staging: greybus: correct SPDX License Identifier

Replace SPDX License Identifier comments with C comments.
Reported by checkpatch.

Signed-off-by: Ioannis Valasakis <code@wizofe.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: Remove redundant license text

Now that the SPDX tag is in all greybus files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Acked-by: David Lin <dtwlin@gmail.com>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Acked-by: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: add SPDX identifiers to all greybus driver files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/staging/greybus files files with the correct SPDX
license identifier based on the license text in the file itself. The
SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Cc: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Acked-by: David Lin <dtwlin@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: arche: remove timesync remains

Remove the remaining timesync bits that were left in the arche platform
driver and which prevented the driver from being compiled.

Fixes: bdfb95c4baab ("staging: greybus: remove timesync protocol support")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: remove timesync protocol support

While the timesync protocol was a great idea, it never ended up getting
implemented by any known hardware devices. It's also a bit
"interesting" in how it ties into the platform controller.

So, just remove it for now. It's not needed, no one uses it, and it's a
stumbling block in getting the greybus core code merged out of the
staging tree. If anyone wants it in the future, reverting this patch is
a great place to start from.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

greybus: timesync: Add timesync core driver

This patch adds the core timesync functionality.

0. arche-platform.c/arche-apb-ctrl.c
Modifies the platform layer to hook the incoming TIME_SYNC signal up to
the timesync strobe IRQ handler. If the arche-platform driver can't
satisfy the request for the wake-detect line, it will return -EAGAIN and
the calling work-queue must reschedule the attempt to get exclusive
access to the wake-detect pin logic. A private data field is added to
the arche-platform driver to enable passing of a timesync pointer to the
ISR responsible for synchronizing time.

1. timesync.c
A new file added which contains all of the logic associated with sending
greybus commands to SVC, APBx or Interfaces to enable, disable and
disseminate timing information.

2. timesync_platform.c
Any platform/arch specific code goes into timesync_platform.c.
Originally the idea was to keep the x86 and ARM arch dependencies in a
timesync_platform_arch.c file - however with further refinement that's
currently not necessary however just-in-case it becomes necessary to
resuscitate arch or platform specific methods for accessing timer
resources that access shouldn't be part of the core timesync.c logic and
so for the moment we access these timer resources through a thin access
layer in timesync_platform.c. Expect this to go away long term ideally.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Acked-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-platform: Export fn to allow timesync driver to change the state

With the addition of the timesync driver and looking at the hardware
interfaces we have, its clear we need to add a new arche-platform state.

This patch adds ARCHE_PLATFORM_STATE_TIME_SYNC to the arche-platform driver
to facilitate transition to the TIME_SYNC state if-and-only-if the
arche-platform driver is in the ACTIVE state.

This is mainly needed as wake/detect lines are shared between TIMESYNC
operation and basic control functionality of APBs. So during TIMESYNC
we want to make sure that the events on wake/detect lines are
ignored by the arche-platform APB reset logic.

This patch adds one exported function, which can be invoked from
timesync driver code, allowing, switching between
ARCHE_PLATFORM_STATE_TIME_SYNC <=> ARCHE_PLATFORM_STATE_ACTIVE states.

[ bryan.odonoghue@linaro.org: Added mutex, massaged commit text ]

Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Suggested-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-ctrl: Don't expose driver internals to arche-platform driver

We have chosen the *ugly* way of registering two platform drivers from
the module_init() of only one of them, so that we can avoid having two
separate modules for them.

But we should still be doing this in a sane way. There is no need to
expose internals of arche-ctrl to arche-platform, like PM-ops, probe,
resume, id-table, etc. Just expose an init and a exit callback.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-apb-ctrl: Export operational fns from driver

In order to use single wake/detect line for both APB's we need to have
access to APB operational functions to parent/SVC driver.
So export coldboot, standby_boot, fw_flashing and poweroff operation
functions from the driver.

Testing Done: Tested on EVT1.2 and DB3.5 platform

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-platform: Introduce FW_FLASHING state

Introduce FW_FLASHING state to arche-platform driver, to enable
user space to flash/upgrade SVC firmware.

Command to enter into flashing state:

# echo fw_flashing > /sys/devices/arche_platform.*/state

Testing Done: Tested on EVT1.2 and DB3.5 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-platform: make apb_state common to both platform drivers

Make 'enum apb_state' common to both platform drivers, so that
both drivers can make use of same state and user will have
unified control configuration across devices (SVC, APB1 and APB2)

Testing Done: Tested on EVT1.2 and DB3.5 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: arche-platform: merge arche-apb-ctrl and arche-platform

No need to have two separate arche platform drivers, that's just crazy,
so merge them both together to be only one kernel module.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Tested-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>