drm/ofdrm: Do not include <drm/drm_plane_helper.h>

Remove unnecessary include statements for <drm/drm_plane_helper.h>.
The file contains helpers for non-atomic code and should not be
required by most drivers. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204090852.1650-7-tzimmermann@suse.de

drm/ofdrm: Preallocate format-conversion buffer in atomic_check

Preallocate the format-conversion state's storage in the plane's
atomic_check function if a format conversion is necessary. Allows
the update to fail if no memory is available. Avoids the same
allocation within atomic_update, which may not fail.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231009141018.11291-5-tzimmermann@suse.de

drm/format-helper: Pass format-conversion state to helpers

Pass an instance of struct drm_format_conv_state to DRM's format
conversion helpers. Update all callers.

Most drivers can use the format-conversion state from their shadow-
plane state. The shadow plane's destroy function releases the
allocated buffer. Drivers will later be able to allocate a buffer
of appropriate size in their plane's atomic_check code.

The gud driver uses a separate thread for committing updates. For
now, the update worker contains its own format-conversion state.

Images in the format-helper tests are small. The tests preallocate
a static page for the temporary buffer. Unloading the module releases
the memory.

v6:
* update patch for ssd132x support
v5:
* avoid using unusupported shadow-plane state in repaper (Noralf)
* fix documentation (Noralf, kernel test robot)
v3:
* store buffer in shadow-plane state (Javier, Maxime)
* replace ARRAY_SIZE() with sizeof() (Jani)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com> # ssd130x
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Lechner <david@lechnology.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231009141018.11291-4-tzimmermann@suse.de

drm/tiny: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert the tiny drm drivers from always returning zero in the
remove callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230507162616.1368908-50-u.kleine-koenig@pengutronix.de

drm: Use of_property_read_bool() for boolean properties

It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties.
Convert reading boolean properties to of_property_read_bool().

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20230310144706.1542295-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

drm/fb-helper: Replace bpp/depth parameter by color mode

Replace the combination of bpp and depth with a single color-mode
argument. Handle special cases in simpledrm and ofdrm. Hard-code
XRGB8888 as fallback format for cases where no given format works.

The color-mode argument accepts the same values as the kernel's video
parameter. These are mostly bpp values between 1 and 32. The exceptions
are 15, which has a color depth of 15 and a bpp value of 16; and 32,
which has a color depth of 24 and a bpp value of 32.

v4:
* add back lost test for bpp_specified (Maira)
* add Fixes tag (Daniel)
v3:
* fix ofdrm build (Maxime)
v2:
* minimize changes (Daniel)
* use drm_driver_legacy_fb_format() (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Maíra Canal <mcanal@igalia.com> # vc4 and vkms
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes: 37c90d589dc0 ("drm/fb-helper: Fix single-probe color-format selection")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230106112324.22055-1-tzimmermann@suse.de

drm/format-helper: Simplify drm_fb_build_fourcc_list()

The DRM helper drm_fb_build_fourcc_list() creates a list of color
formats for primary planes of the generic drivers. Simplify the helper:

- It used to mix and filter native and emulated formats as provided
by the driver. Now the only emulated format is XRGB8888, which is
required as fallback by legacy software. Drop support for emulating
any other formats.
- Also convert alpha formats to their non-alpha counterparts. Generic
drivers don't support primary planes with alpha formats and some
DTs incorrectly advertise alpha channels for non-alpha hardware. So
only export non-alpha formats for primary planes.

With the simplified helper, scrap format lists of the affected generic
drivers. All they need is the firmware buffer's native format, from which
the helper creates the list of color formats.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102112927.26565-13-tzimmermann@suse.de

drm/ofdrm: Set preferred depth from format of scanout buffer

Set the preferred depth from the format of the scanout buffer. The
value cannot be hardcoded, as the scanout buffer is only known at
runtime. Keeping the existing switch statement just duplicates the
driver's existing logic for format detection.

Also remove the FIXME comment from the call to drm_fbdev_generic_setup()
as the driver now handles color depth and bpp values correctly.

v2:
* fix commit-message typo

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123115348.2521-5-tzimmermann@suse.de

drm/fb-helper: Move generic fbdev emulation into separate source file

Move the generic fbdev implementation into its own source and header
file. Adapt drivers. No functional changes, but some of the internal
helpers have been renamed to fit into the drm_fbdev_ naming scheme.

v3:
* rename drm_fbdev.{c,h} to drm_fbdev_generic.{c,h}
* rebase onto vmwgfx changes
* rebase onto xlnx changes
* fix include statements in amdgpu

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-22-tzimmermann@suse.de

drm/ofdrm: Cast error pointers to void __iomem *

Cast error pointers when returning them as void __iomem *. Fixes
a number of Sparse warnings, such as the ones shown below.

