Re: [RFC PATCH v2 09/14] mtd: nand: add sunxi NFC dt bindings doc

[Boris BREZILLON <b.brezillon.dev@gmail.com>]

Hello Rob,

Le 29/01/2014 18:11, Rob Herring a écrit :
> On Wed, Jan 29, 2014 at 8:34 AM, Boris BREZILLON
> <b.brezillon.dev@gmail.com> wrote:
>> Add the sunxi NAND Flash Controller dt bindings documentation.
>>
>> Signed-off-by: Boris BREZILLON <b.brezillon.dev@gmail.com>
>> ---
>>   .../devicetree/bindings/mtd/sunxi-nand.txt         |   46 ++++++++++++++++++++
>>   1 file changed, 46 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/mtd/sunxi-nand.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/sunxi-nand.txt b/Documentation/devicetree/bindings/mtd/sunxi-nand.txt
>> new file mode 100644
>> index 0000000..b0e55a3
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mtd/sunxi-nand.txt
>> @@ -0,0 +1,46 @@
>> +Allwinner NAND Flash Controller (NFC)
>> +
>> +Required properties:
>> +- compatible : "allwinner,sun4i-nand".
>> +- reg : shall contain registers location and length for data and reg.
>> +- interrupts : shall define the nand controller interrupt.
>> +- #address-cells: shall be set to 1. Encode the nand CS.
>> +- #size-cells : shall be set to 0.
>> +- clocks : shall reference nand controller clocks.
>> +- clock-names : nand controller internal clock names. Shall contain :
>> +    * "ahb_clk" : AHB gating clock
>> +    * "sclk" : nand controller clock
>> +
>> +Optional children nodes:
>> +Children nodes represent the available nand chips.
>> +
>> +Optional properties:
> For the controller or per nand chip?
>
>> +- onfi,nand-timing-mode : mandatory if the chip does not support the ONFI
>> +  standard.
> Add to generic nand binding.
>
>> +- allwinner,rb : shall contain the native Ready/Busy ids.
>> + or
>> +- rb-gpios : shall contain the gpios used as R/B pins.
> Isn't allwinner,rb implied by a lack of rb-gpios property. Or no R/B
> pin is an option?
Both are optional. In case none of the properties are defined the dev_ready
callback is set to NULL and the nand_base waiting loop is used.

> If so, don't you need some fixed time delay
> properties like max erase time?

This is handled in nand_base (using the chip_delay field), but I guess 
we could
use the information retrieved from nand timings and the operation in 
progress...

> rb-gpios could be added to the generic nand binding as well.
Sure.
>
> Rob