drivers/hid/hid-roccat.c

File Facts

System

Linux kernel

Corpus path

drivers/hid/hid-roccat.c

Extension

.c

Size

10787 bytes

Lines

464

Domain

Driver Families

Bucket

drivers/hid

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/cdev.h
• linux/poll.h
• linux/sched/signal.h
• linux/hid-roccat.h
• linux/module.h

Detected Declarations

• struct roccat_report
• struct roccat_device
• struct roccat_reader
• function roccat_read
• function roccat_poll
• function roccat_open
• function roccat_release
• function roccat_report_event
• function list_for_each_entry
• function roccat_connect
• function roccat_disconnect
• function roccat_ioctl
• function roccat_init
• function roccat_exit
• module init roccat_init
• export roccat_report_event
• export roccat_connect
• export roccat_disconnect

Annotated Snippet

static const struct file_operations roccat_ops = {
	.owner = THIS_MODULE,
	.read = roccat_read,
	.poll = roccat_poll,
	.open = roccat_open,
	.release = roccat_release,
	.llseek = noop_llseek,
	.unlocked_ioctl = roccat_ioctl,
};

static int __init roccat_init(void)
{
	int retval;
	dev_t dev_id;

	retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR,
			ROCCAT_MAX_DEVICES, "roccat");
	if (retval < 0) {
		pr_warn("can't get major number\n");
		goto error;
	}

	roccat_major = MAJOR(dev_id);

	cdev_init(&roccat_cdev, &roccat_ops);
	retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);

	if (retval < 0) {
		pr_warn("cannot add cdev\n");
		goto cleanup_alloc_chrdev_region;
	}
	return 0;


 cleanup_alloc_chrdev_region:
	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
 error:
	return retval;
}

static void __exit roccat_exit(void)
{
	dev_t dev_id = MKDEV(roccat_major, 0);

	cdev_del(&roccat_cdev);
	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
}

module_init(roccat_init);
module_exit(roccat_exit);

MODULE_AUTHOR("Stefan Achatz");
MODULE_DESCRIPTION("USB Roccat char device");
MODULE_LICENSE("GPL v2");

Annotation

• Immediate include surface: `linux/cdev.h`, `linux/poll.h`, `linux/sched/signal.h`, `linux/hid-roccat.h`, `linux/module.h`.
• Detected declarations: `struct roccat_report`, `struct roccat_device`, `struct roccat_reader`, `function roccat_read`, `function roccat_poll`, `function roccat_open`, `function roccat_release`, `function roccat_report_event`, `function list_for_each_entry`, `function roccat_connect`.
• Atlas domain: Driver Families / drivers/hid.
• 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.