wireless: ti: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200225003408.GA28675@embeddedor

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin st fifth floor boston ma 02110
1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 246 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

wlcore: create private static_data area and add operation to parse it

The wl18xx firmware has more information in the static_data than
wl12xx. To be able to parse that in an abstracted way, this patch
adds a priv area to the static data struct and an operation that
allows the lower driver to parse it if necessary.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>

wlcore/wl12xx: move top initialization to wl12xx

The top registers initialization is very specific to the actual
hardware used, even the way in which we read from and write to the top
registers varies from chip to chip. This patch moves all top
registers initialization to wl12xx. Also add a boot op for the wlcore
module to call at the right time and a few callbacks with the common
called to be called from the lower drivers boot operations.

Signed-off-by: Luciano Coelho <coelho@ti.com>

wlcore/wl12xx: implement chip-specific register tables

Add register tables support in wlcore, add some new IO functions to
read and write to chip-specific register and data addresses. Move
some common register values from wl12xx to wlcore and add the
registers table to wl12xx.

Signed-off-by: Luciano Coelho <coelho@ti.com>

wl12xx/wlcore: move wl1271 struct to wlcore and add ops

In order to add chip-specific operations and prepare for future
elements that need to be set by the lower driver, move the wl1271
structure to the wlcore.h file and add an empty placeholder for the
operations structure.

Signed-off-by: Luciano Coelho <coelho@ti.com>

wl12xx/wlcore: rename wl12xx to wlcore

Rename the wl12xx driver directory to wlcore as an initial step
towards the split of the driver into wlcore and wl12xx. We just
rename the directory first to keep git blame happy.

Signed-off-by: Luciano Coelho <coelho@ti.com>