[U-Boot] [PATCH 12/20] arm/km: add support for external switchconfiguration

[Valentin Longchamp]

Hello Prafulla,

On 07/03/2012 10:17 AM, Prafulla Wadaskar wrote:
>> -----Original Message-----
>> From: Valentin Longchamp [mailto:valentin.longchamp at keymile.com]
>> Sent: 21 June 2012 18:40
>> To: Prafulla Wadaskar
>> Cc: prafulla at mavell.com; holger.brunck at keymile.com; u-
>> boot at lists.denx.de
>> Subject: Re: [U-Boot] [PATCH 12/20] arm/km: add support for external
>> switchconfiguration
>>
>> Hi Prafulla,
>>
>> On 06/12/2012 06:39 AM, Prafulla Wadaskar wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: u-boot-bounces at lists.denx.de [mailto:u-boot-
>>>> bounces at lists.denx.de] On Behalf Of Valentin Longchamp
>>>> Sent: 07 June 2012 15:37
>>>> To: prafulla at mavell.com
>>>> Cc: Valentin Longchamp; holger.brunck at keymile.com; u-
>>>> boot at lists.denx.de
>>>> Subject: [U-Boot] [PATCH 12/20] arm/km: add support for external
>>>> switch configuration
>>>>
>>>> This can be used if we do not want to use an EEPROM for the
>>>> configuration.
>>>>
>>>> Signed-off-by: Valentin Longchamp <valentin.longchamp at keymile.com>
>>>> ---
>>>>  board/keymile/common/common.h         |    7 --
>>>>  board/keymile/km_arm/managed_switch.c |  169
>>>> +++++++++++++++++++++++++++++++--
>>>>  board/keymile/km_arm/managed_switch.h |   99 +++++++++++++++++++
>>>
>>> What is managed switch? Which chip it supports? Why it is sitting
>> here and not in generic folder?
>>>
>>
>> In this case, the switch is a Marvell 88E52xxx (don't remember the
>> exact model)
>> that is connected to the GE port of the Kirkwood and that gets
>> configured by the
>> Kirkwood through a MDIO link, using indirect addressing.
>>
>> We do not have the pretention to write a generic driver for such
>> switches/addressing, but we need this functionnality on some boards,
>> that's why
>> we have kept it in our own folder and not in a generic driver folder.
>>
>> I will add the above precisions to the commit message for an optional
>> v3 of the
>> "updates for the Keymile Marvell boards" series so that this is more
>> clear.
> 
> Dear Valentin
> We must keep develop it as generic driver.
> 
> Regards...
> Prafulla . . .
> 

Sure it would be great if we had the time and resources to contribute a generic
driver for these switches. Unfortunately it is not the case and we have only
developed a simple driver with limited features that suits our current needs.

Since we know it's very limited, we have intentionally chosen to put in in our
board/keymile directory so that it's obvious that it is (currently) not intended
to be used nor was it tested on other boards or with other switches.

The question now is: does u-boot allow some boards (or family of boards) to
integrate some board codes or drivers ? It was until now our understanding that
u-boot allows this. This code definitely fits into this category.

As for the generic driver, if someone contributes one (the current driver can be
used as a basis), we will be very happy to drop this code and use the generic
driver.

Valentin