Linux 4.15-rc8

Daniel requested this for so the intel CI won't fall over on drm-next
so often.

drm/tegra: Changes for v4.16-rc1

The bulk of these changes are preparation work and addition of support
for Tegra186. Currently only HDMI output (the primary output on Jetson
TX2) is supported, but the hardware is also capable of doing DSI and
DisplayPort.

Tegra DRM now also uses the atomic commit helpers instead of the open-
coded variant that was only doing half its job. As a bit of a byproduct
of the Tegra186 support the driver also gained HDMI 2.0 as well as zpos
property support.

Along the way there are also a few patches to clean up a few things and
fix minor issues.

* tag 'drm/tegra/for-4.16-rc1-fixes' of git://anongit.freedesktop.org/tegra/linux: (51 commits)
  drm/tegra: dc: Properly cleanup overlay planes
  drm/tegra: dc: Fix possible_crtcs mask for planes
  drm/tegra: dc: Restore YUV overlay support
  drm/tegra: dc: Implement legacy blending
  drm/tegra: Correct timeout in tegra_syncpt_wait
  drm/tegra: gem: Correct iommu_map_sg() error checking
  drm/tegra: dc: Link DC1 to DC0 on Tegra20
  drm/tegra: Fix non-debugfs builds
  drm/tegra: dpaux: Keep reset defaults for hybrid pad parameters
  drm/tegra: Mark Tegra186 display hub PM functions __maybe_unused
  drm/tegra: Use IOMMU groups
  gpu: host1x: Use IOMMU groups
  drm/tegra: Implement zpos property
  drm/tegra: dc: Remove redundant spinlock
  drm/tegra: dc: Use direct offset to plane registers
  drm/tegra: dc: Support more formats
  drm/tegra: fb: Force alpha formats
  drm/tegra: dpaux: Add Tegra186 support
  drm/tegra: dpaux: Implement runtime PM
  drm/tegra: sor: Support HDMI 2.0 modes
  ...

The SOR0 found on Tegra124 and Tegra210 only supports eDP and LVDS and
therefore has a slightly different clock tree than the SOR1 which does
not support eDP, but HDMI and DP instead.

Commit e1335e2f0cfc ("drm/tegra: sor: Reimplement pad clock") breaks
setups with eDP because the sor->clk_out clock is uninitialized and
therefore setting the parent clock (either the safe clock or either of
the display PLLs) fails, which can cause hangs later on since there is
no clock driving the module.

Fix this by falling back to the module clock for sor->clk_out on those
setups. This guarantees that the module will always be clocked by an
enabled clock and hence prevents those hangs.

Fixes: e1335e2f0cfc ("drm/tegra: sor: Reimplement pad clock")
Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

The first overlay plane can leak if initialization of the second overlay
plane fails. Fix this by properly destroying the first overlay plane on
error.

Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Cursor and overlay planes use a possible_crtcs mask based on the DC pipe
number. However, DRM requires each bit in the mask to correspond to the
index of the CRTC, which will be different from the DC pipe number for a
configuration where the first display controller is disabled, or where a
deferred probe leads to the first display controller being probed after
the first.

Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Commit ebae8d07435a ("drm/tegra: dc: Implement legacy blending") broke
support for YUV overlays by accident. The reason is that YUV formats are
considered opaque because they have no alpha component, but on the other
hand no corresponding format with an alpha component can be returned. In
the case of YUV formats, the opaque format is the same as the alpha
format, so add the special case to restore YUV overlay support.

Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

This implements alpha blending on legacy display controllers (Tegra20,
Tegra30 and Tegra114). While it's theoretically possible to support the
zpos property to enable userspace to specify the Z-order of each plane
individually, this is not currently supported and the same fixed Z-
order as previously defined is used.

Reverts commit 71835caa00e8 ("drm/tegra: fb: Force alpha formats") since
the opaque formats are now supported.

Reported-by: Dmitry Osipenko <digetx@gmail.com>
Fixes: 7772fdaef939 ("drm/tegra: Support ARGB and ABGR formats")
Signed-off-by: Thierry Reding <treding@nvidia.com>

host1x_syncpt_wait() takes timeout value in jiffies, but DRM passes it in
milliseconds.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

iommu_map_sg() doesn't return a error value, but a size of the requested
IOMMU mapping or zero in case of error.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Hardware reset isn't actually broken on Tegra20, but there is a
dependency on the first display controller to be taken out of reset for
the second to be enabled successfully. Model this dependency using a PM
device link.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[treding@nvidia.com: minor cleanups, extend commit message]
Signed-off-by: Thierry Reding <treding@nvidia.com>