| Message ID | 20240705225821.13196-1-zajec5@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | dt-bindings: nvmem: convert U-Boot env to a layout | expand |
Hi Rafał, zajec5@gmail.com wrote on Sat, 6 Jul 2024 00:58:21 +0200: > From: Rafał Miłecki <rafal@milecki.pl> > > 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> > --- > I'm sending this PATCH without Linux changes to see if this is the > right approach - for developers and (DT) maintainers to review it first. > > My previous attempt (see above Link) turned out in refusal so I'm just > trying to save some time in case this one goes wrong as well. > > Hopefully the included example (which I really think we should add) > explains well how I think this binding should be used with layouts. > > If I get some positive feedback I'll work on V2 with actual Linux > changes. > I am still in favor of this change. I know from a binding perspective it might be questionable; but from an OS perspective it makes total sense to deprecated the old U-Boot env "device" driver in favor of this. Thanks, Miquèl
On 8.07.2024 08:32, Miquel Raynal wrote: > zajec5@gmail.com wrote on Sat, 6 Jul 2024 00:58:21 +0200: > >> From: Rafał Miłecki <rafal@milecki.pl> >> >> 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> >> --- >> I'm sending this PATCH without Linux changes to see if this is the >> right approach - for developers and (DT) maintainers to review it first. >> >> My previous attempt (see above Link) turned out in refusal so I'm just >> trying to save some time in case this one goes wrong as well. >> >> Hopefully the included example (which I really think we should add) >> explains well how I think this binding should be used with layouts. >> >> If I get some positive feedback I'll work on V2 with actual Linux >> changes. >> > > I am still in favor of this change. I know from a binding perspective > it might be questionable; but from an OS perspective it makes total > sense to deprecated the old U-Boot env "device" driver in favor of this. Please note that at this point I didn't decide to deprecate the old binding (using "u-boot,env" for flash device partition). That would require mixing "nvmem-layout" with "partitions" which I believe Rob objected to. My PATCH in its current form just allows reusing this binding with "nvmem-layout"s which is needed for cases where we agreed to allow "nvmem-layout" (UBI volumes and pure - non-MTD - NVMEM devices). If we want to refactor this binding in MTD partitions context I hope we can handle that at different time if we agree on some solution. I hope and I don't think this should be a blocked for this PATCH.
On Sat, 06 Jul 2024 00:58:21 +0200, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > 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> > --- > I'm sending this PATCH without Linux changes to see if this is the > right approach - for developers and (DT) maintainers to review it first. > > My previous attempt (see above Link) turned out in refusal so I'm just > trying to save some time in case this one goes wrong as well. > > Hopefully the included example (which I really think we should add) > explains well how I think this binding should be used with layouts. > > If I get some positive feedback I'll work on V2 with actual Linux > changes. > > .../bindings/nvmem/layouts/nvmem-layout.yaml | 1 + > .../nvmem/{ => layouts}/u-boot,env.yaml | 39 ++++++++++++++++--- > 2 files changed, 35 insertions(+), 5 deletions(-) > rename Documentation/devicetree/bindings/nvmem/{ => layouts}/u-boot,env.yaml (75%) > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml index 3b40f7880774..382507060651 100644 --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml @@ -21,6 +21,7 @@ oneOf: - $ref: fixed-layout.yaml - $ref: kontron,sl28-vpd.yaml - $ref: onie,tlv-layout.yaml + - $ref: u-boot,env.yaml properties: compatible: true diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml similarity index 75% rename from Documentation/devicetree/bindings/nvmem/u-boot,env.yaml rename to Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml index 9c36afc7084b..56a8f55d4a09 100644 --- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml +++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml @@ -1,10 +1,10 @@ # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause %YAML 1.2 --- -$id: http://devicetree.org/schemas/nvmem/u-boot,env.yaml# +$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# -title: U-Boot environment variables +title: U-Boot environment variables layout description: | U-Boot uses environment variables to store device parameters and @@ -21,9 +21,6 @@ description: | This binding allows marking storage device (as containing env data) and specifying used format. - Right now only flash partition case is covered but it may be extended to e.g. - UBI volumes in the future. - Variables can be defined as NVMEM device subnodes. maintainers: @@ -42,6 +39,7 @@ properties: const: brcm,env reg: + description: Partition offset and size for env on top of MTD maxItems: 1 bootcmd: @@ -58,6 +56,17 @@ properties: description: The first argument is a MAC address offset. const: 1 +allOf: + - if: + properties: + $nodename: + not: + contains: + pattern: "^partition@[0-9a-f]+$" + then: + properties: + reg: false + additionalProperties: false examples: @@ -101,3 +110,23 @@ examples: }; }; }; + - | + partition@0 { + reg = <0x0 0x100000>; + label = "ubi"; + compatible = "linux,ubi"; + + volumes { + ubi-volume-u-boot-env { + volname = "env"; + + nvmem-layout { + compatible = "u-boot,env"; + + ethaddr { + #nvmem-cell-cells = <1>; + }; + }; + }; + }; + };