0;
+}
+
+static int applespi_send_cmd_msg(struct applespi_data *applespi);
+
+static void applespi_msg_complete(struct applespi_data *applespi,
+				  bool is_write_msg, bool is_read_compl)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	if (is_read_compl)
+		applespi->read_active = false;
+	if (is_write_msg)
+		applespi->write_active = false;
+
+	if (applespi->drain && !applespi->write_active)
+		wake_up_all(&applespi->drain_complete);
+
+	if (is_write_msg) {
+		applespi->cmd_msg_queued = false;
+		applespi_send_cmd_msg(applespi);
+	}
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
+static void applespi_async_write_complete(void *context)
+{
+	struct applespi_data *applespi = context;
+	enum applespi_evt_type evt_type = applespi->cmd_evt_type;
+
+	applespi_get_trace_fun(evt_type)(evt_type, PT_WRITE,
+					 applespi->tx_buffer,
+					 APPLESPI_PACKET_SIZE);
+	applespi_get_trace_fun(evt_type)(evt_type, PT_STATUS,
+					 applespi->tx_status,
+					 APPLESPI_STATUS_SIZE);
+
+	if (!applespi_check_write_status(applespi, applespi->wr_m.status)) {
+		/*
+		 * If we got an error, we presumably won't get the expected
+		 * response message either.
+		 */
+		applespi_msg_complete(applespi, true, false);
+	}
+}
+
+static int applespi_send_cmd_msg(struct applespi_data *applespi)
+{
+	u16 crc;
+	int sts;
+	struct spi_packet *packet = (struct spi_packet *)applespi->tx_buffer;
+	struct message *message = (struct message *)packet->data;
+	u16 msg_len;
+	u8 device;
+
+	/* check if draining */
+	if (applespi->drain)
+		return 0;
+
+	/* check whether send is in progress */
+	if (applespi->cmd_msg_queued)
+		return 0;
+
+	/* set up packet */
+	memset(packet, 0, APPLESPI_PACKET_SIZE);
+
+	/* are we processing init commands? */
+	if (applespi->want_tp_info_cmd) {
+		applespi->want_tp_info_cmd = false;
+		applespi->want_mt_init_cmd = true;
+		applespi->cmd_evt_type = ET_CMD_TP_INI;
+
+		/* build init command */
+		device = PACKET_DEV_INFO;
+
+		message->type = cpu_to_le16(0x1020);
+		msg_len = sizeof(message->tp_info_command);
+
+		message->zero = 0x02;
+		message->rsp_buf_len = cpu_to_le16(0x0200);
+
+	} else if (applespi->want_mt_init_cmd) {
+		applespi->want_mt_init_cmd = false;
+		applespi->cmd_evt_type = ET_CMD_TP_INI;
+
+		/* build init command */
+		device = PACKET_DEV_TPAD;
+
+		message->type = cpu_to_le16(0x0252);
+		msg_len = sizeof(message->init_mt_command);
+
+		message->init_mt_command.cmd = cpu_to_le16(0x0102);
+
+	/* do we need caps-lock command? */
+	} else if (applespi->want_cl_led_on != applespi->have_cl_led_on) {
+		applespi->have_cl_led_on = applespi->want_cl_led_on;
+		applespi->cmd_evt_type = ET_CMD_CL;
+
+		/* build led command */
+		device = PACKET_DEV_KEYB;
+
+		message->type = cpu_to_le16(0x0151);
+		msg_len = sizeof(message->capsl_command);
+
+		message->capsl_command.unknown = 0x01;
+		message->capsl_command.led = applespi->have_cl_led_on ? 2 : 0;
+
+	/* do we need backlight command? */
+	} else if (applespi->want_bl_level != applespi->have_bl_level) {
+		applespi->have_bl_level = applespi->want_bl_level;
+		applespi->cmd_evt_type = ET_CMD_BL;
+
+		/* build command buffer */
+		device = PACKET_DEV_KEYB;
+
+		message->type = cpu_to_le16(0xB051);
+		msg_len = sizeof(message->bl_command);
+
+		message->bl_command.const1 = cpu_to_le16(0x01B0);
+		message->bl_command.level =
+				cpu_to_le16(applespi->have_bl_level);
+
+		if (applespi->have_bl_level > 0)
+			message->bl_command.const2 = cpu_to_le16(0x01F4);
+		else
+			message->bl_command.const2 = cpu_to_le16(0x0001);
+
+	/* everything's up-to-date */
+	} else {
+		return 0;
+	}
+
+	/* finalize packet */
+	packet->flags = PACKET_TYPE_WRITE;
+	packet->device = device;
+	packet->length = cpu_to_le16(MSG_HEADER_SIZE + msg_len);
+
+	message->counter = applespi->cmd_msg_cntr++ % (U8_MAX + 1);
+
+	message->length = cpu_to_le16(msg_len - 2);
+	if (!message->rsp_buf_len)
+		message->rsp_buf_len = message->length;
+
+	crc = crc16(0, (u8 *)message, le16_to_cpu(packet->length) - 2);
+	put_unaligned_le16(crc, &message->data[msg_len - 2]);
+
+	crc = crc16(0, (u8 *)packet, sizeof(*packet) - 2);
+	packet->crc16 = cpu_to_le16(crc);
+
+	/* send command */
+	sts = applespi_async(applespi, &applespi->wr_m,
+			     applespi_async_write_complete);
+	if (sts) {
+		dev_warn(&applespi->spi->dev,
+			 "Error queueing async write to device: %d\n", sts);
+		return sts;
+	}
+
+	applespi->cmd_msg_queued = true;
+	applespi->write_active = true;
+
+	return 0;
+}
+
+static void applespi_init(struct applespi_data *applespi, bool is_resume)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	if (is_resume)
+		applespi->want_mt_init_cmd = true;
+	else
+		applespi->want_tp_info_cmd = true;
+	applespi_send_cmd_msg(applespi);
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
+static int applespi_set_capsl_led(struct applespi_data *applespi,
+				  bool capslock_on)
+{
+	unsigned long flags;
+	int sts;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	applespi->want_cl_led_on = capslock_on;
+	sts = applespi_send_cmd_msg(applespi);
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+
+	return sts;
+}
+
+static void applespi_set_bl_level(struct led_classdev *led_cdev,
+				  enum led_brightness value)
+{
+	struct applespi_data *applespi =
+		container_of(led_cdev, struct applespi_data, backlight_info);
+	unsigned long flags;
+	int sts;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	if (value == 0) {
+		applespi->want_bl_level = value;
+	} else {
+		/*
+		 * The backlight does not turn on till level 32, so we scale
+		 * the range here so that from a user's perspective it turns
+		 * on at 1.
+		 */
+		applespi->want_bl_level =
+			((value * KBD_BL_LEVEL_ADJ) / KBD_BL_LEVEL_SCALE +
+			 KBD_BL_LEVEL_MIN);
+	}
+
+	sts = applespi_send_cmd_msg(applespi);
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
+static int applespi_event(struct input_dev *dev, unsigned int type,
+			  unsigned int code, int value)
+{
+	struct applespi_data *applespi = input_get_drvdata(dev);
+
+	switch (type) {
+	case EV_LED:
+		applespi_set_capsl_led(applespi, !!test_bit(LED_CAPSL, dev->led));
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/* lifted from the BCM5974 driver and renamed from raw2int */
+/* convert 16-bit little endian to signed integer */
+static inline int le16_to_int(__le16 x)
+{
+	return (signed short)le16_to_cpu(x);
+}
+
+static void applespi_debug_update_dimensions(struct applespi_data *applespi,
+					     const struct tp_finger *f)
+{
+	applespi->tp_dim_min_x = min_t(int, applespi->tp_dim_min_x, f->abs_x);
+	applespi->tp_dim_max_x = max_t(int, applespi->tp_dim_max_x, f->abs_x);
+	applespi->tp_dim_min_y = min_t(int, applespi->tp_dim_min_y, f->abs_y);
+	applespi->tp_dim_max_y = max_t(int, applespi->tp_dim_max_y, f->abs_y);
+}
+
+static int applespi_tp_dim_open(struct inode *inode, struct file *file)
+{
+	struct applespi_data *applespi = inode->i_private;
+
+	file->private_data = applespi;
+
+	snprintf(applespi->tp_dim_val, sizeof(applespi->tp_dim_val),
+		 "0x%.4x %dx%d+%u+%u\n",
+		 applespi->touchpad_input_dev->id.product,
+		 applespi->tp_dim_min_x, applespi->tp_dim_min_y,
+		 applespi->tp_dim_max_x - applespi->tp_dim_min_x,
+		 applespi->tp_dim_max_y - applespi->tp_dim_min_y);
+
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t applespi_tp_dim_read(struct file *file, char __user *buf,
+				    size_t len, loff_t *off)
+{
+	struct applespi_data *applespi = file->private_data;
+
+	return simple_read_from_buffer(buf, len, off, applespi->tp_dim_val,
+				       strlen(applespi->tp_dim_val));
+}
+
+static const struct file_operations applespi_tp_dim_fops = {
+	.owner = THIS_MODULE,
+	.open = applespi_tp_dim_open,
+	.read = applespi_tp_dim_read,
+	.llseek = no_llseek,
+};
+
+static void report_finger_data(struct input_dev *input, int slot,
+			       const struct input_mt_pos *pos,
+			       const struct tp_finger *f)
+{
+	input_mt_slot(input, slot);
+	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+
+	input_report_abs(input, ABS_MT_TOUCH_MAJOR,
+			 le16_to_int(f->touch_major) << 1);
+	input_report_abs(input, ABS_MT_TOUCH_MINOR,
+			 le16_to_int(f->touch_minor) << 1);
+	input_report_abs(input, ABS_MT_WIDTH_MAJOR,
+			 le16_to_int(f->tool_major) << 1);
+	input_report_abs(input, ABS_MT_WIDTH_MINOR,
+			 le16_to_int(f->tool_minor) << 1);
+	input_report_abs(input, ABS_MT_ORIENTATION,
+			 MAX_FINGER_ORIENTATION - le16_to_int(f->orientation));
+	input_report_abs(input, ABS_MT_POSITION_X, pos->x);
+	input_report_abs(input, ABS_MT_POSITION_Y, pos->y);
+}
+
+static void report_tp_state(struct applespi_data *applespi,
+			    struct touchpad_protocol *t)
+{
+	const struct tp_finger *f;
+	struct input_dev *input;
+	const struct applespi_tp_info *tp_info = &applespi->tp_info;
+	int i, n;
+
+	/* touchpad_input_dev is set async in worker */
+	input = smp_load_acquire(&applespi->touchpad_input_dev);
+	if (!input)
+		return;	/* touchpad isn't initialized yet */
+
+	n = 0;
+
+	for (i = 0; i < t->number_of_fingers; i++) {
+		f = &t->fingers[i];
+		if (le16_to_int(f->touch_major) == 0)
+			continue;
+		applespi->pos[n].x = le16_to_int(f->abs_x);
+		applespi->pos[n].y = tp_info->y_min + tp_info->y_max -
+				     le16_to_int(f->abs_y);
+		n++;
+
+		if (applespi->debug_tp_dim)
+			applespi_debug_update_dimensions(applespi, f);
+	}
+
+	input_mt_assign_slots(input, applespi->slots, applespi->pos, n, 0);
+
+	for (i = 0; i < n; i++)
+		report_finger_data(input, applespi->slots[i],
+				   &applespi->pos[i], &t->fingers[i]);
+
+	input_mt_sync_frame(input);
+	input_report_key(input, BTN_LEFT, t->clicked);
+
+	input_sync(input);
+}
+
+static const struct applespi_key_translation *
+applespi_find_translation(const struct applespi_key_translation *table, u16 key)
+{
+	const struct applespi_key_translation *trans;
+
+	for (trans = table; trans->from; trans++)
+		if (trans->from == key)
+			return trans;
+
+	return NULL;
+}
+
+static unsigned int applespi_translate_fn_key(unsigned int key, int fn_pressed)
+{
+	const struct applespi_key_translation *trans;
+	int do_translate;
+
+	trans = applespi_find_translation(applespi_fn_codes, key);
+	if (trans) {
+		if (trans->flags & APPLE_FLAG_FKEY)
+			do_translate = (fnmode == 2 && fn_pressed) ||
+				       (fnmode == 1 && !fn_pressed);
+		else
+			do_translate = fn_pressed;
+
+		if (do_translate)
+			key = trans->to;
+	}
+
+	return key;
+}
+
+static unsigned int applespi_translate_iso_layout(unsigned int key)
+{
+	const struct applespi_key_translation *trans;
+
+	trans = applespi_find_translation(apple_iso_keyboard, key);
+	if (trans)
+		key = trans->to;
+
+	return key;
+}
+
+static unsigned int applespi_code_to_key(u8 code, int fn_pressed)
+{
+	unsigned int key = applespi_scancodes[code];
+
+	if (fnmode)
+		key = applespi_translate_fn_key(key, fn_pressed);
+	if (iso_layout)
+		key = applespi_translate_iso_layout(key);
+	return key;
+}
+
+static void
+applespi_remap_fn_key(struct keyboard_protocol *keyboard_protocol)
+{
+	unsigned char tmp;
+	u8 bit = BIT(fnremap - 1);
+
+	if (!fnremap || fnremap > ARRAY_SIZE(applespi_controlcodes) ||
+	    !applespi_controlcodes[fnremap - 1])
+		return;
+
+	tmp = keyboard_protocol->fn_pressed;
+	keyboard_protocol->fn_pressed = !!(keyboard_protocol->modifiers & bit);
+	if (tmp)
+		keyboard_protocol->modifiers |= bit;
+	else
+		keyboard_protocol->modifiers &= ~bit;
+}
+
+static void
+applespi_handle_keyboard_event(struct applespi_data *applespi,
+			       struct keyboard_protocol *keyboard_protocol)
+{
+	unsigned int key;
+	int i, j;
+
+	compiletime_assert(ARRAY_SIZE(applespi_controlcodes) ==
+			   sizeof_field(struct keyboard_protocol, modifiers) * 8,
+			   "applespi_controlcodes has wrong number of entries");
+
+	/* check for rollover overflow, which is signalled by all keys == 1 */
+	for (i = 0; i < MAX_ROLLOVER; i++) {
+		if (keyboard_protocol->keys_pressed[i] != 1)
+			break;
+	}
+
+	if (i == MAX_ROLLOVER)	/* all keys were 1 */
+		return;
+
+	/* remap fn key if desired */
+	applespi_remap_fn_key(keyboard_protocol);
+
+	/* check released keys */
+	for (i = 0; i < MAX_ROLLOVER; i++) {
+		for (j = 0; j < MAX_ROLLOVER; j++) {
+			if (applespi->last_keys_pressed[i] ==
+			    keyboard_protocol->keys_pressed[j])
+				break;
+		}
+
+		if (j < MAX_ROLLOVER)	/* key is still pressed */
+			continue;
+
+		key = applespi_code_to_key(applespi->last_keys_pressed[i],
+					   applespi->last_keys_fn_pressed[i]);
+		input_report_key(applespi->keyboard_input_dev, key, 0);
+		applespi->last_keys_fn_pressed[i] = 0;
+	}
+
+	/* check pressed keys */
+	for (i = 0; i < MAX_ROLLOVER; i++) {
+		if (keyboard_protocol->keys_pressed[i] <
+				ARRAY_SIZE(applespi_scancodes) &&
+		    keyboard_protocol->keys_pressed[i] > 0) {
+			key = applespi_code_to_key(
+					keyboard_protocol->keys_pressed[i],
+					keyboard_protocol->fn_pressed);
+			input_report_key(applespi->keyboard_input_dev, key, 1);
+			applespi->last_keys_fn_pressed[i] =
+					keyboard_protocol->fn_pressed;
+		}
+	}
+
+	/* check control keys */
+	for (i = 0; i < ARRAY_SIZE(applespi_controlcodes); i++) {
+		if (keyboard_protocol->modifiers & BIT(i))
+			input_report_key(applespi->keyboard_input_dev,
+					 applespi_controlcodes[i], 1);
+		else
+			input_report_key(applespi->keyboard_input_dev,
+					 applespi_controlcodes[i], 0);
+	}
+
+	/* check function key */
+	if (keyboard_protocol->fn_pressed && !applespi->last_fn_pressed)
+		input_report_key(applespi->keyboard_input_dev, KEY_FN, 1);
+	else if (!keyboard_protocol->fn_pressed && applespi->last_fn_pressed)
+		input_report_key(applespi->keyboard_input_dev, KEY_FN, 0);
+	applespi->last_fn_pressed = keyboard_protocol->fn_pressed;
+
+	/* done */
+	input_sync(applespi->keyboard_input_dev);
+	memcpy(&applespi->last_keys_pressed, keyboard_protocol->keys_pressed,
+	       sizeof(applespi->last_keys_pressed));
+}
+
+static const struct applespi_tp_info *applespi_find_touchpad_info(__u8 model)
+{
+	const struct applespi_tp_model_info *info;
+
+	for (info = applespi_tp_models; info->model; info++) {
+		if (info->model == model)
+			return &info->tp_info;
+	}
+
+	return NULL;
+}
+
+static int
+applespi_register_touchpad_device(struct applespi_data *applespi,
+				  struct touchpad_info_protocol *rcvd_tp_info)
+{
+	const struct applespi_tp_info *tp_info;
+	struct input_dev *touchpad_input_dev;
+	int sts;
+
+	/* set up touchpad dimensions */
+	tp_info = applespi_find_touchpad_info(rcvd_tp_info->model_no);
+	if (!tp_info) {
+		dev_warn(&applespi->spi->dev,
+			 "Unknown touchpad model %x - falling back to MB8 touchpad\n",
+			 rcvd_tp_info->model_no);
+		tp_info = &applespi_tp_models[0].tp_info;
+	}
+
+	applespi->tp_info = *tp_info;
+
+	if (touchpad_dimensions[0]) {
+		int x, y, w, h;
+
+		sts = sscanf(touchpad_dimensions, "%dx%d+%u+%u", &x, &y, &w, &h);
+		if (sts == 4) {
+			dev_info(&applespi->spi->dev,
+				 "Overriding touchpad dimensions from module param\n");
+			applespi->tp_info.x_min = x;
+			applespi->tp_info.y_min = y;
+			applespi->tp_info.x_max = x + w;
+			applespi->tp_info.y_max = y + h;
+		} else {
+			dev_warn(&applespi->spi->dev,
+				 "Invalid touchpad dimensions '%s': must be in the form XxY+W+H\n",
+				 touchpad_dimensions);
+			touchpad_dimensions[0] = '\0';
+		}
+	}
+	if (!touchpad_dimensions[0]) {
+		snprintf(touchpad_dimensions, sizeof(touchpad_dimensions),
+			 "%dx%d+%u+%u",
+			 applespi->tp_info.x_min,
+			 applespi->tp_info.y_min,
+			 applespi->tp_info.x_max - applespi->tp_info.x_min,
+			 applespi->tp_info.y_max - applespi->tp_info.y_min);
+	}
+
+	/* create touchpad input device */
+	touchpad_input_dev = devm_input_allocate_device(&applespi->spi->dev);
+	if (!touchpad_input_dev) {
+		dev_err(&applespi->spi->dev,
+			"Failed to allocate touchpad input device\n");
+		return -ENOMEM;
+	}
+
+	touchpad_input_dev->name = "Apple SPI Touchpad";
+	touchpad_input_dev->phys = "applespi/input1";
+	touchpad_input_dev->dev.parent = &applespi->spi->dev;
+	touchpad_input_dev->id.bustype = BUS_SPI;
+	touchpad_input_dev->id.vendor = SYNAPTICS_VENDOR_ID;
+	touchpad_input_dev->id.product =
+			rcvd_tp_info->model_no << 8 | rcvd_tp_info->model_flags;
+
+	/* basic properties */
+	input_set_capability(touchpad_input_dev, EV_REL, REL_X);
+	input_set_capability(touchpad_input_dev, EV_REL, REL_Y);
+
+	__set_bit(INPUT_PROP_POINTER, touchpad_input_dev->propbit);
+	__set_bit(INPUT_PROP_BUTTONPAD, touchpad_input_dev->propbit);
+
+	/* finger touch area */
+	input_set_abs_params(touchpad_input_dev, ABS_MT_TOUCH_MAJOR,
+			     0, 5000, 0, 0);
+	input_set_abs_params(touchpad_input_dev, ABS_MT_TOUCH_MINOR,
+			     0, 5000, 0, 0);
+
+	/* finger approach area */
+	input_set_abs_params(touchpad_input_dev, ABS_MT_WIDTH_MAJOR,
+			     0, 5000, 0, 0);
+	input_set_abs_params(touchpad_input_dev, ABS_MT_WIDTH_MINOR,
+			     0, 5000, 0, 0);
+
+	/* finger orientation */
+	input_set_abs_params(touchpad_input_dev, ABS_MT_ORIENTATION,
+			     -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION,
+			     0, 0);
+
+	/* finger position */
+	input_set_abs_params(touchpad_input_dev, ABS_MT_POSITION_X,
+			     applespi->tp_info.x_min, applespi->tp_info.x_max,
+			     0, 0);
+	input_set_abs_params(touchpad_input_dev, ABS_MT_POSITION_Y,
+			     applespi->tp_info.y_min, applespi->tp_info.y_max,
+			     0, 0);
+
+	/* touchpad button */
+	input_set_capability(touchpad_input_dev, EV_KEY, BTN_LEFT);
+
+	/* multitouch */
+	input_mt_init_slots(touchpad_input_dev, MAX_FINGERS,
+			    INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
+			    INPUT_MT_TRACK);
+
+	/* register input device */
+	sts = input_register_device(touchpad_input_dev);
+	if (sts) {
+		dev_err(&applespi->spi->dev,
+			"Unable to register touchpad input device (%d)\n", sts);
+		return sts;
+	}
+
+	/* touchpad_input_dev is read async in spi callback */
+	smp_store_release(&applespi->touchpad_input_dev, touchpad_input_dev);
+
+	return 0;
+}
+
+static void applespi_worker(struct work_struct *work)
+{
+	struct applespi_data *applespi =
+		container_of(work, struct applespi_data, work);
+
+	applespi_register_touchpad_device(applespi, &applespi->rcvd_tp_info);
+}
+
+static void applespi_handle_cmd_response(struct applespi_data *applespi,
+					 struct spi_packet *packet,
+					 struct message *message)
+{
+	if (packet->device == PACKET_DEV_INFO &&
+	    le16_to_cpu(message->type) == 0x1020) {
+		/*
+		 * We're not allowed to sleep here, but registering an input
+		 * device can sleep.
+		 */
+		applespi->rcvd_tp_info = message->tp_info;
+		schedule_work(&applespi->work);
+		return;
+	}
+
+	if (le16_to_cpu(message->length) != 0x0000) {
+		dev_warn_ratelimited(&applespi->spi->dev,
+				     "Received unexpected write response: length=%x\n",
+				     le16_to_cpu(message->length));
+		return;
+	}
+
+	if (packet->device == PACKET_DEV_TPAD &&
+	    le16_to_cpu(message->type) == 0x0252 &&
+	    le16_to_cpu(message->rsp_buf_len) == 0x0002)
+		dev_info(&applespi->spi->dev, "modeswitch done.\n");
+}
+
+static bool applespi_verify_crc(struct applespi_data *applespi, u8 *buffer,
+				size_t buflen)
+{
+	u16 crc;
+
+	crc = crc16(0, buffer, buflen);
+	if (crc) {
+		dev_warn_ratelimited(&applespi->spi->dev,
+				     "Received corrupted packet (crc mismatch)\n");
+		trace_applespi_bad_crc(ET_RD_CRC, READ, buffer, buflen);
+
+		return false;
+	}
+
+	return true;
+}
+
+static void applespi_debug_print_read_packet(struct applespi_data *applespi,
+					     struct spi_packet *packet)
+{
+	unsigned int evt_type;
+
+	if (packet->flags == PACKET_TYPE_READ &&
+	    packet->device == PACKET_DEV_KEYB)
+		evt_type = ET_RD_KEYB;
+	else if (packet->flags == PACKET_TYPE_READ &&
+		 packet->device == PACKET_DEV_TPAD)
+		evt_type = ET_RD_TPAD;
+	else if (packet->flags == PACKET_TYPE_WRITE)
+		evt_type = applespi->cmd_evt_type;
+	else
+		evt_type = ET_RD_UNKN;
+
+	applespi_get_trace_fun(evt_type)(evt_type, PT_READ, applespi->rx_buffer,
+					 APPLESPI_PACKET_SIZE);
+}
+
+static void applespi_got_data(struct applespi_data *applespi)
+{
+	struct spi_packet *packet;
+	struct message *message;
+	unsigned int msg_len;
