lkml.org 
[lkml]   [2022]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 1/3] dt-bindings: mtd: partitions: Support label only partition
On Thu, Jun 09, 2022 at 09:57:52PM +0200, Ansuel Smith wrote:
> On Thu, Jun 09, 2022 at 12:32:52PM -0600, Rob Herring wrote:
> > On Mon, Jun 06, 2022 at 05:14:15PM +0200, Ansuel Smith wrote:
> > > Document new partition nodes that declare only the label instead of the
> > > reg used to provide an OF node for partition registred at runtime by
> > > parsers. This is required for nvmem system to declare and detect
> > > nvmem-cells.
> > >
> > > With these special partitions, the reg / offset is not required.
> > > The label binding is used to match the partition allocated by the
> > > parser at runtime and the parser will provide reg and offset of the mtd.
> > >
> > > NVMEM will use the data from the parser and provide the NVMEM cells
> > > declared in the DTS, "connecting" the dynamic partition with a
> > > static declaration of cells in them.
> > >
> > > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > > ---
> > > .../bindings/mtd/partitions/partition.yaml | 16 ++++++++++++++--
> > > 1 file changed, 14 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
> > > index e1ac08064425..bff6fb980e6b 100644
> > > --- a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
> > > +++ b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
> > > @@ -11,6 +11,13 @@ description: |
> > > relative offset and size specified. Depending on partition function extra
> > > properties can be used.
> > >
> > > + A partition may be dynamically allocated by a specific parser at runtime.
> > > + In this specific case, the label is required instead of the reg.
> > > + This is used to assign an OF node to the dynamiccally allocated partition
> > > + so that subsystem like NVMEM can provide an OF node and declare NVMEM cells.
> > > + The OF node will be assigned only if the partition label declared match the
> > > + one assigned by the parser at runtime.
> > > +
> > > maintainers:
> > > - Rafał Miłecki <rafal@milecki.pl>
> > >
> > > @@ -22,6 +29,8 @@ properties:
> > > label:
> > > description: The label / name for this partition. If omitted, the label
> > > is taken from the node name (excluding the unit address).
> > > + With dynamically allocated partition the label is required and won't
> > > + fallback to the node name.
> >
> > Generally, label is never required being something for humans rather
> > than the s/w to consume. I don't see any reason why we can't still use
> > the node name (with 'partition-' stripped off).
> >
>
> How to enforce the use of 'partition-'? Should the driver then check the
> node name and reject any wrong node name (and return error)?

The schema can do it either in the parent (of partition nodes) schema or
with $nodename 'property'.

$nodename:
oneOf:
- pattern: '^.*@.*$'
- pattern: '^partition-.*$'

or:

if:
not:
required:
- reg
then:
properties:
$nodename:
pattern: '^partition-.*$'


The latter is a bit clearer on the intent I think.

> > If the purpose is to define what the partition contains, then
> > 'compatible' is the right thing for that.
> >
>
> Introducing a compatible means creating another scheme I think or we can
> add that special compatible in the partition scheme?

It would be another schema. You could make 'compatible' required here
perhaps, but maybe there's a use for an empty node?

Rob

\
 
 \ /
  Last update: 2022-06-10 19:03    [W:0.106 / U:0.600 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site