Documentation/leds/leds-lp55xx.rst

Source file repositories/reference/linux-study-clean/Documentation/leds/leds-lp55xx.rst

File Facts

System: Linux kernel
Corpus path: Documentation/leds/leds-lp55xx.rst
Extension: .rst
Size: 6837 bytes
Lines: 225
Domain: Support Tooling And Documentation
Bucket: Documentation
Inferred role: Support Tooling And Documentation: documentation
Status: atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

No C-style include directives detected by the generator.

Detected Declarations

No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

=================================================
LP5521/LP5523/LP55231/LP5562/LP8501 Common Driver
=================================================

Authors: Milo(Woogyom) Kim <milo.kim@ti.com>

Description
-----------
LP5521, LP5523/55231, LP5562 and LP8501 have common features as below.

  Register access via the I2C
  Device initialization/deinitialization
  Create LED class devices for multiple output channels
  Device attributes for user-space interface
  Program memory for running LED patterns

The LP55xx common driver provides these features using exported functions.

  lp55xx_init_device() / lp55xx_deinit_device()
  lp55xx_register_leds() / lp55xx_unregister_leds()
  lp55xx_register_sysfs() / lp55xx_unregister_sysfs()

( Driver Structure Data )

In lp55xx common driver, two different data structure is used.

* lp55xx_led
    control multi output LED channels such as led current, channel index.
* lp55xx_chip
    general chip control such like the I2C and platform data.

For example, LP5521 has maximum 3 LED channels.
LP5523/55231 has 9 output channels::

  lp55xx_chip for LP5521 ... lp55xx_led #1
			     lp55xx_led #2
			     lp55xx_led #3

  lp55xx_chip for LP5523 ... lp55xx_led #1
			     lp55xx_led #2
				   .
				   .
			     lp55xx_led #9

( Chip Dependent Code )

To support device specific configurations, special structure
'lpxx_device_config' is used.

  - Maximum number of channels
  - Reset command, chip enable command
  - Chip specific initialization
  - Brightness control register access
  - Setting LED output current
  - Program memory address access for running patterns
  - Additional device specific attributes

( Firmware Interface )

LP55xx family devices have the internal program memory for running
various LED patterns.

This pattern data is saved as a file in the user-land or
hex byte string is written into the memory through the I2C.

LP55xx common driver supports the firmware interface.

LP55xx chips have three program engines.

To load and run the pattern, the programming sequence is following.

Annotation

Atlas domain: Support Tooling And Documentation / Documentation.
Implementation status: atlas-only.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.