drm/vc4: fix typo

Replace 'pack' with 'back'.

Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231023085929.1445594-1-dario.binacchi@amarulasolutions.com

drm/vc4: Add comments for which HVS_PIXEL_ORDER_xxx defines apply

The HVS_PIXEL_ORDER_xxx defines apply to specific HVS_PIXEL_FORMAT_xxx
modes, so add comments to make this obvious.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-12-1f8e0770798b@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/vc4: hvs: Correct interrupt masking bit assignment for HVS5

HVS5 has moved the interrupt enable bits around within the
DISPCTRL register, therefore the configuration has to be updated
to account for this.

Fixes: c54619b0bfb3 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-4-1f8e0770798b@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/vc4: hvs: SCALER_DISPBKGND_AUTOHS is only valid on HVS4

The bit used for SCALER_DISPBKGND_AUTOHS in SCALER_DISPBKGNDX
has been repurposed on HVS5 to configure whether a display can
win back-to-back arbitration wins for the COB.

This is not desirable, therefore only select this bit on HVS4,
and explicitly clear it on HVS5.

Fixes: c54619b0bfb3 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-3-1f8e0770798b@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/vc4: hvs: Set AXI panic modes

The HVS can change AXI request mode based on how full the COB
FIFOs are.
Until now the vc4 driver has been relying on the firmware to
have set these to sensible values.

With HVS channel 2 now being used for live video, change the
panic mode for all channels to be explicitly set by the driver,
and the same for all channels.

Fixes: c54619b0bfb3 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-2-1f8e0770798b@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/vc4: drop unexpected word "the" in the comments

there is an unexpected word "the" in the comments that need to be dropped

file: drivers/gpu/drm/vc4/vc4_regs.h
line: 267
/* Set when the the downstream tries to read from the display FIFO
changed to
/* Set when the downstream tries to read from the display FIFO

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220621130550.126915-1-jiangjian@cdjrlc.com

drm/vc4: hvs: Fix frame count register readout

In order to get the field currently being output, the driver has been
using the display FIFO frame count in the HVS, reading a 6-bit field at
the offset 12 in the DISPSTATx register.

While that field is indeed at that location for the FIFO 1 and 2, the
one for the FIFO0 is actually in the DISPSTAT1 register, at the offset
18.

Fixes: e538092cb15c ("drm/vc4: Enable precise vblank timestamping for interlaced modes.")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20220331143744.777652-3-maxime@cerno.tech

drm/vc4: hdmi: Support HDMI YUV output

In addition to the RGB444 output, the BCM2711 HDMI controller supports
the YUV444 and YUV422 output formats.

Let's add support for them in the driver, but still use RGB as the
preferred format.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220222164042.403112-8-maxime@cerno.tech

drm/vc4: hdmi: Replace CSC_CTL hardcoded value by defines

On BCM2711, the HDMI_CSC_CTL register value has been hardcoded to an
opaque value. Let's replace it with properly defined values.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-9-maxime@cerno.tech

drm/vc4: plane: Add support for YUV color encodings and ranges

The BT601/BT709 color encoding and limited vs full
range properties were not being exposed, defaulting
always to BT601 limited range.

Expose the parameters and set the registers appropriately.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20211215091739.135042-4-maxime@cerno.tech

drm/vc4: hdmi: Set HDMI_MAI_FMT

The hardware uses this for generating the right audio
data island packets when using formats other than PCM

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210525132354.297468-8-maxime@cerno.tech

drm/vc4: hdmi: Support the BCM2711 HDMI controllers

Now that the driver is ready for it, let's bring in the HDMI controllers
variants for the BCM2711.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b540c7a9ebb7ad51da39271a8388b69c7e27e582.1599120059.git-series.maxime@cerno.tech

drm/vc4: hdmi: Switch to blank pixels when disabled

In order to avoid pixels getting stuck in an unflushable FIFO, we need when
we disable the HDMI controller to switch away from getting our pixels from
the pixelvalve and instead use blank pixels, and switch back to the
pixelvalve when we enable the HDMI controller.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fde3efb1ad79f4476a73d310cbba3ec07dc6dabe.1599120059.git-series.maxime@cerno.tech

drm/vc4: hdmi: Implement a register layout abstraction

The HDMI controllers found in the BCM2711 have most of the registers
reorganized in multiple registers areas and at different offsets than
previously found.

