U-Boot stores its setup as environment variables. It's a list of
key-value pairs stored on flash device with a custom header.
This commit adds an NVMEM driver that:
1. Provides NVMEM access to environment vars binary data
2. Extracts variables as NVMEM cells
Current Linux's NVMEM sysfs API allows reading whole NVMEM data block.
It can be used by user-space tools for reading U-Boot env vars block
without the hassle of finding its location. Parsing will still need to
be re-done there.
Kernel-parsed NVMEM cells can be read however by Linux drivers. This may
be useful for Ethernet drivers for reading device MAC address which is
often stored as U-Boot env variable.
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220916122100.170016-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull SPDX updates from Greg KH:
"Here is the set of SPDX comment updates for 6.0-rc1.
Nothing huge here, just a number of updated SPDX license tags and
cleanups based on the review of a number of common patterns in GPLv2
boilerplate text.
Also included in here are a few other minor updates, two USB files,
and one Documentation file update to get the SPDX lines correct.
All of these have been in the linux-next tree for a very long time"
* tag 'spdx-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (28 commits)
Documentation: samsung-s3c24xx: Add blank line after SPDX directive
x86/crypto: Remove stray comment terminator
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_406.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_398.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_391.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_390.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_385.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_320.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_319.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_318.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_298.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_292.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_179.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 2)
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 1)
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_160.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_152.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_149.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_147.RULE
treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_133.RULE
...
Add support for Microchip OTP controller available on SAMA7G5. The OTPC
controls the access to a non-volatile memory. The memory behind OTPC is
organized into packets, packets are composed by a fixed length header
(4 bytes long) and a variable length payload (payload length is available
in the header). When software request the data at an offset in memory
the OTPC will return (via header + data registers) the whole packet that
has a word at that offset. For the OTP memory layout like below:
offset OTP Memory layout
. .
. ... .
. .
0x0E +-----------+ <--- packet X
| header X |
0x12 +-----------+
| payload X |
0x16 | |
| |
0x1A | |
+-----------+
. .
. ... .
. .
if user requests data at address 0x16 the data started at 0x0E will be
returned by controller. User will be able to fetch the whole packet
starting at 0x0E (or parts of the packet) via proper registers. The same
packet will be returned if software request the data at offset 0x0E or
0x12 or 0x1A.
The OTP will be populated by Microchip with at least 2 packets first one
being boot configuration packet and the 2nd one being temperature
calibration packet. The packet order will be preserved b/w different chip
revisions but the packet sizes may change.
For the above reasons and to keep the same software able to work on all
chip variants the read function of the driver is working with a packet
id instead of an offset in OTP memory.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220706100627.6534-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on the normalized pattern:
this program is free software you can redistribute it and/or modify it
under the terms of the gnu general public license as published by the
free software foundation version 2 this program is distributed as is
without any warranty of any kind whether express or implied without
even the implied warranty of merchantability or fitness for a
particular purpose see the gnu general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference.
Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
