staging: greybus: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, buInputt the one of
ida_alloc_range()/ida_alloc_max() is inclusive. So a -1 has been added when
needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2e7bbdaf8a495bb1273396395b5c779363287581.1705350141.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: fw-management: make fw_mgmt_class constant

Now that the driver core allows for struct class to be in read-only
memory, making all 'class' structures to be declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at load time.

Cc: Alex Elder <elder@kernel.org>
Cc: greybus-dev@lists.linaro.org
Reviewed-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/2023100534-catty-moodiness-099e@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: Fix indentation in fw-management.c

Reported by Checkpatch:
CHECK: Alignment should match open parenthesis

Signed-off-by: Uri Arev <me@wantyapps.xyz>
Link: https://lore.kernel.org/r/20220523182226.405159-1-me@wantyapps.xyz
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: firmware: s/_LEN/_SIZE

Alex Elder pointed out that the macros also count the trailing NULL
('\0') character and so it should be using SIZE instead of LEN.

This patch makes that change.

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

greybus: firmware: Add 'status' byte to backend fw version response

The backend processor may not be ready to return the version of firmware
it is running by the time AP requests for it. The greybus specification
is updated to return 1-byte 'status' to return the error type, RETRY is
one of them.

This patch implements that in greybus now.

Note that the version structure was common across interface and backend
version requests earlier, but that is changing as well.

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

greybus: firmware: Add new status types for backend updated request

The specification got updated with two more status values, add their
support in greybus.

As retry isn't really an error, skip printing error messages for it as
well.

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

greybus: firmware: Add runtime PM support

This patch implements runtime PM support for firmware management bundle.
This guarantees that the bundle will be active, while the AP or the
Module is trying to exchange any operations over any of the CPorts.

- Firmware Management CPort:

Runtime PM get/put calls are placed around the ioctl calls, which are
all implemented as blocking ioctls.

- Component Authentication CPort:

Runtime PM get/put calls are placed around the ioctl calls, which are
all implemented as blocking ioctls.

- SPI:

Uses the interface provided by spilib.c and runtime PM get/put are
called around connection usage.

- firmware-download:

This is the most tricky one. All operations on this CPort are
initiated from the Module and not from the AP. And the AP needs to do
runtime_pm_get() before any request is received over this CPort.

The module doesn't send any request over this connection, unless the
AP has requested the module over firmware management CPort to download
a firmware package over firmware download CPort.

And so the runtime PM get/put calls around the ioctls in
fw-management.c are sufficient to handle the firmware management CPort
as well.

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

greybus: firmware: prefix char-device with 'gb-'

This will make it consistent with any other character devices we have
for greybus and let us identify greybus character devices easily.

Compiled tested only.

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

greybus: Add comment about the mode_switch_started flag

Add a comment to describe the purpose of the flag.

Suggested-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
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: fw-mgmt: Add hooks to do mode-switch

This is the last step to required to finish the mode switch story. That
is, call the hook provided by Interface layer to accomplish mode switch.

Tested on EVT 1.5 with gpbridge-test module.

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

greybus: fw-management: Fix error message's text

Just reword it to make it sound better.

Compile tested.

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: fw-management: Fix 'make check' warnings

Fix below warnings observed with 'make check'.

~/ara/greybus/fw-management.c:438:33: warning: incorrect type in assignment (different base types)
~/ara/greybus/fw-management.c:438:33: expected unsigned short [unsigned] [addressable] [assigned] [usertype] major
~/ara/greybus/fw-management.c:438:33: got restricted __le16 [usertype] <noident>
~/ara/greybus/fw-management.c:439:33: warning: incorrect type in assignment (different base types)
~/ara/greybus/fw-management.c:439:33: expected unsigned short [unsigned] [addressable] [assigned] [usertype] minor
~/ara/greybus/fw-management.c:439:33: got restricted __le16 [usertype] <noident>

Reported-by: Greg Kroah-Hartman <gregkh@google.com>
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: fw-management: Free fw-mgmt only after all users are gone

The fw-management driver rightly destroys the char device on
connection-exit, but that doesn't guarantee that all of the users of the
device are gone.

Userspace may still be holding file-descriptor of the char device and
can initiate new ioctl operations. And that *will* lead to kernel crash.

To avoid this issue, manage struct users with kref, manage a list of
'struct fw-mgmt' and start using the structure only after getting its
kref incremented.

The important part is the routine get_fw_mgmt(), which increments the
reference to the struct before returning it to the caller. The list of
fw-mgmt structs in protected with a mutex to avoid any races around
that.

The kref is incremented once the char device is opened and dropped only
when it is closed.

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

greybus: fw-management: Add ioctl to initiate mode-switch

Once the interface firmware is loaded successfully to a module,
userspace can ask it to mode switch to the newly loaded firmware.

This patch provides a new ioctl to initiate mode switch.

Userspace can initiate a mode switch if it has previously loaded the
interface firmware successfully, otherwise the firmware core rejects it.

Also, once the mode-switch is initiated, disallow any more interactions
from the userspace.

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

greybus: fw-management: Add firmware-management protocol driver

This patch adds Firmware Management Protocol support to firmware core,
which allows the AP to manage firmware on an Interface.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jun Li <li_jun@projectara.com>
Tested-by: Karthik Ravi Shankar <karthikrs@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>