[PATCH v1 1/3] ARM: dts: am335x-bone: add support for beaglebone NAND cape

[Robert Nelson]

On Wed, Mar 12, 2014 at 1:57 PM, Nishanth Menon <nm at ti.com> wrote:
> On Wed, Mar 12, 2014 at 1:26 PM, Gupta, Pekon <pekon at ti.com> wrote:
>> Hi,
>>
>>>From: Menon, Nishanth
>>>>On 03/12/2014 05:49 AM, Pekon Gupta wrote:
>>>> Beaglebone Board can be connected to expansion boards to add devices to them.
>>>> These expansion boards are called 'capes'. This patch adds support for
>>>> following versions of Beaglebone(AM335x) NAND capes
>>>> (a) NAND Device with bus-width=16, block-size=128k, page-size=2k, oob-size=64
>>>> (b) NAND Device with bus-width=16, block-size=256k, page-size=4k, oob-size=224
>>>> Further information and datasheets can be found at [1] and [2]
>> [...]
>>>> [1] http://beagleboardtoys.info/index.php?title=BeagleBone_Memory_Expansion
>>>> [2] http://beagleboardtoys.info/index.php?title=BeagleBone_4Gb_16-Bit_NAND_Module
>>>>
>>>> Signed-off-by: Pekon Gupta <pekon at ti.com>
>>>> ---
>>>>  arch/arm/boot/dts/am335x-bone.dts | 123 ++++++++++++++++++++++++++++++++++++++
>>>>  1 file changed, 123 insertions(+)
>>>>
>>>> diff --git a/arch/arm/boot/dts/am335x-bone.dts b/arch/arm/boot/dts/am335x-bone.dts
>>>> index 94ee427..be2c572 100644
>>>> --- a/arch/arm/boot/dts/am335x-bone.dts
>>>> +++ b/arch/arm/boot/dts/am335x-bone.dts
>>>
>>>better to make a nand_cape dts which includes the am335x-bone.dts?
>>>
>> Actually, I'm not in favor of having too many "xx_board_common.dts" files,
>> because it un-necessarily complexes things.
>>
>> We already have "arch/arm/boot/dts/am335x-bone-common.dtsi" which just saves
>> some lines common to DTS of both Beaglebone-LT(white) and Beaglebone-Black.
>> And, there is no guarantee that Beaglebone-LT(white) will remain compatible to
>> Beaglebone-black in future.
>> Example: some capes are not compatible to beaglebone-black [1], [2].
>>
>> So, I prefer to keep separate GPMC NAND nodes separately in both DTS,
>> unless there is a strong convincing reason otherwise.
>>
>>
>> [1] http://elinux.org/CircuitCo:BeagleBoardToys
>> [2] http://elinux.org/BeagleBone_Black_Capes
>
>
>
> Right, and adding NAND, GPMC nodes and asking folks to uncomment
> sections into a generic board file (which by default has none) makes
> more sense? I dont use NAND capes or might create my own cape. overo
> has the same challenges as bone family has.I dont see asking folks to
> uncomment entries to use the cape is a nicer alternative to having
> more dts entries.

This is just going to get more messy with every cape addition. Should
we maybe just leave a basic BeagleBone & BeagleBone Black dts file in
mainline kernel.org.

Then create a repo on github.com/beagleboard/ with every
<bone/black>-<first level cape>.dts option?

Regards,

-- 
Robert Nelson
http://www.rcn-ee.com/