staging: greybus: Replace zero-length array by DECLARE_FLEX_ARRAY() helper

The code currently uses C90 standard extension based zero length array
struct which is now deprecated and the new C99 standard extension of
flexible array declarations are to be used instead. Also, the macro
DECLARE_FLEX_ARRAY() allows to use single flexible array member in a
structure. Refer to these links [1], [2], and [3] for details.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://lore.kernel.org/lkml/YxKY6O2hmdwNh8r8@work
[3] https://lore.kernel.org/lkml/20210827163015.3141722-2-keescook@chromium.org/

Issue identified using Coccinelle flexible_array.cocci semantic patch.

Signed-off-by: Deepak R Varma <drv@mailo.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/Y7WYzkIOqaHOxDDS@qemulion
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: move core include files to include/linux/greybus/

With the goal of moving the core of the greybus code out of staging, the
include files need to be moved to include/linux/greybus.h and
include/linux/greybus/

Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Cc: Rui Miguel Silva <rmfrfs@gmail.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Cc: greybus-dev@lists.linaro.org
Cc: devel@driverdev.osuosl.org
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Alex Elder <elder@kernel.org>
Link: https://lore.kernel.org/r/20190825055429.18547-8-gregkh@linuxfoundation.org
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>

greybus: usb: constify hc_driver structures

The hc_driver structure is only passed as the first argument to
usb_create_hcd, which is declared as const. Thus the hc_driver structure
itself can be const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

greybus: gbphy: Remove protocol specific version handling

We should be using the generic version handling at bundle level, instead
of at protocol level for bridged PHY devices as well.

The bundle version handling is already in place, though it is *not* used
today as we haven't bumped the version of control protocol yet.

Remove protocol specific handling for bridged PHY devices.

Tested on EVT 1.5 with gpbridge-test module. No nuttx changes are
required with this.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: Remove unused VERSION specific macros

We don't use these anymore. Drop them.

Note that some macro's specific to bridged PHY devices aren't removed in
the patch, as gbsim will break otherwise. They will be removed
separately.

Compile tested.

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

greybus: gpbridge: rename 'gpbridge' to 'gbphy' everywhere

The 'gpbridge' name didn't relaly reflect what the bus is; which
is a bus for bridged-phy devices. So, rename all instances
of 'gpbridge' to more appropriate 'gbphy'

Testing Done:
Build and boot tested. 'lsgb' will stop displaying 'GPBridge' devices
until I change the library to reflect this change.

Signed-off-by: Sandeep Patil <patil_sandeep@projectara.com>
Suggested-by: Greg Kroah-Hartman <gregkh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: Create separate module

Create separate module for usb gpbridge driver.

Tested on EVT 1.5 by inserting GP test module, all the devices were
enumerated correctly.

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

greybus: USB: convert to a gpbridge driver

This converts the USB driver to be a gpbridge driver, moving it away
from the "legacy" interface.

It's not like this code even does anything at the moment, how much
trouble could we cause with this change? :)

Testing Done: Tested on gbsim.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
[vaibhav.hiremath@linaro.org: 1.Changed code to retain init/exit fns of
drivers. 2.Exit path fix. 3. Fixed review comments]
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: convert drivers to use connection->private set/get

This converts all drivers to use the gb_connection_get_data() and
gb_connection_set_data() functions to make it a bit more explicit as to
what is going on.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: gpbridge.h: move protocol init/exit prototypes

Create gpbridge.h for the gpbridge-specific function prototypes, the
rest of the greybus drivers don't care about them.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>

greybus: usb: use the bundle struct device instead of the connector

We are removing struct device from the gb_connection structure in the
near future. The gb_bundle structure's struct device should be used as
a replacement.

This patch moves the usb driver to use the bundle pointer instead of the
connection pointer.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

greybus: usb: Drop get_version support

This is done from a common place now, no need to replicate it.

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

greybus: usb: Use (already defined) major/minor macros

We already have macros for these, use them instead of writing fixed
values.

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

greybus: usb: disable protocol driver

The USB bridged-PHY protocol driver currently depends on changes to USB
core that are not yet upstream.

Disable for now.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: implement hub_control callback

Implement the hub_control callback.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: fix hc_driver fields

Fix hc_driver description, product_desc and flags fields.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: fix hcd allocation, deregistration and deallocation

Fix allocation, deregistration and deallocation of USB HCD, and update
the hcd_priv helper functions.

The HCD private data was not allocated correctly, something which would
lead to a crash when accessed in hcd_start. The HCD was neither
reregistered or deallocated on connection tear down.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: renumber operation types

Renumber the current operation types.

NOTE: Protocol change.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: clean up driver

Remove unused, broken or unneeded code and constructs.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: operation: allow atomic operation allocations

Add gfp mask argument to gb_operation_create to allow operations to be
allocated in atomic context.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: Rename gb_gpbridge_protocol_driver() as gb_builtin_protocol_driver()

This macro is also required by core protocols like control and svc, and
hence the 'gpbridge' name doesn't fit anymore.

Lets call this macro gb_builtin_protocol_driver().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: Use gb_gpbridge_protocol_init()

Start using gb_gpbridge_protocol_init() in gpbridge drivers.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: usb: silence compiler warning

This driver is being rewritten, but let's silence a pointer-to-int-cast
compiler warning meanwhile.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

greybus: remove unused version-response structs

These aren't used anymore and so can be removed.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

greybus: create get_version() routines with the help of a macro

This gets rid of lots of duplication of code.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

greybus: Remove "-gb" suffix from .c files

Some files are prefixed with "gb-" and some are suffixed with "-gb". The
rationale behind the first one is that the modules would be named so, i.e.
gb-*.ko. But there is no reason to keep the "-gb" suffix in the second case.

Remove the unnecessary suffix.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>