Re: [PATCH v10 0/2] drm: bridge: Add NWL MIPI DSI host controller support

Hi, On Fri, Mar 20, 2020 at 07:49:08PM +0100, Guido Günther wrote:

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

Is there anything in can do to get this into drm-misc? Cheers, -- Guido

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 mainline rocktech-jh057n00900 DSI panel driver on next-20200317 and on the Librem5 with the a Mantix MLAF057WE51-X DSI panel driver (not yet mainline) The DCSS (submitted for mainline inclusion now too) can also act as input source.

Changes from v10:

• Per review comments by Sam Ravnborg https://lore.kernel.org/dri-devel/20200318214639.GA971@ravnborg.org/
  • Drop header-test-y since kernel lost support
  • Handle drm_bridge_attach's new flags argument
  • Add Acked-by: to binding patch, thanks!
• Move to next-20200319

Changes from v9:

• Per review comments by Robert Chiras https://lore.kernel.org/dri-devel/1575366594.6423.61.camel@nxp.com/
  • don't mix DSI host and bridge initialization
  • only select output source once
  • defer probe when panel is not ready to fix usage as a module
  • use correct reset sequence as described by Robert (and provided by NWL)
  • use mode->clock instead of mode->crtc_clock
• Add tested by from Martin Kepplinger, thanks!
• Drop platform specific data (as suggested previously by Laurent Pinchart and Andrzej Hajda) since imx8q* needs another set of abstractions with the new reset sequence and that's easier to do when adding imx8q* support rather then adding wrong abstraction now.
• Update bindings to use proper clock and irq names to make the example match reality more closely.
• Use `fallthrough;` instead of /* Fall through */ in switch statements
• Move to next-20200226

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/c86b7ca2-7799-eafd-c380-e4b55152083...
  • 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 lkp@intel.com https://lore.kernel.org/linux-arm-kernel/201909230644.qfSKbNf9%25lkp@intel.c... 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 lkp@intel.com 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_dsi_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

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 | 216 +++ drivers/gpu/drm/bridge/Kconfig | 16 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/nwl-dsi.c | 1218 +++++++++++++++++ drivers/gpu/drm/bridge/nwl-dsi.h | 144 ++ 5 files changed, 1595 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

-- 2.23.0

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