Merge tag 'drm-misc-next-2022-04-28' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 5.19:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
  - Introduction of display-helper module, and rework of the DP, DSC,
    HDCP, HDMI and SCDC headers
  - doc: Improvements for tiny drivers, link to external resources
  - formats: helper to convert from RGB888 and RGB565 to XRGB8888
  - modes: make width-mm/height-mm check mandatory in of_get_drm_panel_display_mode
  - ttm: Convert from kvmalloc_array to kvcalloc

Driver Changes:
  - bridge:
    - analogix_dp: Fix error handling in probe
    - dw_hdmi: Coccinelle fixes
    - it6505: Fix Kconfig dependency on DRM_DP_AUX_BUS
  - panel:
    - new panel: DataImage FG040346DSSWBG04
  - amdgpu: ttm_eu cleanups
  - mxsfb: Rework CRTC mode setting
  - nouveau: Make some variables static
  - sun4i: Drop drm_display_info.is_hdmi caching, support for the
    Allwinner D1
  - vc4: Drop drm_display_info.is_hdmi caching
  - vmwgfx: Fence improvements

Signed-off-by: Dave Airlie <airlied@redhat.com>

# gpg: Signature made Thu 28 Apr 2022 17:52:13 AEST
# gpg:                using EDDSA key 5C1337A45ECA9AEB89060E9EE3EF0D6F671851C5
# gpg: Can't check signature: No public key
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220428075237.yypztjha7hetphcd@houat

2 files changed, 83 insertions, 20 deletions

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index c3ce91eecbc1..2d473bc64c9f 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -226,40 +226,43 @@ Panel Self Refresh Helper Reference
 HDCP Helper Functions Reference
 ===============================
 
-.. kernel-doc:: drivers/gpu/drm/drm_hdcp.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_hdcp_helper.c
    :export:
 
 Display Port Helper Functions Reference
 =======================================
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
    :doc: dp helpers
 
-.. kernel-doc:: include/drm/dp/drm_dp_helper.h
+.. kernel-doc:: include/drm/display/drm_dp.h
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c
+.. kernel-doc:: include/drm/display/drm_dp_helper.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
    :export:
 
 Display Port CEC Helper Functions Reference
 ===========================================
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
    :doc: dp cec helpers
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
    :export:
 
 Display Port Dual Mode Adaptor Helper Functions Reference
 =========================================================
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
    :doc: dp dual mode helpers
 
-.. kernel-doc:: include/drm/dp/drm_dp_dual_mode_helper.h
+.. kernel-doc:: include/drm/display/drm_dp_dual_mode_helper.h
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
    :export:
 
 Display Port MST Helpers
@@ -268,19 +271,19 @@ Display Port MST Helpers
 Overview
 --------
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
    :doc: dp mst helper
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
    :doc: Branch device and port refcounting
 
 Functions Reference
 -------------------
 
-.. kernel-doc:: include/drm/dp/drm_dp_mst_helper.h
+.. kernel-doc:: include/drm/display/drm_dp_mst_helper.h
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
    :export:
 
 Topology Lifetime Internals
@@ -289,7 +292,7 @@ Topology Lifetime Internals
 These functions aren't exported to drivers, but are documented here to help make
 the MST topology helpers easier to understand
 
-.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
    :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
                drm_dp_mst_topology_put_mstb
                drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
@@ -323,13 +326,13 @@ MIPI DSI Helper Functions Reference
 Display Stream Compression Helper Functions Reference
 =====================================================
 
-.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
    :doc: dsc helpers
 
-.. kernel-doc:: include/drm/drm_dsc.h
+.. kernel-doc:: include/drm/display/drm_dsc.h
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
    :export:
 
 Output Probing Helper Functions Reference
@@ -353,13 +356,13 @@ EDID Helper Functions Reference
 SCDC Helper Functions Reference
 ===============================
 
-.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
    :doc: scdc helpers
 
-.. kernel-doc:: include/drm/drm_scdc_helper.h
+.. kernel-doc:: include/drm/display/drm_scdc_helper.h
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
    :export:
 