The logic however remains pretty much the same, so it doesn't really make
sense to create a whole new driver and we should share the code as much as
possible.

Let's implement some indirection to wrap around a register and depending on
the variant will lookup the associated register on that particular variant.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3070236daff920e7edd11c5a72ac31fd0f6a656b.1599120059.git-series.maxime@cerno.tech

drm/vc4: crtc: Add BCM2711 pixelvalves

The BCM2711 has 5 pixelvalves, so now that our driver is ready, let's add
support for them.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/2553ec9ece0d8a0e5299ff74ed932a38703c5db9.1599120059.git-series.maxime@cerno.tech

drm/vc4: crtc: Assign output to channel automatically

The HVS found in the BCM2711 has 6 outputs and 3 FIFOs, with each output
being connected to a pixelvalve, and some muxing between the FIFOs and
outputs.

Any output cannot feed from any FIFO though, and they all have a bunch of
constraints.

In order to support this, let's store the possible FIFOs each output can be
assigned to in the vc4_crtc_data, and use that information at atomic_check
time to iterate over all the CRTCs enabled and assign them FIFOs.

The channel assigned is then set in the vc4_crtc_state so that the rest of
the driver can use it.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/f9aba3814ef37156ff36f310118cdd3954dd3dc5.1599120059.git-series.maxime@cerno.tech

drm/vc4: Add support for the BCM2711 HVS5

The HVS found in the BCM2711 is slightly different from the previous
generations.

Most notably, the display list layout changes a bit, the LBM doesn't have
the same size and the formats ordering for some formats is swapped.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1d02fab3b916d639c2dc05608c117bbd8230ebe8.1599120059.git-series.maxime@cerno.tech

drm/vc4: Convert register accessors to FIELD_*

The VC4_SET_FIELD and VC4_GET_FIELD are reimplementing most of the logic
already defined in FIELD_SET and FIELD_GET. Let's convert the vc4 macros to
use the FIELD_* macros.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200703135713.985810-1-maxime@cerno.tech

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>

drm/vc4: Report HVS underrun errors

Add a debugfs entry and helper for reporting HVS underrun errors as
well as helpers for masking and unmasking the underrun interrupts.
Add an IRQ handler and initial IRQ configuration.
Rework related register definitions to take the channel number.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190220155124.25022-2-paul.kocialkowski@bootlin.com

drm/vc4: Define missing PITCH0_SINK_PIX field

This is needed to support X/Y negative placement of planes using
T-format buffers.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180803092231.26446-2-boris.brezillon@bootlin.com

drm/vc4: Fix TILE_Y_OFFSET definitions

Y_OFFSET field starts at bit 8 not 7.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180803092231.26446-1-boris.brezillon@bootlin.com

drm/vc4: Add support for SAND modifier.

This is the format generated by VC4's H.264 engine, and preferred by
the ISP as well. By displaying SAND buffers directly, we can avoid
needing to use the ISP to rewrite the SAND H.264 output to linear
before display.

This is a joint effort by Dave Stevenson (who wrote the initial patch
and DRM demo) and Eric Anholt (drm_fourcc.h generalization, safety
checks, RGBA support).

v2: Make the parameter macro give all of the middle 48 bits (suggested
by Daniels). Fix fourcc_mod_broadcom_mod()'s bits/shift being
swapped. Mark NV12/21 as supported, not YUV420.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Daniel Stone <daniels@collabora.com> (v1)
Cc: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180316220435.31416-3-eric@anholt.net

drm/vc4: Add support for plane alpha

The HVS supports mixing fixed alpha with per-pixel alpha or
setting a fixed plane alpha in case there is no per-pixel information.
This allows us to support the generic DRM plane alpha property.

Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180421000954.18936-1-stschake@gmail.com

drm/vc4: Add some missing HVS register definitions.

