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

From: Kumar Gala
Date: Wed Sep 24 2008 - 10:01:42 EST



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@xxxxxxxxxxxxx>
---
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
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