drivers/rtc/rtc-cmos.c

File Facts

System

Linux kernel

Corpus path

drivers/rtc/rtc-cmos.c

Extension

.c

Size

37511 bytes

Lines

1512

Domain

Driver Families

Bucket

drivers/rtc

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.
• Touches IRQ or DMA behavior; this matters for the representative real-device path.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/acpi.h
• linux/kernel.h
• linux/module.h
• linux/init.h
• linux/interrupt.h
• linux/spinlock.h
• linux/platform_device.h
• linux/log2.h
• linux/pm.h
• linux/of.h
• linux/of_platform.h
• asm/i8259.h
• asm/processor.h
• linux/dmi.h
• linux/mc146818rtc.h
• asm/hpet.h

Detected Declarations

• struct cmos_rtc
• struct cmos_read_alarm_callback_param
• struct cmos_set_alarm_callback_param
• function cmos_use_acpi_alarm
• function cmos_use_acpi_alarm
• function is_intr
• function other
• function hpet_mask_rtc_irq_bit
• function hpet_set_rtc_irq_bit
• function hpet_set_alarm_time
• function hpet_set_periodic_freq
• function hpet_rtc_timer_init
• function hpet_register_irq_handler
• function hpet_unregister_irq_handler
• function use_hpet_alarm
• function cmos_read_bank2
• function cmos_write_bank2
• function cmos_read_bank2
• function cmos_write_bank2
• function cmos_read_time
• function cmos_set_time
• function cmos_read_alarm_callback
• function cmos_read_alarm
• function cmos_checkintr
• function cmos_irq_enable
• function cmos_irq_disable
• function cmos_validate_alarm
• function cmos_set_alarm_callback
• function cmos_set_alarm
• function cmos_alarm_irq_enable
• function cmos_procfs
• function cmos_nvram_read
• function cmos_nvram_write
• function cmos_interrupt
• function rtc_handler
• function acpi_rtc_event_setup
• function acpi_rtc_event_cleanup
• function rtc_wake_on
• function rtc_wake_off
• function use_acpi_alarm_quirks
• function use_acpi_alarm_quirks
• function cmos_check_acpi_rtc_status
• function acpi_rtc_event_setup
• function cmos_do_shutdown
• function cmos_do_remove
• function cmos_aie_poweroff
• function cmos_suspend
• function cmos_poweroff

Annotated Snippet

module_init(cmos_init);

static void __exit cmos_exit(void)
{
	if (platform_driver_registered)
		platform_driver_unregister(&cmos_platform_driver);
}
module_exit(cmos_exit);


MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `linux/acpi.h`, `linux/kernel.h`, `linux/module.h`, `linux/init.h`, `linux/interrupt.h`, `linux/spinlock.h`, `linux/platform_device.h`, `linux/log2.h`.
• Detected declarations: `struct cmos_rtc`, `struct cmos_read_alarm_callback_param`, `struct cmos_set_alarm_callback_param`, `function cmos_use_acpi_alarm`, `function cmos_use_acpi_alarm`, `function is_intr`, `function other`, `function hpet_mask_rtc_irq_bit`, `function hpet_set_rtc_irq_bit`, `function hpet_set_alarm_time`.
• Atlas domain: Driver Families / drivers/rtc.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
• IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.

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.