../drivers/gpu/drm/tiny/ofdrm.c:439:31: warning: incorrect type in return expression (different address spaces)
../drivers/gpu/drm/tiny/ofdrm.c:439:31: expected void [noderef] __iomem *
../drivers/gpu/drm/tiny/ofdrm.c:439:31: got void *
../drivers/gpu/drm/tiny/ofdrm.c:442:31: warning: incorrect type in return expression (different address spaces)
../drivers/gpu/drm/tiny/ofdrm.c:442:31: expected void [noderef] __iomem *
../drivers/gpu/drm/tiny/ofdrm.c:442:31: got void *

See [1] for the bug report.

v3:
* use IOMEM_ERR_PTR() (Javier)

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/dri-devel/202210200016.yiQzPIy0-lkp@intel.com/ # [1]
Link: https://patchwork.freedesktop.org/patch/msgid/20221103101627.32502-3-tzimmermann@suse.de

drm/ofdrm: Convert PCI IDs to CPU endianness for comparing

Properties of 32-bit integers are returned from the OF device tree
as type __be32. Convert PCI vendor and device IDs from __be32 to host
endianness before comparing them to constants. All relevant machines
are old, big-endian Macintosh systems; hence the bug never happened
in practice.

Fixes sparse warnings shown below.

drivers/gpu/drm/tiny/ofdrm.c:237:17: warning: restricted __be32 degrades to integer
drivers/gpu/drm/tiny/ofdrm.c:238:18: warning: restricted __be32 degrades to integer
drivers/gpu/drm/tiny/ofdrm.c:238:54: warning: restricted __be32 degrades to integer

See [1] for the bug report.

v2:
* convert endianness (Alex)

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/dri-devel/202210192208.D888I6X7-lkp@intel.com/ # [1]
Link: https://patchwork.freedesktop.org/patch/msgid/20221103101627.32502-2-tzimmermann@suse.de

drm/ofdrm: Support big-endian scanout buffers

All DRM formats assume little-endian byte order. On big-endian systems,
it is likely that the scanout buffer is in big endian as well. Update
the format accordingly and add endianness conversion to the format-helper
library. Also opt-in to allocated buffers in host format by default.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-6-tzimmermann@suse.de

drm/ofdrm: Support color management

Support the CRTC's color-management property and implement each model's
palette support.

The OF hardware has different methods of setting the palette. The
respective code has been taken from fbdev's offb and refactored into
per-model device functions. The device functions integrate this
functionality into the overall modesetting.

As palette handling is a CRTC property that depends on the primary
plane's color format, the plane's atomic_check helper now updates the
format field in ofdrm's custom CRTC state. The CRTC's atomic_flush
helper updates the palette for the format as needed.

v4:
* use cpu_to_be32() (Geert)
v3:
* lookup CRTC state with drm_atomic_get_new_crtc_state()
* access HW palette with writeb(), writel(), and readl() (Ben)
* declare register values as u32

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-5-tzimmermann@suse.de

drm/ofdrm: Add per-model device function

Add a per-model device-function structure in preparation of adding
color-management support. Detection of the individual models has been
taken from fbdev's offb.

v3:
* define constants for PCI ids (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-4-tzimmermann@suse.de

drm/ofdrm: Add CRTC state

Add a dedicated CRTC state to ofdrm to later store information for
palette updates.

v3:
* rework CRTC state helpers (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-3-tzimmermann@suse.de

drm/ofdrm: Add ofdrm for Open Firmware framebuffers

Open Firmware provides basic display output via the 'display' node.
DT platform code already provides a device that represents the node's
framebuffer. Add a DRM driver for the device. The display mode and
color format is pre-initialized by the system's firmware. Runtime
modesetting via DRM is not possible. The display is useful during
early boot stages or as error fallback.

Similar functionality is already provided by fbdev's offb driver,
which is insufficient for modern userspace. The old driver includes
support for BootX device tree, which can be found on old 32-bit
PowerPC Macintosh systems. If these are still in use, the
functionality can be added to ofdrm or implemented in a new
driver. As with simpledrm, the fbdev driver cannot be selected if
ofdrm is already enabled.

Two notable points about the driver:

* Reading the framebuffer aperture from the device tree is not
reliable on all systems. Ofdrm takes the heuristics and a comment
from offb to pick the correct range.

* No resource management may be tied to the underlying PCI device.
Otherwise the handover to the native driver will fail with a resource
conflict. PCI management is therefore done as part of the platform
device's cleanup.

The driver has been tested on qemu's ppc64le emulation. The device
hand-over has been tested with bochs.

v5:
* use drm_atomic_helper_check_crtc_primary_plane()
v4:
* set preferred depth to the correct value
* set bpp value for console emulation
* output scanout-buffer parameters with drm_dbg()
v3:
* reintegrate FWFB helpers into ofdrm
* use damage iterator
* sync GEM BOs with drm_gem_fb_{begin,end}_cpu_access()
* fix various atomic_check helpers
* remove CRTC atomic_{enable,disable} (Javier)
* compute stride with drm_format_info_min_pitch() (Daniel)
v2:
* removed simple-pipe helpers
* built driver on top of FWFB helpers
* merged all init code into single function
* make PCI support optional (Michal)
* support COMPILE_TEST (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

convert
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-2-tzimmermann@suse.de