Re: [PATCH v13 5/6] drm/imx: Introduce i.MX8qm/qxp DPU DRM

[Liu Ying <victor.liu@nxp.com>]

Hi Marcel,

On Wed, 2023-01-04 at 10:01 +0000, Marcel Ziswiler wrote:
> Hi Liu
> 
> Thank you very much!
> 
> On Wed, 2022-10-19 at 10:02 +0800, Liu Ying wrote:
> > This patch introduces i.MX8qm/qxp Display Processing Unit(DPU) DRM
> > support.
> > 
> > DPU is comprised of two main components that include a blit engine
> > for
> > 2D graphics accelerations(with composition support) and a display
> > controller for display output processing, as well as a command
> > sequencer.
> > Outside of DPU, optional prefetch engines, a.k.a, Prefetch Resolve
> > Gasket(PRG) and Display Prefetch Resolve(DPR), can fetch data from
> > memory
> > prior to some DPU fetchunits of blit engine and display
> > controller.  The
> > prefetch engines support reading linear formats and resolving
> > Vivante GPU
> > tile formats.
> > 
> > This patch adds kernel modesetting support for the display
> > controller part.
> > The driver supports two CRTCs per display controller, planes backed
> > by
> > four fetchunits(decode0/1, fetchlayer, fetchwarp), fetchunit
> > allocation
> > logic for the two CRTCs, prefetch engines(with tile resolving
> > supported),
> > plane upscaling/deinterlacing/yuv2rgb CSC/alpha blending and CRTC
> > gamma
> > correction.  The registers of the controller is accessed without
> > command
> > sequencer involved, instead just by using CPU.
> > 
> > Reference manual can be found at:
> > 
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.nxp.com%2Fwebapp%2FDownload%3FcolCode%3DIMX8DQXPRM&data=05%7C01%7Cvictor.liu%40nxp.com%7Cf90aa93b0cb145ed962e08daee3a9c4e%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C638084232760483936%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=4oy%2BQF%2BnTzinsMhjq5swmvVDZSZwK8h%2BtUbOIxveqHE%3D&reserved=0
> > 
> > Reviewed-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > v12->v13:
> > * Drop 'drm->irq_enabled = true;' to fix a potential build break
> >   reported by 'kernel test robot <lkp@intel.com>'. drm->irq_enabled
> >   should not be used by imx-dpu drm as it is only used by legacy
> >   drivers with userspace modesetting.
> > 
> > v11->v12:
> > * Rebase upon v6.1-rc1.
> > * Minor update on Kconfigs, struct names and macro names due to the
> > rebase.
> > 
> > v10->v11:
> > * Rebase upon v6.0-rc1.
> > * Include drm_blend.h and drm_framebuffer.h in dpu-kms.c and dpu-
> > plane.c
> >   to fix build errors due to the rebase.
> > * Fix a checkpatch warning for dpu-crtc.c.
> > * Properly use dev_err_probe() to return it's return value directly
> > where
> >   possible.
> > 
> > v9->v10:
> > * Make 'checkpatch.pl --strict' happier.
> > * Add Laurentiu's R-b tag.
> > 
> > v8->v9:
> > * Use drm_atomic_get_new_plane_state() in
> > dpu_plane_atomic_update(). (Laurentiu)
> > * Drop getting DPU DT alias ID, as it is unused.
> > * Get the DPR interrupt(dpr_wrap) by name.
> > 
> > v7->v8:
> > * Update dpu_plane_atomic_check() and dpu_plane_atomic_update(),
> > due to DRM
> >   plane helper functions API change(atomic_check and atomic_update)
> > from DRM
> >   atomic core.  Also, rename plane->state variables and relevant
> > DPU plane
> >   state variables in those two functions to reflect they are new
> > states, like
> >   the patch 'drm: Rename plane->state variables in atomic update
> > and disable'
> >   recently landed in drm-misc-next.
> > * Replace drm_gem_fb_prepare_fb() with
> > drm_gem_plane_helper_prepare_fb(),
> >   due to DRM core API change.
> > * Use 256byte DPR burst length for GPU standard tile and 128byte
> > DPR burst
> >   length for 32bpp GPU super tile to align with the latest version
> > of internal
> >   HW documention.
> > 
> > v6->v7:
> > * Fix return value of dpu_get_irqs() if platform_get_irq() fails.
> > (Laurentiu)
> > * Use the function array dpu_irq_handler[] to store individual DPU
> > irq handlers.
> >   (Laurentiu)
> > * Call get/put() hooks directly to get/put DPU fetchunits for DPU
> > plane groups.
> >   (Laurentiu)
> > * Shorten the names of individual DPU irq handlers by using DPU
> > unit abbrev
> >   names to make writing dpu_irq_handler[] easier.
> > 
> > v5->v6:
> > * Do not use macros where possible. (Laurentiu)
> > * Break dpu_plane_atomic_check() into some smaller functions.
> > (Laurentiu)
> > * Address some minor comments from Laurentiu.
> > * Add dpu_crtc_err() helper marco to tell dmesg which CRTC
> > generates error.
> > * Drop calling dev_set_drvdata() from dpu_drm_bind/unbind() as it
> > is done
> >   in dpu_drm_probe().
> > * Some trivial tweaks.
> > 
> > v4->v5:
> > * Rebase up onto the latest drm-misc-next branch and remove the
> > hook to
> >   drm_atomic_helper_legacy_gamma_set(), because it was dropped by
> > the newly
> >   landed commit 'drm: automatic legacy gamma support'.
> > * Remove a redundant blank line from dpu_plane_atomic_update().
> > 
> > v3->v4:
> > * No change.
> > 
> > v2->v3:
> > * Fix build warnings Reported-by: kernel test robot <lkp@intel.com>
> > .
> > * Drop build dependency on IMX_SCU, as dummy SCU functions have
> > been added in
> >   header files by the patch 'firmware: imx: add dummy functions'
> > which has
> >   landed in linux-next/master branch.
> > 
> > v1->v2:
> > * Add compatible for i.MX8qm DPU, as this is tested with i.MX8qm
> > LVDS displays.
> >   (Laurentiu)
> > * Fix PRG burst size and stride. (Laurentiu)
