[FOR 3.4 PATCH 5/6] atmel/nand: add DT support
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Mon Jan 30 16:56:31 EST 2012
On 10:31 Sun 29 Jan , Simon Glass wrote:
> Hi,
>
> On Fri, Jan 27, 2012 at 9:10 PM, Jean-Christophe PLAGNIOL-VILLARD
> <plagnioj at jcrosoft.com> wrote:
> > use a local copy of board informatin and fill with DT data
> >
> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
> > Cc: devicetree-discuss at lists.ozlabs.org
> > Cc: linux-mtd at lists.infradead.org
> > ---
> > .../devicetree/bindings/mtd/atmel-nand.txt | 41 ++++++++
> > drivers/mtd/nand/atmel_nand.c | 107 ++++++++++++++++----
> > 2 files changed, 130 insertions(+), 18 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/mtd/atmel-nand.txt
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> > new file mode 100644
> > index 0000000..a910ab9
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> > @@ -0,0 +1,41 @@
> > +Atmel NAND flash
> > +
> > +Required properties:
> > +- compatible : "atmel,at91rm9200-nand".
> > +- reg : should specify localbus address and size used for the chip,
> > + and if availlable the ECC.
> > +- atmel,nand-addr-offset : offset for the address latch.
> > +- atmel,nand-cmd-offset : offset for the command latch.
> > +- #address-cells, #size-cells : Must be present if the device has sub-nodes
> > + representing partitions.
> > +
> > +- gpios : specifies the gpio pins to control the NAND device. detect is an
> > + optional gpio and may be set to 0 if not present.
>
> What does this mean please? What is 'detect' and what 'control' do the
> gpios provide?
>
> Below you have two GPIOs pioC 13 and pioC 14. I think the binding
> should document the two GPIOs, the order, and what they are for.
no as it's said in the binding the detect pin is optional
>
> > +
> > +Optional properties:
> > +- nand-ecc-mode : String, operation mode of the NAND ecc mode, soft by default.
> > + Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
> > + "soft_bch".
> > +- nand-bus-width : 8 or 16 bus width if not present 8
> > +- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
> > +
> > +Examples:
> > +nand0: nand at 40000000,0 {
> > + compatible = "atmel,at91rm9200-nand";
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + reg = <0x40000000 0x10000000
> > + 0xffffe800 0x200
> > + >;
> > + atmel,nand-addr-offset = <21>;
> > + atmel,nand-cmd-offset = <22>;
> > + nand-on-flash-bbt = <1>;
> > + nand-ecc-mode = "soft";
> > + gpios = <&pioC 13 0
> > + &pioC 14 0
> > + 0
>
> Sorry, I haven't seen this before, perhaps it is a standard thing in
> Linux. Does 0 mean end of list? Can we not just use the property's
> size value for this?
0 means not used as specified in the DT
Best Regards,
J.
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