xref: /linux/Documentation/ABI/stable/sysfs-bus-nvmem (revision 55d0969c451159cff86949b38c39171cab962069)
1What:		/sys/bus/nvmem/devices/.../force_ro
2Date:		June 2024
3KernelVersion:	6.11
4Contact:	Marek Vasut <marex@denx.de>
5Description:
6		This read/write attribute allows users to set read-write
7		devices as read-only and back to read-write from userspace.
8		This can be used to unlock and relock write-protection of
9		devices which are generally locked, except during sporadic
10		programming operation.
11		Read returns '0' or '1' for read-write or read-only modes
12		respectively.
13		Write parses one of 'YyTt1NnFf0', or [oO][NnFf] for "on"
14		and "off", i.e. what kstrtobool() supports.
15		Note: This file is only present if CONFIG_NVMEM_SYSFS
16		is enabled.
17
18What:		/sys/bus/nvmem/devices/.../nvmem
19Date:		July 2015
20KernelVersion:	4.2
21Contact:	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
22Description:
23		This file allows user to read/write the raw NVMEM contents.
24		Permissions for write to this file depends on the nvmem
25		provider configuration.
26		Note: This file is only present if CONFIG_NVMEM_SYSFS
27		is enabled
28
29		ex::
30
31		  hexdump /sys/bus/nvmem/devices/qfprom0/nvmem
32
33		  0000000 0000 0000 0000 0000 0000 0000 0000 0000
34		  *
35		  00000a0 db10 2240 0000 e000 0c00 0c00 0000 0c00
36		  0000000 0000 0000 0000 0000 0000 0000 0000 0000
37		  ...
38		  *
39		  0001000
40
41What:		/sys/bus/nvmem/devices/.../type
42Date:		November 2018
43KernelVersion:	5.0
44Contact:	Alexandre Belloni <alexandre.belloni@bootlin.com>
45Description:
46		This read-only attribute allows user to read the NVMEM
47		device type. Supported types are "Unknown", "EEPROM",
48		"OTP", "Battery backed", "FRAM".
49		Note: This file is only present if CONFIG_NVMEM_SYSFS
50		is enabled.
51