lkml.org 
[lkml]   [2013]   [Jun]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 2/2] Make non-linear GPIO ranges accesible from gpiolib
From
On Tue, Jun 25, 2013 at 5:31 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 06/25/2013 08:56 AM, Linus Walleij wrote:
>> On Fri, Jun 21, 2013 at 11:17 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:
>>> On 06/20/2013 05:57 AM, Christian Ruppert wrote:
>>
>>>> Your remark seems to reflect one of the following two hardware
>>>> architectures:
>>>>
>>>> +- SPI
>>>> Physical pins --- GPIO --- pinctrl -+- I2C
>>>> +- mmc
>>>
>>> (that's diagram 1)
>>>
>>>>
>>>> +- GPIO
>>>> Physical pins -+ +- SPI
>>>> +- pinctrl -+- I2C
>>>> +- mmc
>>>
>>> (that's diagram 2)
>>>
>>>> TB10x hardware architecture:
>>>>
>>>> +- SPI
>>>> Physical pins --- pinctrl -+- I2C
>>>> +- mmc
>>>> +- GPIO
>>>
>>> (that's diagram 3)
>>>
>>> No, I was thinking of diagram 3 above. I'm not sure if diagrams (1) or
>>> (2) are common or exist?
>>
>> The U300 pin controller is obviously of type (1) as it can spy on
>> the signals.
>
> U300 HW might be diagram (1) - I can't say since I'm not familiar with
> the HW. However, the fact that GPIO can spy on signals in no way at all
> implies that the HW must conform to diagram (1).

That's true. And I don't know what it actually is in this case.
That hardware is actually weird in many ways, thanks to
helpful HW engineers modeling use cases into the HW.

>> The Nomadik pin controller is basically type (2).

This I know however to be true, as I have access to the
low-level schematics of the ASIC.

Yours,
Linus Walleij


\
 
 \ /
  Last update: 2013-06-25 18:01    [W:0.122 / U:2.772 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site