At least the RGBA expand field we should have been setting, because we
aren't expanding correctly for 565 -> 8888. Other registers are ones
that may be interesting for various projects that have been discussed.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stefan Schake <stschake@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1523479755-20812-2-git-send-email-stschake@gmail.com

drm/vc4: Set premultiplied for alpha formats

Alpha formats in DRM are assumed to be premultiplied, so we should be
setting the PREMULT bit in the plane configuration for HVS.

Changes from v1:
- Use correct has_alpha

Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1520556817-97297-2-git-send-email-stschake@gmail.com

drm/vc4: Expose performance counters to userspace

The V3D engine has various hardware counters which might be interesting
to userspace performance analysis tools.

Expose new ioctls to create/destroy a performance monitor object and
query the counter values of this perfmance monitor.

Note that a perfomance monitor is given an ID that is only valid on the
file descriptor it has been allocated from. A performance monitor can be
attached to a CL submission and the driver will enable HW counters for
this request and update the performance monitor values at the end of the
job.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180112090926.12538-1-boris.brezillon@free-electrons.com

drm/vc4: add HDMI CEC support

This patch adds support to VC4 for CEC. It is under a separate
Kconfig option to keep everyone using VC4 from needing to pull in the
CEC core.

Thanks to Eric Anholt for providing me with the CEC register information.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20170716104804.48308-4-hverkuil@xs4all.nl

drm/vc4: Add T-format scanout support.

The T tiling format is what V3D uses for textures, with no raster
support at all until later revisions of the hardware (and always at a
large 3D performance penalty). If we can't scan out V3D's format,
then we often need to do a relayout at some stage of the pipeline,
either right before texturing from the scanout buffer (common in X11
without a compositor) or between a tiled screen buffer right before
scanout (an option I've considered in trying to resolve this
inconsistency, but which means needing to use the dirty fb ioctl and
having some update policy).

T-format scanout lets us avoid either of those shadow copies, for a
massive, obvious performance improvement to X11 window dragging
without a compositor. Unfortunately, enabling a compositor to work
around the discrepancy has turned out to be too costly in memory
consumption for the Raspbian distribution.

Because the HVS operates a scanline at a time, compositing from T does
increase the memory bandwidth cost of scanout. On my 1920x1080@32bpp
display on a RPi3, we go from about 15% of system memory bandwidth
with linear to about 20% with tiled. However, for X11 this still ends
up being a huge performance win in active usage.

This patch doesn't yet handle src_x/src_y offsetting within the tiled
buffer. However, we fail to do so for untiled buffers already.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170608001336.12842-1-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drm/vc4: Add HDMI audio support

The HDMI encoder IP embeds all needed blocks to output audio, with a
custom DAI called MAI moving audio between the two parts of the HDMI
core. This driver now exposes a sound card to let users stream audio
to their display.

Using the hdmi-codec driver has been considered here, but MAI meant
having to significantly rework hdmi-codec, and it would have left
little shared code with the I2S mode anyway.

The encoder requires that the audio be SPDIF-formatted frames only,
which alsalib will format-convert for us.

This patch is the combined work of Eric Anholt (initial register setup
with a separate dmaengine driver and using simple-audio-card) and
Boris Brezillon (moving it all into HDMI, massive debug to get it
actually working), and which Eric has the permission to release.

v2: Drop "-audio" from sound card name, since that's already implied
(suggestion by Boris)

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170227202803.12855-2-eric@anholt.net

drm/vc4: Add support for feeding DSI encoders from the pixel valve.

We have to set a different pixel format, which tells the hardware to
use the pix_width field that's fed in sideband from the DSI encoder to
divide the "pixel" clock.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161214194621.16499-6-eric@anholt.net

drm/vc4: Set up SCALER_DISPCTRL at boot.

We want the HVS on, obviously, and we also want DSP3 (PV1's source) to
be muxed from HVS channel 2 like we expect in vc4_crtc.c. The
firmware wasn't setting the DSP3 mux up when both the LCD and HDMI
were disabled.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161214194621.16499-5-eric@anholt.net

drm/vc4: Fix ->clock_select setting for the VEC encoder

PV_CONTROL_CLK_SELECT_VEC is actually 2 and not 0. Fix the definition and
rework the vc4_set_crtc_possible_masks() to cover the full range of the
PV_CONTROL_CLK_SELECT field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add support for double-clocked modes.

