arch/powerpc/sysdev/cpm2.c

File Facts

System

Linux kernel

Corpus path

arch/powerpc/sysdev/cpm2.c

Extension

.c

Size

8331 bytes

Lines

345

Domain

Architecture Layer

Bucket

arch/powerpc

Inferred role

Architecture Layer: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

• CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/errno.h
• linux/sched.h
• linux/kernel.h
• linux/param.h
• linux/string.h
• linux/mm.h
• linux/interrupt.h
• linux/module.h
• linux/of.h
• asm/io.h
• asm/irq.h
• asm/page.h
• asm/cpm2.h
• asm/rheap.h
• sysdev/fsl_soc.h

Detected Declarations

• struct cpm2_ioports
• function cpm2_reset
• function cpm_command
• function __cpm2_setbrg
• function cpm2_clk_setup
• function cpm2_smc_clk_setup
• function cpm2_set_pin
• export cpm2_immr
• export cpm_command
• export __cpm2_setbrg

Annotated Snippet

struct cpm2_ioports {
	u32 dir, par, sor, odr, dat;
	u32 res[3];
};

void __init cpm2_set_pin(int port, int pin, int flags)
{
	struct cpm2_ioports __iomem *iop =
		(struct cpm2_ioports __iomem *)&cpm2_immr->im_ioport;

	pin = 1 << (31 - pin);

	if (flags & CPM_PIN_OUTPUT)
		setbits32(&iop[port].dir, pin);
	else
		clrbits32(&iop[port].dir, pin);

	if (!(flags & CPM_PIN_GPIO))
		setbits32(&iop[port].par, pin);
	else
		clrbits32(&iop[port].par, pin);

	if (flags & CPM_PIN_SECONDARY)
		setbits32(&iop[port].sor, pin);
	else
		clrbits32(&iop[port].sor, pin);

	if (flags & CPM_PIN_OPENDRAIN)
		setbits32(&iop[port].odr, pin);
	else
		clrbits32(&iop[port].odr, pin);
}

Annotation

• Immediate include surface: `linux/errno.h`, `linux/sched.h`, `linux/kernel.h`, `linux/param.h`, `linux/string.h`, `linux/mm.h`, `linux/interrupt.h`, `linux/module.h`.
• Detected declarations: `struct cpm2_ioports`, `function cpm2_reset`, `function cpm_command`, `function __cpm2_setbrg`, `function cpm2_clk_setup`, `function cpm2_smc_clk_setup`, `function cpm2_set_pin`, `export cpm2_immr`, `export cpm_command`, `export __cpm2_setbrg`.
• Atlas domain: Architecture Layer / arch/powerpc.
• Implementation status: integration implementation candidate.
• 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.