drivers/watchdog/shwdt.c

File Facts

System

Linux kernel

Corpus path

drivers/watchdog/shwdt.c

Extension

.c

Size

9026 bytes

Lines

343

Domain

Driver Families

Bucket

drivers/watchdog

Inferred role

Driver Families: exported/initcall integration point

Status

integration 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.
• 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.
• 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/module.h
• linux/moduleparam.h
• linux/platform_device.h
• linux/init.h
• linux/types.h
• linux/spinlock.h
• linux/watchdog.h
• linux/pm_runtime.h
• linux/fs.h
• linux/mm.h
• linux/slab.h
• linux/io.h
• linux/clk.h
• linux/err.h
• asm/watchdog.h

Detected Declarations

• struct sh_wdt
• function sh_wdt_start
• function sh_wdt_stop
• function sh_wdt_keepalive
• function sh_wdt_set_heartbeat
• function sh_wdt_ping
• function sh_wdt_probe
• function sh_wdt_remove
• function sh_wdt_shutdown
• function sh_wdt_init
• function sh_wdt_exit
• module init sh_wdt_init

Annotated Snippet

module_init(sh_wdt_init);
module_exit(sh_wdt_exit);

MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("SuperH watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);

module_param(clock_division_ratio, int, 0);
MODULE_PARM_DESC(clock_division_ratio,
	"Clock division ratio. Valid ranges are from 0x5 (1.31ms) "
	"to 0x7 (5.25ms). (default=" __MODULE_STRING(WTCSR_CKS_4096) ")");

module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat,
	"Watchdog heartbeat in seconds. (1 <= heartbeat <= 3600, default="
				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

Annotation

• Immediate include surface: `linux/module.h`, `linux/moduleparam.h`, `linux/platform_device.h`, `linux/init.h`, `linux/types.h`, `linux/spinlock.h`, `linux/watchdog.h`, `linux/pm_runtime.h`.
• Detected declarations: `struct sh_wdt`, `function sh_wdt_start`, `function sh_wdt_stop`, `function sh_wdt_keepalive`, `function sh_wdt_set_heartbeat`, `function sh_wdt_ping`, `function sh_wdt_probe`, `function sh_wdt_remove`, `function sh_wdt_shutdown`, `function sh_wdt_init`.
• Atlas domain: Driver Families / drivers/watchdog.
• 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.