ipu_plane_atomic_set_base is called from ipu_plane_atomic_update in two
different places, depending on whether drm_atomic_crtc_needs_modeset is
true. Also depending on the same condition, this function does two
different things.
This patch removes the indirection by merging the relevant parts into
ipu_plane_atomic_update, making the actual code flow more obvious as a
result. Also remove the duplicate planar format comment, which is
already found in ipu_plane_atomic_check.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NLiu Ying <gnuiyl@gmail.com>

If the framebuffer pixel format is planar YUV and unchanged, but the U
or V plane offsets change, do not return an error, but request a modeset
instead.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NLiu Ying <gnuiyl@gmail.com>

Without this patch, after enabling the overlay plane with an RGBA
framebuffer, switching to a framebuffer without alpha channel would
cause the plane to vanish, since the pixel local alpha is constant
zero in that case. Disable local alpha again when setting an opaque
framebuffer.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Odd x/y offsets are not allowed for horizontally/vertically chroma
subsampled planar YUV formats.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NLiu Ying <gnuiyl@gmail.com>

Before accessing the u/v offset(aka, u/vbo for IPUv3) of the old plane state's
relevant fb, we should make sure the fb is in YU12 or YV12 pixel format(which
are the two YUV pixel formats we support only), otherwise, we are likely to
trigger BUG_ON() in drm_plane_state_to_u/vbo() since the fb's pixel format is
probably not YU12 or YV12.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=98150
Fixes: c6c1f9bc ("drm/imx: Add active plane reconfiguration support")
Cc: stable@vger.kernel.org # 4.8
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We are checking for NULL here, when we should be checking for error
pointers.

Fixes: 54db5dec ("drm/imx: drop deprecated load/unload drm_driver ops")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We added active plane reconfiguration support by forcing a full modeset
operation.  So, looking at old_plane_state->fb to determine whether we need
to set u/v offset(aka, u/vbo for IPUv3) in ipu_plane_atomic_set_base()
or not is no more correct.  Instead, we should do that only when we don't
need modeset.

Fixes: c6c1f9bc ("drm/imx: Add active plane reconfiguration support")
Cc: stable@vger.kernel.org # 4.8
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We added active plane reconfiguration support by forcing a full modeset
operation.  So, looking at old_plane_state->fb to determine whether we need to
switch EBA buffer(for hardware double buffering) in ipu_plane_atomic_set_base()
or not is no more correct.  Instead, we should do that only when we don't need
modeset, otherwise, we initialize the two EBA buffers with the buffer address.

Fixes: c6c1f9bc ("drm/imx: Add active plane reconfiguration support")
Cc: stable@vger.kernel.org # 4.8
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The imx_drm_bind function causes a warning in linux-next when
CONFIG_DRM_FBDEV_EMULATION is not set:

drivers/gpu/drm/imx/imx-drm-core.c: In function 'imx_drm_bind':
drivers/gpu/drm/imx/imx-drm-core.c:441:1: error: label 'err_unbind' defined but not used [-Werror=unused-label]

I don't understand why the warning only showed up now, as the
code has not been modified recently, but there is an obvious
fix in adding another #if for the symbol.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: c1ff5a7a ("drm/imx: Remove local fbdev emulation Kconfig option")
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The atomic conversion lost the notification to let the DRM core
know about the current state of the CRTC vblank interrupts. This
regressed the ability of the core to reject page flip attempts
on currently disabled CRTCs. Add back the notifications.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Don't leave any bridge or panel attached to a stale driver instance
when unbinding, to allow reattachment on a rebind.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Don't leave the bridge attached to a stale driver instance when
unbinding, to allow reattachment on a rebind.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Make sure to leave a clean panel state behind and allow to
properly attach to the panel again on a rebind.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We don't support configuring active plane on-the-fly for imx-drm.
The relevant CRTC should be disabled before the plane configuration.
Of course, the plane itself should be disabled as well.
This patch adds active plane reconfiguration support by forcing CRTC
mode change and disabling-enabling plane in plane's ->atomic_update
callback.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Tested-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

This allows the atomic helper to wait on them, instead of open-coding
the same in the imx-drm driver.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

ipu_disable_plane is the only left caller of ipu_plane_disable.
Having those 2 similar named functions is confusing and superfluous,
so fold them into 1.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Instead let drm_mode_config_cleanup() do the work when taking down
the master device. This requires all cleanup functions to be
properly hooked up to the mode object .destroy callback.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Drop the load/unload driver ops, as they are deprecated because of their
inherent races, with devices being visible to userspace before they are
fully initialized.

