gcc-6 warns about a pointless loop in exynos_drm_subdrv_open:

drivers/gpu/drm/exynos/exynos_drm_core.c: In function 'exynos_drm_subdrv_open':
drivers/gpu/drm/exynos/exynos_drm_core.c:104:199: error: self-comparison always evaluates to false [-Werror=tautological-compare]
  list_for_each_entry_reverse(subdrv, &subdrv->list, list) {

Here, the list_for_each_entry_reverse immediately terminates because
the subdrv pointer is compared to itself as the loop end condition.

If we were to take the current subdrv pointer as the start of the
list (as we would do if list_for_each_entry_reverse() was not a macro),
we would iterate backwards over the &exynos_drm_subdrv_list anchor,
which would be even worse.

Instead, we need to use list_for_each_entry_continue_reverse()
to go back over each subdrv that was successfully opened until
the first entry.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

This adds very rudimentary TCON (timing controller for raw LCD displays)
support to enable the bypass mode in order to use the DCU controller on
Freescale/NXP Vybrid SoC's.

Additionally the register clock and pixel clock has been separated, but
are currently still enabled and disabled pairwise.

Other than that, fixes and cleanups accross the driver.

* 'for-next' of http://git.agner.ch/git/linux-drm-fsl-dcu:
  drm/fsl-dcu: increment version and date
  drm/fsl-dcu: implement lastclose callback
  drm/fsl-dcu: disable output polling on driver unload
  drm/fsl-dcu: deallocate fbdev CMA on unload
  drm/fsl-dcu: use variable name dev for struct drm_device
  drm/fsl-dcu: handle missing panel gracefully
  drm/fsl-dcu: detach panel on destroy
  drm/layerscape: reduce excessive stack usage
  drm/fsl-dcu: add TCON driver
  drm/fsl-dcu: use common clock framework for pixel clock divider
  drm/fsl-dcu: add extra clock for pixel clock
  drm/fsl-dcu: disable clock on initialization failure and remove

Merge tag 'sun4i-drm-for-4.7' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into drm-next

Allwinner DRM driver for 4.7

This pull request introduces the sun4i driver, meant to be used on the
older Allwinner SoCs (A10, A13, A20, A23, A31 and A33).

It currently supports only the A13, which has one of the simplest video
pipeline. Support for other video components and SoCs will be added
eventually.

It supports only a RGB or composite output. It doesn't do HDMI, VGA, LVDS
or power management yet, but that will come in time as well.

* tag 'sun4i-drm-for-4.7' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
  MAINTAINERS: Add a maintainer for the Allwinner DRM driver
  drm: sun4i: tv: Add NTSC output standard
  drm: sun4i: tv: Add PAL output standard
  drm: sun4i: Add composite output
  drm: sun4i: Add RGB output
  drm: Add Allwinner A10 Display Engine support
  drm: sun4i: Add DT bindings documentation
  drm: fb: Add seq_file definition

Add myself as the maintainer of the new Allwinner DRM driver.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Add the settings to support the NTSC standard.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Now that we have support for the composite output, we can start adding new
supported standards. Start with PAL, and we will add other eventually.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Some Allwinner SoCs have an IP called the TV encoder that is used to output
composite and VGA signals. In such a case, we need to use the second TCON
channel.

Add support for that TV encoder.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

One of the A10 display pipeline possible output is an RGB interface to
drive LCD panels directly. This is done through the first channel of the
TCON that will output our video signals directly.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

The Allwinner A10 and subsequent SoCs share the same display pipeline, with
variations in the number of controllers (1 or 2), or the presence or not of
some output (HDMI, TV, VGA) or not.

Add a driver with a limited set of features for now, and we will hopefully
support all of them eventually
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

The display pipeline of the Allwinner A10 is involving several loosely
coupled components.

Add a documentation for the bindings.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Otherwise, building with DEBUG_FS enabled will trigger a build warning
because we're using a structure that has not been declared.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Need to move the free function around a bit, but otherwise mostly
just removing code.

Specifically we can nuke all the _locked variants since the weak idr
reference is now protected by the idr_mutex, which we never hold
anywhere expect in the lookup/reg/unreg functions. And those never
call anything else.

