[PATCH v5 00/11] drm: add support for Atmel HLCDC Display Controller

Harivel, Anthony Anthony.Harivel at emtrion.de
Tue Sep 9 01:09:25 PDT 2014

I used this patch to add LCD support on our SBC-SAMA5d36 with a mainline kernel and it works properly. I used fb-test to test the framebuffer and I tested the DRI device with modetest and I can set a mode and set planes.

Tested-by: Anthony Harivel <anthony.harivel at emtrion.de>

-----Original Message-----
From: Boris BREZILLON [mailto:boris.brezillon at free-electrons.com]
Sent: Monday, September 08, 2014 10:44 AM
To: David Airlie; dri-devel at lists.freedesktop.org; Samuel Ortiz; Lee Jones; Thierry Reding; linux-pwm at vger.kernel.org; Nicolas Ferre; Jean-Christophe Plagniol-Villard; Alexandre Belloni; Andrew Victor
Cc: Laurent Pinchart; Bo Shen; Ludovic Desroches; Rob Herring; Pawel Moll; Mark Rutland; Ian Campbell; Kumar Gala; devicetree at vger.kernel.org; Boris BREZILLON
Subject: [PATCH v5 00/11] drm: add support for Atmel HLCDC Display Controller


This patch series adds support for Atmel HLCDC (HLCD Controller) available on some Atmel SoCs (i.e. the sama5d3 family).

The HLCDC actually provides a Display Controller and a PWM device, hence I decided to declare an MFD device exposing 2 subdevices: a display controller and a PWM chip.
This also solves a circular dependency issue preventing HLCDC driver from unloading.
The HLCDC request a drm_panel device, which request a backlight device (a PWM backlight), which depends on a PWM which is provided by the HLCDC driver (hlcdc -> panel -> backlight -> hlcdc (pwm part)).

The current implementation only supports sama5d3 SoCs but other SoCs should be easily ported by defining new compatible strings and adding HLCDC description structures for these SoCs (Ludovic tested this driver on an
at91sam9x5 board).

The drivers supports basic CRTC functionalities, several overlays and an hardware cursor.

At the moment, it only supports connection to LCD panels through an RGB connector (defined as an LVDS connector in my implementation), though connection to other kind of devices (like DRM bridges) could be added later.

It also supports several RGB formats on all planes and some YUV formats on the HEO overlay plane.

This series depends those series: [1] and [2].

I know you're all quite busy, but I was expecting to get support for atmel's HLCDC block in 3.18, and given the lack of review I got on the DRM and PWM parts I doubt it can happen :-(.

Moreover, the dependencies ([1] and [2]) are stuck too.
The first one has been reviewed by Rob, but didn't get any feedback after that. David, Rob, is there anything blocking this series ?
The second patch series contains some rework I've done to describe the transfer format used on a connector bus. Laurent, Thierry, you're the one who suggested this rework. Could you give your opinion on my implementation ?

Best Regards,



Changes since v4:
- fix a few more bugs in rotation handling (rotation was buggy on some
- return connector_status_unknown until a panel is exposed by the
  drm_panel infrastructure (prevent fbdev creation until everyting is
  in place)
- rework Kconfig MFD_ATMEL_HLCDC selection to simplify the configuration
  (automatically select this option when selecting the HLCDC PMW or DRM
  driver, instead of depending on this option)

Changes since v3:
- rework the layer code to simplify several parts (locking and layer
- make use of the drm_flip_work infrastructure
- rely on default HW cursor implementation using on the cursor plane
- rework the display controller DT bindings (based on OF graph
- add rotation support
- retrive RGB bus format from drm_display_info
- drop the dynamic pinctrl state selection
- rework HLCDC output handling (previously specialized to interface
  with LCD panels)
- drop ".module = THIS_MODULE" lines
- change display controller compatible string

Changes since v2:
- fix coding style issues (macro indentation)
- make use of GENMASK in several places
- declare regmap config as a static structure
- rework hlcdc plane update API
- rework cursor handling to make use of the new plane update API
- fix backporch config
- do not use devm_regmap_init_mmio_clk to avoid extra clk_enable
  clk disable calls when accessing registers
- explicitely include regmap and clk headers instead of relying on
  atmel-hlcdc.h inclusions
- make the atmel-hlcdc driver depends on CONFIG_OF
- separate DT bindings documentation from driver implementation
- support several pin muxing for HLCDC pins on sama5d3 SoCs

Changes since v1:
- replace the backlight driver by a PWM driver
- make use of drm_panel infrastructure
- split driver code in several subsystem: MFD, PWM and DRM
- add support for overlays
- add support for hardware cursor

Boris BREZILLON (11):
  mfd: add atmel-hlcdc driver
  mfd: add documentation for atmel-hlcdc DT bindings
  pwm: add support for atmel-hlcdc-pwm device
  pwm: add DT bindings documentation for atmel-hlcdc-pwm driver
  drm: add Atmel HLCDC Display Controller support
  drm: add DT bindings documentation for atmel-hlcdc-dc driver
  ARM: AT91/dt: split sama5d3 lcd pin definitions to match RGB mode
  ARM: AT91/dt: add alternative pin muxing for sama5d3 lcd pins
  ARM: at91/dt: define the HLCDC node available on sama5d3 SoCs
  ARM: at91/dt: add LCD panel description to sama5d3xdm.dtsi
  ARM: at91/dt: enable the LCD panel on sama5d3xek boards

 .../devicetree/bindings/drm/atmel-hlcdc-dc.txt     |  54 ++
 .../devicetree/bindings/mfd/atmel-hlcdc.txt        |  50 ++
 .../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt    |  55 ++
 arch/arm/boot/dts/sama5d31ek.dts                   |  20 +
 arch/arm/boot/dts/sama5d33ek.dts                   |  20 +
 arch/arm/boot/dts/sama5d34ek.dts                   |  20 +
 arch/arm/boot/dts/sama5d36ek.dts                   |  20 +
 arch/arm/boot/dts/sama5d3_lcd.dtsi                 | 205 ++++-
 arch/arm/boot/dts/sama5d3xdm.dtsi                  |  58 ++
 drivers/gpu/drm/Kconfig                            |   2 +
 drivers/gpu/drm/Makefile                           |   1 +
 drivers/gpu/drm/atmel-hlcdc/Kconfig                |  13 +
 drivers/gpu/drm/atmel-hlcdc/Makefile               |   7 +
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c     | 286 +++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c       | 488 ++++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h       | 224 ++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c    | 656 ++++++++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.h    | 403 ++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c   | 476 ++++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c    | 836 +++++++++++++++++++++
 drivers/mfd/Kconfig                                |   6 +
 drivers/mfd/Makefile                               |   1 +
 drivers/mfd/atmel-hlcdc.c                          | 118 +++
 drivers/pwm/Kconfig                                |  10 +
 drivers/pwm/Makefile                               |   1 +
 drivers/pwm/pwm-atmel-hlcdc.c                      | 229 ++++++
 include/linux/mfd/atmel-hlcdc.h                    |  78 ++
 27 files changed, 4306 insertions(+), 31 deletions(-)  create mode 100644 Documentation/devicetree/bindings/drm/atmel-hlcdc-dc.txt
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
 create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/Kconfig
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/Makefile
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.h
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
 create mode 100644 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
 create mode 100644 drivers/mfd/atmel-hlcdc.c  create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c  create mode 100644 include/linux/mfd/atmel-hlcdc.h


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