| Message ID | 20181004130110.8496-9-ricardo.ribalda@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v6,01/10] mtd: physmap_of: Release resources on error | expand |
On Thu, 4 Oct 2018 15:01:09 +0200 Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote: > Add documentation for gpio-addr-flash. This binding allow creating > flash devices that are paged using GPIOs. > > Cc: devicetree@vger.kernel.org > Reviewed-by: Rob Herring <robh@kernel.org> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> > --- > .../bindings/mtd/mtd,gpio-addr-flash.txt | 25 +++++++++++++++++++ > 1 file changed, 25 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > > diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > new file mode 100644 > index 000000000000..304a33880f9e > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > @@ -0,0 +1,25 @@ > +Memory Mapped flash with some address lines addressed using GPIOs > + > +Handle the case where a flash device is mostly addressed using physical > +line and supplemented by GPIOs. This way you can hook up say a 8MiB flash > +to a 2MiB memory range and use the GPIOs to select a particular range. > + > + - compatible : must be "mtd,gpio-addr-flash", "cfi-flash"; I keep thinking you don't need a specific binding, just add an optional addr-gpios property to the generic physmap binding and that should do the trick. Plus, "*mtd*,gpio-addr-flash" is a linux-ism, and DT bindings should be OS-agnostic. > + - reg : Address range of the mtd chip that is memory mapped, this is, > + on the previous example 2MiB. > + - addr-gpios: List of GPIO specifiers that will be used to address the MSBs > + address lines. The order goes from LSB to MSB. > + > +For the rest of the properties, see mtd-physmap.txt. > + > +The device tree may optionally contain sub-nodes describing partitions of the > +address space. Check partition.txt for more details. > + > +Example: > + > + flash@300000 { > + compatible = "mtd,gpio-addr-flash", "cfi-flash"; > + bank-width = <2>; > + reg = < 0x00300000 0x00200000 >; > + addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>; > + } ;
Hi Boris On Thu, Oct 4, 2018 at 4:02 PM Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > On Thu, 4 Oct 2018 15:01:09 +0200 > Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote: > > > Add documentation for gpio-addr-flash. This binding allow creating > > flash devices that are paged using GPIOs. > > > > Cc: devicetree@vger.kernel.org > > Reviewed-by: Rob Herring <robh@kernel.org> > > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> > > --- > > .../bindings/mtd/mtd,gpio-addr-flash.txt | 25 +++++++++++++++++++ > > 1 file changed, 25 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > > > > diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > > new file mode 100644 > > index 000000000000..304a33880f9e > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt > > @@ -0,0 +1,25 @@ > > +Memory Mapped flash with some address lines addressed using GPIOs > > + > > +Handle the case where a flash device is mostly addressed using physical > > +line and supplemented by GPIOs. This way you can hook up say a 8MiB flash > > +to a 2MiB memory range and use the GPIOs to select a particular range. > > + > > + - compatible : must be "mtd,gpio-addr-flash", "cfi-flash"; > > I keep thinking you don't need a specific binding, just add an optional > addr-gpios property to the generic physmap binding and that should do > the trick. Plus, "*mtd*,gpio-addr-flash" is a linux-ism, and DT > bindings should be OS-agnostic. > That is a very good point. Please take a look to v10, and tell me what do you think. It does not require a specific binding and also it can be build optionally. Regards! > > + - reg : Address range of the mtd chip that is memory mapped, this is, > > + on the previous example 2MiB. > > + - addr-gpios: List of GPIO specifiers that will be used to address the MSBs > > + address lines. The order goes from LSB to MSB. > > + > > +For the rest of the properties, see mtd-physmap.txt. > > + > > +The device tree may optionally contain sub-nodes describing partitions of the > > +address space. Check partition.txt for more details. > > + > > +Example: > > + > > + flash@300000 { > > + compatible = "mtd,gpio-addr-flash", "cfi-flash"; > > + bank-width = <2>; > > + reg = < 0x00300000 0x00200000 >; > > + addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>; > > + } ; >
diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt new file mode 100644 index 000000000000..304a33880f9e --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt @@ -0,0 +1,25 @@ +Memory Mapped flash with some address lines addressed using GPIOs + +Handle the case where a flash device is mostly addressed using physical +line and supplemented by GPIOs. This way you can hook up say a 8MiB flash +to a 2MiB memory range and use the GPIOs to select a particular range. + + - compatible : must be "mtd,gpio-addr-flash", "cfi-flash"; + - reg : Address range of the mtd chip that is memory mapped, this is, + on the previous example 2MiB. + - addr-gpios: List of GPIO specifiers that will be used to address the MSBs + address lines. The order goes from LSB to MSB. + +For the rest of the properties, see mtd-physmap.txt. + +The device tree may optionally contain sub-nodes describing partitions of the +address space. Check partition.txt for more details. + +Example: + + flash@300000 { + compatible = "mtd,gpio-addr-flash", "cfi-flash"; + bank-width = <2>; + reg = < 0x00300000 0x00200000 >; + addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>; + } ;