Another benefit of this is that this patch switches the weak reference
logic from kref_put_mutex to kref_get_unless_zero. And the later is in
general more flexible wrt accomodating multiple weak references
protected by different locks, which might or might not come handy
eventually.

But one consequence of that switch is that we need to acquire the
blob_lock from the free function for the list_del calls. That's a bit
tricky to pull off, but works well if we pick the exact same scheme as
is already used for framebuffers. Most important changes:

- filp list is maintainer by create/destroy_blob ioctls directly
  (already the case, so we can just remove the redundant list_del from
  the free function).

- filp close handler walks the filp-private list lockless - works
  because we know no one else can access it. I copied the same comment
  from the fb code over to explain this.

- Otherwise we need to sufficiently restrict blob_lock critical
  sections to avoid all the unreference calls. Easy to do once the
  blob_lock only protects the list, and no longer the weak reference.

Cc: Dave Airlie <airlied@gmail.com>
Cc: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Random drive-by refactoring I spotted.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Dave Airlie had at least the refcount leak fixed in a later patch (but
that patch does other things which need a bit more work). But we still
have the trouble that silly userspace could hit the WARN_ON in
drm_mode_object_find.

Fix this all up to make sure we don't leak objects, and don't spew
into demsg.

Fixes: d0f37cf6 ("drm/mode: move framebuffer reference into object.")
Testcase: igt/kms_addfb_basic/invalid-*-prop*
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Slipped through the cracks in my review. The one issue I spotted
is that drm_mode_object_find now acquires references and can be
used on FB objects, which caused follow-on bugs in get/set_prop ioctls.
Follow-up patches will fix that.

[airlied: fixup some incr fb/decr object mixups]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge branch 'topic-arcpgu-v6' of https://github.com/foss-for-synopsys-dwc-arc-processors/linux into drm-next

This is DRM driver for ARC PGU - simple bitstreamer used on
Synopsys ARC SDP boards (both AXS101 and AXS103).

* 'topic-arcpgu-v6' of https://github.com/foss-for-synopsys-dwc-arc-processors/linux:
  arc: axs10x - add support of ARC PGU
  MAINTAINERS: Add maintainer for ARC PGU display controller
  drm: Add DT bindings documentation for ARC PGU display controller
  drm: Add support of ARC PGU display controller

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

One cannot rename the struct at this point, so might as well remove the
comment.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

misc rcar changes.

* 'drm/next/du' of git://linuxtv.org/pinchartl/fbdev:
  drm: rcar-du: Fix compilation warning
  drm: rcar-du: Use ARCH_RENESAS
  drm: rcar-du: Clarify vsp dependency

Synopsys DesignWare ARC SDP boards sport ARC SDP display
controller attached to ADV7511 HDMI encoder.

That change adds desctiption of both ARC PGU and ADV7511 in
ARC SDP'd base-board Device Tree.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: devicetree@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org

This updates MAINTEINERS file with information about maintainer of
ARC PGU display controller driver.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org

This add DT bindings documentation for ARC PGU display controller.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: devicetree@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Acked-by: Rob Herring <robh@kernel.org>

ARC PGU could be found on some development boards from Synopsys.
This is a simple byte streamer that reads data from a framebuffer
and sends data to the single encoder.
Signed-off-by: Carlos Palminha <palminha@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-snps-arc@lists.infradead.org

The driver supports now a second platform and received several
fixes, hence a version increment is justified.
Signed-off-by: Stefan Agner <stefan@agner.ch>

Use CMA helper drm_fbdev_cma_restore_mode to restore fbdev mode
in process which uses drm/kms dies.
Signed-off-by: Stefan Agner <stefan@agner.ch>

Disabling output polling before unloading the driver.
Signed-off-by: Stefan Agner <stefan@agner.ch>

Free fbdev CMA using drm_fbdev_cma_fini on unload. This fixes
a warning when unloading the driver:
WARNING: CPU: 0 PID: 164 at drivers/gpu/drm/drm_crtc.c:5930 drm_mode_config_cleanup+0x204/0x208
Signed-off-by: Stefan Agner <stefan@agner.ch>

