drivers/media/pci/tw5864/tw5864-util.c

File Facts

System

Linux kernel

Corpus path

drivers/media/pci/tw5864/tw5864-util.c

Extension

.c

Size

930 bytes

Lines

39

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

• tw5864.h

Detected Declarations

• function tw5864_indir_writeb
• function tw5864_indir_readb

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
#include "tw5864.h"

void tw5864_indir_writeb(struct tw5864_dev *dev, u16 addr, u8 data)
{
	int retries = 30000;

	while (tw_readl(TW5864_IND_CTL) & BIT(31) && --retries)
		;
	if (!retries)
		dev_err(&dev->pci->dev,
			"tw_indir_writel() retries exhausted before writing\n");

	tw_writel(TW5864_IND_DATA, data);
	tw_writel(TW5864_IND_CTL, addr << 2 | TW5864_RW | TW5864_ENABLE);
}

u8 tw5864_indir_readb(struct tw5864_dev *dev, u16 addr)
{
	int retries = 30000;

	while (tw_readl(TW5864_IND_CTL) & BIT(31) && --retries)
		;
	if (!retries)
		dev_err(&dev->pci->dev,
			"tw_indir_readl() retries exhausted before reading\n");

	tw_writel(TW5864_IND_CTL, addr << 2 | TW5864_ENABLE);

	retries = 30000;
	while (tw_readl(TW5864_IND_CTL) & BIT(31) && --retries)
		;
	if (!retries)
		dev_err(&dev->pci->dev,
			"tw_indir_readl() retries exhausted at reading\n");

	return tw_readl(TW5864_IND_DATA);
}

Annotation

• Immediate include surface: `tw5864.h`.
• Detected declarations: `function tw5864_indir_writeb`, `function tw5864_indir_readb`.
• 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.