| Message ID | 20240925214544.6114-6-ansuelsmth@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,v2,1/5] block: add support for defining read-only partitions | expand |
On Wed, Sep 25, 2024 at 11:45:25PM +0200, Christian Marangi wrote: > Document support for defining a partition table in the mmc-card node. > > This is needed if the eMMC doesn't have a partition table written and > the bootloader of the device load data by using absolute offset of the > block device. This is common on embedded device that have eMMC installed > to save space and have non removable block devices. > > If an OF partition table is detected, any partition table written in the > eMMC will be ignored and won't be parsed. > > eMMC provide a generic disk for user data and if supported (JEDEC 4.4+) > also provide two additional disk ("boot0" and "boot1") for special usage > of boot operation where normally is stored the bootloader or boot info. > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> > --- > .../devicetree/bindings/mmc/mmc-card.yaml | 57 +++++++++++++++++++ > 1 file changed, 57 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml > index fd347126449a..58b6593a0f60 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml > +++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml > @@ -13,6 +13,10 @@ description: | > This documents describes the devicetree bindings for a mmc-host controller > child node describing a mmc-card / an eMMC. > > + It's possible to define a fixed partition table for an eMMC for the user > + partition and one of the 2 boot partition (boot0/boot1) if supported by the > + eMMC. > + > properties: > compatible: > const: mmc-card > @@ -26,6 +30,30 @@ properties: > Use this to indicate that the mmc-card has a broken hpi > implementation, and that hpi should not be used. > > + "#address-cells": > + const: 0 > + > + "#size-cells": > + const: 0 Don't need these properties. > + > +patternProperties: > + "^partitions(-boot[01])?$": > + $ref: /schemas/block/partitions/partitions.yaml > + > + patternProperties: > + "^partition@[0-9a-f]+$": > + $ref: /schemas/block/partitions/partition.yaml > + > + properties: > + reg: > + multipleOf: 512 I was going to suggest this, but I think it won't actually work because it could be 2 cells for address and/or size. Rob
diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml index fd347126449a..58b6593a0f60 100644 --- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml +++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml @@ -13,6 +13,10 @@ description: | This documents describes the devicetree bindings for a mmc-host controller child node describing a mmc-card / an eMMC. + It's possible to define a fixed partition table for an eMMC for the user + partition and one of the 2 boot partition (boot0/boot1) if supported by the + eMMC. + properties: compatible: const: mmc-card @@ -26,6 +30,30 @@ properties: Use this to indicate that the mmc-card has a broken hpi implementation, and that hpi should not be used. + "#address-cells": + const: 0 + + "#size-cells": + const: 0 + +patternProperties: + "^partitions(-boot[01])?$": + $ref: /schemas/block/partitions/partitions.yaml + + patternProperties: + "^partition@[0-9a-f]+$": + $ref: /schemas/block/partitions/partition.yaml + + properties: + reg: + multipleOf: 512 + + required: + - reg + - label + + unevaluatedProperties: false + required: - compatible - reg @@ -42,6 +70,35 @@ examples: compatible = "mmc-card"; reg = <0>; broken-hpi; + + #address-cells = <0>; + #size-cells = <0>; + + partitions { + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + label = "kernel"; /* Kernel */ + reg = <0x0 0x2000000>; /* 32 MB */ + }; + + partition@2000000 { + label = "rootfs"; + reg = <0x2000000 0x40000000>; /* 1GB */ + }; + }; + + partitions-boot0 { + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + label = "bl"; + reg = <0x0 0x2000000>; /* 32MB */ + read-only; + }; + }; }; };
Document support for defining a partition table in the mmc-card node. This is needed if the eMMC doesn't have a partition table written and the bootloader of the device load data by using absolute offset of the block device. This is common on embedded device that have eMMC installed to save space and have non removable block devices. If an OF partition table is detected, any partition table written in the eMMC will be ignored and won't be parsed. eMMC provide a generic disk for user data and if supported (JEDEC 4.4+) also provide two additional disk ("boot0" and "boot1") for special usage of boot operation where normally is stored the bootloader or boot info. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> --- .../devicetree/bindings/mmc/mmc-card.yaml | 57 +++++++++++++++++++ 1 file changed, 57 insertions(+)