Uwe Kleine-K?nig writes:

Hello Huang,

On Fri, Jul 08, 2011 at 05:27:11PM +0800, Huang Shijie wrote:

quoted

quoted

quoted

quoted

quoted

The init function is used only to set up iomux, so the logical replacement is
a pointer to the iomux data, and calling mxs_iomux_setup_multiple_pads
directly from the driver.

Why not put the iomux stuff into the per-machine table and get rid of
the init callback, too?

The mmc (ssp) has pin conflict with gpmi on both mx23evk and mx28evk.
So, it's better to initialize the pin when the driver(GPMI or MMC)
is enabled.

What do you do to prevent userspace from trying to use both devices?

The board can not support the two devices at the same time.
So the user can only use one device with the board.

quoted

I guess you need to configure the hardware somehow to switch between the
two using a jumper? Isn't it possible to detect the hardware setting and
setup the muxer accordingly?

IMHO an per-device init-callback is the wrong approach to solve a pin
conflict.

Do you have any good solution about this?

Put the pinmux corresponding to the one device that currently works in
the pinmux list!?

#define 'that currently works'

For a dedicated system that may not be a problem. But for development
kits and modular systems that allow peripheral modules to be plugged
in there is no 'one device that currently works'.


Lothar Wa?mann
-- 
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch?ftsf?hrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info at karo-electronics.de
___________________________________________________________