[v8,0/2] drm: bridge: Add NWL MIPI DSI host controller support

Message

Guido Günther Dec. 2, 2019, 7:35 p.m. UTC

This adds initial support for the NWL MIPI DSI Host controller found on i.MX8
SoCs.

It adds support for the i.MX8MQ but the same IP core can also be found on e.g.
i.MX8QXP. I added the necessary hooks to support other imx8 variants but since
I only have imx8mq boards to test I omitted the platform data for other SoCs.

The code is based on NXPs BSP so I added Robert Chiras as Co-authored-by.

The most notable changes over the BSP driver are
 - Calculate HS mode timing from phy_configure_opts_mipi_dphy
 - Perform all clock setup via DT
 - Merge nwl-imx and nwl drivers
 - Add B0 silion revision quirk
 - become a bridge driver to hook into mxsfb / dcss
   imx-display-subsystem so it makes sense to make it drive a bridge for dsi as
   well).
 - Use panel_bridge to attach the panel
 - Use multiplex framework instead of accessing syscon directly

This has been tested on a Librem 5 devkit using mxsfb with Robert's patches[1]
and the rocktech-jh057n00900 panel driver on next-20191018. The DCSS (there's
was an initial of that driver now) can also act as input source.

Changes from v8:
- Drop reset quirk. It's not needed with mxsfb and sometimes triggers a shifted display.

Changes from v7:
- Per review comments by Andrzej Hajda
  https://lore.kernel.org/linux-arm-kernel/[e-mail]/
  - Drop spare empty line
  - handle nwl_dsi_write errors
  - better handle read errors
  - unwind in case of error in nwl_dsi_enable
  - use bridge_to_dsi() instead of accessing driver_private
  - don't log on -EPROBEDEFER when fething the reset controller
  - use endpoint number to determine input
- Spotted by kbuild test robot <[e-mail]>
  https://lore.kernel.org/linux-arm-kernel/[e-mail]/
  Use signed return type for nwl_dsi_get_dpi_pixel_format
- Drop connector type from drm_panel_bridge_add
- Don't forget to set an error value on dsi reads

Changes from v5:
- Per review comments by Andrzej Hajda
  https://lists.freedesktop.org/archives/dri-devel/2019-September/235281.html
  - Fix include file ordering
  - Add a comment to nwl_dsi_platform_data that will allow to add support
    at least for the i.MX8QM
  - Merge driver into a single file plus the register defs in a separate header
- Make more functions and structs static

Changes from v4:
- Collect Reviewed-by: from Rob Herring, thanks!
  https://lists.freedesktop.org/archives/dri-devel/2019-September/233979.html
- Spotted by kbuild test robot <[e-mail]>
  https://lists.freedesktop.org/archives/dri-devel/2019-September/233860.html
  https://lists.freedesktop.org/archives/dri-devel/2019-September/233863.html
  - fix format string for size_t
  - Use DIV64_U64_ROUND_UP to fix build on 32 bit architectures
    We can't use simple shift sind d and n are similar in size and
    we need full precision
- Fix debug cfg_t_post debug print out
- Avoid PSEC_PER_SEC
- Move timeout / overflow handling out of nwl_dsi_finish_transmission,
  it would never end up being reported since the call to the function
  was guarded by flags.
- Drop 'support for' from KConfig title to make it match the other
  drivers in that submenu

Changes from v3:
- Per review comments by Robert Chiras
  https://lists.freedesktop.org/archives/dri-devel/2019-August/232580.html
  - Add Robert's {Signed-off,Tested}-by:
  - Respect number of lanes when calculting bandwidth limits
  - Drop duplicate NWL_DSI_ENABLE_MULT_PKTS setup
- Per testing by Rober Chiras
  https://lists.freedesktop.org/archives/dri-devel/2019-August/233688.html
  - Drop duplicate (and too early) drm_bridge_add() in nwl_dir_probe() that
    made mxsfb fail to connect to the bridge since the panel_bridge was not up
    yet. drm_bridge_add() happens in nwl_dsi_host_attach() where after the
    panel_bridge was set up.
- Per review comments by Rob Herring on bindings
  https://lists.freedesktop.org/archives/dri-devel/2019-August/233196.html
  - drop description from power-domains and resets
  - allow BSD 2 clause license as well
  - make ports more specific
  - add #address-cells, #size-cells as required
  - use additionalProperties
  - panel is of type object

Changes from v2:
- Per review comments by Rob Herring
  https://lists.freedesktop.org/archives/dri-devel/2019-August/230448.html
  - bindings:
    - Simplify by restricting to fsl,imx8mq-nwl-dsi
    - document reset lines
    - add port@{0,1}
    - use a real compatible string for the panel
    - resets are required
- Per review comments by Arnd Bergmann
  https://lists.freedesktop.org/archives/dri-devel/2019-August/230868.html
  - Don't access iomuxc_gpr regs directly. This allows us to drop the
    first patch in the series with the iomuxc_gpr field defines.
- Per review comments by Laurent Pinchart
  Fix wording in bindings
- Add mux-controls to bindings
- Don't print error message on dphy probe deferral

