[U-Boot] [PATCH v2 6/7] tegra: Select I2C ordering for Seaboard

[Simon Glass]

Hi Stephen,

On Fri, Feb 3, 2012 at 4:41 PM, Stephen Warren <swarren at nvidia.com> wrote:
> On 02/03/2012 05:36 PM, Simon Glass wrote:
>> Hi Stephen,
>>
>> On Fri, Feb 3, 2012 at 4:25 PM, Stephen Warren <swarren at nvidia.com> wrote:
>>> On 02/03/2012 05:19 PM, Simon Glass wrote:
>>>> Hi Stephen,
>>>>
>>>> On Fri, Feb 3, 2012 at 4:14 PM, Stephen Warren <swarren at nvidia.com> wrote:
>>>>> On 02/03/2012 04:24 PM, Simon Glass wrote:
>>>>>> Hi Stephen,
>>>>>>
>>>>>> On Thu, Jan 19, 2012 at 12:56 PM, Stephen Warren <swarren at nvidia.com> wrote:
>>>>>>> On 01/12/2012 12:00 PM, Simon Glass wrote:
>>>>>>>> Select the port ordering for I2C on Seaboard.
>>>>>>>>
>>>>>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>>>>>> Acked-by: Stephen Warren <swarren at nvidia.com>
>>>>>>>
>>>>>>> This isn't the patch that I ack'd.
>>>>>>
>>>>>> Sorry, I added the disable.
>>>>>>
>>>>>>>
>>>>>>>> diff --git a/board/nvidia/dts/tegra2-seaboard.dts b/board/nvidia/dts/tegra2-seaboard.dts
>>>>>>>
>>>>>>> Unrelated to this patch, but shouldn't that be tegra-seaboard.dts not
>>>>>>> tegra2-seaboard.dts to match the naming in the kernel?
>>>>>>>
>>>>>>>> @@ -44,4 +49,9 @@
>>>>>>>>       usb at c5004000 {
>>>>>>>>               status = "disabled";
>>>>>>>>       };
>>>>>>>> +
>>>>>>>> +     i2c at 7000c400 {
>>>>>>>> +             status = "disabled";
>>>>>>>> +     };
>>>>>>>> +
>>>>>>>>  };
>>>>>>>
>>>>>>> That chunk wasn't in the original patch, and doesn't match the kernel's
>>>>>>> .dts file (and I believe that I2C controller really is in use, so
>>>>>>> shouldn't be disabled).
>>>>>>
>>>>>> It cannot be used - remember the discussion about pinmux? We elected
>>>>>> to disable I2C1 at present since you didn't like my nvidia,pinmux
>>>>>> binding for selecting which value to pass to funcmux. The fix is to
>>>>>> pass 1 instead of 0 for that port, but we have no clean way to specify
>>>>>> this.
>>>>>>
>>>>>> Rather disable it than leave it enabled and not working.
>>>>>
>>>>> Rather than having the .dts file not correctly describe the HW, wouldn't
>>>>> it be better to limit U-Boot's to only initializing the 1 I2C controller
>>>>> that it knows the valid pinmux setting for?
>>>>
>>>> Well, on Seaboard I2C2 (sorry, not I2C1 as I said in my email) is not
>>>> used or connected to anything, so it is a reasonable description of
>>>> the hardware. The other 3 pinmux settings are valid.
>>>
>>> As best I can tell from my schematics, all 4 I2C ports are used on both
>>> Seaboard and Springbank.
>>
>> I don't know about Springbank, but this patch is for Seaboard.
>>
>> There is nothing on the bus and I can't see anything on the schematic.
>> Can you please tell me what it is used for and which pins you are
>> referring to?
>
> GEN2_I2C_SCL/SDA are connected to:
>
> J4 (battery or charger)
> TPM
> J6 (touchscreen connector)
> J26 (mini PCIe)
> J18 (satellite board)
>
> I assume you have access to the schematics?

OK I see - in U-Boot the TPM will be used even if the others aren't.
But the point is that I cannot set the correct pinmux value for that
port, since you don't want 'nvidia,pinmux = <1>' in the device tree
file. So I think I need to disable it for Seaboard.

Regards,
Simon

>
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