include/linux/comedi/comedi_8255.h

File Facts

System

Linux kernel

Corpus path

include/linux/comedi/comedi_8255.h

Extension

.h

Size

1416 bytes

Lines

55

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/errno.h

Detected Declarations

• struct comedi_device
• struct comedi_subdevice
• function subdev_8255_io_init

Annotated Snippet

#ifndef _COMEDI_8255_H
#define _COMEDI_8255_H

#include <linux/errno.h>

#define I8255_SIZE		0x04

#define I8255_DATA_A_REG	0x00
#define I8255_DATA_B_REG	0x01
#define I8255_DATA_C_REG	0x02
#define I8255_CTRL_REG		0x03
#define I8255_CTRL_C_LO_IO	BIT(0)
#define I8255_CTRL_B_IO		BIT(1)
#define I8255_CTRL_B_MODE	BIT(2)
#define I8255_CTRL_C_HI_IO	BIT(3)
#define I8255_CTRL_A_IO		BIT(4)
#define I8255_CTRL_A_MODE(x)	((x) << 5)
#define I8255_CTRL_CW		BIT(7)

struct comedi_device;
struct comedi_subdevice;

#ifdef CONFIG_HAS_IOPORT
int subdev_8255_io_init(struct comedi_device *dev, struct comedi_subdevice *s,
			unsigned long regbase);
#else
static inline int subdev_8255_io_init(struct comedi_device *dev,
				      struct comedi_subdevice *s,
				      unsigned long regbase)
{
	return -ENXIO;
}
#endif

int subdev_8255_mm_init(struct comedi_device *dev, struct comedi_subdevice *s,
			unsigned long regbase);

int subdev_8255_cb_init(struct comedi_device *dev, struct comedi_subdevice *s,
			int (*io)(struct comedi_device *dev, int dir, int port,
				  int data, unsigned long context),
			unsigned long context);

unsigned long subdev_8255_regbase(struct comedi_subdevice *s);

#endif

Annotation

• Immediate include surface: `linux/errno.h`.
• Detected declarations: `struct comedi_device`, `struct comedi_subdevice`, `function subdev_8255_io_init`.
• Atlas domain: Core OS / Core Kernel Interface.
• 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.