On Fri, Jun 21, 2013 at 11:17 PM, Stephen Warren [off-list ref] wrote:

On 06/20/2013 05:57 AM, Christian Ruppert wrote:

quoted

Your remark seems to reflect one of the following two hardware
architectures:

                                                     +- SPI
                 Physical pins --- GPIO --- pinctrl -+- I2C
                                                     +- mmc

(that's diagram 1)

quoted

                                +- GPIO
                 Physical pins -+           +- SPI
                                +- pinctrl -+- I2C
                                            +- mmc

(that's diagram 2)

quoted

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.

The Nomadik pin controller is basically type (2).

Maybe this is part of the explanation to why we sometimes tend
to talk past each other :-D

(I would replace the string "pinctrl" with "pinmux" above,
as I just did in my documentation patch adding these
diagrams.)

Yours,
Linus Walleij