[v4] Add ITE IT61620 MIPI DSI to HDMI bridge driver

[PATCH v4 0/3] Add ITE IT61620 MIPI DSI to HDMI bridge driver
Posted by Pet Weng 1 day, 15 hours ago
This patch series adds support for the ITE IT61620 MIPI DSI to HDMI 
bridge chip.

The IT61620 is an I2C-controlled bridge that receives MIPI DSI input 
and outputs HDMI signals. A single-port MIPI DSI input is converted to 
an HDMI 1.4 output. This series introduces:
- A device tree binding YAML file describing the hardware
- A new DRM bridge driver implementing the basic functionality
- A MAINTAINERS entry for the driver

Signed-off-by: Pet Weng <pet.weng@ite.com.tw>
---
Changes in v4:
- In patch 1								[Krzysztof]
 1. Remove redundant "description" fields from interrupts and regulators
 2. Drop pinctrl-names and pinctrl-0; driver does not require them
 3. Remove port/endpoint properties already covered by video interfaces schema
 4. Fix example indentation to 4 spaces for readability
- In patch 2								[Jani]
 1. Use connector->display_info from DRM helper instead of parsing EDID manually
- In patch 2								[Dmitry]
 1. Remove redundant powered check in reg access
 2. Use TMDS character rate instead of pixel clock for N/CTS
 3. Use consistent lowercase naming for tmds.
 4. Use test_bit() instead of custom bit-test helper
 5. Use tmds_char_rate_valid instead of custom mode_valid
 6. Use custom EDID read instead of DDC bus for segment handling
 7. Drop redundant atomic feature check
 8. Pass flags directly to drm_bridge_attach()
 9. Check DRM_BRIDGE_ATTACH_NO_CONNECTOR flag before drm_bridge_attach()
 10. Short-circuit HPD update if connector status unchanged
 11. Remove unnecessary NULL check for connector state
 12. Rename cached_edid to edid since it's no longer cached
 13. Remove redundant sample rate checks; rely on hdmi-codec validation
 14. Remove unsupported 18-bit audio sample size; rely on hdmi-codec
 15. Remove unnecessary fmt switch; rely on hdmi-codec defaults
 16. Check and propagate errors from it61620_audio_update_hw_params instead of
     ignoring them
- In patch 3								[Krzysztof]
 1. Remove unnecessary T: field pointing to git; subsystem already defines it
- Link to v3: https://lore.kernel.org/r/20251009-it61620-0714-v3-0-5d682d028441@ite.com.tw

Changes in v3:
- Wrapped description lines to comply with 80-character line length limit
  in patch 1.								[Rob]
- Renamed node from "it61620@58" to "bridge@58" in patch 1.		[Rob]
- Add port@2 for I2S audio input in patch 1.				[Dmitry]
- Updated the Kconfig dependency from CRYPTO and CRYPTO_HASH to 
  CRYPTO_LIB_SHA1 in patch 2.						[Eric]
- In patch 2								[Dmitry]
 1. Audio and InfoFrame
   - Rename audfmt to i2s_input_format for clarity.
   - Remove unused infoframe[HDMI_INFOFRAME_SIZE(AUDIO)].
 2. Platform data and structure
   - Drop platform data usage; migrate members into struct it61620
 3. Code organization
   - Reorder functions to avoid the need for forward declarations.
   - Add static inline to small helper functions
     (e.g. bridge_to_it61620()).
 4. HDCP handling
   - Make HDCP enable/disable conditional on conn_state->content_protection.
   - Report authentication result using drm_hdcp_update_content_protection().
 5. Error handling
   - Replace manual error path with dev_err_probe().
 6. Power management
   - Inline suspend/resume callbacks.
   - Use DEFINE_RUNTIME_DEV_PM_OPS() instead of explicit struct definition.
 7. Bridge callbacks
   - Drop empty bridge_detach().
   - Inline it61620_bridge_mode_valid().
 8. EDID handling
   - Remove unnecessary cached EDID duplication.
 9. Mode set and pixel clock
   - Move mode handling to atomic_enable().
   - Keep only pixelclock for future N/CTS audio calculations.
 10. Logging
    - Replace noisy drm_err() calls with drm_dbg().
 11. InfoFrame support
    - Add support for SPD and Vendor InfoFrames.
- Link to v2: https://lore.kernel.org/r/20250828-it61620-0714-v2-0-586f5934d5f8@ite.com.tw

Changes in v2:
- Call the sha1() library function instead of using the crypto_shash
  "sha1" in patch 2.
- Rewrite it61620_hdmi_ddc_wait() with readx_poll_timeout() in patch 2.	[Pin-yen]
- Rewrite it61620_hdmi_hdcp_wait_ksv_list() with readx_poll_timeout() in
  patch 2.
- Replace interrupts-extended with interrupts in patch 1.		[Rob]
- Replace dsi-lanes with the standard property data-lanes from the graph
  binding.								[Rob]
- Replace "#/$defs/port-base" with "#/properties/port" in patch 1.	[Rob]
- Drop unused labels and "hdmi" for the node name.			[Rob]
- Drop status in patch 1.						[Rob]
- Link to v1: https://lore.kernel.org/r/20250714-it61620-0714-v1-0-3761164d0b98@ite.com.tw

---
Pet Weng (3):
      dt-binding: display: Add ITE IT61620 MIPI DSI to HDMI bridge
      drm/bridge: Add ITE IT61620 MIPI DSI to HDMI bridge driver
      MAINTAINERS: Add entry for ITE IT61620 MIPI to HDMI bridge driver

 .../bindings/display/bridge/ite,it61620.yaml       |  140 +
 MAINTAINERS                                        |    7 +
 drivers/gpu/drm/bridge/Kconfig                     |   18 +
 drivers/gpu/drm/bridge/Makefile                    |    1 +
 drivers/gpu/drm/bridge/ite-it61620.c               | 2787 ++++++++++++++++++++
 5 files changed, 2953 insertions(+)
---
base-commit: 34bd4deba1e55e93c74977dee31783ebdf68d8ba
change-id: 20250714-it61620-0714-ab4ab4ceff29

Best regards,
-- 
Pet Weng <pet.weng@ite.com.tw>