Changes from v1:
- Per review comments by Sam Ravnborg
  https://lists.freedesktop.org/archives/dri-devel/2019-July/228130.html
  - Change binding docs to YAML
  - build: Don't always visit imx-nwl/
  - build: Add header-test-y
  - Sort headers according to DRM convention
  - Use drm_display_mode instead of videmode
- Per review comments by Fabio Estevam
  https://lists.freedesktop.org/archives/dri-devel/2019-July/228299.html
  - Don't restrict build to ARCH_MXC
  - Drop unused includes
  - Drop unreachable code in imx_nwl_dsi_bridge_mode_fixup()
  - Drop remaining calls of dev_err() and use DRM_DEV_ERR()
    consistently.
  - Use devm_platform_ioremap_resource()
  - Drop devm_free_irq() in probe() error path
  - Use single line comments where sufficient
  - Use <linux/time64.h> instead of defining USEC_PER_SEC
  - Make input source select imx8 specific
  - Drop <asm/unaligned.h> inclusion (after removal of get_unaligned_le32)
  - Drop all EXPORT_SYMBOL_GPL() for functions used in the same module
    but different source files.
  - Drop nwl_dsi_enable_{rx,tx}_clock() by invoking clk_prepare_enable()
    directly
  - Remove pointless comment
- Laurent Pinchart
  https://lists.freedesktop.org/archives/dri-devel/2019-July/228313.html
  https://lists.freedesktop.org/archives/dri-devel/2019-July/228308.html
  - Drop (on iMX8MQ) unused csr regmap
  - Use NWL_MAX_PLATFORM_CLOCKS everywhere
  - Drop get_unaligned_le32() usage
  - remove duplicate 'for the' in binding docs
  - Don't include unused <linux/clk-provider.h>
  - Don't include unused <linux/component.h>
  - Drop dpms_mode for tracking state, trust the drm layer on that
  - Use pm_runtime_put() instead of pm_runtime_put_sync()
  - Don't overwrite encoder type
  - Make imx_nwl_platform_data const
  - Use the reset controller API instead of open coding that platform specific
    part
  - Use <linux/bitfield.h> intead of making up our own defines
  - name mipi_dsi_transfer less generic: nwl_dsi_transfer
  - ensure clean in .remove by calling mipi_dsi_host_unregister.
  - prefix constants by NWL_DSI_
  - properly format transfer_direction enum
  - simplify platform clock handling
  - Don't modify state in mode_fixup() and use mode_set() instead
  - Drop bridge detach(), already handle by nwl_dsi_host_detach()
  - Drop USE_*_QUIRK() macros
- Drop (for now) unused clock defnitions. 'pixel' and 'bypass' clock will be
  used for i.MX8 SoCs but since they're unused atm drop the definitions - but
  keep the logic to enable/disable several clocks in place since we know we'll
  need it in the future.

Changes from v0:
- Add quirk for IMQ8MQ silicon B0 revision to not mess with the
  system reset controller on power down since enable() won't work
  otherwise.
- Drop devm_free_irq() handled by the device driver core
- Disable tx esc clock after the phy power down to unbreak
  disable/enable (unblank/blank)
- Add ports to dt binding docs
- Select GENERIC_PHY_MIPI_DPHY instead of GENERIC_PHY for
  phy_mipi_dphy_get_default_config
- Select DRM_MIPI_DSI
- Include drm_print.h to fix build on next-20190408
- Drop some debugging messages
- Newline terminate all DRM_ printouts
- Turn component driver into a drm bridge

[0]: https://lists.freedesktop.org/archives/dri-devel/2019-May/219484.html
[1]: https://patchwork.freedesktop.org/series/62822/

Guido Günther (2):
  dt-bindings: display/bridge: Add binding for NWL mipi dsi host
    controller
  drm/bridge: Add NWL MIPI DSI host controller support

 .../bindings/display/bridge/nwl-dsi.yaml      |  203 +++
 drivers/gpu/drm/bridge/Kconfig                |   16 +
 drivers/gpu/drm/bridge/Makefile               |    3 +
 drivers/gpu/drm/bridge/nwl-dsi.c              | 1230 +++++++++++++++++
 drivers/gpu/drm/bridge/nwl-dsi.h              |  144 ++
 5 files changed, 1596 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml
 create mode 100644 drivers/gpu/drm/bridge/nwl-dsi.c
 create mode 100644 drivers/gpu/drm/bridge/nwl-dsi.h