+	unsigned int off;
+	unsigned int rem;
+	unsigned int len;
+
+	/* process packet header */
+	if (!applespi_verify_crc(applespi, applespi->rx_buffer,
+				 APPLESPI_PACKET_SIZE)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+		if (applespi->drain) {
+			applespi->read_active = false;
+			applespi->write_active = false;
+
+			wake_up_all(&applespi->drain_complete);
+		}
+
+		spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+
+		return;
+	}
+
+	packet = (struct spi_packet *)applespi->rx_buffer;
+
+	applespi_debug_print_read_packet(applespi, packet);
+
+	off = le16_to_cpu(packet->offset);
+	rem = le16_to_cpu(packet->remaining);
+	len = le16_to_cpu(packet->length);
+
+	if (len > sizeof(packet->data)) {
+		dev_warn_ratelimited(&applespi->spi->dev,
+				     "Received corrupted packet (invalid packet length %u)\n",
+				     len);
+		goto msg_complete;
+	}
+
+	/* handle multi-packet messages */
+	if (rem > 0 || off > 0) {
+		if (off != applespi->saved_msg_len) {
+			dev_warn_ratelimited(&applespi->spi->dev,
+					     "Received unexpected offset (got %u, expected %u)\n",
+					     off, applespi->saved_msg_len);
+			goto msg_complete;
+		}
+
+		if (off + rem > MAX_PKTS_PER_MSG * APPLESPI_PACKET_SIZE) {
+			dev_warn_ratelimited(&applespi->spi->dev,
+					     "Received message too large (size %u)\n",
+					     off + rem);
+			goto msg_complete;
+		}
+
+		if (off + len > MAX_PKTS_PER_MSG * APPLESPI_PACKET_SIZE) {
+			dev_warn_ratelimited(&applespi->spi->dev,
+					     "Received message too large (size %u)\n",
+					     off + len);
+			goto msg_complete;
+		}
+
+		memcpy(applespi->msg_buf + off, &packet->data, len);
+		applespi->saved_msg_len += len;
+
+		if (rem > 0)
+			return;
+
+		message = (struct message *)applespi->msg_buf;
+		msg_len = applespi->saved_msg_len;
+	} else {
+		message = (struct message *)&packet->data;
+		msg_len = len;
+	}
+
+	/* got complete message - verify */
+	if (!applespi_verify_crc(applespi, (u8 *)message, msg_len))
+		goto msg_complete;
+
+	if (le16_to_cpu(message->length) != msg_len - MSG_HEADER_SIZE - 2) {
+		dev_warn_ratelimited(&applespi->spi->dev,
+				     "Received corrupted packet (invalid message length %u - expected %u)\n",
+				     le16_to_cpu(message->length),
+				     msg_len - MSG_HEADER_SIZE - 2);
+		goto msg_complete;
+	}
+
+	/* handle message */
+	if (packet->flags == PACKET_TYPE_READ &&
+	    packet->device == PACKET_DEV_KEYB) {
+		applespi_handle_keyboard_event(applespi, &message->keyboard);
+
+	} else if (packet->flags == PACKET_TYPE_READ &&
+		   packet->device == PACKET_DEV_TPAD) {
+		struct touchpad_protocol *tp;
+		size_t tp_len;
+
+		tp = &message->touchpad;
+		tp_len = sizeof(*tp) +
+			 tp->number_of_fingers * sizeof(tp->fingers[0]);
+
+		if (le16_to_cpu(message->length) + 2 != tp_len) {
+			dev_warn_ratelimited(&applespi->spi->dev,
+					     "Received corrupted packet (invalid message length %u - num-fingers %u, tp-len %zu)\n",
+					     le16_to_cpu(message->length),
+					     tp->number_of_fingers, tp_len);
+			goto msg_complete;
+		}
+
+		if (tp->number_of_fingers > MAX_FINGERS) {
+			dev_warn_ratelimited(&applespi->spi->dev,
+					     "Number of reported fingers (%u) exceeds max (%u))\n",
+					     tp->number_of_fingers,
+					     MAX_FINGERS);
+			tp->number_of_fingers = MAX_FINGERS;
+		}
+
+		report_tp_state(applespi, tp);
+
+	} else if (packet->flags == PACKET_TYPE_WRITE) {
+		applespi_handle_cmd_response(applespi, packet, message);
+	}
+
+msg_complete:
+	applespi->saved_msg_len = 0;
+
+	applespi_msg_complete(applespi, packet->flags == PACKET_TYPE_WRITE,
+			      true);
+}
+
+static void applespi_async_read_complete(void *context)
+{
+	struct applespi_data *applespi = context;
+
+	if (applespi->rd_m.status < 0) {
+		dev_warn(&applespi->spi->dev, "Error reading from device: %d\n",
+			 applespi->rd_m.status);
+		/*
+		 * We don't actually know if this was a pure read, or a response
+		 * to a write. But this is a rare error condition that should
+		 * never occur, so clearing both flags to avoid deadlock.
+		 */
+		applespi_msg_complete(applespi, true, true);
+	} else {
+		applespi_got_data(applespi);
+	}
+
+	acpi_finish_gpe(NULL, applespi->gpe);
+}
+
+static u32 applespi_notify(acpi_handle gpe_device, u32 gpe, void *context)
+{
+	struct applespi_data *applespi = context;
+	int sts;
+	unsigned long flags;
+
+	trace_applespi_irq_received(ET_RD_IRQ, PT_READ);
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	if (!applespi->suspended) {
+		sts = applespi_async(applespi, &applespi->rd_m,
+				     applespi_async_read_complete);
+		if (sts)
+			dev_warn(&applespi->spi->dev,
+				 "Error queueing async read to device: %d\n",
+				 sts);
+		else
+			applespi->read_active = true;
+	}
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+
+	return ACPI_INTERRUPT_HANDLED;
+}
+
+static int applespi_get_saved_bl_level(struct applespi_data *applespi)
+{
+	struct efivar_entry *efivar_entry;
+	u16 efi_data = 0;
+	unsigned long efi_data_len;
+	int sts;
+
+	efivar_entry = kmalloc(sizeof(*efivar_entry), GFP_KERNEL);
+	if (!efivar_entry)
+		return -ENOMEM;
+
+	memcpy(efivar_entry->var.VariableName, EFI_BL_LEVEL_NAME,
+	       sizeof(EFI_BL_LEVEL_NAME));
+	efivar_entry->var.VendorGuid = EFI_BL_LEVEL_GUID;
+	efi_data_len = sizeof(efi_data);
+
+	sts = efivar_entry_get(efivar_entry, NULL, &efi_data_len, &efi_data);
+	if (sts && sts != -ENOENT)
+		dev_warn(&applespi->spi->dev,
+			 "Error getting backlight level from EFI vars: %d\n",
+			 sts);
+
+	kfree(efivar_entry);
+
+	return sts ? sts : efi_data;
+}
+
+static void applespi_save_bl_level(struct applespi_data *applespi,
+				   unsigned int level)
+{
+	efi_guid_t efi_guid;
+	u32 efi_attr;
+	unsigned long efi_data_len;
+	u16 efi_data;
+	int sts;
+
+	/* Save keyboard backlight level */
+	efi_guid = EFI_BL_LEVEL_GUID;
+	efi_data = (u16)level;
+	efi_data_len = sizeof(efi_data);
+	efi_attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
+		   EFI_VARIABLE_RUNTIME_ACCESS;
+
+	sts = efivar_entry_set_safe(EFI_BL_LEVEL_NAME, efi_guid, efi_attr, true,
+				    efi_data_len, &efi_data);
+	if (sts)
+		dev_warn(&applespi->spi->dev,
+			 "Error saving backlight level to EFI vars: %d\n", sts);
+}
+
+static int applespi_probe(struct spi_device *spi)
+{
+	struct applespi_data *applespi;
+	acpi_handle spi_handle = ACPI_HANDLE(&spi->dev);
+	acpi_status acpi_sts;
+	int sts, i;
+	unsigned long long gpe, usb_status;
+
+	/* check if the USB interface is present and enabled already */
+	acpi_sts = acpi_evaluate_integer(spi_handle, "UIST", NULL, &usb_status);
+	if (ACPI_SUCCESS(acpi_sts) && usb_status) {
+		/* let the USB driver take over instead */
+		dev_info(&spi->dev, "USB interface already enabled\n");
+		return -ENODEV;
+	}
+
+	/* allocate driver data */
+	applespi = devm_kzalloc(&spi->dev, sizeof(*applespi), GFP_KERNEL);
+	if (!applespi)
+		return -ENOMEM;
+
+	applespi->spi = spi;
+
+	INIT_WORK(&applespi->work, applespi_worker);
+
+	/* store the driver data */
+	spi_set_drvdata(spi, applespi);
+
+	/* create our buffers */
+	applespi->tx_buffer = devm_kmalloc(&spi->dev, APPLESPI_PACKET_SIZE,
+					   GFP_KERNEL);
+	applespi->tx_status = devm_kmalloc(&spi->dev, APPLESPI_STATUS_SIZE,
+					   GFP_KERNEL);
+	applespi->rx_buffer = devm_kmalloc(&spi->dev, APPLESPI_PACKET_SIZE,
+					   GFP_KERNEL);
+	applespi->msg_buf = devm_kmalloc_array(&spi->dev, MAX_PKTS_PER_MSG,
+					       APPLESPI_PACKET_SIZE,
+					       GFP_KERNEL);
+
+	if (!applespi->tx_buffer || !applespi->tx_status ||
+	    !applespi->rx_buffer || !applespi->msg_buf)
+		return -ENOMEM;
+
+	/* set up our spi messages */
+	applespi_setup_read_txfrs(applespi);
+	applespi_setup_write_txfrs(applespi);
+
+	/* cache ACPI method handles */
+	acpi_sts = acpi_get_handle(spi_handle, "SIEN", &applespi->sien);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev,
+			"Failed to get SIEN ACPI method handle: %s\n",
+			acpi_format_exception(acpi_sts));
+		return -ENODEV;
+	}
+
+	acpi_sts = acpi_get_handle(spi_handle, "SIST", &applespi->sist);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev,
+			"Failed to get SIST ACPI method handle: %s\n",
+			acpi_format_exception(acpi_sts));
+		return -ENODEV;
+	}
+
+	/* switch on the SPI interface */
+	sts = applespi_setup_spi(applespi);
+	if (sts)
+		return sts;
+
+	sts = applespi_enable_spi(applespi);
+	if (sts)
+		return sts;
+
+	/* setup the keyboard input dev */
+	applespi->keyboard_input_dev = devm_input_allocate_device(&spi->dev);
+
+	if (!applespi->keyboard_input_dev)
+		return -ENOMEM;
+
+	applespi->keyboard_input_dev->name = "Apple SPI Keyboard";
+	applespi->keyboard_input_dev->phys = "applespi/input0";
+	applespi->keyboard_input_dev->dev.parent = &spi->dev;
+	applespi->keyboard_input_dev->id.bustype = BUS_SPI;
+
+	applespi->keyboard_input_dev->evbit[0] =
+			BIT_MASK(EV_KEY) | BIT_MASK(EV_LED) | BIT_MASK(EV_REP);
+	applespi->keyboard_input_dev->ledbit[0] = BIT_MASK(LED_CAPSL);
+
+	input_set_drvdata(applespi->keyboard_input_dev, applespi);
+	applespi->keyboard_input_dev->event = applespi_event;
+
+	for (i = 0; i < ARRAY_SIZE(applespi_scancodes); i++)
+		if (applespi_scancodes[i])
+			input_set_capability(applespi->keyboard_input_dev,
+					     EV_KEY, applespi_scancodes[i]);
+
+	for (i = 0; i < ARRAY_SIZE(applespi_controlcodes); i++)
+		if (applespi_controlcodes[i])
+			input_set_capability(applespi->keyboard_input_dev,
+					     EV_KEY, applespi_controlcodes[i]);
+
+	for (i = 0; i < ARRAY_SIZE(applespi_fn_codes); i++)
+		if (applespi_fn_codes[i].to)
+			input_set_capability(applespi->keyboard_input_dev,
+					     EV_KEY, applespi_fn_codes[i].to);
+
+	input_set_capability(applespi->keyboard_input_dev, EV_KEY, KEY_FN);
+
+	sts = input_register_device(applespi->keyboard_input_dev);
+	if (sts) {
+		dev_err(&applespi->spi->dev,
+			"Unable to register keyboard input device (%d)\n", sts);
+		return -ENODEV;
+	}
+
+	/*
+	 * The applespi device doesn't send interrupts normally (as is described
+	 * in its DSDT), but rather seems to use ACPI GPEs.
+	 */
+	acpi_sts = acpi_evaluate_integer(spi_handle, "_GPE", NULL, &gpe);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev,
+			"Failed to obtain GPE for SPI slave device: %s\n",
+			acpi_format_exception(acpi_sts));
+		return -ENODEV;
+	}
+	applespi->gpe = (int)gpe;
+
+	acpi_sts = acpi_install_gpe_handler(NULL, applespi->gpe,
+					    ACPI_GPE_LEVEL_TRIGGERED,
+					    applespi_notify, applespi);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev,
+			"Failed to install GPE handler for GPE %d: %s\n",
+			applespi->gpe, acpi_format_exception(acpi_sts));
+		return -ENODEV;
+	}
+
+	applespi->suspended = false;
+
+	acpi_sts = acpi_enable_gpe(NULL, applespi->gpe);
+	if (ACPI_FAILURE(acpi_sts)) {
+		dev_err(&applespi->spi->dev,
+			"Failed to enable GPE handler for GPE %d: %s\n",
+			applespi->gpe, acpi_format_exception(acpi_sts));
+		acpi_remove_gpe_handler(NULL, applespi->gpe, applespi_notify);
+		return -ENODEV;
+	}
+
+	/* trigger touchpad setup */
+	applespi_init(applespi, false);
+
+	/*
+	 * By default this device is not enabled for wakeup; but USB keyboards
+	 * generally are, so the expectation is that by default the keyboard
+	 * will wake the system.
+	 */
+	device_wakeup_enable(&spi->dev);
+
+	/* set up keyboard-backlight */
+	sts = applespi_get_saved_bl_level(applespi);
+	if (sts >= 0)
+		applespi_set_bl_level(&applespi->backlight_info, sts);
+
+	applespi->backlight_info.name            = "spi::kbd_backlight";
+	applespi->backlight_info.default_trigger = "kbd-backlight";
+	applespi->backlight_info.brightness_set  = applespi_set_bl_level;
+
+	sts = devm_led_classdev_register(&spi->dev, &applespi->backlight_info);
+	if (sts)
+		dev_warn(&applespi->spi->dev,
+			 "Unable to register keyboard backlight class dev (%d)\n",
+			 sts);
+
+	/* set up debugfs entries for touchpad dimensions logging */
+	applespi->debugfs_root = debugfs_create_dir("applespi", NULL);
+	if (IS_ERR(applespi->debugfs_root)) {
+		if (PTR_ERR(applespi->debugfs_root) != -ENODEV)
+			dev_warn(&applespi->spi->dev,
+				 "Error creating debugfs root entry (%ld)\n",
+				 PTR_ERR(applespi->debugfs_root));
+	} else {
+		struct dentry *ret;
+
+		ret = debugfs_create_bool("enable_tp_dim", 0600,
+					  applespi->debugfs_root,
+					  &applespi->debug_tp_dim);
+		if (IS_ERR(ret))
+			dev_dbg(&applespi->spi->dev,
+				"Error creating debugfs entry enable_tp_dim (%ld)\n",
+				PTR_ERR(ret));
+
+		ret = debugfs_create_file("tp_dim", 0400,
+					  applespi->debugfs_root, applespi,
+					  &applespi_tp_dim_fops);
+		if (IS_ERR(ret))
+			dev_dbg(&applespi->spi->dev,
+				"Error creating debugfs entry tp_dim (%ld)\n",
+				PTR_ERR(ret));
+	}
+
+	return 0;
+}
+
+static void applespi_drain_writes(struct applespi_data *applespi)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	applespi->drain = true;
+	wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
+			    applespi->cmd_msg_lock);
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
+static void applespi_drain_reads(struct applespi_data *applespi)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	wait_event_lock_irq(applespi->drain_complete, !applespi->read_active,
+			    applespi->cmd_msg_lock);
+
+	applespi->suspended = true;
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
+static int applespi_remove(struct spi_device *spi)
+{
+	struct applespi_data *applespi = spi_get_drvdata(spi);
+
+	applespi_drain_writes(applespi);
+
+	acpi_disable_gpe(NULL, applespi->gpe);
+	acpi_remove_gpe_handler(NULL, applespi->gpe, applespi_notify);
+	device_wakeup_disable(&spi->dev);
+
+	applespi_drain_reads(applespi);
+
+	debugfs_remove_recursive(applespi->debugfs_root);
+
+	return 0;
+}
+
+static void applespi_shutdown(struct spi_device *spi)
+{
+	struct applespi_data *applespi = spi_get_drvdata(spi);
+
+	applespi_save_bl_level(applespi, applespi->have_bl_level);
+}
+
+static int applespi_poweroff_late(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct applespi_data *applespi = spi_get_drvdata(spi);
+
+	applespi_save_bl_level(applespi, applespi->have_bl_level);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int applespi_suspend(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct applespi_data *applespi = spi_get_drvdata(spi);
+	acpi_status acpi_sts;
+	int sts;
+
+	/* turn off caps-lock - it'll stay on otherwise */
+	sts = applespi_set_capsl_led(applespi, false);
+	if (sts)
+		dev_warn(&applespi->spi->dev,
+			 "Failed to turn off caps-lock led (%d)\n", sts);
+
+	applespi_drain_writes(applespi);
+
+	/* disable the interrupt */
+	acpi_sts = acpi_disable_gpe(NULL, applespi->gpe);
+	if (ACPI_FAILURE(acpi_sts))
+		dev_err(&applespi->spi->dev,
+			"Failed to disable GPE handler for GPE %d: %s\n",
+			applespi->gpe, acpi_format_exception(acpi_sts));
+
+	applespi_drain_reads(applespi);
+
+	return 0;
+}
+
+static int applespi_resume(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct applespi_data *applespi = spi_get_drvdata(spi);
+	acpi_status acpi_sts;
+	unsigned long flags;
+
+	/* ensure our flags and state reflect a newly resumed device */
+	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+	applespi->drain = false;
+	applespi->have_cl_led_on = false;
+	applespi->have_bl_level = 0;
+	applespi->cmd_msg_queued = false;
+	applespi->read_active = false;
+	applespi->write_active = false;
+
+	applespi->suspended = false;
+
+	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+
+	/* switch on the SPI interface */
+	applespi_enable_spi(applespi);
+
+	/* re-enable the interrupt */
+	acpi_sts = acpi_enable_gpe(NULL, applespi->gpe);
+	if (ACPI_FAILURE(acpi_sts))
+		dev_err(&applespi->spi->dev,
+			"Failed to re-enable GPE handler for GPE %d: %s\n",
+			applespi->gpe, acpi_format_exception(acpi_sts));
+
+	/* switch the touchpad into multitouch mode */
+	applespi_init(applespi, true);
+
+	return 0;
+}
+#endif
+
+static const struct acpi_device_id applespi_acpi_match[] = {
+	{ "APP000D", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, applespi_acpi_match);
+
+const struct dev_pm_ops applespi_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(applespi_suspend, applespi_resume)
+	.poweroff_late	= applespi_poweroff_late,
+};
+
+static struct spi_driver applespi_driver = {
+	.driver		= {
+		.name			= "applespi",
+		.acpi_match_table	= applespi_acpi_match,
+		.pm			= &applespi_pm_ops,
+	},
+	.probe		= applespi_probe,
+	.remove		= applespi_remove,
+	.shutdown	= applespi_shutdown,
+};
+
+module_spi_driver(applespi_driver)
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MacBook(Pro) SPI Keyboard/Touchpad driver");
+MODULE_AUTHOR("Federico Lorenzi");
+MODULE_AUTHOR("Ronald Tschalär");
diff --git a/drivers/input/keyboard/applespi.h b/drivers/input/keyboard/applespi.h
new file mode 100644
index 000000000000..7f5ab10c597a
--- /dev/null
+++ b/drivers/input/keyboard/applespi.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * MacBook (Pro) SPI keyboard and touchpad driver
+ *
+ * Copyright (c) 2015-2019 Federico Lorenzi
+ * Copyright (c) 2017-2019 Ronald Tschalär
+ */
+
+#ifndef _APPLESPI_H_
+#define _APPLESPI_H_
+
+enum applespi_evt_type {
+	ET_CMD_TP_INI = BIT(0),
+	ET_CMD_BL = BIT(1),
+	ET_CMD_CL = BIT(2),
+	ET_RD_KEYB = BIT(8),
+	ET_RD_TPAD = BIT(9),
+	ET_RD_UNKN = BIT(10),
+	ET_RD_IRQ = BIT(11),
+	ET_RD_CRC = BIT(12),
+};
+
+enum applespi_pkt_type {
+	PT_READ,
+	PT_WRITE,
+	PT_STATUS,
+};
+
+#endif /* _APPLESPI_H_ */
diff --git a/drivers/input/keyboard/applespi_trace.h b/drivers/input/keyboard/applespi_trace.h
new file mode 100644
index 000000000000..5e965e1974c7
--- /dev/null
+++ b/drivers/input/keyboard/applespi_trace.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * MacBook (Pro) SPI keyboard and touchpad driver
+ *
+ * Copyright (c) 2015-2019 Federico Lorenzi
+ * Copyright (c) 2017-2019 Ronald Tschalär
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM applespi
+
+#if !defined(_APPLESPI_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define _APPLESPI_TRACE_H_
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+#include "applespi.h"
+
+DECLARE_EVENT_CLASS(dump_message_template,
+	TP_PROTO(enum applespi_evt_type evt_type,
+		 enum applespi_pkt_type pkt_type,
+		 u8 *buf,
+		 size_t len),
+
+	TP_ARGS(evt_type, pkt_type, buf, len),
+
+	TP_STRUCT__entry(
+		__field(enum applespi_evt_type, evt_type)
+		__field(enum applespi_pkt_type, pkt_type)
+		__field(size_t, len)
+		__dynamic_array(u8, buf, len)
+	),
+
+	TP_fast_assign(
+		__entry->evt_type = evt_type;
+		__entry->pkt_type = pkt_type;
+		__entry->len = len;
+		memcpy(__get_dynamic_array(buf), buf, len);
+	),
+
+	TP_printk("%-6s: %s",
+		  __print_symbolic(__entry->pkt_type,
+				   { PT_READ, "read" },
+				   { PT_WRITE, "write" },
+				   { PT_STATUS, "status" }
+		  ),
+		  __print_hex(__get_dynamic_array(buf), __entry->len))
+);
+
+#define DEFINE_DUMP_MESSAGE_EVENT(name)			\
+DEFINE_EVENT(dump_message_template, name,		\
+	TP_PROTO(enum applespi_evt_type evt_type,	\
+		 enum applespi_pkt_type pkt_type,	\
+		 u8 *buf,				\
+		 size_t len),				\
+	TP_ARGS(evt_type, pkt_type, buf, len)		\
+)
+
+DEFINE_DUMP_MESSAGE_EVENT(applespi_tp_ini_cmd);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_backlight_cmd);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_caps_lock_cmd);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_keyboard_data);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_touchpad_data);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_unknown_data);
+DEFINE_DUMP_MESSAGE_EVENT(applespi_bad_crc);
+
+TRACE_EVENT(applespi_irq_received,
+	TP_PROTO(enum applespi_evt_type evt_type,
+		 enum applespi_pkt_type pkt_type),
+
+	TP_ARGS(evt_type, pkt_type),
+
+	TP_STRUCT__entry(
+		__field(enum applespi_evt_type, evt_type)
+		__field(enum applespi_pkt_type, pkt_type)
+	),
+
+	TP_fast_assign(
+		__entry->evt_type = evt_type;
+		__entry->pkt_type = pkt_type;
+	),
+
+	"\n"
+);
+
+#endif /* _APPLESPI_TRACE_H_ */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../drivers/input/keyboard
+#define TRACE_INCLUDE_FILE applespi_trace
+#include <trace/define_trace.h>
+
-- 
2.20.1