Move this code into the driver bind/unbind routines bracketed by the
proper drm_dev_alloc/register and drm_dev_unregister/unref calls.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

When the destroy path is called the plane should already be
disabled. If not, this is a core bug and should not be worked
around in the driver.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We don't support configuring active plane on-the-fly for imx-drm.
The relevant CRTC should be disabled before the plane configuration.
Of course, the plane itself should be disabled as well.

This patch adds active plane reconfiguration support by forcing CRTC
mode change in plane's ->atomic_check callback so that the CRTC
will be disabled before the plane configuration.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The IPUv3 display controller behind imx-drm needs all planes of
a CRTC be disabled when the CRTC is disabled.
The DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET flag reflects this
hardware requirement.  Let's use the flag for imx-drm.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Now that the drm atomic core supports the callback ->atomic_disable,
we may replace the legacy one ->disable with it.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Drivers may set the NO_DISABLE_AFTER_MODESET flag in the 'flags' parameter
of the helper drm_atomic_helper_commit_planes() if the relevant display
controllers(e.g., IPUv3 for imx-drm) require to disable a CRTC's planes
when the CRTC is disabled. The helper would skip the ->atomic_disable
call for a plane if the CRTC of the old plane state needs a modesetting
operation. Of course, the drivers need to disable the planes in their CRTC
disable callbacks since no one else would do that.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1472461923-14364-1-git-send-email-gnuiyl@gmail.com

Everyone who uses the fbdev emulation helpers doesn't need to include
fb.h directly. Remove it.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-3-git-send-email-daniel.vetter@ffwll.ch

Add support to attach a drm_bridge to imx-ldb in addition to
existing support to attach a LVDS panel.

This patch does a simple code refactoring by moving code
from for_each_child_of_node iterator to a new function named
imx_ldb_panel_ddc(). This was necessary to allow the panel ddc
code to run only when the imx_ldb is not attached to a bridge.

Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: NPeter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Using atomic_mode_set instead of mode_set allows to access crtc
and connector states in addition to the modes. This allows to
remove the connector list walk.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

imx_drm_handle_vblank() is just a simple wrapper of drm_crtc_handle_vblank()
without doing any thing fancy - drm_crtc_handle_vblank() can be called
directly.  So, let's remove the wrapper.
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

There is no one calling imx_drm_crtc_id() and it is just a simple
wrapper of drm_crtc_index() without doing any thing fancy - the
drivers may call drm_crtc_index() directly.  So, let's remove the
wrapper.
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

There is no one calling imx_drm_crtc_vblank_get/_put() and
they are just two simple wrappers of drm_crtc_vblank_get/_put()
without doing any thing fancy - the drivers may call
drm_crtc_vblank_get/_put() directly.  So, let's remove the two
wrappers.
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The 'de-active' and 'pixelclk-active' DT properties are evaluated
by of_parse_display_timing() called from  of_get_drm_display_mode(),
but later lost in the conversion from videomode.flags to
drm_display_mode.flags.
Enhance of_get_drm_display_mode() to also return the bus flags in a
separate variable, so that they can be passed on to the ipu-di
driver.
Signed-off-by: NLothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The code in imx_ldb_encoder_mode_set crashes with a NULL pointer
dereference trying to access crtc->state->state, which was previously
cleared by drm_atomic_helper_swap_state:

