[PATCH v17 0/3] leds: add new LED driver for TI LP5812

Nam Tran
2025-10-21T15:59:36Z

This patch series adds initial support for the TI LP5812,
a 4x3 matrix RGB LED driver with autonomous engine control.
This version provides a minimal, clean implementation focused
on core functionality only. The goal is to upstream a solid
foundation, with the expectation that additional features can
be added incrementally in future patches.

The driver integrates with the LED multicolor framework and
supports a set of basic sysfs interfaces for LED control and
chip management.

Signed-off-by: Nam Tran <trannamatk@gmail.com>
---
Changes in v17:
- Dropped direct_mode from ti,scan-mode property.
- Updated logic so that omitting ti,scan-mode now implies direct-drive mode by default.
- Refactor lp5812_parse_led_channel() to simplify function arguments.
- Mark lp5812_cfg as const since it contains only static configuration data.
- Link to v16: https://lore.kernel.org/linux-leds/20251013173551.108205-1-trannamatk@gmail.com/

Changes in v16:
- Renamed property 'ti,operation-mode' to 'ti,scan-mode'.
- Simplified allowed values using regex pattern instead of long enum list.
- Updated description accordingly and noted 'direct_mode' as default.
- Updated core driver to match the binding change.
- Link to v15: https://lore.kernel.org/linux-leds/20251005153337.94025-1-trannamatk@gmail.com/

Changes in v15:
- Removed all custom sysfs attributes; driver now fully relies on standard LED multicolor class interfaces.
- Added new device tree property `ti,operation-mode` to configure direct, TCM, and mix scan modes.
- Dropped previous Reviewed-by tag from the binding patch due to property addition.
- Removed ABI documentation since no new sysfs entries are created.
- Updated lp5812.rst documentation accordingly.
- Link to v14: https://lore.kernel.org/linux-leds/20250907160944.149104-1-trannamatk@gmail.com/

Changes in v14:
- Replaced inline constants with proper macros for readability and maintainability.
- Refactored lp5812_read() and lp5812_write() to simplify logic and improve clarity.
- Updated lp5812_fault_clear() to use switch() instead of if/else chain.
- Refactored parse_drive_mode() for cleaner logic, removed string parsing of concatenated data.
- Updated activate_store() and led_current_store() to replace strsep()/kstrtoint() parsing with sscanf().
- Removed redundant comments and renamed variables for better clarity.
- Link to v13: https://lore.kernel.org/lkml/20250818012654.143058-1-trannamatk@gmail.com/

Changes in v13:
- Fixes build warnings reported by kernel test robot:
- Inconsistent indent in lp5812_probe()
- Uninitialized variable 'ret' in lp5812_multicolor_brightness()
- Drop of_match_ptr() and directly assign of_match_table, as the driver is DT-only.
- Link to v12: https://lore.kernel.org/lkml/20250728065814.120769-1-trannamatk@gmail.com/

Changes in v12:
- Reordered helper functions above lp5812_probe() for better structure.
- Clarified DT-only support by removing fallback paths and i2c_device_id table.
- Directly assign platform_data to the correct pointer instead of relying on
string comparisons (LP5812_SC_LED, LP5812_MC_LED) and container_of() casting.
This simplifies the logic and avoids unnecessary type checks.
- Removed redundant messages.
- Update ABI documentation to reflect reduced feature set.
- Link to v11: https://lore.kernel.org/lkml/20250714172355.84609-1-trannamatk@gmail.com/

Changes in v11:
- Drop autonomous animation and other advanced features; reduce driver to core functionality only.
- Simplify LED parsing to use a unified path.
- Clean up and streamline code
- Use alphabetically ordered includes
- Remove redundant comments
- Fix style issues (e.g., comment capitalization, code placement)
- Update ABI documentation to reflect reduced feature set.
- Link to v10: https://lore.kernel.org/lkml/20250618183205.113344-1-trannamatk@gmail.com/