> > * Put 'ports' OF node to fix the bail-out logic in dpu_drm_probe().
> > (Laurentiu)
> > 
> >  drivers/gpu/drm/imx/Kconfig               |    1 +
> >  drivers/gpu/drm/imx/Makefile              |    1 +
> >  drivers/gpu/drm/imx/dpu/Kconfig           |    9 +
> >  drivers/gpu/drm/imx/dpu/Makefile          |   10 +
> >  drivers/gpu/drm/imx/dpu/dpu-constframe.c  |  171 ++++
> >  drivers/gpu/drm/imx/dpu/dpu-core.c        | 1044
> > +++++++++++++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-crtc.c        |  969
> > +++++++++++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-crtc.h        |   72 ++
> >  drivers/gpu/drm/imx/dpu/dpu-disengcfg.c   |  117 +++
> >  drivers/gpu/drm/imx/dpu/dpu-dprc.c        |  715 ++++++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-dprc.h        |   40 +
> >  drivers/gpu/drm/imx/dpu/dpu-drv.c         |  290 ++++++
> >  drivers/gpu/drm/imx/dpu/dpu-drv.h         |   28 +
> >  drivers/gpu/drm/imx/dpu/dpu-extdst.c      |  299 ++++++
> >  drivers/gpu/drm/imx/dpu/dpu-fetchdecode.c |  292 ++++++
> >  drivers/gpu/drm/imx/dpu/dpu-fetcheco.c    |  224 +++++
> >  drivers/gpu/drm/imx/dpu/dpu-fetchlayer.c  |  152 +++
> >  drivers/gpu/drm/imx/dpu/dpu-fetchunit.c   |  610 ++++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-fetchunit.h   |  195 ++++
> >  drivers/gpu/drm/imx/dpu/dpu-fetchwarp.c   |  248 +++++
> >  drivers/gpu/drm/imx/dpu/dpu-framegen.c    |  395 ++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-gammacor.c    |  223 +++++
> >  drivers/gpu/drm/imx/dpu/dpu-hscaler.c     |  275 ++++++
> >  drivers/gpu/drm/imx/dpu/dpu-kms.c         |  542 +++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-kms.h         |   23 +
> >  drivers/gpu/drm/imx/dpu/dpu-layerblend.c  |  348 +++++++
> >  drivers/gpu/drm/imx/dpu/dpu-plane.c       |  804 ++++++++++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-plane.h       |   59 ++
> >  drivers/gpu/drm/imx/dpu/dpu-prg.c         |  433 +++++++++
> >  drivers/gpu/drm/imx/dpu/dpu-prg.h         |   45 +
> >  drivers/gpu/drm/imx/dpu/dpu-prv.h         |  231 +++++
> >  drivers/gpu/drm/imx/dpu/dpu-tcon.c        |  250 +++++
> >  drivers/gpu/drm/imx/dpu/dpu-vscaler.c     |  308 ++++++
> >  drivers/gpu/drm/imx/dpu/dpu.h             |  385 ++++++++
> >  34 files changed, 9808 insertions(+)
> >  create mode 100644 drivers/gpu/drm/imx/dpu/Kconfig
> >  create mode 100644 drivers/gpu/drm/imx/dpu/Makefile
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-constframe.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-core.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-crtc.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-crtc.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-disengcfg.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-dprc.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-dprc.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-drv.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-drv.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-extdst.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetchdecode.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetcheco.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetchlayer.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetchunit.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetchunit.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-fetchwarp.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-framegen.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-gammacor.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-hscaler.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-kms.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-kms.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-layerblend.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-plane.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-plane.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-prg.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-prg.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-prv.h
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-tcon.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu-vscaler.c
> >  create mode 100644 drivers/gpu/drm/imx/dpu/dpu.h
> 
> [snip]
> 
> > diff --git a/drivers/gpu/drm/imx/dpu/dpu-drv.c
> > b/drivers/gpu/drm/imx/dpu/dpu-drv.c
> > new file mode 100644
> > index 000000000000..2a2dd92269c8
> > --- /dev/null
> > +++ b/drivers/gpu/drm/imx/dpu/dpu-drv.c
> > @@ -0,0 +1,290 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +
> > +/*
> > + * Copyright 2019,2020,2022 NXP
> > + */
> > +
> > +#include <linux/component.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_drv.h>
> 
> This may also need the following addition:
> 
> #include <drm/drm_fbdev_generic.h>
> 
> Otherwise I do get the following error on compilation:
> 
>   CC [M]  drivers/gpu/drm/imx/dpu/dpu-drv.o
> /var/home/zim/Sources/linux-next.git/drivers/gpu/drm/imx/dpu/dpu-
> drv.c: In function 'dpu_drm_bind':
> /var/home/zim/Sources/linux-next.git/drivers/gpu/drm/imx/dpu/dpu-
> drv.c:99:9: error: implicit declaration of
> function 'drm_fbdev_generic_setup' [-Werror=implicit-function-
> declaration]
>    99 |         drm_fbdev_generic_setup(drm, legacyfb_depth);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
> make[7]: *** [/var/home/zim/Sources/linux-
> next.git/scripts/Makefile.build:252: drivers/gpu/drm/imx/dpu/dpu-
> drv.o] Error 1
> make[7]: *** Waiting for unfinished jobs....