Re: [PATCH v5 2/2] Input: add Apple SPI keyboard and trackpad driver.

[Andy Shevchenko]

On Mon, Apr 15, 2019 at 01:13:00AM -0700, Ronald Tschalär wrote:
> The keyboard and trackpad on recent MacBook's (since 8,1) and
> MacBookPro's (13,* and 14,*) are attached to an SPI controller instead
> of USB, as previously. The higher level protocol is not publicly
> documented and hence has been reverse engineered. As a consequence there
> are still a number of unknown fields and commands. However, the known
> parts have been working well and received extensive testing and use.
> 
> In order for this driver to work, the proper SPI drivers need to be
> loaded too; for MB8,1 these are spi_pxa2xx_platform and spi_pxa2xx_pci;
> for all others they are spi_pxa2xx_platform and intel_lpss_pci. For this
> reason enabling this driver in the config implies enabling the above
> drivers.

Thank you for an update.
I suddenly realized couple of places where something maybe optimized.

Nevertheless, FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> 
> CC: Federico Lorenzi <federico@travelground.com>
> CC: Lukas Wunner <lukas@wunner.de>
> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=99891
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=108331
> Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
> ---
>  drivers/input/keyboard/Kconfig          |   15 +
>  drivers/input/keyboard/Makefile         |    1 +
>  drivers/input/keyboard/applespi.c       | 1985 +++++++++++++++++++++++
>  drivers/input/keyboard/applespi.h       |   29 +
>  drivers/input/keyboard/applespi_trace.h |   94 ++
>  5 files changed, 2124 insertions(+)
>  create mode 100644 drivers/input/keyboard/applespi.c
>  create mode 100644 drivers/input/keyboard/applespi.h
>  create mode 100644 drivers/input/keyboard/applespi_trace.h
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index a878351f1643..d0a9e7fa2508 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -70,6 +70,21 @@ config KEYBOARD_AMIGA
>  config ATARI_KBD_CORE
>  	bool
>  
> +config KEYBOARD_APPLESPI
> +	tristate "Apple SPI keyboard and trackpad"
> +	depends on ACPI && EFI
> +	depends on SPI
> +	depends on X86 || COMPILE_TEST
> +	imply SPI_PXA2XX
> +	imply SPI_PXA2XX_PCI
> +	imply MFD_INTEL_LPSS_PCI
> +	help
> +	  Say Y here if you are running Linux on any Apple MacBook8,1 or later,
> +	  or any MacBookPro13,* or MacBookPro14,*.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called applespi.
> +
>  config KEYBOARD_ATARI
>  	tristate "Atari keyboard"
>  	depends on ATARI
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 182e92985dbf..9283fee2505a 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_KEYBOARD_ADP5520)		+= adp5520-keys.o
>  obj-$(CONFIG_KEYBOARD_ADP5588)		+= adp5588-keys.o
>  obj-$(CONFIG_KEYBOARD_ADP5589)		+= adp5589-keys.o
>  obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
> +obj-$(CONFIG_KEYBOARD_APPLESPI)		+= applespi.o
>  obj-$(CONFIG_KEYBOARD_ATARI)		+= atakbd.o
>  obj-$(CONFIG_KEYBOARD_ATKBD)		+= atkbd.o
>  obj-$(CONFIG_KEYBOARD_BCM)		+= bcm-keypad.o
> diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c
> new file mode 100644
> index 000000000000..5c3d7687e346
> --- /dev/null
> +++ b/drivers/input/keyboard/applespi.c
> @@ -0,0 +1,1985 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * MacBook (Pro) SPI keyboard and touchpad driver
> + *
> + * Copyright (c) 2015-2018 Federico Lorenzi
> + * Copyright (c) 2017-2018 Ronald Tschalär
> + */
> +
> +/*
> + * The keyboard and touchpad controller on the MacBookAir6, MacBookPro12,
> + * MacBook8 and newer can be driven either by USB or SPI. However the USB
> + * pins are only connected on the MacBookAir6 and 7 and the MacBookPro12.
> + * All others need this driver. The interface is selected using ACPI methods:
> + *
> + * * UIEN ("USB Interface Enable"): If invoked with argument 1, disables SPI
> + *   and enables USB. If invoked with argument 0, disables USB.
> + * * UIST ("USB Interface Status"): Returns 1 if USB is enabled, 0 otherwise.
> + * * SIEN ("SPI Interface Enable"): If invoked with argument 1, disables USB
> + *   and enables SPI. If invoked with argument 0, disables SPI.
> + * * SIST ("SPI Interface Status"): Returns 1 if SPI is enabled, 0 otherwise.
> + * * ISOL: Resets the four GPIO pins used for SPI. Intended to be invoked with
> + *   argument 1, then once more with argument 0.
> + *
> + * UIEN and UIST are only provided on models where the USB pins are connected.
> + *
> + * SPI-based Protocol
> + * ------------------
> + *
> + * The device and driver exchange messages (struct message); each message is
> + * encapsulated in one or more packets (struct spi_packet). There are two types
> + * of exchanges: reads, and writes. A read is signaled by a GPE, upon which one
> + * message can be read from the device. A write exchange consists of writing a
> + * command message, immediately reading a short status packet, and then, upon
> + * receiving a GPE, reading the response message. Write exchanges cannot be
> + * interleaved, i.e. a new write exchange must not be started till the previous
> + * write exchange is complete. Whether a received message is part of a read or
> + * write exchange is indicated in the encapsulating packet's flags field.
> + *
> + * A single message may be too large to fit in a single packet (which has a
> + * fixed, 256-byte size). In that case it will be split over multiple,
> + * consecutive packets.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/crc16.h>
> +#include <linux/debugfs.h>
> +#include <linux/delay.h>
> +#include <linux/efi.h>
> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/spi/spi.h>
> +#include <linux/wait.h>
> +#include <linux/workqueue.h>
> +
> +#include <asm/barrier.h>
> +#include <asm/unaligned.h>
> +
> +#define CREATE_TRACE_POINTS
> +#include "applespi.h"
> +#include "applespi_trace.h"
> +
> +#define APPLESPI_PACKET_SIZE	256
> +#define APPLESPI_STATUS_SIZE	4
> +
> +#define PACKET_TYPE_READ	0x20
> +#define PACKET_TYPE_WRITE	0x40
> +#define PACKET_DEV_KEYB		0x01
> +#define PACKET_DEV_TPAD		0x02
> +#define PACKET_DEV_INFO		0xd0
> +
> +#define MAX_ROLLOVER		6
> +
> +#define MAX_FINGERS		11
> +#define MAX_FINGER_ORIENTATION	16384
> +#define MAX_PKTS_PER_MSG	2
> +
> +#define KBD_BL_LEVEL_MIN	32U
> +#define KBD_BL_LEVEL_MAX	255U
> +#define KBD_BL_LEVEL_SCALE	1000000U
> +#define KBD_BL_LEVEL_ADJ	\
> +	((KBD_BL_LEVEL_MAX - KBD_BL_LEVEL_MIN) * KBD_BL_LEVEL_SCALE / 255U)
> +
> +#define EFI_BL_LEVEL_NAME	L"KeyboardBacklightLevel"
> +#define EFI_BL_LEVEL_GUID	EFI_GUID(0xa076d2af, 0x9678, 0x4386, 0x8b, 0x58, 0x1f, 0xc8, 0xef, 0x04, 0x16, 0x19)
> +
> +#define APPLE_FLAG_FKEY		0x01
> +
> +#define SPI_RW_CHG_DELAY_US	100	/* from experimentation, in µs */
> +
> +#define SYNAPTICS_VENDOR_ID	0x06cb
> +
> +static unsigned int fnmode = 1;
> +module_param(fnmode, uint, 0644);
> +MODULE_PARM_DESC(fnmode, "Mode of Fn key on Apple keyboards (0 = disabled, [1] = fkeyslast, 2 = fkeysfirst)");
> +
> +static unsigned int fnremap;
> +module_param(fnremap, uint, 0644);
> +MODULE_PARM_DESC(fnremap, "Remap Fn key ([0] = no-remap; 1 = left-ctrl, 2 = left-shift, 3 = left-alt, 4 = left-meta, 6 = right-shift, 7 = right-alt, 8 = right-meta)");
> +
> +static bool iso_layout;
> +module_param(iso_layout, bool, 0644);
> +MODULE_PARM_DESC(iso_layout, "Enable/Disable hardcoded ISO-layout of the keyboard. ([0] = disabled, 1 = enabled)");
> +
> +static char touchpad_dimensions[40];
> +module_param_string(touchpad_dimensions, touchpad_dimensions,
> +		    sizeof(touchpad_dimensions), 0444);
> +MODULE_PARM_DESC(touchpad_dimensions, "The pixel dimensions of the touchpad, as XxY+W+H .");
> +
> +/**
> + * struct keyboard_protocol - keyboard message.
> + * message.type = 0x0110, message.length = 0x000a
> + *
> + * @unknown1:		unknown
> + * @modifiers:		bit-set of modifier/control keys pressed
> + * @unknown2:		unknown
> + * @keys_pressed:	the (non-modifier) keys currently pressed
> + * @fn_pressed:		whether the fn key is currently pressed
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct keyboard_protocol {
> +	__u8			unknown1;
> +	__u8			modifiers;
> +	__u8			unknown2;
> +	__u8			keys_pressed[MAX_ROLLOVER];
> +	__u8			fn_pressed;
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct tp_finger - single trackpad finger structure, le16-aligned
> + *
> + * @origin:		zero when switching track finger
> + * @abs_x:		absolute x coodinate
> + * @abs_y:		absolute y coodinate
> + * @rel_x:		relative x coodinate
> + * @rel_y:		relative y coodinate
> + * @tool_major:		tool area, major axis
> + * @tool_minor:		tool area, minor axis
> + * @orientation:	16384 when point, else 15 bit angle
> + * @touch_major:	touch area, major axis
> + * @touch_minor:	touch area, minor axis
> + * @unused:		zeros
> + * @pressure:		pressure on forcetouch touchpad
> + * @multi:		one finger: varies, more fingers: constant
> + * @crc16:		on last finger: crc over the whole message struct
> + *			(i.e. message header + this struct) minus the last
> + *			@crc16 field; unknown on all other fingers.
> + */
> +struct tp_finger {
> +	__le16 origin;
> +	__le16 abs_x;
> +	__le16 abs_y;
> +	__le16 rel_x;
> +	__le16 rel_y;
> +	__le16 tool_major;
> +	__le16 tool_minor;
> +	__le16 orientation;
> +	__le16 touch_major;
> +	__le16 touch_minor;
> +	__le16 unused[2];
> +	__le16 pressure;
> +	__le16 multi;
> +	__le16 crc16;
> +};
> +
> +/**
> + * struct touchpad_protocol - touchpad message.
> + * message.type = 0x0210
> + *
> + * @unknown1:		unknown
> + * @clicked:		1 if a button-click was detected, 0 otherwise
> + * @unknown2:		unknown
> + * @number_of_fingers:	the number of fingers being reported in @fingers
> + * @clicked2:		same as @clicked
> + * @unknown3:		unknown
> + * @fingers:		the data for each finger
> + */
> +struct touchpad_protocol {
> +	__u8			unknown1[1];
> +	__u8			clicked;
> +	__u8			unknown2[28];
> +	__u8			number_of_fingers;
> +	__u8			clicked2;
> +	__u8			unknown3[16];
> +	struct tp_finger	fingers[0];
> +};
> +
> +/**
> + * struct command_protocol_tp_info - get touchpad info.
> + * message.type = 0x1020, message.length = 0x0000
> + *
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct command_protocol_tp_info {
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct touchpad_info - touchpad info response.
> + * message.type = 0x1020, message.length = 0x006e
> + *
> + * @unknown1:		unknown
> + * @model_flags:	flags (vary by model number, but significance otherwise
> + *			unknown)
> + * @model_no:		the touchpad model number
> + * @unknown2:		unknown
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct touchpad_info_protocol {
> +	__u8			unknown1[105];
> +	__u8			model_flags;
> +	__u8			model_no;
> +	__u8			unknown2[3];
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct command_protocol_mt_init - initialize multitouch.
> + * message.type = 0x0252, message.length = 0x0002
> + *
> + * @cmd:		value: 0x0102
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct command_protocol_mt_init {
> +	__le16			cmd;
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct command_protocol_capsl - toggle caps-lock led
> + * message.type = 0x0151, message.length = 0x0002
> + *
> + * @unknown:		value: 0x01 (length?)
> + * @led:		0 off, 2 on
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct command_protocol_capsl {
> +	__u8			unknown;
> +	__u8			led;
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct command_protocol_bl - set keyboard backlight brightness
> + * message.type = 0xB051, message.length = 0x0006
> + *
> + * @const1:		value: 0x01B0
> + * @level:		the brightness level to set
> + * @const2:		value: 0x0001 (backlight off), 0x01F4 (backlight on)
> + * @crc16:		crc over the whole message struct (message header +
> + *			this struct) minus this @crc16 field
> + */
> +struct command_protocol_bl {
> +	__le16			const1;
> +	__le16			level;
> +	__le16			const2;
> +	__le16			crc16;
> +};
> +
> +/**
> + * struct message - a complete spi message.
> + *
> + * Each message begins with fixed header, followed by a message-type specific
> + * payload, and ends with a 16-bit crc. Because of the varying lengths of the
> + * payload, the crc is defined at the end of each payload struct, rather than
> + * in this struct.
> + *
> + * @type:	the message type
> + * @zero:	always 0
> + * @counter:	incremented on each message, rolls over after 255; there is a
> + *		separate counter for each message type.
> + * @rsp_buf_len:response buffer length (the exact nature of this field is quite
> + *		speculative). On a request/write this is often the same as
> + *		@length, though in some cases it has been seen to be much larger
> + *		(e.g. 0x400); on a response/read this the same as on the
> + *		request; for reads that are not responses it is 0.
> + * @length:	length of the remainder of the data in the whole message
> + *		structure (after re-assembly in case of being split over
> + *		multiple spi-packets), minus the trailing crc. The total size
> + *		of the message struct is therefore @length + 10.
> + */
> +struct message {
> +	__le16		type;
> +	__u8		zero;
> +	__u8		counter;
> +	__le16		rsp_buf_len;
> +	__le16		length;
> +	union {
> +		struct keyboard_protocol	keyboard;
> +		struct touchpad_protocol	touchpad;
> +		struct touchpad_info_protocol	tp_info;
> +		struct command_protocol_tp_info	tp_info_command;
> +		struct command_protocol_mt_init	init_mt_command;
> +		struct command_protocol_capsl	capsl_command;
> +		struct command_protocol_bl	bl_command;
> +		__u8				data[0];
> +	};
> +};
> +
> +/* type + zero + counter + rsp_buf_len + length */
> +#define MSG_HEADER_SIZE	8
> +
> +/**
> + * struct spi_packet - a complete spi packet; always 256 bytes. This carries
> + * the (parts of the) message in the data. But note that this does not
> + * necessarily contain a complete message, as in some cases (e.g. many
> + * fingers pressed) the message is split over multiple packets (see the
> + * @offset, @remaining, and @length fields). In general the data parts in
> + * spi_packet's are concatenated until @remaining is 0, and the result is an
> + * message.
> + *
> + * @flags:	0x40 = write (to device), 0x20 = read (from device); note that
> + *		the response to a write still has 0x40.
> + * @device:	1 = keyboard, 2 = touchpad
> + * @offset:	specifies the offset of this packet's data in the complete
> + *		message; i.e. > 0 indicates this is a continuation packet (in
> + *		the second packet for a message split over multiple packets
> + *		this would then be the same as the @length in the first packet)
> + * @remaining:	number of message bytes remaining in subsequents packets (in
> + *		the first packet of a message split over two packets this would
> + *		then be the same as the @length in the second packet)
> + * @length:	length of the valid data in the @data in this packet
> + * @data:	all or part of a message
> + * @crc16:	crc over this whole structure minus this @crc16 field. This
> + *		covers just this packet, even on multi-packet messages (in
> + *		contrast to the crc in the message).
> + */
> +struct spi_packet {
> +	__u8			flags;
> +	__u8			device;
> +	__le16			offset;
> +	__le16			remaining;
> +	__le16			length;
> +	__u8			data[246];
> +	__le16			crc16;
> +};
> +
> +struct spi_settings {
> +	u64	spi_cs_delay;		/* cs-to-clk delay in us */
> +	u64	reset_a2r_usec;		/* active-to-receive delay? */
> +	u64	reset_rec_usec;		/* ? (cur val: 10) */
> +};
> +
> +/* this mimics struct drm_rect */
> +struct applespi_tp_info {
> +	int	x_min;
> +	int	y_min;
> +	int	x_max;
> +	int	y_max;
> +};
> +
> +struct applespi_data {
> +	struct spi_device		*spi;
> +	struct spi_settings		spi_settings;
> +	struct input_dev		*keyboard_input_dev;
> +	struct input_dev		*touchpad_input_dev;
> +
> +	u8				*tx_buffer;
> +	u8				*tx_status;
> +	u8				*rx_buffer;
> +
> +	u8				*msg_buf;
> +	unsigned int			saved_msg_len;
> +
> +	struct applespi_tp_info		tp_info;
> +
> +	u8				last_keys_pressed[MAX_ROLLOVER];
> +	u8				last_keys_fn_pressed[MAX_ROLLOVER];
> +	u8				last_fn_pressed;
> +	struct input_mt_pos		pos[MAX_FINGERS];
> +	int				slots[MAX_FINGERS];
> +	int				gpe;
> +	acpi_handle			sien;
> +	acpi_handle			sist;
> +
> +	struct spi_transfer		dl_t;
> +	struct spi_transfer		rd_t;
> +	struct spi_message		rd_m;
> +
> +	struct spi_transfer		ww_t;
> +	struct spi_transfer		wd_t;
> +	struct spi_transfer		wr_t;
> +	struct spi_transfer		st_t;
> +	struct spi_message		wr_m;
> +
> +	bool				want_tp_info_cmd;
> +	bool				want_mt_init_cmd;
> +	bool				want_cl_led_on;
> +	bool				have_cl_led_on;
> +	unsigned int			want_bl_level;
> +	unsigned int			have_bl_level;
> +	unsigned int			cmd_msg_cntr;
> +	/* lock to protect the above parameters and flags below */
> +	spinlock_t			cmd_msg_lock;
> +	bool				cmd_msg_queued;
> +	enum applespi_evt_type		cmd_evt_type;
> +
> +	struct led_classdev		backlight_info;
> +
> +	bool				suspended;
> +	bool				drain;
> +	wait_queue_head_t		drain_complete;
> +	bool				read_active;
> +	bool				write_active;
> +
> +	struct work_struct		work;
> +	struct touchpad_info_protocol	rcvd_tp_info;
> +
> +	struct dentry			*debugfs_root;
> +	bool				debug_tp_dim;
> +	char				tp_dim_val[40];
> +	int				tp_dim_min_x;
> +	int				tp_dim_max_x;
> +	int				tp_dim_min_y;
> +	int				tp_dim_max_y;
> +};
> +
> +static const unsigned char applespi_scancodes[] = {
> +	0, 0, 0, 0,
> +	KEY_A, KEY_B, KEY_C, KEY_D, KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J,
> +	KEY_K, KEY_L, KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T,
> +	KEY_U, KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z,
> +	KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
> +	KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB, KEY_SPACE, KEY_MINUS,
> +	KEY_EQUAL, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH, 0,
> +	KEY_SEMICOLON, KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA, KEY_DOT, KEY_SLASH,
> +	KEY_CAPSLOCK,
> +	KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9,
> +	KEY_F10, KEY_F11, KEY_F12, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> +	KEY_RIGHT, KEY_LEFT, KEY_DOWN, KEY_UP,
> +	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_102ND,
> +	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> +	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_RO, 0, KEY_YEN, 0, 0, 0, 0, 0,
> +	0, KEY_KATAKANAHIRAGANA, KEY_MUHENKAN
> +};
> +
> +/*
> + * This must have exactly as many entries as there are bits in
> + * struct keyboard_protocol.modifiers .
> + */
> +static const unsigned char applespi_controlcodes[] = {
> +	KEY_LEFTCTRL,
> +	KEY_LEFTSHIFT,
> +	KEY_LEFTALT,
> +	KEY_LEFTMETA,
> +	0,
> +	KEY_RIGHTSHIFT,
> +	KEY_RIGHTALT,
> +	KEY_RIGHTMETA
> +};
> +
> +struct applespi_key_translation {
> +	u16 from;
> +	u16 to;
> +	u8 flags;
> +};
> +
> +static const struct applespi_key_translation applespi_fn_codes[] = {
> +	{ KEY_BACKSPACE, KEY_DELETE },
