On Tuesday, July 12, 2016 3:14:47 PM CEST Wan Zongshun wrote:

On 2016?07?12? 12:30, Wan Zongshun wrote:

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On 2016?07?12? 00:04, Arnd Bergmann wrote:

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On Sunday, July 10, 2016 3:27:21 PM CEST Wan Zongshun wrote:

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+ifeq ($(CONFIG_SOC_NUC970),)
  obj-y                          := irq.o time.o mfp.o gpio.o clock.o
  obj-y                          += clksel.o dev.o cpu.o
+endif
  # W90X900 CPU support files

When mfp.o is disabled like this, I get a link error in two drivers
using the exported interface:

ERROR: "mfp_set_groupg" [drivers/spi/spi-nuc900.ko] undefined!
ERROR: "mfp_set_groupi" [drivers/input/keyboard/w90p910_keypad.ko]
undefined!

Why remove mfp modules? this multifunction pin driver should be used for
those two drivers, if no mfp_set_groupX, I don't think driver can work.

Now mfp has standard driver subsystem?

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Any idea for a better migration strategy?

Arnd, If you still think the mfp should be removed, we can send a series 
patches to instead of using mfp interface quickly, and do mfp set in 
local driver. Do you think it is ok?

I don't think setting it locally in the driver is a good idea.

In the long run, this should go through the pinctrl framework, but
there is no need to implement that right away. Until then, I think
using the existing mfp.o code is fine, it will just need to be
adapted slightly to understand the DT based device names.

	Arnd