U-Boot environment variables can be stored in various data sources. MTD
is just one of available options. Refactor DT binding into a layout so
it can be used with UBI volumes and other NVMEM devices.
Link: https://lore.kernel.org/all/20231221173421.13737-1-zajec5@gmail.com/
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240902142952.71639-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the introduction of NVMEM layouts, new NVMEM content structures
should be defined as such. We should also try to convert / migrate
existing NVMEM content bindings to layouts.
This commit handles fixed NVMEM cells. So far they had to be defined
directly - as device subnodes. With this change it's allowed to put them
in the DT node named "nvmem-layout".
Having NVMEM cells in separated node is preferred as it draws a nice
line between NVMEM device and its content. It results in cleaner
bindings.
FWIW a very similar situation has happened to MTD devices and their
partitions: see commit 5d96ea42eb ("dt-bindings: mtd: Clarify all
partition subnodes").
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <20230611140330.154222-24-srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
compatible networking device.
Describe all the possible NVMEM cells that can be produced by this
layout parser.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118063932.6418-14-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The nvmem devices description works like this:
* Most cases (EEPROM & co):
eeprom@x {
compatible = "<eeprom-compatible>";
...
};
* MTD case:
flash@y {
compatible = "<flash-compatible>";
...
otp {
compatible = "user-otp"; /* or "factory-otp" */
...
};
};
In the former case, the nvmem device is "eeprom@x", while in the latter
case the nvmem device is "otp".
Nvmem devices can produce nvmem cells. The current way to describe nvmem
cells is to locate them by providing their static byte and bit offset
and length. These information are stored in subnodes of the nvmem
device.
It is now a fact that such description does not fit more advanced use
cases where the location or the size of the cells may vary. There are
currently three known situations which require being described
differently: Kontron's SL28 VPD, ONIE's TLV table and U-Boot's
environment variables.
Hence, we need a way to describe the parsers that must be used in order
to make the dynamic discovery of the nvmem cells. This new description
must fit both use cases (the generic situation and the MTD case).
Let's create in both cases a container node named nvmem-layout whose
content will depend on the parser. Right now nvmem-layout.yaml is
"empty", but references to additional layout parser bindings will be
inserted in the near future. The final goal being something that looks
like:
* Most cases (EEPROM & co):
eeprom@x {
compatible = "<eeprom-compatible>";
...
nvmem-layout {
compatible = "<parser-compatible>";
...
};
};
* MTD case:
flash@y {
compatible = "<flash-compatible>";
...
otp {
compatible = "user-otp"; /* or "factory-otp" */
...
nvmem-layout {
compatible = "<parser-compatible>";
...
};
};
};
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118063932.6418-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