> +	{ KEY_ENTER,	KEY_INSERT },
> +	{ KEY_F1,	KEY_BRIGHTNESSDOWN,	APPLE_FLAG_FKEY },
> +	{ KEY_F2,	KEY_BRIGHTNESSUP,	APPLE_FLAG_FKEY },
> +	{ KEY_F3,	KEY_SCALE,		APPLE_FLAG_FKEY },
> +	{ KEY_F4,	KEY_DASHBOARD,		APPLE_FLAG_FKEY },
> +	{ KEY_F5,	KEY_KBDILLUMDOWN,	APPLE_FLAG_FKEY },
> +	{ KEY_F6,	KEY_KBDILLUMUP,		APPLE_FLAG_FKEY },
> +	{ KEY_F7,	KEY_PREVIOUSSONG,	APPLE_FLAG_FKEY },
> +	{ KEY_F8,	KEY_PLAYPAUSE,		APPLE_FLAG_FKEY },
> +	{ KEY_F9,	KEY_NEXTSONG,		APPLE_FLAG_FKEY },
> +	{ KEY_F10,	KEY_MUTE,		APPLE_FLAG_FKEY },
> +	{ KEY_F11,	KEY_VOLUMEDOWN,		APPLE_FLAG_FKEY },
> +	{ KEY_F12,	KEY_VOLUMEUP,		APPLE_FLAG_FKEY },
> +	{ KEY_RIGHT,	KEY_END },
> +	{ KEY_LEFT,	KEY_HOME },
> +	{ KEY_DOWN,	KEY_PAGEDOWN },
> +	{ KEY_UP,	KEY_PAGEUP },
> +	{ }
> +};
> +
> +static const struct applespi_key_translation apple_iso_keyboard[] = {
> +	{ KEY_GRAVE,	KEY_102ND },
> +	{ KEY_102ND,	KEY_GRAVE },
> +	{ }
> +};
> +
> +struct applespi_tp_model_info {
> +	u16			model;
> +	struct applespi_tp_info	tp_info;
> +};
> +
> +static const struct applespi_tp_model_info applespi_tp_models[] = {
> +	{
> +		.model = 0x04,	/* MB8 MB9 MB10 */
> +		.tp_info = { -5087, -182, 5579, 6089 },
> +	},
> +	{
> +		.model = 0x05,	/* MBP13,1 MBP13,2 MBP14,1 MBP14,2 */
> +		.tp_info = { -6243, -170, 6749, 7685 },
> +	},
> +	{
> +		.model = 0x06,	/* MBP13,3 MBP14,3 */
> +		.tp_info = { -7456, -163, 7976, 9283 },
> +	},
> +	{}
> +};
> +
> +typedef void (*applespi_trace_fun)(enum applespi_evt_type,
> +				   enum applespi_pkt_type, u8 *, size_t);
> +
> +static applespi_trace_fun applespi_get_trace_fun(enum applespi_evt_type type)
> +{
> +	switch (type) {
> +	case ET_CMD_TP_INI:
> +		return trace_applespi_tp_ini_cmd;
> +	case ET_CMD_BL:
> +		return trace_applespi_backlight_cmd;
> +	case ET_CMD_CL:
> +		return trace_applespi_caps_lock_cmd;
> +	case ET_RD_KEYB:
> +		return trace_applespi_keyboard_data;
> +	case ET_RD_TPAD:
> +		return trace_applespi_touchpad_data;
> +	case ET_RD_UNKN:
> +		return trace_applespi_unknown_data;
> +	default:
> +		WARN_ONCE(1, "Unknown msg type %d", type);
> +		return trace_applespi_unknown_data;
> +	}
> +}
> +
> +static void applespi_setup_read_txfrs(struct applespi_data *applespi)
> +{
> +	struct spi_message *msg = &applespi->rd_m;
> +	struct spi_transfer *dl_t = &applespi->dl_t;
> +	struct spi_transfer *rd_t = &applespi->rd_t;
> +
> +	memset(dl_t, 0, sizeof(*dl_t));
> +	memset(rd_t, 0, sizeof(*rd_t));
> +
> +	dl_t->delay_usecs = applespi->spi_settings.spi_cs_delay;
> +
> +	rd_t->rx_buf = applespi->rx_buffer;
> +	rd_t->len = APPLESPI_PACKET_SIZE;
> +
> +	spi_message_init(msg);
> +	spi_message_add_tail(dl_t, msg);
> +	spi_message_add_tail(rd_t, msg);
> +}
> +
> +static void applespi_setup_write_txfrs(struct applespi_data *applespi)
> +{
> +	struct spi_message *msg = &applespi->wr_m;
> +	struct spi_transfer *wt_t = &applespi->ww_t;
> +	struct spi_transfer *dl_t = &applespi->wd_t;
> +	struct spi_transfer *wr_t = &applespi->wr_t;
> +	struct spi_transfer *st_t = &applespi->st_t;
> +
> +	memset(wt_t, 0, sizeof(*wt_t));
> +	memset(dl_t, 0, sizeof(*dl_t));
> +	memset(wr_t, 0, sizeof(*wr_t));
> +	memset(st_t, 0, sizeof(*st_t));
> +
> +	/*
> +	 * All we need here is a delay at the beginning of the message before
> +	 * asserting cs. But the current spi API doesn't support this, so we
> +	 * end up with an extra unnecessary (but harmless) cs assertion and
> +	 * deassertion.
> +	 */
> +	wt_t->delay_usecs = SPI_RW_CHG_DELAY_US;
> +	wt_t->cs_change = 1;
> +
> +	dl_t->delay_usecs = applespi->spi_settings.spi_cs_delay;
> +
> +	wr_t->tx_buf = applespi->tx_buffer;
> +	wr_t->len = APPLESPI_PACKET_SIZE;
> +	wr_t->delay_usecs = SPI_RW_CHG_DELAY_US;
> +
> +	st_t->rx_buf = applespi->tx_status;
> +	st_t->len = APPLESPI_STATUS_SIZE;
> +
> +	spi_message_init(msg);
> +	spi_message_add_tail(wt_t, msg);
> +	spi_message_add_tail(dl_t, msg);
> +	spi_message_add_tail(wr_t, msg);
> +	spi_message_add_tail(st_t, msg);
> +}
> +
> +static int applespi_async(struct applespi_data *applespi,
> +			  struct spi_message *message, void (*complete)(void *))
> +{
> +	message->complete = complete;
> +	message->context = applespi;
> +
> +	return spi_async(applespi->spi, message);
> +}
> +
> +static inline bool applespi_check_write_status(struct applespi_data *applespi,
> +					       int sts)
> +{
> +	static u8 status_ok[] = { 0xac, 0x27, 0x68, 0xd5 };
> +
> +	if (sts < 0) {
> +		dev_warn(&applespi->spi->dev, "Error writing to device: %d\n",
> +			 sts);
> +		return false;
> +	}
> +
> +	if (memcmp(applespi->tx_status, status_ok, APPLESPI_STATUS_SIZE)) {
> +		dev_warn(&applespi->spi->dev, "Error writing to device: %*ph\n",
> +			 APPLESPI_STATUS_SIZE, applespi->tx_status);
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
> +static int applespi_get_spi_settings(struct applespi_data *applespi)
> +{
> +	struct acpi_device *adev = ACPI_COMPANION(&applespi->spi->dev);
> +	const union acpi_object *o;
> +	struct spi_settings *settings = &applespi->spi_settings;
> +
> +	if (!acpi_dev_get_property(adev, "spiCSDelay", ACPI_TYPE_BUFFER, &o))
> +		settings->spi_cs_delay = *(u64 *)o->buffer.pointer;
> +	else
> +		dev_warn(&applespi->spi->dev,
> +			 "Property spiCSDelay not found\n");
> +
> +	if (!acpi_dev_get_property(adev, "resetA2RUsec", ACPI_TYPE_BUFFER, &o))
> +		settings->reset_a2r_usec = *(u64 *)o->buffer.pointer;
> +	else
> +		dev_warn(&applespi->spi->dev,
> +			 "Property resetA2RUsec not found\n");
> +
> +	if (!acpi_dev_get_property(adev, "resetRecUsec", ACPI_TYPE_BUFFER, &o))
> +		settings->reset_rec_usec = *(u64 *)o->buffer.pointer;
> +	else
> +		dev_warn(&applespi->spi->dev,
> +			 "Property resetRecUsec not found\n");
> +
> +	dev_dbg(&applespi->spi->dev,
> +		"SPI settings: spi_cs_delay=%llu reset_a2r_usec=%llu reset_rec_usec=%llu\n",
> +		settings->spi_cs_delay, settings->reset_a2r_usec,
> +		settings->reset_rec_usec);
> +
> +	return 0;
> +}
> +
> +static int applespi_setup_spi(struct applespi_data *applespi)
> +{
> +	int sts;
> +
> +	sts = applespi_get_spi_settings(applespi);
> +	if (sts)
> +		return sts;
> +
> +	spin_lock_init(&applespi->cmd_msg_lock);
> +	init_waitqueue_head(&applespi->drain_complete);
> +
> +	return 0;
> +}
> +
> +static int applespi_enable_spi(struct applespi_data *applespi)
> +{
> +	acpi_status acpi_sts;
> +	unsigned long long spi_status;
> +
> +	/* check if SPI is already enabled, so we can skip the delay below */
> +	acpi_sts = acpi_evaluate_integer(applespi->sist, NULL, NULL,
> +					 &spi_status);
> +	if (ACPI_SUCCESS(acpi_sts) && spi_status)
> +		return 0;
> +
> +	/* SIEN(1) will enable SPI communication */
> +	acpi_sts = acpi_execute_simple_method(applespi->sien, NULL, 1);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev, "SIEN failed: %s\n",
> +			acpi_format_exception(acpi_sts));
> +		return -ENODEV;
> +	}
> +
> +	/*
> +	 * Allow the SPI interface to come up before returning. Without this
> +	 * delay, the SPI commands to enable multitouch mode may not reach
> +	 * the trackpad controller, causing pointer movement to break upon
> +	 * resume from sleep.
> +	 */
> +	msleep(50);
> +
> +	return 0;
> +}
> +
> +static int applespi_send_cmd_msg(struct applespi_data *applespi);
> +
> +static void applespi_msg_complete(struct applespi_data *applespi,
> +				  bool is_write_msg, bool is_read_compl)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	if (is_read_compl)
> +		applespi->read_active = false;
> +	if (is_write_msg)
> +		applespi->write_active = false;
> +
> +	if (applespi->drain && !applespi->write_active)
> +		wake_up_all(&applespi->drain_complete);
> +
> +	if (is_write_msg) {
> +		applespi->cmd_msg_queued = false;
> +		applespi_send_cmd_msg(applespi);
> +	}
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +}
> +
> +static void applespi_async_write_complete(void *context)
> +{
> +	struct applespi_data *applespi = context;
> +	enum applespi_evt_type evt_type = applespi->cmd_evt_type;
> +
> +	applespi_get_trace_fun(evt_type)(evt_type, PT_WRITE,
> +					 applespi->tx_buffer,
> +					 APPLESPI_PACKET_SIZE);
> +	applespi_get_trace_fun(evt_type)(evt_type, PT_STATUS,
> +					 applespi->tx_status,
> +					 APPLESPI_STATUS_SIZE);
> +
> +	if (!applespi_check_write_status(applespi, applespi->wr_m.status)) {
> +		/*
> +		 * If we got an error, we presumably won't get the expected
> +		 * response message either.
> +		 */
> +		applespi_msg_complete(applespi, true, false);
> +	}
> +}
> +
> +static int applespi_send_cmd_msg(struct applespi_data *applespi)
> +{
> +	u16 crc;
> +	int sts;
> +	struct spi_packet *packet = (struct spi_packet *)applespi->tx_buffer;
> +	struct message *message = (struct message *)packet->data;
> +	u16 msg_len;
> +	u8 device;
> +
> +	/* check if draining */
> +	if (applespi->drain)
> +		return 0;
> +
> +	/* check whether send is in progress */
> +	if (applespi->cmd_msg_queued)
> +		return 0;
> +
> +	/* set up packet */
> +	memset(packet, 0, APPLESPI_PACKET_SIZE);
> +
> +	/* are we processing init commands? */
> +	if (applespi->want_tp_info_cmd) {
> +		applespi->want_tp_info_cmd = false;
> +		applespi->want_mt_init_cmd = true;
> +		applespi->cmd_evt_type = ET_CMD_TP_INI;
> +
> +		/* build init command */
> +		device = PACKET_DEV_INFO;
> +
> +		message->type = cpu_to_le16(0x1020);
> +		msg_len = sizeof(message->tp_info_command);
> +
> +		message->zero = 0x02;
> +		message->rsp_buf_len = cpu_to_le16(0x0200);
> +
> +	} else if (applespi->want_mt_init_cmd) {
> +		applespi->want_mt_init_cmd = false;
> +		applespi->cmd_evt_type = ET_CMD_TP_INI;
> +
> +		/* build init command */
> +		device = PACKET_DEV_TPAD;
> +
> +		message->type = cpu_to_le16(0x0252);
> +		msg_len = sizeof(message->init_mt_command);
> +
> +		message->init_mt_command.cmd = cpu_to_le16(0x0102);
> +
> +	/* do we need caps-lock command? */
> +	} else if (applespi->want_cl_led_on != applespi->have_cl_led_on) {
> +		applespi->have_cl_led_on = applespi->want_cl_led_on;
> +		applespi->cmd_evt_type = ET_CMD_CL;
> +
> +		/* build led command */
> +		device = PACKET_DEV_KEYB;
> +
> +		message->type = cpu_to_le16(0x0151);
> +		msg_len = sizeof(message->capsl_command);
> +
> +		message->capsl_command.unknown = 0x01;
> +		message->capsl_command.led = applespi->have_cl_led_on ? 2 : 0;
> +
> +	/* do we need backlight command? */
> +	} else if (applespi->want_bl_level != applespi->have_bl_level) {
> +		applespi->have_bl_level = applespi->want_bl_level;
> +		applespi->cmd_evt_type = ET_CMD_BL;
> +
> +		/* build command buffer */
> +		device = PACKET_DEV_KEYB;
> +
> +		message->type = cpu_to_le16(0xB051);
> +		msg_len = sizeof(message->bl_command);
> +
> +		message->bl_command.const1 = cpu_to_le16(0x01B0);
> +		message->bl_command.level =
> +				cpu_to_le16(applespi->have_bl_level);
> +
> +		if (applespi->have_bl_level > 0)
> +			message->bl_command.const2 = cpu_to_le16(0x01F4);
> +		else
> +			message->bl_command.const2 = cpu_to_le16(0x0001);
> +
> +	/* everything's up-to-date */
> +	} else {
> +		return 0;
> +	}
> +
> +	/* finalize packet */
> +	packet->flags = PACKET_TYPE_WRITE;
> +	packet->device = device;
> +	packet->length = cpu_to_le16(MSG_HEADER_SIZE + msg_len);
> +
> +	message->counter = applespi->cmd_msg_cntr++ % (U8_MAX + 1);
> +
> +	message->length = cpu_to_le16(msg_len - 2);
> +	if (!message->rsp_buf_len)
> +		message->rsp_buf_len = message->length;
> +
> +	crc = crc16(0, (u8 *)message, le16_to_cpu(packet->length) - 2);
> +	put_unaligned_le16(crc, &message->data[msg_len - 2]);
> +
> +	crc = crc16(0, (u8 *)packet, sizeof(*packet) - 2);
> +	packet->crc16 = cpu_to_le16(crc);
> +
> +	/* send command */
> +	sts = applespi_async(applespi, &applespi->wr_m,
> +			     applespi_async_write_complete);
> +	if (sts) {
> +		dev_warn(&applespi->spi->dev,
> +			 "Error queueing async write to device: %d\n", sts);
> +		return sts;
> +	}
> +
> +	applespi->cmd_msg_queued = true;
> +	applespi->write_active = true;
> +
> +	return 0;
> +}
> +
> +static void applespi_init(struct applespi_data *applespi, bool is_resume)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	if (is_resume)
> +		applespi->want_mt_init_cmd = true;
> +	else
> +		applespi->want_tp_info_cmd = true;
> +	applespi_send_cmd_msg(applespi);
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +}
> +
> +static int applespi_set_capsl_led(struct applespi_data *applespi,
> +				  bool capslock_on)
> +{
> +	unsigned long flags;
> +	int sts;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	applespi->want_cl_led_on = capslock_on;
> +	sts = applespi_send_cmd_msg(applespi);
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +
> +	return sts;
> +}
> +
> +static void applespi_set_bl_level(struct led_classdev *led_cdev,
> +				  enum led_brightness value)
> +{
> +	struct applespi_data *applespi =
> +		container_of(led_cdev, struct applespi_data, backlight_info);
> +	unsigned long flags;
> +	int sts;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	if (value == 0) {
> +		applespi->want_bl_level = value;
> +	} else {
> +		/*
> +		 * The backlight does not turn on till level 32, so we scale
> +		 * the range here so that from a user's perspective it turns
> +		 * on at 1.
> +		 */
> +		applespi->want_bl_level =
> +			((value * KBD_BL_LEVEL_ADJ) / KBD_BL_LEVEL_SCALE +
> +			 KBD_BL_LEVEL_MIN);
> +	}
> +
> +	sts = applespi_send_cmd_msg(applespi);
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +}
> +
> +static int applespi_event(struct input_dev *dev, unsigned int type,
> +			  unsigned int code, int value)
> +{
> +	struct applespi_data *applespi = input_get_drvdata(dev);
> +
> +	switch (type) {
> +	case EV_LED:
> +		applespi_set_capsl_led(applespi, !!test_bit(LED_CAPSL, dev->led));
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +/* lifted from the BCM5974 driver and renamed from raw2int */
> +/* convert 16-bit little endian to signed integer */
> +static inline int le16_to_int(__le16 x)
> +{
> +	return (signed short)le16_to_cpu(x);
> +}
> +
> +static void applespi_debug_update_dimensions(struct applespi_data *applespi,
> +					     const struct tp_finger *f)
> +{
> +	applespi->tp_dim_min_x = min_t(int, applespi->tp_dim_min_x, f->abs_x);
> +	applespi->tp_dim_max_x = max_t(int, applespi->tp_dim_max_x, f->abs_x);
> +	applespi->tp_dim_min_y = min_t(int, applespi->tp_dim_min_y, f->abs_y);
> +	applespi->tp_dim_max_y = max_t(int, applespi->tp_dim_max_y, f->abs_y);
> +}
> +
> +static int applespi_tp_dim_open(struct inode *inode, struct file *file)
> +{
> +	struct applespi_data *applespi = inode->i_private;
> +
> +	file->private_data = applespi;
> +
> +	snprintf(applespi->tp_dim_val, sizeof(applespi->tp_dim_val),
> +		 "0x%.4x %dx%d+%u+%u\n",
> +		 applespi->touchpad_input_dev->id.product,
> +		 applespi->tp_dim_min_x, applespi->tp_dim_min_y,
> +		 applespi->tp_dim_max_x - applespi->tp_dim_min_x,
> +		 applespi->tp_dim_max_y - applespi->tp_dim_min_y);
> +
> +	return nonseekable_open(inode, file);
> +}
> +
> +static ssize_t applespi_tp_dim_read(struct file *file, char __user *buf,
> +				    size_t len, loff_t *off)
> +{
> +	struct applespi_data *applespi = file->private_data;
> +
> +	return simple_read_from_buffer(buf, len, off, applespi->tp_dim_val,
> +				       strlen(applespi->tp_dim_val));
> +}
> +
> +static const struct file_operations applespi_tp_dim_fops = {
> +	.owner = THIS_MODULE,
> +	.open = applespi_tp_dim_open,
> +	.read = applespi_tp_dim_read,
> +	.llseek = no_llseek,
> +};
> +
> +static void report_finger_data(struct input_dev *input, int slot,
> +			       const struct input_mt_pos *pos,
> +			       const struct tp_finger *f)
> +{
> +	input_mt_slot(input, slot);
> +	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
> +
> +	input_report_abs(input, ABS_MT_TOUCH_MAJOR,
> +			 le16_to_int(f->touch_major) << 1);
> +	input_report_abs(input, ABS_MT_TOUCH_MINOR,
> +			 le16_to_int(f->touch_minor) << 1);
> +	input_report_abs(input, ABS_MT_WIDTH_MAJOR,
> +			 le16_to_int(f->tool_major) << 1);
> +	input_report_abs(input, ABS_MT_WIDTH_MINOR,
> +			 le16_to_int(f->tool_minor) << 1);
> +	input_report_abs(input, ABS_MT_ORIENTATION,
> +			 MAX_FINGER_ORIENTATION - le16_to_int(f->orientation));
> +	input_report_abs(input, ABS_MT_POSITION_X, pos->x);
> +	input_report_abs(input, ABS_MT_POSITION_Y, pos->y);
> +}
> +
> +static void report_tp_state(struct applespi_data *applespi,
> +			    struct touchpad_protocol *t)
> +{
> +	const struct tp_finger *f;
> +	struct input_dev *input;
> +	const struct applespi_tp_info *tp_info = &applespi->tp_info;
> +	int i, n;
> +
> +	/* touchpad_input_dev is set async in worker */
> +	input = smp_load_acquire(&applespi->touchpad_input_dev);
> +	if (!input)
> +		return;	/* touchpad isn't initialized yet */
> +
> +	n = 0;
> +
> +	for (i = 0; i < t->number_of_fingers; i++) {
> +		f = &t->fingers[i];
> +		if (le16_to_int(f->touch_major) == 0)
> +			continue;
> +		applespi->pos[n].x = le16_to_int(f->abs_x);
> +		applespi->pos[n].y = tp_info->y_min + tp_info->y_max -
> +				     le16_to_int(f->abs_y);
> +		n++;
> +
> +		if (applespi->debug_tp_dim)
> +			applespi_debug_update_dimensions(applespi, f);
> +	}
> +
> +	input_mt_assign_slots(input, applespi->slots, applespi->pos, n, 0);
> +
> +	for (i = 0; i < n; i++)
> +		report_finger_data(input, applespi->slots[i],
> +				   &applespi->pos[i], &t->fingers[i]);
> +
> +	input_mt_sync_frame(input);
> +	input_report_key(input, BTN_LEFT, t->clicked);
> +
> +	input_sync(input);
> +}
> +
> +static const struct applespi_key_translation *
> +applespi_find_translation(const struct applespi_key_translation *table, u16 key)
> +{
> +	const struct applespi_key_translation *trans;
> +
> +	for (trans = table; trans->from; trans++)
> +		if (trans->from == key)
> +			return trans;
> +
> +	return NULL;
> +}
> +
> +static unsigned int applespi_translate_fn_key(unsigned int key, int fn_pressed)
> +{
> +	const struct applespi_key_translation *trans;
> +	int do_translate;
> +
> +	trans = applespi_find_translation(applespi_fn_codes, key);
> +	if (trans) {
> +		if (trans->flags & APPLE_FLAG_FKEY)
> +			do_translate = (fnmode == 2 && fn_pressed) ||
> +				       (fnmode == 1 && !fn_pressed);
> +		else
> +			do_translate = fn_pressed;
> +
> +		if (do_translate)
> +			key = trans->to;
> +	}
> +
> +	return key;
> +}
> +
> +static unsigned int applespi_translate_iso_layout(unsigned int key)
> +{
> +	const struct applespi_key_translation *trans;
> +
> +	trans = applespi_find_translation(apple_iso_keyboard, key);
> +	if (trans)
> +		key = trans->to;
> +
> +	return key;
> +}
> +
> +static unsigned int applespi_code_to_key(u8 code, int fn_pressed)
> +{
> +	unsigned int key = applespi_scancodes[code];
> +
> +	if (fnmode)
> +		key = applespi_translate_fn_key(key, fn_pressed);
> +	if (iso_layout)
> +		key = applespi_translate_iso_layout(key);
> +	return key;
> +}
> +
> +static void
> +applespi_remap_fn_key(struct keyboard_protocol *keyboard_protocol)
> +{
> +	unsigned char tmp;