The driver uses different variable names for struct drm_device
across functions which is confusing. Stick to the more common
variable name dev. While at it, remove unnecessary if statement
in error handling.
Signed-off-by: Stefan Agner <stefan@agner.ch>

If the device tree property fsl,panel is missing, drm_panel_attach
is called with a NULL pointer as first argument. Having a panel is
basically mandatory since RGB is the only supported connector.
Check if a panel node has been found, return -ENODEV and cleanup
otherwise.
Signed-off-by: Stefan Agner <stefan@agner.ch>

Disable the earlier attached panel on connector destroy.
Signed-off-by: Stefan Agner <stefan@agner.ch>

The fsl-dcu driver copies a drm_mode_config object to its
stack but then only accesses a single member (dpms_property)
once. The data structure is large enough to trigger a warning
about the amount of kernel stack being used:

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c: In function 'fsl_dcu_drm_connector_create':
drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c:182:1: error: the frame size of 1040 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

This changes the fsl_dcu_drm_connector_create() function to
only access the drm_mode_config by reference, which is also
more efficient.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 109eee2f ("drm/layerscape: Add Freescale DCU DRM driver")
Signed-off-by: Stefan Agner <stefan@agner.ch>

Add driver for the TCON (timing controller) module. The TCON module
is a separate module attached after the DCU (display controller
unit). Each DCU instance has its own, directly connected TCON
instance. The DCU's RGB and timing signals are passing through
the TCON module. TCON can provide timing signals for raw TFT panels
or operate in a bypass mode which leaves all signals unaltered.

The driver currently only supports the bypass mode.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stefan Agner <stefan@agner.ch>

Use the common clock framework to calculate the pixel clock
dividier. The previous implementation rounded down the calculated
factor. Thanks to the CLK_DIVIDER_ROUND_CLOSEST flag using the
common clock framework divider implementation improves the pixel
clock accuracy in some cases. Ontop of that it also allows to see
the actual pixel clock in the sysfs clock summary.
Signed-off-by: Stefan Agner <stefan@agner.ch>

The Vybrid DCU variant has two independent clock inputs, one
for the registers (IPG bus clock) and one for the pixel clock.
Support this distinction in the DCU DRM driver while staying
backward compatible for old device trees.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stefan Agner <stefan@agner.ch>

Fix error handling during probe by reordering initialization and
adding a error path which disables clock again. Also disable the
clock on remove.
Signed-off-by: Stefan Agner <stefan@agner.ch>

Commit d63c25e4 ("drm: rcar-du: Use generic
drm_connector_register_all() helper") left an unused local variable
behind. Remove it.

Fixes: d63c25e4 ("drm: rcar-du: Use generic drm_connector_register_all() helper")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Make use of ARCH_RENESAS in place of ARCH_SHMOBILE.

This is part of an ongoing process to migrate from ARCH_SHMOBILE to
ARCH_RENESAS the motivation for which being that RENESAS seems to be a more
appropriate name than SHMOBILE for the majority of Renesas ARM based SoCs.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The VSP1 compositor code in DRM links against the respective V4L
driver, but the dependency is not expressed correctly in Kconfig,
which leads to a build error when the DRM driver is built-in
and the V4L driver is a module:

drivers/gpu/built-in.o: In function `rcar_du_vsp_plane_atomic_update':
rcar-du/rcar_du_vsp.c:183: undefined reference to `vsp1_du_atomic_update'

This patch avoids the problem by ensuring that the DRM VSP code can
only be enabled if the V4L driver is linked into the kernel, or
both are loadable modules.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6d62ef3a ("drm: rcar-du: Expose the VSP1 compositor through KMS planes")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Since ref counting is in the object now we can just call the
normal interfaces.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

This reduces the fb_lock to just protecting the num_fb/fb_list.

"Previously fb refcounting, and especially the weak reference
(kref_get_unless_zero) used in fb lookups have been protected by fb_lock.
But with the refactoring to share refcounting in the drm_mode_object base
class that switched to being protected by idr_mutex, which means fb_lock
critical sections can be reduced."
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>