This build break is caused by the below commit introduced in v6.2-rc1. 
The include/drm/drm_fbdev_generic.h head file was newly introduced in
the commit.
8ab59da26bc0 (drm/fb-helper: Move generic fbdev emulation into separate
source file)

I've rebased this patch set upon drm-misc-next to fix this build break
by including the head file and sent v14 for review.

> 
> > +#include <drm/drm_fb_helper.h>
> > +#include <drm/drm_gem_dma_helper.h>
> > +#include <drm/drm_modeset_helper.h>
> > +#include <drm/drm_of.h>
> > +#include <drm/drm_print.h>
> > +#include <drm/drm_probe_helper.h>
> > +
> > +#include "dpu-drv.h"
> > +#include "dpu-kms.h"
> > +
> > +#define DRIVER_NAME    "imx-dpu-drm"
> 
> [snip]
> 
> I am trying to actually get this to work on Apalis iMX8 [1] and
> Colibri iMX8X [2] but so far I am still missing
> some crucial recent changes on the SoC device tree side for the dc-
> pixel-link (e.g. fsl,dc-id and fsl,dc-
> stream-id),  lvds-csr (e.g. dropped clock-names) and/or dpr-channel
> (e.g. interrupts-extended especially the
> resp. dc0_irqsteer numbers) parts. If you know of a recent complete
> git tree with working examples like back in
> the day [3], let me know. Let's see...

Like I commented in another thread(
https://patchwork.kernel.org/project/linux-arm-kernel/patch/20230118072656.18845-6-marcel@ziswiler.com/
), I'll see if I can share some local patches/changes to you in some
way as we don't have any official git to share them, or please wait
until they are submitted for review.

Regards,
Liu Ying

> 
> [1] 
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> Cheers
> 
> Marcel