> +	u8 bit = BIT(fnremap - 1);

The above is UB and I'm sorry I didn't find this earlier.

So, something like this would work

	u8 bit = BIT((fnremap - 1) & 0x07);

> +
> +	if (!fnremap || fnremap > ARRAY_SIZE(applespi_controlcodes) ||
> +	    !applespi_controlcodes[fnremap - 1])
> +		return;
> +
> +	tmp = keyboard_protocol->fn_pressed;
> +	keyboard_protocol->fn_pressed = !!(keyboard_protocol->modifiers & bit);
> +	if (tmp)
> +		keyboard_protocol->modifiers |= bit;
> +	else
> +		keyboard_protocol->modifiers &= ~bit;
> +}
> +
> +static void
> +applespi_handle_keyboard_event(struct applespi_data *applespi,
> +			       struct keyboard_protocol *keyboard_protocol)
> +{
> +	unsigned int key;
> +	int i, j;
> +
> +	compiletime_assert(ARRAY_SIZE(applespi_controlcodes) ==
> +			   sizeof_field(struct keyboard_protocol, modifiers) * 8,
> +			   "applespi_controlcodes has wrong number of entries");
> +

> +	/* check for rollover overflow, which is signalled by all keys == 1 */
> +	for (i = 0; i < MAX_ROLLOVER; i++) {
> +		if (keyboard_protocol->keys_pressed[i] != 1)
> +			break;
> +	}
> +
> +	if (i == MAX_ROLLOVER)	/* all keys were 1 */
> +		return;

Since keys_pressed is an array of byte values, it may be replaced with
memchr_inv().

> +
> +	/* remap fn key if desired */
> +	applespi_remap_fn_key(keyboard_protocol);
> +
> +	/* check released keys */
> +	for (i = 0; i < MAX_ROLLOVER; i++) {

> +		for (j = 0; j < MAX_ROLLOVER; j++) {
> +			if (applespi->last_keys_pressed[i] ==
> +			    keyboard_protocol->keys_pressed[j])
> +				break;
> +		}
> +
> +		if (j < MAX_ROLLOVER)	/* key is still pressed */
> +			continue;

And memchr() here.

