Re: multipath mux question

[Tony Lindgren <tony@atomide.com>]

* Grazvydas Ignotas <notasas@gmail.com> [100703 00:21]:
> Hi,
> 
> on OMAP3 CBB package GPIO126 can be muxed on 2 pins: mmc1_dat4 and
> cam_strobe. On pandora mmc1_dat4 is connected to mmc1 write protect,
> this makes omap2_mmc_mux() call omap_mux_init_gpio() on GPIO126, which
> muxes both pins and warns:
> mux: Multiple gpio paths for gpio126

OK.
 
> This results in unusable GPIO. I wonder how should I handle this,
> perhaps overriding mux by calling omap_mux_init_signal() after
> omap2_hsmmc_init() call? Or maybe omap_mux_init_gpio() should be
> patched not to set up GPIOs if it encounters multiple paths?

To me the safest route is the second option you suggest where
we refuse to mux GPIO pins that have multiple outputs. 

We should just print a warning and return an error. Then we should
also start checking the return values for omap_mux_init_gpio
now that the code is converted over to use the new mux code.

If you do a patch, please do it against omap for-next branch
as omap_mux_init_gpio has a pending patch for MUXABLE_GPIO_MODE3.

Regards,

Tony