| Message ID | 20210510171800.27225-1-miquel.raynal@bootlin.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [v4] dt-binding: mtd: nand: Document the cs-gpios property | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | success | |
| robh/dt-meta-schema | success | |
| robh/dtbs-check | fail | build log |
On Mon, 10 May 2021 19:18:00 +0200, Miquel Raynal wrote: > To reach higher capacities, arrays of chips are now pretty common. > Unfortunately, most of the controllers have been designed a decade ago > and did not all anticipate the need for several chip-selects. The new > cs-gpios property allows to workaround this limitation by adding as many > GPIO chip-select as needed. > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > --- > > Resending only the binding patch of the series, with the following > changes requested by Rob: > * Fixed the coherency between cs-gpios and gpios-cs > * Added maxItems: 8 (this is a good enough value for most of the cases I > guess, this can be increased later if needed). > * Adding maxItems: 8 lead to an error when checking the example, > minItems: 8 had to be added as well to the schema to fix it, not sure > this was expected or not. > > .../bindings/mtd/nand-controller.yaml | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > Reviewed-by: Rob Herring <robh@kernel.org>
On Mon, 2021-05-10 at 17:18:00 UTC, Miquel Raynal wrote: > To reach higher capacities, arrays of chips are now pretty common. > Unfortunately, most of the controllers have been designed a decade ago > and did not all anticipate the need for several chip-selects. The new > cs-gpios property allows to workaround this limitation by adding as many > GPIO chip-select as needed. > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > Reviewed-by: Rob Herring <robh@kernel.org> Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next. Miquel
diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml index 678b39952502..bd217e6f5018 100644 --- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml +++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml @@ -38,6 +38,17 @@ properties: ranges: true + cs-gpios: + minItems: 1 + maxItems: 8 + description: + Array of chip-select available to the controller. The first + entries are a 1:1 mapping of the available chip-select on the + NAND controller (even if they are not used). As many additional + chip-select as needed may follow and should be phandles of GPIO + lines. 'reg' entries of the NAND chip subnodes become indexes of + this array when this property is present. + patternProperties: "^nand@[a-f0-9]$": type: object @@ -164,14 +175,19 @@ examples: nand-controller { #address-cells = <1>; #size-cells = <0>; + cs-gpios = <0>, <&gpioA 1>; /* A single native CS is available */ /* controller specific properties */ nand@0 { - reg = <0>; + reg = <0>; /* Native CS */ nand-use-soft-ecc-engine; nand-ecc-algo = "bch"; /* controller specific properties */ }; + + nand@1 { + reg = <1>; /* GPIO CS */ + }; };
To reach higher capacities, arrays of chips are now pretty common. Unfortunately, most of the controllers have been designed a decade ago and did not all anticipate the need for several chip-selects. The new cs-gpios property allows to workaround this limitation by adding as many GPIO chip-select as needed. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- Resending only the binding patch of the series, with the following changes requested by Rob: * Fixed the coherency between cs-gpios and gpios-cs * Added maxItems: 8 (this is a good enough value for most of the cases I guess, this can be increased later if needed). * Adding maxItems: 8 lead to an error when checking the example, minItems: 8 had to be added as well to the schema to fix it, not sure this was expected or not. .../bindings/mtd/nand-controller.yaml | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)