> +
> +		key = applespi_code_to_key(applespi->last_keys_pressed[i],
> +					   applespi->last_keys_fn_pressed[i]);
> +		input_report_key(applespi->keyboard_input_dev, key, 0);
> +		applespi->last_keys_fn_pressed[i] = 0;
> +	}
> +
> +	/* check pressed keys */
> +	for (i = 0; i < MAX_ROLLOVER; i++) {
> +		if (keyboard_protocol->keys_pressed[i] <
> +				ARRAY_SIZE(applespi_scancodes) &&
> +		    keyboard_protocol->keys_pressed[i] > 0) {
> +			key = applespi_code_to_key(
> +					keyboard_protocol->keys_pressed[i],
> +					keyboard_protocol->fn_pressed);
> +			input_report_key(applespi->keyboard_input_dev, key, 1);
> +			applespi->last_keys_fn_pressed[i] =
> +					keyboard_protocol->fn_pressed;
> +		}
> +	}
> +
> +	/* check control keys */
> +	for (i = 0; i < ARRAY_SIZE(applespi_controlcodes); i++) {
> +		if (keyboard_protocol->modifiers & BIT(i))
> +			input_report_key(applespi->keyboard_input_dev,
> +					 applespi_controlcodes[i], 1);
> +		else
> +			input_report_key(applespi->keyboard_input_dev,
> +					 applespi_controlcodes[i], 0);
> +	}
> +
> +	/* check function key */
> +	if (keyboard_protocol->fn_pressed && !applespi->last_fn_pressed)
> +		input_report_key(applespi->keyboard_input_dev, KEY_FN, 1);
> +	else if (!keyboard_protocol->fn_pressed && applespi->last_fn_pressed)
> +		input_report_key(applespi->keyboard_input_dev, KEY_FN, 0);
> +	applespi->last_fn_pressed = keyboard_protocol->fn_pressed;
> +
> +	/* done */
> +	input_sync(applespi->keyboard_input_dev);
> +	memcpy(&applespi->last_keys_pressed, keyboard_protocol->keys_pressed,
> +	       sizeof(applespi->last_keys_pressed));
> +}
> +
> +static const struct applespi_tp_info *applespi_find_touchpad_info(__u8 model)
> +{
> +	const struct applespi_tp_model_info *info;
> +
> +	for (info = applespi_tp_models; info->model; info++) {
> +		if (info->model == model)
> +			return &info->tp_info;
> +	}
> +
> +	return NULL;
> +}
> +
> +static int
> +applespi_register_touchpad_device(struct applespi_data *applespi,
> +				  struct touchpad_info_protocol *rcvd_tp_info)
> +{
> +	const struct applespi_tp_info *tp_info;
> +	struct input_dev *touchpad_input_dev;
> +	int sts;
> +
> +	/* set up touchpad dimensions */
> +	tp_info = applespi_find_touchpad_info(rcvd_tp_info->model_no);
> +	if (!tp_info) {
> +		dev_warn(&applespi->spi->dev,
> +			 "Unknown touchpad model %x - falling back to MB8 touchpad\n",
> +			 rcvd_tp_info->model_no);
> +		tp_info = &applespi_tp_models[0].tp_info;
> +	}
> +
> +	applespi->tp_info = *tp_info;
> +
> +	if (touchpad_dimensions[0]) {
> +		int x, y, w, h;
> +
> +		sts = sscanf(touchpad_dimensions, "%dx%d+%u+%u", &x, &y, &w, &h);
> +		if (sts == 4) {
> +			dev_info(&applespi->spi->dev,
> +				 "Overriding touchpad dimensions from module param\n");
> +			applespi->tp_info.x_min = x;
> +			applespi->tp_info.y_min = y;
> +			applespi->tp_info.x_max = x + w;
> +			applespi->tp_info.y_max = y + h;
> +		} else {
> +			dev_warn(&applespi->spi->dev,
> +				 "Invalid touchpad dimensions '%s': must be in the form XxY+W+H\n",
> +				 touchpad_dimensions);
> +			touchpad_dimensions[0] = '\0';
> +		}
> +	}
> +	if (!touchpad_dimensions[0]) {
> +		snprintf(touchpad_dimensions, sizeof(touchpad_dimensions),
> +			 "%dx%d+%u+%u",
> +			 applespi->tp_info.x_min,
> +			 applespi->tp_info.y_min,
> +			 applespi->tp_info.x_max - applespi->tp_info.x_min,
> +			 applespi->tp_info.y_max - applespi->tp_info.y_min);
> +	}
> +
> +	/* create touchpad input device */
> +	touchpad_input_dev = devm_input_allocate_device(&applespi->spi->dev);
> +	if (!touchpad_input_dev) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to allocate touchpad input device\n");
> +		return -ENOMEM;
> +	}
> +
> +	touchpad_input_dev->name = "Apple SPI Touchpad";
> +	touchpad_input_dev->phys = "applespi/input1";
> +	touchpad_input_dev->dev.parent = &applespi->spi->dev;
> +	touchpad_input_dev->id.bustype = BUS_SPI;
> +	touchpad_input_dev->id.vendor = SYNAPTICS_VENDOR_ID;
> +	touchpad_input_dev->id.product =
> +			rcvd_tp_info->model_no << 8 | rcvd_tp_info->model_flags;
> +
> +	/* basic properties */
> +	input_set_capability(touchpad_input_dev, EV_REL, REL_X);
> +	input_set_capability(touchpad_input_dev, EV_REL, REL_Y);
> +
> +	__set_bit(INPUT_PROP_POINTER, touchpad_input_dev->propbit);
> +	__set_bit(INPUT_PROP_BUTTONPAD, touchpad_input_dev->propbit);
> +
> +	/* finger touch area */
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_TOUCH_MAJOR,
> +			     0, 5000, 0, 0);
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_TOUCH_MINOR,
> +			     0, 5000, 0, 0);
> +
> +	/* finger approach area */
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_WIDTH_MAJOR,
> +			     0, 5000, 0, 0);
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_WIDTH_MINOR,
> +			     0, 5000, 0, 0);
> +
> +	/* finger orientation */
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_ORIENTATION,
> +			     -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION,
> +			     0, 0);
> +
> +	/* finger position */
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_POSITION_X,
> +			     applespi->tp_info.x_min, applespi->tp_info.x_max,
> +			     0, 0);
> +	input_set_abs_params(touchpad_input_dev, ABS_MT_POSITION_Y,
> +			     applespi->tp_info.y_min, applespi->tp_info.y_max,
> +			     0, 0);
> +
> +	/* touchpad button */
> +	input_set_capability(touchpad_input_dev, EV_KEY, BTN_LEFT);
> +
> +	/* multitouch */
> +	input_mt_init_slots(touchpad_input_dev, MAX_FINGERS,
> +			    INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
> +			    INPUT_MT_TRACK);
> +
> +	/* register input device */
> +	sts = input_register_device(touchpad_input_dev);
> +	if (sts) {
> +		dev_err(&applespi->spi->dev,
> +			"Unable to register touchpad input device (%d)\n", sts);
> +		return sts;
> +	}
> +
> +	/* touchpad_input_dev is read async in spi callback */
> +	smp_store_release(&applespi->touchpad_input_dev, touchpad_input_dev);
> +
> +	return 0;
> +}
> +
> +static void applespi_worker(struct work_struct *work)
> +{
> +	struct applespi_data *applespi =
> +		container_of(work, struct applespi_data, work);
> +
> +	applespi_register_touchpad_device(applespi, &applespi->rcvd_tp_info);
> +}
> +
> +static void applespi_handle_cmd_response(struct applespi_data *applespi,
> +					 struct spi_packet *packet,
> +					 struct message *message)
> +{
> +	if (packet->device == PACKET_DEV_INFO &&
> +	    le16_to_cpu(message->type) == 0x1020) {
> +		/*
> +		 * We're not allowed to sleep here, but registering an input
> +		 * device can sleep.
> +		 */
> +		applespi->rcvd_tp_info = message->tp_info;
> +		schedule_work(&applespi->work);
> +		return;
> +	}
> +
> +	if (le16_to_cpu(message->length) != 0x0000) {
> +		dev_warn_ratelimited(&applespi->spi->dev,
> +				     "Received unexpected write response: length=%x\n",
> +				     le16_to_cpu(message->length));
> +		return;
> +	}
> +
> +	if (packet->device == PACKET_DEV_TPAD &&
> +	    le16_to_cpu(message->type) == 0x0252 &&
> +	    le16_to_cpu(message->rsp_buf_len) == 0x0002)
> +		dev_info(&applespi->spi->dev, "modeswitch done.\n");
> +}
> +
> +static bool applespi_verify_crc(struct applespi_data *applespi, u8 *buffer,
> +				size_t buflen)
> +{
> +	u16 crc;
> +
> +	crc = crc16(0, buffer, buflen);
> +	if (crc) {
> +		dev_warn_ratelimited(&applespi->spi->dev,
> +				     "Received corrupted packet (crc mismatch)\n");
> +		trace_applespi_bad_crc(ET_RD_CRC, READ, buffer, buflen);
> +
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
> +static void applespi_debug_print_read_packet(struct applespi_data *applespi,
> +					     struct spi_packet *packet)
> +{
> +	unsigned int evt_type;
> +
> +	if (packet->flags == PACKET_TYPE_READ &&
> +	    packet->device == PACKET_DEV_KEYB)
> +		evt_type = ET_RD_KEYB;
> +	else if (packet->flags == PACKET_TYPE_READ &&
> +		 packet->device == PACKET_DEV_TPAD)
> +		evt_type = ET_RD_TPAD;
> +	else if (packet->flags == PACKET_TYPE_WRITE)
> +		evt_type = applespi->cmd_evt_type;
> +	else
> +		evt_type = ET_RD_UNKN;
> +
> +	applespi_get_trace_fun(evt_type)(evt_type, PT_READ, applespi->rx_buffer,
> +					 APPLESPI_PACKET_SIZE);
> +}
> +
> +static void applespi_got_data(struct applespi_data *applespi)
> +{
> +	struct spi_packet *packet;
> +	struct message *message;
> +	unsigned int msg_len;
> +	unsigned int off;
> +	unsigned int rem;
> +	unsigned int len;
> +
> +	/* process packet header */
> +	if (!applespi_verify_crc(applespi, applespi->rx_buffer,
> +				 APPLESPI_PACKET_SIZE)) {
> +		unsigned long flags;
> +
> +		spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +		if (applespi->drain) {
> +			applespi->read_active = false;
> +			applespi->write_active = false;
> +
> +			wake_up_all(&applespi->drain_complete);
> +		}
> +
> +		spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +
> +		return;
> +	}
> +
> +	packet = (struct spi_packet *)applespi->rx_buffer;
> +
> +	applespi_debug_print_read_packet(applespi, packet);
> +
> +	off = le16_to_cpu(packet->offset);
> +	rem = le16_to_cpu(packet->remaining);
> +	len = le16_to_cpu(packet->length);
> +
> +	if (len > sizeof(packet->data)) {
> +		dev_warn_ratelimited(&applespi->spi->dev,
> +				     "Received corrupted packet (invalid packet length %u)\n",
> +				     len);
> +		goto msg_complete;
> +	}
> +
> +	/* handle multi-packet messages */
> +	if (rem > 0 || off > 0) {
> +		if (off != applespi->saved_msg_len) {
> +			dev_warn_ratelimited(&applespi->spi->dev,
> +					     "Received unexpected offset (got %u, expected %u)\n",
> +					     off, applespi->saved_msg_len);
> +			goto msg_complete;
> +		}
> +
> +		if (off + rem > MAX_PKTS_PER_MSG * APPLESPI_PACKET_SIZE) {
> +			dev_warn_ratelimited(&applespi->spi->dev,
> +					     "Received message too large (size %u)\n",
> +					     off + rem);
> +			goto msg_complete;
> +		}
> +
> +		if (off + len > MAX_PKTS_PER_MSG * APPLESPI_PACKET_SIZE) {
> +			dev_warn_ratelimited(&applespi->spi->dev,
> +					     "Received message too large (size %u)\n",
> +					     off + len);
> +			goto msg_complete;
> +		}
> +
> +		memcpy(applespi->msg_buf + off, &packet->data, len);
> +		applespi->saved_msg_len += len;
> +
> +		if (rem > 0)
> +			return;
> +
> +		message = (struct message *)applespi->msg_buf;
> +		msg_len = applespi->saved_msg_len;
> +	} else {
> +		message = (struct message *)&packet->data;
> +		msg_len = len;
> +	}
> +
> +	/* got complete message - verify */
> +	if (!applespi_verify_crc(applespi, (u8 *)message, msg_len))
> +		goto msg_complete;
> +
> +	if (le16_to_cpu(message->length) != msg_len - MSG_HEADER_SIZE - 2) {
> +		dev_warn_ratelimited(&applespi->spi->dev,
> +				     "Received corrupted packet (invalid message length %u - expected %u)\n",
> +				     le16_to_cpu(message->length),
> +				     msg_len - MSG_HEADER_SIZE - 2);
> +		goto msg_complete;
> +	}
> +
> +	/* handle message */
> +	if (packet->flags == PACKET_TYPE_READ &&
> +	    packet->device == PACKET_DEV_KEYB) {
> +		applespi_handle_keyboard_event(applespi, &message->keyboard);
> +
> +	} else if (packet->flags == PACKET_TYPE_READ &&
> +		   packet->device == PACKET_DEV_TPAD) {
> +		struct touchpad_protocol *tp;
> +		size_t tp_len;
> +
> +		tp = &message->touchpad;
> +		tp_len = sizeof(*tp) +
> +			 tp->number_of_fingers * sizeof(tp->fingers[0]);
> +
> +		if (le16_to_cpu(message->length) + 2 != tp_len) {
> +			dev_warn_ratelimited(&applespi->spi->dev,
> +					     "Received corrupted packet (invalid message length %u - num-fingers %u, tp-len %zu)\n",
> +					     le16_to_cpu(message->length),
> +					     tp->number_of_fingers, tp_len);
> +			goto msg_complete;
> +		}
> +
> +		if (tp->number_of_fingers > MAX_FINGERS) {
> +			dev_warn_ratelimited(&applespi->spi->dev,
> +					     "Number of reported fingers (%u) exceeds max (%u))\n",
> +					     tp->number_of_fingers,
> +					     MAX_FINGERS);
> +			tp->number_of_fingers = MAX_FINGERS;
> +		}
> +
> +		report_tp_state(applespi, tp);
> +
> +	} else if (packet->flags == PACKET_TYPE_WRITE) {
> +		applespi_handle_cmd_response(applespi, packet, message);
> +	}
> +
> +msg_complete:
> +	applespi->saved_msg_len = 0;
> +
> +	applespi_msg_complete(applespi, packet->flags == PACKET_TYPE_WRITE,
> +			      true);
> +}
> +
> +static void applespi_async_read_complete(void *context)
> +{
> +	struct applespi_data *applespi = context;
> +
> +	if (applespi->rd_m.status < 0) {
> +		dev_warn(&applespi->spi->dev, "Error reading from device: %d\n",
> +			 applespi->rd_m.status);
> +		/*
> +		 * We don't actually know if this was a pure read, or a response
> +		 * to a write. But this is a rare error condition that should
> +		 * never occur, so clearing both flags to avoid deadlock.
> +		 */
> +		applespi_msg_complete(applespi, true, true);
> +	} else {
> +		applespi_got_data(applespi);
> +	}
> +
> +	acpi_finish_gpe(NULL, applespi->gpe);
> +}
> +
> +static u32 applespi_notify(acpi_handle gpe_device, u32 gpe, void *context)
> +{
> +	struct applespi_data *applespi = context;
> +	int sts;
> +	unsigned long flags;
> +
> +	trace_applespi_irq_received(ET_RD_IRQ, PT_READ);
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	if (!applespi->suspended) {
> +		sts = applespi_async(applespi, &applespi->rd_m,
> +				     applespi_async_read_complete);
> +		if (sts)
> +			dev_warn(&applespi->spi->dev,
> +				 "Error queueing async read to device: %d\n",
> +				 sts);
> +		else
> +			applespi->read_active = true;
> +	}
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +
> +	return ACPI_INTERRUPT_HANDLED;
> +}
> +
> +static int applespi_get_saved_bl_level(struct applespi_data *applespi)
> +{
> +	struct efivar_entry *efivar_entry;
> +	u16 efi_data = 0;
> +	unsigned long efi_data_len;
> +	int sts;
> +
> +	efivar_entry = kmalloc(sizeof(*efivar_entry), GFP_KERNEL);
> +	if (!efivar_entry)
> +		return -ENOMEM;
> +
> +	memcpy(efivar_entry->var.VariableName, EFI_BL_LEVEL_NAME,
> +	       sizeof(EFI_BL_LEVEL_NAME));
> +	efivar_entry->var.VendorGuid = EFI_BL_LEVEL_GUID;
> +	efi_data_len = sizeof(efi_data);
> +
> +	sts = efivar_entry_get(efivar_entry, NULL, &efi_data_len, &efi_data);
> +	if (sts && sts != -ENOENT)
> +		dev_warn(&applespi->spi->dev,
> +			 "Error getting backlight level from EFI vars: %d\n",
> +			 sts);
> +
> +	kfree(efivar_entry);
> +
> +	return sts ? sts : efi_data;
> +}
> +
> +static void applespi_save_bl_level(struct applespi_data *applespi,
> +				   unsigned int level)
> +{
> +	efi_guid_t efi_guid;
> +	u32 efi_attr;
> +	unsigned long efi_data_len;
> +	u16 efi_data;
> +	int sts;
> +
> +	/* Save keyboard backlight level */
> +	efi_guid = EFI_BL_LEVEL_GUID;
> +	efi_data = (u16)level;
> +	efi_data_len = sizeof(efi_data);
> +	efi_attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +		   EFI_VARIABLE_RUNTIME_ACCESS;
> +
> +	sts = efivar_entry_set_safe(EFI_BL_LEVEL_NAME, efi_guid, efi_attr, true,
> +				    efi_data_len, &efi_data);
> +	if (sts)
> +		dev_warn(&applespi->spi->dev,
> +			 "Error saving backlight level to EFI vars: %d\n", sts);
> +}
> +
> +static int applespi_probe(struct spi_device *spi)
