drm/pl111: Fix FB depth on IMPD-1 framebuffer

The last argument to the function drm_fbdev_dma_setup() was
changed from desired BPP to desired depth.

In our case the desired depth was 15 but BPP was 16, so we
specified 16 as BPP and we relied on the FB emulation core to
select a format with a suitable depth for the limited bandwidth
and end up with e.g. XRGB1555 like in the past:

[drm] Initialized pl111 1.0.0 20170317 for c1000000.display on minor 0
drm-clcd-pl111 c1000000.display: [drm] requested bpp 16, scaled depth down to 15
drm-clcd-pl111 c1000000.display: enable IM-PD1 CLCD connectors
Console: switching to colour frame buffer device 80x30
drm-clcd-pl111 c1000000.display: [drm] fb0: pl111drmfb frame buffer device

However the current code will fail at that:

[drm] Initialized pl111 1.0.0 20170317 for c1000000.display on minor 0
drm-clcd-pl111 c1000000.display: [drm] bpp/depth value of 16/16 not supported
drm-clcd-pl111 c1000000.display: [drm] No compatible format found
drm-clcd-pl111 c1000000.display: [drm] *ERROR* fbdev: Failed to setup generic emulation (ret=-12)

Fix this by passing the desired depth of 15 for the IM/PD-1 display
instead of 16 to drm_fbdev_dma_setup().

The desired depth is however in turn used for bandwidth limiting
calculations and that was done with a simple / integer division,
whereas we now have to modify that to use DIV_ROUND_UP() so that
we get DIV_ROUND_UP(15, 2) = 2 not 15/2 = 1.

After this the display works again on the Integrator/AP IM/PD-1.

Cc: Emma Anholt <emma@anholt.net>
Cc: stable@vger.kernel.org
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 37c90d589dc0 ("drm/fb-helper: Fix single-probe color-format selection")
Link: https://lore.kernel.org/dri-devel/20230102112927.26565-1-tzimmermann@suse.de/
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230515092943.1401558-1-linus.walleij@linaro.org

drm: pl111: Absorb the external register header

The PL111 DRM driver is now the sole user of the external
CLCD registers header file, so let's absorb that into the
pl111_drm.h file and save the external include.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609200446.153209-3-linus.walleij@linaro.org

drm: convert .debugfs_init() hook to return void.

As a result of commit 987d65d01356 (drm: debugfs: make
drm_debugfs_create_files() never fail) and changes to various debugfs
functions in drm/core and across various drivers, there is no need for
the drm_driver.debugfs_init() hook to have a return value. Therefore,
declare it as void.

This also includes refactoring all users of the .debugfs_init() hook to
return void across the subsystem.

v2: include changes to the hook and drivers that use it in one patch to
prevent driver breakage and enable individual successful compilation of
this change.

References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html
Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-18-wambui.karugax@gmail.com

drm/pl111: drop use of drmP.h

Drop use of the deprecated drmP.h header.
Sort includes in blocks while touching the files.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190716064220.18157-4-sam@ravnborg.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443

Based on 1 normalized pattern(s):

this program is free software and is provided to you under the terms
of the gnu general public license version 2 as published by the free
software foundation and any use by you of this program is subject to
the terms of such gnu licence

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 13 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.691558990@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drm/pl111: Support Nomadik LCDC variant

The Nomadik has a variant of the PL110 known as "Color LCD
Controller" LCDC. This variant has the same bit ordering as
the DRM subsystem (in difference from the other variants)
and adds a few bits for the control of 5551, 565 etc in the
control register. Notably it also adds a packed RGB888
24BPP mode.

We add support by detecting this variant and also adding a
small plug-in that will mux the LCDC out if the ASIC happens
to be muxed to the other graphics controller (they are
mutually exclusive).

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180621184450.25377-1-linus.walleij@linaro.org

drm/pl111: Enable device-specific assigned memory

The Versatile Express has 8 MB of dedicated video RAM (VRAM)
on the motherboard, which is what we should be using for the
PL111 if available. On this platform, the memory backplane
is constructed so that only this memory will work properly
with the CLCD on the motherboard, using any other memory
area just gives random snow on the display.

The CA9 Versatile Express also has a PL111 instance on its
core tile that can address all memory, and this does not
have the restriction.

The memory is assigned to the device using the memory-region
device tree property and a "shared-dma-pool" reserved
memory pool like this:

reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;

vram: vram@48000000 {
compatible = "shared-dma-pool";
reg = <0x48000000 0x00800000>;
no-map;
};
};

clcd@1f000 {
compatible = "arm,pl111", "arm,primecell";
(...)
memory-region = <&vram>;
}·;

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502134719.8388-2-linus.walleij@linaro.org

drm/pl111: Use max memory bandwidth for resolution

We were previously selecting 1024x768 and 32BPP as the default
set-up for the PL111 consumers.

This does not work on elder systems: the device tree bindings
support a property "max-memory-bandwidth" in bytes/second that
states that if you exceed this the memory bus will saturate.
The result is flickering and unstable images.

