Documentation/ABI/stable/sysfs-bus-nvmem

Source file repositories/reference/linux-study-clean/Documentation/ABI/stable/sysfs-bus-nvmem

File Facts

System: Linux kernel
Corpus path: Documentation/ABI/stable/sysfs-bus-nvmem
Extension: [no extension]
Size: 1632 bytes
Lines: 51
Domain: Support Tooling And Documentation
Bucket: Documentation
Inferred role: Support Tooling And Documentation: Documentation
Status: atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

No C-style include directives detected by the generator.

Detected Declarations

No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

What:		/sys/bus/nvmem/devices/.../force_ro
Date:		June 2024
KernelVersion:	6.11
Contact:	Marek Vasut <marex@denx.de>
Description:
		This read/write attribute allows users to set read-write
		devices as read-only and back to read-write from userspace.
		This can be used to unlock and relock write-protection of
		devices which are generally locked, except during sporadic
		programming operation.
		Read returns '0' or '1' for read-write or read-only modes
		respectively.
		Write parses one of 'YyTt1NnFf0', or [oO][NnFf] for "on"
		and "off", i.e. what kstrtobool() supports.
		Note: This file is only present if CONFIG_NVMEM_SYSFS
		is enabled.

What:		/sys/bus/nvmem/devices/.../nvmem
Date:		July 2015
KernelVersion:	4.2
Contact:	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Description:
		This file allows user to read/write the raw NVMEM contents.
		Permissions for write to this file depends on the nvmem
		provider configuration.
		Note: This file is only present if CONFIG_NVMEM_SYSFS
		is enabled

		ex::

		  hexdump /sys/bus/nvmem/devices/qfprom0/nvmem

		  0000000 0000 0000 0000 0000 0000 0000 0000 0000
		  *
		  00000a0 db10 2240 0000 e000 0c00 0c00 0000 0c00
		  0000000 0000 0000 0000 0000 0000 0000 0000 0000
		  ...
		  *
		  0001000

What:		/sys/bus/nvmem/devices/.../type
Date:		November 2018
KernelVersion:	5.0
Contact:	Alexandre Belloni <alexandre.belloni@bootlin.com>
Description:
		This read-only attribute allows user to read the NVMEM
		device type. Supported types are "Unknown", "EEPROM",
		"OTP", "Battery backed", "FRAM".
		Note: This file is only present if CONFIG_NVMEM_SYSFS
		is enabled.

Annotation

Atlas domain: Support Tooling And Documentation / Documentation.
Implementation status: atlas-only.

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.