> +{
> +	struct applespi_data *applespi;
> +	acpi_handle spi_handle = ACPI_HANDLE(&spi->dev);
> +	acpi_status acpi_sts;
> +	int sts, i;
> +	unsigned long long gpe, usb_status;
> +
> +	/* check if the USB interface is present and enabled already */
> +	acpi_sts = acpi_evaluate_integer(spi_handle, "UIST", NULL, &usb_status);
> +	if (ACPI_SUCCESS(acpi_sts) && usb_status) {
> +		/* let the USB driver take over instead */
> +		dev_info(&spi->dev, "USB interface already enabled\n");
> +		return -ENODEV;
> +	}
> +
> +	/* allocate driver data */
> +	applespi = devm_kzalloc(&spi->dev, sizeof(*applespi), GFP_KERNEL);
> +	if (!applespi)
> +		return -ENOMEM;
> +
> +	applespi->spi = spi;
> +
> +	INIT_WORK(&applespi->work, applespi_worker);
> +
> +	/* store the driver data */
> +	spi_set_drvdata(spi, applespi);
> +
> +	/* create our buffers */
> +	applespi->tx_buffer = devm_kmalloc(&spi->dev, APPLESPI_PACKET_SIZE,
> +					   GFP_KERNEL);
> +	applespi->tx_status = devm_kmalloc(&spi->dev, APPLESPI_STATUS_SIZE,
> +					   GFP_KERNEL);
> +	applespi->rx_buffer = devm_kmalloc(&spi->dev, APPLESPI_PACKET_SIZE,
> +					   GFP_KERNEL);
> +	applespi->msg_buf = devm_kmalloc_array(&spi->dev, MAX_PKTS_PER_MSG,
> +					       APPLESPI_PACKET_SIZE,
> +					       GFP_KERNEL);
> +
> +	if (!applespi->tx_buffer || !applespi->tx_status ||
> +	    !applespi->rx_buffer || !applespi->msg_buf)
> +		return -ENOMEM;
> +
> +	/* set up our spi messages */
> +	applespi_setup_read_txfrs(applespi);
> +	applespi_setup_write_txfrs(applespi);
> +
> +	/* cache ACPI method handles */
> +	acpi_sts = acpi_get_handle(spi_handle, "SIEN", &applespi->sien);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to get SIEN ACPI method handle: %s\n",
> +			acpi_format_exception(acpi_sts));
> +		return -ENODEV;
> +	}
> +
> +	acpi_sts = acpi_get_handle(spi_handle, "SIST", &applespi->sist);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to get SIST ACPI method handle: %s\n",
> +			acpi_format_exception(acpi_sts));
> +		return -ENODEV;
> +	}
> +
> +	/* switch on the SPI interface */
> +	sts = applespi_setup_spi(applespi);
> +	if (sts)
> +		return sts;
> +
> +	sts = applespi_enable_spi(applespi);
> +	if (sts)
> +		return sts;
> +
> +	/* setup the keyboard input dev */
> +	applespi->keyboard_input_dev = devm_input_allocate_device(&spi->dev);
> +
> +	if (!applespi->keyboard_input_dev)
> +		return -ENOMEM;
> +
> +	applespi->keyboard_input_dev->name = "Apple SPI Keyboard";
> +	applespi->keyboard_input_dev->phys = "applespi/input0";
> +	applespi->keyboard_input_dev->dev.parent = &spi->dev;
> +	applespi->keyboard_input_dev->id.bustype = BUS_SPI;
> +
> +	applespi->keyboard_input_dev->evbit[0] =
> +			BIT_MASK(EV_KEY) | BIT_MASK(EV_LED) | BIT_MASK(EV_REP);
> +	applespi->keyboard_input_dev->ledbit[0] = BIT_MASK(LED_CAPSL);
> +
> +	input_set_drvdata(applespi->keyboard_input_dev, applespi);
> +	applespi->keyboard_input_dev->event = applespi_event;
> +
> +	for (i = 0; i < ARRAY_SIZE(applespi_scancodes); i++)
> +		if (applespi_scancodes[i])
> +			input_set_capability(applespi->keyboard_input_dev,
> +					     EV_KEY, applespi_scancodes[i]);
> +
> +	for (i = 0; i < ARRAY_SIZE(applespi_controlcodes); i++)
> +		if (applespi_controlcodes[i])
> +			input_set_capability(applespi->keyboard_input_dev,
> +					     EV_KEY, applespi_controlcodes[i]);
> +
> +	for (i = 0; i < ARRAY_SIZE(applespi_fn_codes); i++)
> +		if (applespi_fn_codes[i].to)
> +			input_set_capability(applespi->keyboard_input_dev,
> +					     EV_KEY, applespi_fn_codes[i].to);
> +
> +	input_set_capability(applespi->keyboard_input_dev, EV_KEY, KEY_FN);
> +
> +	sts = input_register_device(applespi->keyboard_input_dev);
> +	if (sts) {
> +		dev_err(&applespi->spi->dev,
> +			"Unable to register keyboard input device (%d)\n", sts);
> +		return -ENODEV;
> +	}
> +
> +	/*
> +	 * The applespi device doesn't send interrupts normally (as is described
> +	 * in its DSDT), but rather seems to use ACPI GPEs.
> +	 */
> +	acpi_sts = acpi_evaluate_integer(spi_handle, "_GPE", NULL, &gpe);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to obtain GPE for SPI slave device: %s\n",
> +			acpi_format_exception(acpi_sts));
> +		return -ENODEV;
> +	}
> +	applespi->gpe = (int)gpe;
> +
> +	acpi_sts = acpi_install_gpe_handler(NULL, applespi->gpe,
> +					    ACPI_GPE_LEVEL_TRIGGERED,
> +					    applespi_notify, applespi);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to install GPE handler for GPE %d: %s\n",
> +			applespi->gpe, acpi_format_exception(acpi_sts));
> +		return -ENODEV;
> +	}
> +
> +	applespi->suspended = false;
> +
> +	acpi_sts = acpi_enable_gpe(NULL, applespi->gpe);
> +	if (ACPI_FAILURE(acpi_sts)) {
> +		dev_err(&applespi->spi->dev,
> +			"Failed to enable GPE handler for GPE %d: %s\n",
> +			applespi->gpe, acpi_format_exception(acpi_sts));
> +		acpi_remove_gpe_handler(NULL, applespi->gpe, applespi_notify);
> +		return -ENODEV;
> +	}
> +
> +	/* trigger touchpad setup */
> +	applespi_init(applespi, false);
> +
> +	/*
> +	 * By default this device is not enabled for wakeup; but USB keyboards
> +	 * generally are, so the expectation is that by default the keyboard
> +	 * will wake the system.
> +	 */
> +	device_wakeup_enable(&spi->dev);
> +
> +	/* set up keyboard-backlight */
> +	sts = applespi_get_saved_bl_level(applespi);
> +	if (sts >= 0)
> +		applespi_set_bl_level(&applespi->backlight_info, sts);
> +
> +	applespi->backlight_info.name            = "spi::kbd_backlight";
> +	applespi->backlight_info.default_trigger = "kbd-backlight";
> +	applespi->backlight_info.brightness_set  = applespi_set_bl_level;
> +
> +	sts = devm_led_classdev_register(&spi->dev, &applespi->backlight_info);
> +	if (sts)
> +		dev_warn(&applespi->spi->dev,
> +			 "Unable to register keyboard backlight class dev (%d)\n",
> +			 sts);
> +
> +	/* set up debugfs entries for touchpad dimensions logging */
> +	applespi->debugfs_root = debugfs_create_dir("applespi", NULL);
> +	if (IS_ERR(applespi->debugfs_root)) {
> +		if (PTR_ERR(applespi->debugfs_root) != -ENODEV)
> +			dev_warn(&applespi->spi->dev,
> +				 "Error creating debugfs root entry (%ld)\n",
> +				 PTR_ERR(applespi->debugfs_root));
> +	} else {
> +		struct dentry *ret;
> +
> +		ret = debugfs_create_bool("enable_tp_dim", 0600,
> +					  applespi->debugfs_root,
> +					  &applespi->debug_tp_dim);
> +		if (IS_ERR(ret))
> +			dev_dbg(&applespi->spi->dev,
> +				"Error creating debugfs entry enable_tp_dim (%ld)\n",
> +				PTR_ERR(ret));
> +
> +		ret = debugfs_create_file("tp_dim", 0400,
> +					  applespi->debugfs_root, applespi,
> +					  &applespi_tp_dim_fops);
> +		if (IS_ERR(ret))
> +			dev_dbg(&applespi->spi->dev,
> +				"Error creating debugfs entry tp_dim (%ld)\n",
> +				PTR_ERR(ret));
> +	}
> +
> +	return 0;
> +}
> +
> +static void applespi_drain_writes(struct applespi_data *applespi)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	applespi->drain = true;
> +	wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
> +			    applespi->cmd_msg_lock);
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +}
> +
> +static void applespi_drain_reads(struct applespi_data *applespi)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	wait_event_lock_irq(applespi->drain_complete, !applespi->read_active,
> +			    applespi->cmd_msg_lock);
> +
> +	applespi->suspended = true;
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +}
> +
> +static int applespi_remove(struct spi_device *spi)
> +{
> +	struct applespi_data *applespi = spi_get_drvdata(spi);
> +
> +	applespi_drain_writes(applespi);
> +
> +	acpi_disable_gpe(NULL, applespi->gpe);
> +	acpi_remove_gpe_handler(NULL, applespi->gpe, applespi_notify);
> +	device_wakeup_disable(&spi->dev);
> +
> +	applespi_drain_reads(applespi);
> +
> +	debugfs_remove_recursive(applespi->debugfs_root);
> +
> +	return 0;
> +}
> +
> +static void applespi_shutdown(struct spi_device *spi)
> +{
> +	struct applespi_data *applespi = spi_get_drvdata(spi);
> +
> +	applespi_save_bl_level(applespi, applespi->have_bl_level);
> +}
> +
> +static int applespi_poweroff_late(struct device *dev)
> +{
> +	struct spi_device *spi = to_spi_device(dev);
> +	struct applespi_data *applespi = spi_get_drvdata(spi);
> +
> +	applespi_save_bl_level(applespi, applespi->have_bl_level);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int applespi_suspend(struct device *dev)
> +{
> +	struct spi_device *spi = to_spi_device(dev);
> +	struct applespi_data *applespi = spi_get_drvdata(spi);
> +	acpi_status acpi_sts;
> +	int sts;
> +
> +	/* turn off caps-lock - it'll stay on otherwise */
> +	sts = applespi_set_capsl_led(applespi, false);
> +	if (sts)
> +		dev_warn(&applespi->spi->dev,
> +			 "Failed to turn off caps-lock led (%d)\n", sts);
> +
> +	applespi_drain_writes(applespi);
> +
> +	/* disable the interrupt */
> +	acpi_sts = acpi_disable_gpe(NULL, applespi->gpe);
> +	if (ACPI_FAILURE(acpi_sts))
> +		dev_err(&applespi->spi->dev,
> +			"Failed to disable GPE handler for GPE %d: %s\n",
> +			applespi->gpe, acpi_format_exception(acpi_sts));
> +
> +	applespi_drain_reads(applespi);
> +
> +	return 0;
> +}
> +
> +static int applespi_resume(struct device *dev)
> +{
> +	struct spi_device *spi = to_spi_device(dev);
> +	struct applespi_data *applespi = spi_get_drvdata(spi);
> +	acpi_status acpi_sts;
> +	unsigned long flags;
> +
> +	/* ensure our flags and state reflect a newly resumed device */
> +	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
> +
> +	applespi->drain = false;
> +	applespi->have_cl_led_on = false;
> +	applespi->have_bl_level = 0;
> +	applespi->cmd_msg_queued = false;
> +	applespi->read_active = false;
> +	applespi->write_active = false;
> +
> +	applespi->suspended = false;
> +
> +	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
> +
> +	/* switch on the SPI interface */
> +	applespi_enable_spi(applespi);
> +
> +	/* re-enable the interrupt */
> +	acpi_sts = acpi_enable_gpe(NULL, applespi->gpe);
> +	if (ACPI_FAILURE(acpi_sts))
> +		dev_err(&applespi->spi->dev,
> +			"Failed to re-enable GPE handler for GPE %d: %s\n",
> +			applespi->gpe, acpi_format_exception(acpi_sts));
> +
> +	/* switch the touchpad into multitouch mode */
> +	applespi_init(applespi, true);
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct acpi_device_id applespi_acpi_match[] = {
> +	{ "APP000D", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, applespi_acpi_match);
> +
> +const struct dev_pm_ops applespi_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(applespi_suspend, applespi_resume)
> +	.poweroff_late	= applespi_poweroff_late,
> +};
> +
> +static struct spi_driver applespi_driver = {
> +	.driver		= {
> +		.name			= "applespi",
> +		.acpi_match_table	= applespi_acpi_match,
> +		.pm			= &applespi_pm_ops,
> +	},
> +	.probe		= applespi_probe,
> +	.remove		= applespi_remove,
> +	.shutdown	= applespi_shutdown,
> +};
> +
> +module_spi_driver(applespi_driver)
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("MacBook(Pro) SPI Keyboard/Touchpad driver");
> +MODULE_AUTHOR("Federico Lorenzi");
> +MODULE_AUTHOR("Ronald Tschalär");
> diff --git a/drivers/input/keyboard/applespi.h b/drivers/input/keyboard/applespi.h
> new file mode 100644
> index 000000000000..7f5ab10c597a
> --- /dev/null
> +++ b/drivers/input/keyboard/applespi.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * MacBook (Pro) SPI keyboard and touchpad driver
> + *
> + * Copyright (c) 2015-2019 Federico Lorenzi
> + * Copyright (c) 2017-2019 Ronald Tschalär
> + */
> +
> +#ifndef _APPLESPI_H_
> +#define _APPLESPI_H_
> +
> +enum applespi_evt_type {
> +	ET_CMD_TP_INI = BIT(0),
> +	ET_CMD_BL = BIT(1),
> +	ET_CMD_CL = BIT(2),
> +	ET_RD_KEYB = BIT(8),
> +	ET_RD_TPAD = BIT(9),
> +	ET_RD_UNKN = BIT(10),
> +	ET_RD_IRQ = BIT(11),
> +	ET_RD_CRC = BIT(12),
> +};
> +
> +enum applespi_pkt_type {
> +	PT_READ,
> +	PT_WRITE,
> +	PT_STATUS,
> +};
> +
> +#endif /* _APPLESPI_H_ */
> diff --git a/drivers/input/keyboard/applespi_trace.h b/drivers/input/keyboard/applespi_trace.h
> new file mode 100644
> index 000000000000..5e965e1974c7
> --- /dev/null
> +++ b/drivers/input/keyboard/applespi_trace.h
> @@ -0,0 +1,94 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * MacBook (Pro) SPI keyboard and touchpad driver
> + *
> + * Copyright (c) 2015-2019 Federico Lorenzi
> + * Copyright (c) 2017-2019 Ronald Tschalär
> + */
> +
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM applespi
> +
> +#if !defined(_APPLESPI_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
> +#define _APPLESPI_TRACE_H_
> +
> +#include <linux/types.h>
> +#include <linux/tracepoint.h>
> +
> +#include "applespi.h"
> +
> +DECLARE_EVENT_CLASS(dump_message_template,
> +	TP_PROTO(enum applespi_evt_type evt_type,
> +		 enum applespi_pkt_type pkt_type,
> +		 u8 *buf,
> +		 size_t len),
> +
> +	TP_ARGS(evt_type, pkt_type, buf, len),
> +
> +	TP_STRUCT__entry(
> +		__field(enum applespi_evt_type, evt_type)
> +		__field(enum applespi_pkt_type, pkt_type)
> +		__field(size_t, len)
> +		__dynamic_array(u8, buf, len)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->evt_type = evt_type;
> +		__entry->pkt_type = pkt_type;
> +		__entry->len = len;
> +		memcpy(__get_dynamic_array(buf), buf, len);
> +	),
> +
> +	TP_printk("%-6s: %s",
> +		  __print_symbolic(__entry->pkt_type,
> +				   { PT_READ, "read" },
> +				   { PT_WRITE, "write" },
> +				   { PT_STATUS, "status" }
> +		  ),
> +		  __print_hex(__get_dynamic_array(buf), __entry->len))
> +);
> +
> +#define DEFINE_DUMP_MESSAGE_EVENT(name)			\
> +DEFINE_EVENT(dump_message_template, name,		\
> +	TP_PROTO(enum applespi_evt_type evt_type,	\
> +		 enum applespi_pkt_type pkt_type,	\
> +		 u8 *buf,				\
> +		 size_t len),				\
> +	TP_ARGS(evt_type, pkt_type, buf, len)		\
> +)
> +
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_tp_ini_cmd);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_backlight_cmd);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_caps_lock_cmd);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_keyboard_data);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_touchpad_data);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_unknown_data);
> +DEFINE_DUMP_MESSAGE_EVENT(applespi_bad_crc);
> +
> +TRACE_EVENT(applespi_irq_received,
> +	TP_PROTO(enum applespi_evt_type evt_type,
> +		 enum applespi_pkt_type pkt_type),
> +
> +	TP_ARGS(evt_type, pkt_type),
> +
> +	TP_STRUCT__entry(
> +		__field(enum applespi_evt_type, evt_type)
> +		__field(enum applespi_pkt_type, pkt_type)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->evt_type = evt_type;
> +		__entry->pkt_type = pkt_type;
> +	),
> +
> +	"\n"
> +);
> +
> +#endif /* _APPLESPI_TRACE_H_ */
> +
> +/* This part must be outside protection */
> +#undef TRACE_INCLUDE_PATH
> +#define TRACE_INCLUDE_PATH ../../drivers/input/keyboard
> +#define TRACE_INCLUDE_FILE applespi_trace
> +#include <trace/define_trace.h>
> +
> -- 
> 2.20.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 2/2] Input: add Apple SPI keyboard and trackpad driver.

