[PATCH 2/4] powerpc/qe: new call to revert a gpio to a dedicated function

Anton Vorontsov avorontsov at ru.mvista.com
Thu Sep 25 00:11:04 EST 2008


On Wed, Sep 24, 2008 at 09:00:03AM -0500, Kumar Gala wrote:
>
> On Sep 24, 2008, at 6:42 AM, Anton Vorontsov wrote:
>
>> On Tue, Sep 23, 2008 at 11:07:00PM -0500, Kumar Gala wrote:
>>>
>>> On Sep 23, 2008, at 7:03 PM, Anton Vorontsov wrote:
>>>
>>>> qe_gpio_set_dedicated() is a platform specific function, which is  
>>>> used
>>>> to revert a pin to a dedicated function. Caller should have already
>>>> obtained the gpio via gpio_request().
>>>>
>>>> This is needed to support Freescale USB Host Controller.
>>>>
>>>> Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
>>>> ---
>>>> arch/powerpc/include/asm/qe.h     |    1 +
>>>> arch/powerpc/sysdev/qe_lib/gpio.c |   46 ++++++++++++++++++++++++++ 
>>>> ++
>>>> +++++++++
>>>> 2 files changed, 47 insertions(+), 0 deletions(-)
>>>
>>> what do you mean by dedicated function.. be a bit clearer in the  
>>> commit
>>> log.
>>
>> This term is from the QE spec, I didn't invent anything. ;-)
>>
>> "Each pin in the I/O ports can be configured as a general-purpose
>> I/O signal or as a dedicated peripheral interface signal. ...many
>> dedicated peripheral functions are multiplexed onto the ports."
>
> I understand but I think 'dedicated' could be interpreted in another way 
> (like the GPIO pin is dedicated, not that the pin is used for a  
> dedicated SoC block).
>
> If it the commit message had said 'to a dedicated on chip peripheral' it 
> would be clearer.

Ah, ok, I'll fix that.

>>> Also, does this depend on gpio_to_chip() patch?
>>
>> Yeah, the point of exported gpio_to_chip is to let us write
>> this function.
>
> I meant can I take this patch w/o the gpio_to_chip() patch? (not clear  
> from your response)

No, unfortunately you can't. It would be great if we could pass the
whole patchset via single tree (USB? Or -mm to Linus directly?),
so Acks are more than appreciated.


Thanks again,

-- 
Anton Vorontsov
email: cbouatmailru at gmail.com
irc://irc.freenode.net/bd2



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