 HDMI Infoframes Helper Reference
diff --git a/Documentation/gpu/introduction.rst b/Documentation/gpu/introduction.rst
index 25a56e9c0cfd..f05eccd2c07c 100644
--- a/Documentation/gpu/introduction.rst
+++ b/Documentation/gpu/introduction.rst
@@ -112,3 +112,63 @@ Please conduct yourself in a respectful and civilised manner when
 interacting with community members on mailing lists, IRC, or bug
 trackers. The community represents the project as a whole, and abusive
 or bullying behaviour is not tolerated by the project.
+
+Simple DRM drivers to use as examples
+=====================================
+
+The DRM subsystem contains a lot of helper functions to ease writing drivers for
+simple graphic devices. For example, the `drivers/gpu/drm/tiny/` directory has a
+set of drivers that are simple enough to be implemented in a single source file.
+
+These drivers make use of the `struct drm_simple_display_pipe_funcs`, that hides
+any complexity of the DRM subsystem and just requires drivers to implement a few
+functions needed to operate the device. This could be used for devices that just
+need a display pipeline with one full-screen scanout buffer feeding one output.
+
+The tiny DRM drivers are good examples to understand how DRM drivers should look
+like. Since are just a few hundreds lines of code, they are quite easy to read.
+
+External References
+===================
+
+Delving into a Linux kernel subsystem for the first time can be an overwhelming
+experience, one needs to get familiar with all the concepts and learn about the
+subsystem's internals, among other details.
+
+To shallow the learning curve, this section contains a list of presentations
+and documents that can be used to learn about DRM/KMS and graphics in general.
+
+There are different reasons why someone might want to get into DRM: porting an
+existing fbdev driver, write a DRM driver for a new hardware, fixing bugs that
+could face when working on the graphics user-space stack, etc. For this reason,
+the learning material covers many aspects of the Linux graphics stack. From an
+overview of the kernel and user-space stacks to very specific topics.
+
+The list is sorted in reverse chronological order, to keep the most up-to-date
+material at the top. But all of them contain useful information, and it can be
+valuable to go through older material to understand the rationale and context
+in which the changes to the DRM subsystem were made.
+
+Conference talks
+----------------
+
+* `An Overview of the Linux and Userspace Graphics Stack <https://www.youtube.com/watch?v=wjAJmqwg47k>`_ - Paul Kocialkowski (2020)
+* `Getting pixels on screen on Linux: introduction to Kernel Mode Setting <https://www.youtube.com/watch?v=haes4_Xnc5Q>`_ - Simon Ser (2020)
+* `Everything Great about Upstream Graphics <https://www.youtube.com/watch?v=kVzHOgt6WGE>`_ - Daniel Vetter (2019)
+* `An introduction to the Linux DRM subsystem <https://www.youtube.com/watch?v=LbDOCJcDRoo>`_ - Maxime Ripard (2017)
+* `Embrace the Atomic (Display) Age <https://www.youtube.com/watch?v=LjiB_JeDn2M>`_ - Daniel Vetter (2016)
+* `Anatomy of an Atomic KMS Driver <https://www.youtube.com/watch?v=lihqR9sENpc>`_ - Laurent Pinchart (2015)
+* `Atomic Modesetting for Drivers <https://www.youtube.com/watch?v=kl9suFgbTc8>`_ - Daniel Vetter (2015)
+* `Anatomy of an Embedded KMS Driver <https://www.youtube.com/watch?v=Ja8fM7rTae4>`_ - Laurent Pinchart (2013)
+
+Slides and articles
+-------------------
+
+* `Understanding the Linux Graphics Stack <https://bootlin.com/doc/training/graphics/graphics-slides.pdf>`_ - Bootlin (2022)
+* `DRM KMS overview <https://wiki.st.com/stm32mpu/wiki/DRM_KMS_overview>`_ - STMicroelectronics (2021)
+* `Linux graphic stack <https://studiopixl.com/2017-05-13/linux-graphic-stack-an-overview>`_ - Nathan Gauër (2017)
+* `Atomic mode setting design overview, part 1 <https://lwn.net/Articles/653071/>`_ - Daniel Vetter (2015)
+* `Atomic mode setting design overview, part 2 <https://lwn.net/Articles/653466/>`_ - Daniel Vetter (2015)
+* `The DRM/KMS subsystem from a newbie’s point of view <https://bootlin.com/pub/conferences/2014/elce/brezillon-drm-kms/brezillon-drm-kms.pdf>`_ - Boris Brezillon (2014)
+* `A brief introduction to the Linux graphics stack <https://blogs.igalia.com/itoral/2014/07/29/a-brief-introduction-to-the-linux-graphics-stack/>`_ - Iago Toral (2014)
+* `The Linux Graphics Stack <https://blog.mecheye.net/2012/06/the-linux-graphics-stack/>`_ - Jasper St. Pierre (2012)