[Life is hard, and then you die]

  Hi Andy,

On Mon, Apr 15, 2019 at 12:03:46PM +0300, Andy Shevchenko wrote:
> On Mon, Apr 15, 2019 at 01:13:00AM -0700, Ronald Tschalär wrote:
> > The keyboard and trackpad on recent MacBook's (since 8,1) and
> > MacBookPro's (13,* and 14,*) are attached to an SPI controller instead
> > of USB, as previously. The higher level protocol is not publicly
> > documented and hence has been reverse engineered. As a consequence there
> > are still a number of unknown fields and commands. However, the known
> > parts have been working well and received extensive testing and use.
> > 
> > In order for this driver to work, the proper SPI drivers need to be
> > loaded too; for MB8,1 these are spi_pxa2xx_platform and spi_pxa2xx_pci;
> > for all others they are spi_pxa2xx_platform and intel_lpss_pci. For this
> > reason enabling this driver in the config implies enabling the above
> > drivers.
> 
> Thank you for an update.
> I suddenly realized couple of places where something maybe optimized.
> 
> Nevertheless, FWIW,
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Many thanks for all your reviews!

[snip]
> > +static void
> > +applespi_remap_fn_key(struct keyboard_protocol *keyboard_protocol)
> > +{
> > +	unsigned char tmp;
> 
> > +	u8 bit = BIT(fnremap - 1);
> 
> The above is UB and I'm sorry I didn't find this earlier.
> 
> So, something like this would work
> 
> 	u8 bit = BIT((fnremap - 1) & 0x07);

fnremap is already constrained by the following:

> > +
> > +	if (!fnremap || fnremap > ARRAY_SIZE(applespi_controlcodes) ||
> > +	    !applespi_controlcodes[fnremap - 1])
> > +		return;

and the array-size of applespi_controlcodes is constrained to the
number of bits in u8 according to this assertion

> > +	compiletime_assert(ARRAY_SIZE(applespi_controlcodes) ==
> > +			   sizeof_field(struct keyboard_protocol, modifiers) * 8,
> > +			   "applespi_controlcodes has wrong number of entries");

So I don't see that the masking buys anything new.

[snip]
> > +	/* check for rollover overflow, which is signalled by all keys == 1 */
> > +	for (i = 0; i < MAX_ROLLOVER; i++) {
> > +		if (keyboard_protocol->keys_pressed[i] != 1)
> > +			break;
> > +	}
> > +
> > +	if (i == MAX_ROLLOVER)	/* all keys were 1 */
> > +		return;
> 
> Since keys_pressed is an array of byte values, it may be replaced with
> memchr_inv().
> 
> > +
> > +	/* remap fn key if desired */
> > +	applespi_remap_fn_key(keyboard_protocol);
> > +
> > +	/* check released keys */
> > +	for (i = 0; i < MAX_ROLLOVER; i++) {
> > +		for (j = 0; j < MAX_ROLLOVER; j++) {
> > +			if (applespi->last_keys_pressed[i] ==
> > +			    keyboard_protocol->keys_pressed[j])
> > +				break;
> > +		}
> > +
> > +		if (j < MAX_ROLLOVER)	/* key is still pressed */
> > +			continue;
> 
> And memchr() here.

Ah, yes, excellent suggestion. Thanks.


  Cheers,

  Ronald

Re: [PATCH v5 2/2] Input: add Apple SPI keyboard and trackpad driver.

[Andy Shevchenko]

On Mon, Apr 15, 2019 at 04:09:55PM -0700, Life is hard, and then you die wrote:
> On Mon, Apr 15, 2019 at 12:03:46PM +0300, Andy Shevchenko wrote:
> > On Mon, Apr 15, 2019 at 01:13:00AM -0700, Ronald Tschalär wrote:

> > > +static void
> > > +applespi_remap_fn_key(struct keyboard_protocol *keyboard_protocol)
> > > +{
> > > +	unsigned char tmp;
> > 
> > > +	u8 bit = BIT(fnremap - 1);
> > 
> > The above is UB and I'm sorry I didn't find this earlier.
> > 
> > So, something like this would work
> > 
> > 	u8 bit = BIT((fnremap - 1) & 0x07);
> 
> fnremap is already constrained by the following:

"already" is a wrong word here. Compiler checks in the order of appearing, so,
for it it is UB and we need to limit bits to allowed range, up to 31 for
unsigned int.

> 
> > > +
> > > +	if (!fnremap || fnremap > ARRAY_SIZE(applespi_controlcodes) ||
> > > +	    !applespi_controlcodes[fnremap - 1])
> > > +		return;
> 
> and the array-size of applespi_controlcodes is constrained to the
> number of bits in u8 according to this assertion
> 
> > > +	compiletime_assert(ARRAY_SIZE(applespi_controlcodes) ==
> > > +			   sizeof_field(struct keyboard_protocol, modifiers) * 8,
> > > +			   "applespi_controlcodes has wrong number of entries");
> 
> So I don't see that the masking buys anything new.

It buys us the follow to the standard. But gcc is clever enough to strip number
to allowed one.

-- 
With Best Regards,
Andy Shevchenko