    Unable to handle kernel NULL pointer dereference at virtual address 00000010
    pgd = ae08c000
    [00000010] *pgd=3e00e831, *pte=00000000, *ppte=00000000
    Internal error: Oops: 17 [#1] PREEMPT SMP ARM
    Modules linked in:
    CPU: 1 PID: 102 Comm: kmsfb-manage Not tainted 4.7.0-rc5+ #232
    Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
    task: ae058c40 ti: ae04e000 task.ti: ae04e000
    PC is at imx_ldb_encoder_mode_set+0x138/0x2f8
    LR is at 0xae881818
    pc : [<8051a8c8>]    lr : [<ae881818>]    psr: 600f0013
    sp : ae04fc70  ip : ae04fbb0  fp : ae04fcbc
    r10: ae8ea018  r9 : 00000000  r8 : ae246418
    r7 : ae8ea010  r6 : ae8ea308  r5 : 00000000  r4 : 00000000
    r3 : 00000000  r2 : 00000000  r1 : 00000110  r0 : 00000000
    Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
    Control: 10c5387d  Table: 3e08c04a  DAC: 00000051
    Process kmsfb-manage (pid: 102, stack limit = 0xae04e210)
    Stack: (0xae04fc70 to 0xae050000)
    fc60:                                     043ce660 00000001 0000009e 043ce660
    fc80: 00000002 00000000 00000000 af75cf50 00001009 ae23f440 00000001 ae246418
    fca0: 8155a210 ae8ea308 8093c364 ae2464e0 ae04fcec ae04fcc0 804ef350 8051a79c
    fcc0: 00000004 00000004 ae23f440 af3f9000 ae881818 8155a210 af1af200 ae8ea020
    fce0: ae04fd1c ae04fcf0 80519124 804ef060 ae04fd34 00000000 00000000 00000000
    fd00: ae881818 ae23f440 80d4ec8c 00000000 ae04fd34 ae04fd20 804f00b4 80518fac
    fd20: ae23f440 00000000 ae04fd54 ae04fd38 804f2190 804f0074 ae23f440 af3f9000
    fd40: ae04fdd4 ae881818 ae04fd6c ae04fd58 80516390 804f20f4 ae23f440 00000000
    fd60: ae04fd8c ae04fd70 804f26f4 80516348 ae23a000 ae881818 00000001 af3f9000
    fd80: ae04fdac ae04fd90 80502c58 804f2678 ae04fe50 ae23f400 00000001 af3f9000
    fda0: ae04fe1c ae04fdb0 80507a1c 80502bf8 ae23a000 ae058c40 af1af200 ae23f400
    fdc0: ae23a000 af3f9000 ae881818 ae23a00c 80176c7c ae23a000 ae881818 af1af200
    fde0: 00000000 00000000 ae23f400 00000001 ae04fe1c 00000051 ae04fe50 8155a210
    fe00: 80932060 c06864a2 af3f9000 ae246200 ae04fefc ae04fe20 804f9718 805074e8
    fe20: ae04feac ae04fe30 80177360 8017631c 805074dc 00000068 00000068 00000062
    fe40: 00000068 000000a2 ae04fe50 7ef29688 7ef29c40 00000000 00000001 00000018
    fe60: 00000026 00000000 00000000 00000000 00000001 000115bc 05010500 05a0059f
    fe80: 03200000 03360321 00000337 0000003c 00000000 00000040 30383231 30303878
    fea0: 00000000 00000000 00000000 00000000 00000000 00000000 00004000 aea6a140
    fec0: 00000000 80d77b71 00000000 80283110 600f0013 7ef29688 af342bb0 ae250b40
    fee0: 80275440 00000003 ae04e000 00000000 ae04ff7c ae04ff00 80274ac8 804f957c
    ff00: 80283128 80179030 00000000 00000000 80282fd8 ae1e0000 0000003d aea6a1d0
    ff20: 00000002 00000003 00004000 007f8c60 c06864a2 7ef29688 ae04e000 00000000
    ff40: ae04ff6c ae04ff50 80283260 80282fe4 00017050 ae250b41 00000003 ae250b40
    ff60: c06864a2 7ef29688 ae04e000 00000000 ae04ffa4 ae04ff80 80275440 80274a20
    ff80: 00017050 00000001 007f8c60 00000036 801088a4 ae04e000 00000000 ae04ffa8
    ffa0: 80108700 80275408 00017050 00000001 00000003 c06864a2 7ef29688 000115bc
    ffc0: 00017050 00000001 007f8c60 00000036 00000003 00000000 00000026 00000018
    ffe0: 00016f28 7ef29684 0000b7d9 76e4a1e6 400f0030 00000003 3ff7e861 3ff7ec61
    Backtrace:
    [<8051a790>] (imx_ldb_encoder_mode_set) from [<804ef350>] (drm_atomic_helper_commit_modeset_disables+0x2fc/0x3f0)
     r10:ae2464e0 r9:8093c364 r8:ae8ea308 r7:8155a210 r6:ae246418 r5:00000001
     r4:ae23f440
    [<804ef054>] (drm_atomic_helper_commit_modeset_disables) from [<80519124>] (imx_drm_atomic_commit_tail+0x184/0x1e0)
     r10:ae8ea020 r9:af1af200 r8:8155a210 r7:ae881818 r6:af3f9000 r5:ae23f440
     r4:00000004 r3:00000004
    [<80518fa0>] (imx_drm_atomic_commit_tail) from [<804f00b4>] (commit_tail+0x4c/0x68)
     r6:00000000 r5:80d4ec8c r4:ae23f440
    [<804f0068>] (commit_tail) from [<804f2190>] (drm_atomic_helper_commit+0xa8/0xd4)
     r5:00000000 r4:ae23f440
    [<804f20e8>] (drm_atomic_helper_commit) from [<80516390>] (drm_atomic_commit+0x54/0x74)
     r7:ae881818 r6:ae04fdd4 r5:af3f9000 r4:ae23f440
    [<8051633c>] (drm_atomic_commit) from [<804f26f4>] (drm_atomic_helper_set_config+0x88/0xac)
     r5:00000000 r4:ae23f440
    [<804f266c>] (drm_atomic_helper_set_config) from [<80502c58>] (drm_mode_set_config_internal+0x6c/0xf4)
     r7:af3f9000 r6:00000001 r5:ae881818 r4:ae23a000
    [<80502bec>] (drm_mode_set_config_internal) from [<80507a1c>] (drm_mode_setcrtc+0x540/0x5b8)
     r7:af3f9000 r6:00000001 r5:ae23f400 r4:ae04fe50
    [<805074dc>] (drm_mode_setcrtc) from [<804f9718>] (drm_ioctl+0x1a8/0x46c)
     r10:ae246200 r9:af3f9000 r8:c06864a2 r7:80932060 r6:8155a210 r5:ae04fe50
     r4:00000051
    [<804f9570>] (drm_ioctl) from [<80274ac8>] (do_vfs_ioctl+0xb4/0x9e8)
     r10:00000000 r9:ae04e000 r8:00000003 r7:80275440 r6:ae250b40 r5:af342bb0
     r4:7ef29688
    [<80274a14>] (do_vfs_ioctl) from [<80275440>] (SyS_ioctl+0x44/0x6c)
     r10:00000000 r9:ae04e000 r8:7ef29688 r7:c06864a2 r6:ae250b40 r5:00000003
     r4:ae250b41
    [<802753fc>] (SyS_ioctl) from [<80108700>] (ret_fast_syscall+0x0/0x1c)
     r9:ae04e000 r8:801088a4 r7:00000036 r6:007f8c60 r5:00000001 r4:00017050
    Code: 1a000018 e596e034 e59e3368 e59331bc (e5930010)
    ---[ end trace 464e7d3c7f4b9706 ]---