Now that we have infoframes to report the pixel repeat flag, we can
start using it. Fixes locking the 720x480i and 720x576i modes on my
Dell 2408WFP. Like the 1920x1080i case, they don't fit properly on
the screen, though.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Set up the AVI and SPD infoframes.

Fixes a purple bar on the left side of the screen with my Dell
2408WFP. It will also be required for supporting the double-clocked
video modes.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Fix support for interlaced modes on HDMI.

We really do need to be using the halved V fields. I had been
confused by the code I was using as a reference because it stored
halved vsync fields but not halved vdisplay, so it looked like I only
needed to divide vdisplay by 2.

This reverts part of Mario's timestamping fixes that prevented
CRTC_HALVE_V from applying, and instead adjusts the timestamping code
to not use the crtc field in that case.

Fixes locking of 1920x1080x60i on my Dell 2408WFP. There are black
bars on the top and bottom, but I suspect that might be an
under/overscan flags problem as opposed to video timings.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Enable limited range RGB output on HDMI with CEA modes.

Fixes broken grayscale ramps on many HDMI monitors, where large areas
at the ends of the ramp would all appear as black or white.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Implement precise vblank timestamping.

Precise vblank timestamping is implemented via the
usual scanout position based method. On VC4 the
pixelvalves PV do not have a scanout position
register. Only the hardware video scaler HVS has a
similar register which describes which scanline for
the output is currently composited and stored in the
HVS fifo for later consumption by the PV.

This causes a problem in that the HVS runs at a much
faster clock (system clock / audio gate) than the PV
which runs at video mode dot clock, so the unless the
fifo between HVS and PV is full, the HVS will progress
faster in its observable read line position than video
scan rate, so the HVS position reading can't be directly
translated into a scanout position for timestamp correction.

Additionally when the PV is in vblank, it doesn't consume
from the fifo, so the fifo gets full very quickly and then
the HVS stops compositing until the PV enters active scanout
and starts consuming scanlines from the fifo again, making
new space for the HVS to composite.

Therefore a simple translation of HVS read position into
elapsed time since (or to) start of active scanout does
not work, but for the most interesting cases we can still
get useful and sufficiently accurate results:

1. The PV enters active scanout of a new frame with the
fifo of the HVS completely full, and the HVS can refill
any fifo line which gets consumed and thereby freed up by
the PV during active scanout very quickly. Therefore the
PV and HVS work effectively in lock-step during active
scanout with the fifo never having more than 1 scanline
freed up by the PV before it gets refilled. The PV's
real scanout position is therefore trailing the HVS
compositing position as scanoutpos = hvspos - fifosize
and we can get the true scanoutpos as HVS readpos minus
fifo size, so precise timestamping works while in active
scanout, except for the last few scanlines of the frame,
when the HVS reaches end of frame, stops compositing and
the PV catches up and drains the fifo. This special case
would only introduce minor errors though.

2. If we are in vblank, then we can only guess something
reasonable. If called from vblank irq, we assume the irq is
usually dispatched with minimum delay, so we can take a
timestamp taken at entry into the vblank irq handler as a
baseline and then add a full vblank duration until the
guessed start of active scanout. As irq dispatch is usually
pretty low latency this works with relatively low jitter and
good results.

If we aren't called from vblank then we could be anywhere
within the vblank interval, so we return a neutral result,
simply the current system timestamp, and hope for the best.

Measurement shows the generated timestamps to be rather precise,
and at least never off more than 1 vblank duration worst-case.

Limitations: Doesn't work well yet for interlaced video modes,
therefore disabled in interlaced mode for now.

v2: Use the DISPBASE registers to determine the FIFO size (changes
by anholt)

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-and-tested-by: Mario Kleiner <mario.kleiner.de@gmail.com> (v2)

drm/vc4: Make pageflip completion handling more robust.

