drivers/leds/uleds.c

File Facts

System

Linux kernel

Corpus path

drivers/leds/uleds.c

Extension

.c

Size

4713 bytes

Lines

220

Domain

Driver Families

Bucket

drivers/leds

Inferred role

Driver Families: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Defines an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/fs.h
• linux/init.h
• linux/leds.h
• linux/miscdevice.h
• linux/module.h
• linux/poll.h
• linux/sched.h
• linux/slab.h
• uapi/linux/uleds.h

Detected Declarations

• struct uleds_device
• enum uleds_state
• function uleds_brightness_set
• function uleds_open
• function uleds_write
• function strnchr
• function uleds_read
• function uleds_poll
• function uleds_release

Annotated Snippet

static const struct file_operations uleds_fops = {
	.owner		= THIS_MODULE,
	.open		= uleds_open,
	.release	= uleds_release,
	.read		= uleds_read,
	.write		= uleds_write,
	.poll		= uleds_poll,
};

static struct miscdevice uleds_misc = {
	.fops		= &uleds_fops,
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= ULEDS_NAME,
};

module_misc_device(uleds_misc);

MODULE_AUTHOR("David Lechner <david@lechnology.com>");
MODULE_DESCRIPTION("Userspace driver for the LED subsystem");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `linux/fs.h`, `linux/init.h`, `linux/leds.h`, `linux/miscdevice.h`, `linux/module.h`, `linux/poll.h`, `linux/sched.h`, `linux/slab.h`.
• Detected declarations: `struct uleds_device`, `enum uleds_state`, `function uleds_brightness_set`, `function uleds_open`, `function uleds_write`, `function strnchr`, `function uleds_read`, `function uleds_poll`, `function uleds_release`.
• Atlas domain: Driver Families / drivers/leds.
• Implementation status: pattern implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

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.