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

[Kumar Gala <galak@kernel.crashing.org>]

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@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.

>> 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)

- k