drivers/media/pci/mgb4/mgb4_regs.c

File Facts

System

Linux kernel

Corpus path

drivers/media/pci/mgb4/mgb4_regs.c

Extension

.c

Size

742 bytes

Lines

32

Domain

Driver Families

Bucket

drivers/media

Inferred role

Driver Families: implementation source

Status

source 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 or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/ioport.h
• linux/errno.h
• mgb4_regs.h

Detected Declarations

• function Copyright
• function mgb4_regs_free

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2021-2022 Digiteq Automotive
 *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
 */

#include <linux/ioport.h>
#include <linux/errno.h>
#include "mgb4_regs.h"

int mgb4_regs_map(struct resource *res, struct mgb4_regs *regs)
{
	regs->mapbase = res->start;
	regs->mapsize = resource_size(res);

	if (!request_mem_region(regs->mapbase, regs->mapsize, res->name))
		return -EINVAL;
	regs->membase = ioremap(regs->mapbase, regs->mapsize);
	if (!regs->membase) {
		release_mem_region(regs->mapbase, regs->mapsize);
		return -EINVAL;
	}

	return 0;
}

void mgb4_regs_free(struct mgb4_regs *regs)
{
	iounmap(regs->membase);
	release_mem_region(regs->mapbase, regs->mapsize);
}

Annotation

• Immediate include surface: `linux/ioport.h`, `linux/errno.h`, `mgb4_regs.h`.
• Detected declarations: `function Copyright`, `function mgb4_regs_free`.
• Atlas domain: Driver Families / drivers/media.
• Implementation status: source implementation candidate.

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.