Instead of trying to walk only the connectors in atomic state to which we
don't have access, just walk all connectors to find one connected to the
current encoder and containing a bus_format description.

Fixes: 49f98bc4 ("drm/imx: store internal bus configuration in crtc state")
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NLiu Ying <gnuiyl@gmail.com>

Currently enabling Freescale i.MX DRM support automatically pulls
in fbdev dependency. However this dep is unnecessary since
DRM core already handles this for us (DRM_FBDEV_EMULATION).
Signed-off-by: NTobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468586897-32298-8-git-send-email-tjakobi@math.uni-bielefeld.de

Add support for bridge chips connected externally to the i.MX
DISP0/DISP1 DPI interfaces.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

of_get_drm_display_mode() may fail. Check its return code and bail out
on error.
Signed-off-by: NLothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The error message should say "hsync" instead of "vsync" as
we have just checked the "fsl,hsync-pin" property.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

There is no need for doing an extra 'or' operation when reading
the return value from of_property_read_u32().

Just do a simple read instead.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

regulator_set_voltage() may fail, so we better check its return value
and propagate it in the case of error.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Check the return code on panel attach. Avoids a kernel crash later
on if the attach failed.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

This allows the compiler to do type checking.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The internal bus configuration is imx-drm specific crtc state. Store it
in imx_crtc_state and let the encoder atomic_check callbacks determine
bus_flags, bus_format and the sync pins, possibly taking into account
the mode and the connector display info.
The custom imx_drm_encoder structure can be replaced again with
drm_encoder.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>