drm/tegra: Changes for v4.1-rc1

Perhaps the most noteworthy change in this set is the implementation of
a hardware VBLANK counter using host1x syncpoints. The SOR registers can
now be dumped via debugfs, which can be useful while debugging. The IOVA
address space maintained by the driver can also be dumped via debugfs.

Other than than, these changes are mostly cleanup work, such as making
register names more consistent or removing unused code (that was left
over after the atomic mode-setting conversion). There's also a fix for
eDP that makes the driver cope with firmware that already initialized
the display (such as the firmware on the Tegra-based Chromebooks).

* tag 'drm/tegra/for-4.1-rc1' of git://anongit.freedesktop.org/tegra/linux:
  drm/tegra: sor: Reset during initialization
  drm/tegra: gem: Return 64-bit offset for mmap(2)
  drm/tegra: hdmi: Name register fields consistently
  drm/tegra: hdmi: Resets are synchronous
  drm/tegra: dc: Document tegra_dc_state_setup_clock()
  drm/tegra: dc: Remove unused callbacks
  drm/tegra: dc: Remove unused function
  drm/tegra: dc: Use base atomic state helpers
  drm/atomic: Add helpers for state-subclassing drivers
  drm/tegra: dc: Implement hardware VBLANK counter
  gpu: host1x: Export host1x_syncpt_read()
  drm/tegra: sor: Dump registers via debugfs
  drm/tegra: sor: Registers are 32-bit
  drm/tegra: Provide debugfs file for the IOVA space
  drm/tegra: dc: Check for valid parent clock

This function is called by output drivers so should be documented. While
at it, move it to a more appropriate location.

Signed-off-by: Thierry Reding <treding@nvidia.com>

The ->mode_set() and ->mode_set_base() callbacks are no longer used with
full atomic mode-setting drivers, so remove them.

Signed-off-by: Thierry Reding <treding@nvidia.com>

The tegra_dc_setup_clock() function is unused after the conversion to
atomic mode-setting, so remove it.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Instead of duplicating the code, make use of the newly introduced atomic
state duplicate and destroy helpers. This allows changes to the base
atomic state handling to automatically propagate to the Tegra driver and
thereby prevent breakage resulting from both copies going out of sync.

Signed-off-by: Thierry Reding <treding@nvidia.com>

The display controller on Tegra can use syncpoints to count VBLANK
events. syncpoints are 32-bit unsigned integers, so well suited as
VBLANK counters.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Check that the desired parent clock is indeed a valid parent for the
display controller clock. This is purely cosmetic at this point since
the parent clocks are specified in DT and all the currently defined
parents are in fact valid parents of the display controller clock.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Linux 4.0-rc3 backmerge to fix two i915 conflicts, and get
some mainline bug fixes needed for my testing box

Conflicts:
	drivers/gpu/drm/i915/i915_drv.h
	drivers/gpu/drm/i915/intel_display.c

Use cases like rotation require these hooks to have some context so they
know how to prepare and cleanup the frame buffer correctly.

For i915 specifically, object backing pages need to be mapped differently
for different rotation modes and the driver needs to know which mapping to
instantiate and which to tear down when transitioning between them.

v2: Made passed in states const. (Daniel Vetter)

[airlied: add mdp5 and atmel fixups]
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

The code in tegra_crtc_prepare() really belongs in tegra_dc_init(), or
at least most of it. This fixes an issue with VBLANK handling because
tegra_crtc_prepare() would overwrite the interrupt mask register that
tegra_crtc_enable_vblank() had written to to enable VBLANK interrupts.

Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>