Protect both the setup of the pageflip event and the
latching of the new requested displaylist head pointer
by the event lock, so we can't get into a situation
where vc4_atomic_flush latches the new display list via
HVS_WRITE, then immediately gets preempted before queueing
the pageflip event, then the page-flip completes in hw and
the vc4_crtc_handle_page_flip() runs and no-ops due to
lack of a pending pageflip event, then vc4_atomic_flush
continues and only then queues the pageflip event - after
the page flip handling already no-oped. This would cause
flip completion handling only at the next vblank - one
frame too late.

In vc4_crtc_handle_page_flip() check the actual DL head
pointer in SCALER_DISPLACTX against the requested pointer
for page flip to make sure that the flip actually really
completed in the current vblank and doesn't get deferred
to the next one because the DL head pointer was written
a bit too late into SCALER_DISPLISTX, after start of
vblank, and missed the boat. This avoids handling a
pageflip completion too early - one frame too early.

According to Eric, DL head pointer updates which were
written into the HVS DISPLISTX reg get committed to hardware
at the last pixel of active scanout. Our vblank interrupt
handler, as triggered by PV_INT_VFP_START irq, gets to run
earliest at the first pixel of HBLANK at the end of the
last scanline of active scanout, ie. vblank irq handling
runs at least 1 pixel duration after a potential pageflip
completion happened in hardware.

This ordering of events in the hardware, together with the
lock protection and SCALER_DISPLACTX sampling of this patch,
guarantees that pageflip completion handling only runs at
exactly the vblank irq of actual pageflip completion in all
cases.

Background info from Eric about the relative timing of
HVS, PV's and trigger points for interrupts, DL updates:

https://lists.freedesktop.org/archives/dri-devel/2016-May/107510.html

Tested on RPi 2B with hardware timing measurement equipment
and shown to no longer complete flips too early or too late.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add support for gamma ramps.

We could possibly save a bit of power by not requesting gamma
conversion when the ramp happens to be 1:1, but at least if all the
CRTCs are off the SRAM will be disabled.

This should fix brightness sliders in a lot of fullscreen games.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Initialize scaler DISPBKGND on modeset.

We weren't updating the interlaced bit, so we'd scan out incorrectly
if the firmware had brought up the TV encoder and we were switching to
HDMI.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Fix the name of the VSYNCD_EVEN register.

It's used for delaying vsync in interlaced mode.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Bring HDMI up from power off if necessary.

If the firmware hadn't brought up HDMI for us, we need to do its
power-on reset sequence (reset HD and and clear its STANDBY bits,
reset HDMI, and leave the PHY disabled).

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add support for YUV planes.

This supports 420 and 422 subsampling with 2 or 3 planes, tested with
modetest. It doesn't set up chroma subsampling position (which it
appears KMS doesn't deal with yet).

The LBM memory is overallocated in many cases, but apparently the docs
aren't quite correct and I'll probably need to look at the hardware
source to really figure it out.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add support for scaling of display planes.

This implements a simple policy for choosing scaling modes
(trapezoidal for decimation, PPF for magnification), and a single PPF
filter (Mitchell/Netravali's recommendation).

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Fix a typo in a V3D debug register.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add KMS support for Raspberry Pi.

This is enough for fbcon and bringing up X using
xf86-video-modesetting. It doesn't support the 3D accelerator or
power management yet.

v2: Drop FB_HELPER select thanks to Archit's patches. Do manual init
ordering instead of using the .load hook. Structure registration
more like tegra's, but still using the typical "component" code.
Drop no-op hooks for atomic_begin and mode_fixup() now that
they're optional. Drop sentinel in Makefile. Fix minor style
nits I noticed on another reread.

v3: Use the new bcm2835 clk driver to manage pixel/HSM clocks instead
of having a fixed video mode. Use exynos-style component driver
matching instead of devicetree nodes to list the component driver
instances. Rename compatibility strings to say bcm2835, and
distinguish pv0/1/2. Clean up some h/vsync code, and add in
interlaced mode setup. Fix up probe/bind error paths. Use
bitops.h macros for vc4_regs.h

v4: Include i2c.h, allow building under COMPILE_TEST, drop msleep now
that other bugs have been fixed, add timeouts to cpu_relax()
loops, rename hpd-gpio to hpd-gpios.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>