pinctrl: core: Fix regression caused by delayed work for hogs

Commit df61b366af26 ("pinctrl: core: Use delayed work for hogs") caused a regression at least with sh-pfc that is also a GPIO controller as noted by Geert Uytterhoeven <geert@linux-m68k.org>. As the original pinctrl_register() has issues calling pin controller driver functions early before the controller has finished registering, we can't just revert commit df61b366af26. That would break the drivers using GENERIC_PINCTRL_GROUPS or GENERIC_PINMUX_FUNCTIONS. So let's fix the issue with the following steps as a single patch: 1. Revert the late_init parts of commit df61b366af26. The late_init clearly won't work and we have to just give up on fixing pinctrl_register() for GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS. 2. Split pinctrl_register() into two parts By splitting pinctrl_register() into pinctrl_init_controller() and pinctrl_create_and_start() we have better control over when it's safe to call pinctrl_create(). 3. Introduce a new pinctrl_register_and_init() function As suggested by Linus Walleij <linus.walleij@linaro.org>, we can just introduce a new function for the controllers that need pinctrl_create() called later. 4. Convert the four known problem cases to use new function Let's convert pinctrl-imx, pinctrl-single, sh-pfc and ti-iodelay to use the new function to fix the issues. The rest of the drivers can be converted later. Let's also update Documentation/pinctrl.txt accordingly because of the known issues with pinctrl_register().

TLTony Lindgren committed 9 years ago