Changes in v10:
- Address feedback on v9 regarding missing Reviewed-by tag
- Added explanation: binding structure changed significantly to integrate
with the standard leds-class-multicolor.yaml schema and support multi-led@
nodes with nested led@ subnodes. This change introduced a new patternProperties
hierarchy and removed the previous flat led@ layout used in the earlier versions.
So the Reviewed-by tag was dropped out of caution.
- Address binding document feedback
- Use consistent quotes
- Replace 'max-cur' with the standard 'led-max-microamp'
- Remove 'led-cur' property
- Fix mixed indentation
- Updated core driver to align with the updated binding schema.
- Address core driver feedback
- Use for_each_available_child_of_node_scoped() to simplify the code
- Add a return checks for lp5812_write() and lp5812_read()
- Remove unneeded trailing commas
- Fix unsafe usage of stack-allocated strings
- Link to v9: https://lore.kernel.org/lkml/20250617154020.7785-1-trannamatk@gmail.com/

Changes in v9:
- Move driver back to drivers/leds/rgb/
- Integrate with LED multicolor framework
- Refactor and simplify custom sysfs handling
- Extend Device Tree binding to support multi-led@ nodes using leds-class-multicolor.yaml
- Update documentation to reflect the updated sysfs.
- Link to v8: https://lore.kernel.org/lkml/20250427082447.138359-1-trannamatk@gmail.com/

Changes in v8:
- Move driver to drivers/auxdisplay/ instead of drivers/leds/.
- Rename files from leds-lp5812.c/.h to lp5812.c/.h.
- Move ti,lp5812.yaml binding to auxdisplay/ directory,
and update the title and $id to match new path.
- No functional changes to the binding itself (keep Reviewed-by).
- Update commit messages and patch titles to reflect the move.
- Link to v7: https://lore.kernel.org/linux-leds/20250422190121.46839-1-trannamatk@gmail.com/

Changes in v7:
- Mark `chip_leds_map` as const.
- Use consistent `ret` initialization.
- Simplify the function `set_mix_sel_led()`.
- Refactor `dev_config_show()` and `led_auto_animation_show()` to avoid temp buffer, malloc/free.
- Simplify the code and ensure consistent use of mutex lock/unlock in show/store functions.
- Remove `total_leds` and `total_aeu`.
- Link to v6: https://lore.kernel.org/linux-leds/20250419184333.56617-1-trannamatk@gmail.com/

Changes in v6:
- Add `vcc-supply` property to describe the LP5812 power supply.
- Remove `chan-name` property and entire LED subnodes, as they are not needed.
- Update LP5812 LED driver node to Raspberry Pi 4 B Device Tree, based on updated binding.
- Link to v5: https://lore.kernel.org/linux-leds/20250414145742.35713-1-trannamatk@gmail.com/

Changes in v5:
- Rebase on v6.15-rc2
- Removed unused functions (lp5812_dump_regs, lp5812_update_bit).
- Address Krzysztof's review comments
- Link to v4: https://lore.kernel.org/linux-leds/20250405183246.198568-1-trannamatk@gmail.com/
---

Nam Tran (3):
dt-bindings: leds: add TI/National Semiconductor LP5812 LED Driver
leds: add basic support for TI/National Semiconductor LP5812 LED
Driver
docs: leds: Document TI LP5812 LED driver

.../devicetree/bindings/leds/ti,lp5812.yaml | 246 ++++++
Documentation/leds/index.rst | 1 +
Documentation/leds/leds-lp5812.rst | 50 ++
MAINTAINERS | 11 +
drivers/leds/rgb/Kconfig | 13 +
drivers/leds/rgb/Makefile | 1 +
drivers/leds/rgb/leds-lp5812.c | 730 ++++++++++++++++++
drivers/leds/rgb/leds-lp5812.h | 197 +++++
8 files changed, 1249 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/ti,lp5812.yaml
create mode 100644 Documentation/leds/leds-lp5812.rst
create mode 100644 drivers/leds/rgb/leds-lp5812.c
create mode 100644 drivers/leds/rgb/leds-lp5812.h

base-commit: 6548d364a3e850326831799d7e3ea2d7bb97ba08
--
2.25.1