fbdev: omapfb/dsi-cm: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: omapfb/dsi-cm: Don't put .remove() in .exit.text and drop suppress_bind_attrs

On today's platforms the memory savings of putting the remove function
in .exit isn't that relevant any more. It only matters for built-in
drivers and typically saves a few 100k.

The downside is that the driver cannot be unbound at runtime which is
ancient and also slightly complicates testing. Also it requires to mark
the driver struct with __refdata which is needed to suppress a (W=1)
modpost warning:

WARNING: modpost: drivers/video/fbdev/omap2/omapfb/displays/panel-dsi-cm: section mismatch in reference: dsicm_driver+0x4 (section: .data) -> dsicm_remove (section: .exit.text)

To simplify matters, move the remove callback to .text and drop
.suppress_bind_attrs = true.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: omapfb: panel-dsi-cm: Use backlight helper

Instead of retrieving the backlight brightness in struct
backlight_properties manually, and then checking whether the backlight
should be on at all, use backlight_get_brightness() which does all
this and insulates this from future changes.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-omap@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: omapfb: panel-dsi-cm: switch to using gpiod API

Switch the driver from legacy gpio API that is deprecated to the newer
gpiod API that respects line polarities described in ACPI/DT.

Note that because existing DTSes specify incorrect polarity of reset
lines (active high) and GPU drivers have adopted to this, we follow
the suit and use inverted values when controlling reset lines.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

video: fbdev: omapfb: panel-dsi-cm: Use sysfs_emit() instead of snprintf()

Use sysfs_emit instead of scnprintf, snprintf or sprintf.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Jing Yao <yao.jing2@zte.com.cn>
Signed-off-by: Helge Deller <deller@gmx.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 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 #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

video: fbdev: omap2: omapfb: displays: simplify getting .drvdata

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

omapfb: panel-dsi-cm: constify dsicm_attr_group

File size before:
text data bss dec hex filename
4657 464 0 5121 1401 drivers/video/fbdev/omap2/omapfb/displays/panel-dsi-cm.o

File size after adding 'const':
text data bss dec hex filename
4713 400 0 5113 13f9 drivers/video/fbdev/omap2/omapfb/displays/panel-dsi-cm.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

video: fbdev: omap2: omapfb: displays: panel-dsi-cm: Use time comparison kernel macro.

Use time_before_eq() kernel macro for time comparison.

Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>
Cc: tomi.valkeinen@ti.com
Cc: peter.ujfalusi@ti.com
Cc: tj@kernel.org
Cc: mingo@kernel.org
[b.zolnierkie: patch description fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

omapfb: panel-dsi-cm: Remove deprecated create_singlethread_workqueue

The workqueue "workqueue" has only a single workitem(&ddata->ulps_work)
and hence doesn't require ordering. Also, it is not being used on a
memory reclaim path. Hence, the singlethreaded workqueue has been
replaced with the use of system_wq.

System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.

dsicm_remove() calls dsicm_cancel_ulps_work which uses
cancel_delayed_work() to ensure that there are no pending tasks while
disconnecting the driver.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

omapfb: Create new header file for omapfb DSS implementation

Copy the content of video/omapdss.h to a new (video/omapfb_dss.h) header
file and convert the omapfb drivers to use this new file.

The new header file is needed to complete the separation of omapdrm and
omapfb implementation of DSS.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

omapfb: panel-dsi-cm: Remove legacy boot support

The panel is not used by any legacy board files so the legacy (pdata) boot
support can be dropped.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

omapfb: copy omapdss & displays for omapfb

This patch makes a copy of the omapdss driver and the omap panel &
encoder drivers for omapfb. The purpose is to separate omapdrm and
omapfb drivers from each other.

Note that this patch only does a direct copy of the files without any
other modifications. The files are not yet used.

The original files are in:

drivers/video/fbdev/omap2/dss/
drivers/video/fbdev/omap2/displays-new/

Here's a more detailed explanation about this and the following patches,
from the introduction mail of the patch series:

A short background on the current status. We have the following
entities:

* omapdss, located in drivers/video/fbdev/omap2/dss/. This is a driver for the
display subsystem IPs used on OMAP (and related) SoCs. It offers only a
kernel internal API, and does not implement anything for fbdev or drm.

* omapdss panels and encoders, located in
drivers/video/fbdev/omap2/displays-new/. These are panel and external encoder
drivers, which use APIs offered by omapdss driver. These also don't implement
anything for fbdev or drm.

* omapdrm, located in drivers/gpu/drm/omapdrm/. This is a drm driver, which
uses omapdss and the panel/encoder drivers to operate the hardware.

* omapfb, located in drivers/video/fbdev/omap2/omapfb/. This is an fbdev
driver, which uses omapdss and the panel/encoder drivers to operate the
hardware.

* omap_vout, located in drivers/media/platform/omap/. This is a v4l2 driver,
which uses omapdss and omapfb to implement a v4l2 API for the video overlays.

So, on the top level, we have either omapdrm, or omapfb+omap_vout. Both of
those use the same low level drivers. Without going to the historical details
why the architecture is like that, I think it's finally time to change that.

The situation with omapfb+omap_vout is that it still works, but no new features
have been added for a long time, and I want to keep it working as it's still
being used. At some point in the future I'd like to remove omapfb and
omap_vout altogether.

Omapdrm, on the other hand, is being actively developed. Sharing the low level
parts with omapfb makes that development more difficult than it should be. It
also "hides" half of the development, as everything happening in the low level
parts resides under fbdev directory, not in the drm directory.

I've been wanting to clean this up for a long time, but I haven't figured out a
very good way to do it. I still haven't, but here's the best way I have come up
with.

This series makes a full copy of the low level parts, omapdss and panel/encoder
drivers. Both omapfb+omap_vout and omapdrm will have their own versions. The
copy omapfb+omap_vout get is a new copy, and the copy that omapdrm gets is just
the current files moved. This way git will associate the omapdrm version with
the old files.

The omapfb+omap_vout versions won't be touched unless there are some big issues
there.

The omapdrm versions can be refactored and cleaned up, as the omapfb support
code is no longer needed. We can perhaps also merge omapdss and omapdrm into
the same kernel module.

This series only does the copy, and the absolutely necessary parts. No further
cleanups are done yet.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>