Parse the "max-memory-bandwidth" and respect it when
intializing the driver. On the RealView PB11MP, Versatile and
Integrator/CP we get a nice console as default with this code.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180307215819.15814-1-linus.walleij@linaro.org

drm/pl111: Make the default BPP a per-variant variable

The PL110, Integrator and Versatile boards strongly prefer to
use 16 BPP even if other modes are supported, both to keep down
memory consumption and also to easier find a good match to
supported resolutions with consideration taken to the memory
bandwidth of the platforms.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180302090948.6399-2-linus.walleij@linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20180307084316.23623-1-linus.walleij@linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20180307084316.23623-1-linus.walleij@linaro.org

drm/pl111: Do not use deprecated drm_driver.{enable|disable)_vblank

Do not use deprecated drm_driver.{enable|disable)_vblank callbacks,
but use drm_simple_kms_helpe's pipe callbacks instead.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Tested-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1518425574-32671-5-git-send-email-andr2000@gmail.com

drm/pl111: Support variants with broken VBLANK

The early Integrator CLCD synthesized in the Integrator CP and
IM-PD1 FPGAs are broken: their vertical and next base interrupts
are not functional. Support these variants by simply disabling
the use of the vblank interrupt on these variants.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206093540.8147-4-linus.walleij@linaro.org

drm/pl111: Support variants with broken clock divider

The early Integrator CLCD synthesized in the Integrator CP and
IM-PD1 FPGAs are broken: their clock dividers do not work
properly. Support disabling the clock divider and drive the
clock directly from the parent under these circumstances.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206093540.8147-3-linus.walleij@linaro.org

drm/pl111: Properly detect the ARM PL110 variants

With a bit of refactoring we can contain the variant data for
the strange PL110 versions that is feature-incomplete PL110 for
the ARM Integrator/CP and somewhere inbetween PL110 and PL111
for the ARM Versatile AB and Versatile PB.

We also accomodate for the custom duct-taped RGB565/BGR565 support
in the Versatile variant.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206093540.8147-1-linus.walleij@linaro.org

drm/pl111: Use drm_fb_cma_fbdev_init/fini()

Use drm_fb_cma_fbdev_init() and drm_fb_cma_fbdev_fini() which relies on
the fact that drm_device holds a pointer to the drm_fb_helper structure.
This means that the driver doesn't have to keep track of that.
Also use the drm_fb_helper functions directly.

Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20171115142001.45358-11-noralf@tronnes.org

drm/pl111: Add optional variant display en/disable callbacks

The silcon and components around the PL111 may require some
variants to perform special set-up of the display. Add two
callbacks to manage this.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-6-linus.walleij@linaro.org

drm/pl111: Enable PL110 variant

We detect and enable the use of the PL110 variant, an earlier
incarnation of PL111. The only real difference is that the
control and interrupt enable registers have swapped place.
The Versatile AB and Versatile PB have a variant inbetween
PL110 and PL111, it is PL110 but they have already swapped the
two registers so those two need a bit of special handling.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-4-linus.walleij@linaro.org

drm/pl111: Replace custom connector with panel bridge

This replaces the custom connector in the PL111 with the
panel bridge helper.

This works nicely for all standard panels, but since there
are several PL11x-based systems that will need to use the dumb
VGA connector bridge we use drm_of_find_panel_or_bridge()
and make some headroom for dealing with bridges that are
not panels as well, and drop a TODO in the code.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-3-linus.walleij@linaro.org

drm/pl111: Cleanup local header file

The header file contains prototypes for two nonexisting
functions. Get rid of them.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-1-linus.walleij@linaro.org

drm/pl111: Add a debugfs node to dump our registers.

While debugging an X11 display failure, I wanted to see where we were
actually scanning out from. This is probably generally useful to
others that might be working on this device.

v2: Fix uint32_t sparse warning.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518005640.10310-1-eric@anholt.net
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> (v1)

drm/pl111: Register the clock divider and use it.

This is required for the panel to work on bcm911360, where CLCDCLK is
the fixed 200Mhz AXI41 clock. The rate set is still passed up to the
CLCDCLK, for platforms that have a settable rate on that one.

v2: Set SET_RATE_PARENT (caught by Linus Walleij), depend on
COMMON_CLK.
v3: Mark the clk_ops static (caught by Stephen).

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508193348.30236-1-eric@anholt.net
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

drm/pl111: Initial drm/kms driver for pl111

This is a modesetting driver for the pl111 CLCD display controller
found on various ARM platforms such as the Versatile Express. The
driver has only been tested on the bcm911360_entphn platform so far,
with PRIME-based buffer sharing between vc4 and clcd.

It reuses the existing devicetree binding, while not using quite as
many of its properties as the fbdev driver does (those are left for
future work).

v2: Nearly complete rewrite by anholt, cutting 2/3 of the code thanks
to DRM core's excellent new helpers.
v3: Don't match pl110 any more, don't attach if we don't have a DRM
panel, use DRM_GEM_CMA_FOPS, update MAINTAINERS, use the simple
display helper, use drm_gem_cma_dumb_create (same as our wrapper).
v4: Change the driver's .name to not clash with fbdev in sysfs, drop
platform alias, drop redundant "drm" in DRM driver name, hook up
.prepare_fb to the CMA helper so that DMA fences should work.
v5: Move register definitions inside the driver directory, fix build
in COMPILE_TEST and !AMBA mode.
v6: Drop TIM2_CLKSEL for now to be consistent with existing DT
bindings, switch back to external register definitions.

Signed-off-by: Tom Cooksey <tom.cooksey@arm.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> (v5)
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413031746.12921-2-eric@anholt.net