[PATCH] arm: ep93xx: Enable i2c support for ep9302

[Ryan Mallon]

On 22/06/12 05:33, Martin Guy wrote:

> On 11 June 2012 23:50, Ryan Mallon <rmallon at gmail.com> wrote:
>> On 12/06/12 01:45, H Hartley Sweeten wrote:
>>
>>> On Sunday, June 10, 2012 4:58 PM, Ryan Mallon wrote:
>>>> On 10/06/12 22:44, Todor Colov wrote:
>>>>>
>>>>> Enable i2c support for ep9302. i2c support is needed when external RTC is
>>>>> used.
>>>>>
>>>>> Signed-off-by: Todor Colov <todorcolov at gmail.com>
>>>>
>>>> Thanks. Applied to ep93xx-fixes.
>>>
>>> Ryan,
>>>
>>> I'm not sure about this patch...
>>>
>>> The EDB9302 does not have a built-on external RTC connected to the I2C
>>> bus. The EECLK and EEDAT pins are simply routed to two headers. They are
>>> not connected to any I2C devices built onto the board.
>>>
>>> This patch will cause _all_ edb9302 boards to bind the ds1337 driver to the
>>> I2C bus but that device will only exist if a user has connected the part
>>> externally to the board.
>>>
>>> Just my 2 cents...
>>
>>
>> Hmm, the binding is not really a problem, since it will just fail if the
>> ds1337 device is not present at that i2c address. I guess the main problem
>> is if there are users of the edb9302 who want i2c on the headers and others
>> who want to use the pins as gpio. Without being able to auto-detect such
>> boards at runtime (which seems very unlikely) I can't think of a good
>> solution to this, other than it being time for me to do more DT reading :-).
>>
>> I'm inclined to leave the patch in. The ep93xx doesn't have a lot of users,
>> so I think it is okay to tailor it a bit to the users we do have. I'm happy
>> to revert it, and find a better solution if this breaks someone else's
>> setup.
> 
> Hi folks
>  Can I add that the SimpleMachines.it Sim.One board, based on the
> EP9307, has a DS1337 on the I2C bus, for which the define is
> machine_is_sim_one()  However, the existing Linux kernel already
> read/writes this chip successfully, so I'm not sure what advantage
> this change would bring for that board.


Hi Martin,

Sorry for the late reply, I've been on holiday. The change only affects
the Cirrus EDB-9302 board. The Sim.one is managed by a separate board file.

> If you would like to test
> your patch on that board too, we may be able to ship you an enginering
> sample; if that would be useful please reply by private email.

I already have one of the Sim.one boards. Thanks.

~Ryan