pinctrl: mediatek: Fix EINT pins input debounce time configuration

The External Interrupt Controller (EINTC) on all of the supported
MediaTek SoCs does support input debouncing, but not all of them
index the debounce time values (DBNC_SETTING registers) the same way.

Before this change, in some cases, as an example, requesting a debounce
time of 16 milliseconds would mistakenly set the relative DBNC_SETTING
register to 0x2, resulting in a way shorter debounce time of 500uS.

To fix the aforementioned issue, define three different debounce_time
arrays, reflecting the correct register index for each value and for
each register index variant, and make sure that each SoC pinctrl
driver uses the right one.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221111094106.18486-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: mediatek: mark dummy helpers as 'static inline'

mtk_eint_set_debounce and mtk_eint_find_irq are defined as stub functions
in a header file, but without marking them as 'static inline', we get
a copy for each file that includes the header:

drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.o: In function `mtk_eint_set_debounce':
pinctrl-mtk-common-v2.c:(.text+0x134): multiple definition of `mtk_eint_set_debounce'
drivers/pinctrl/mediatek/pinctrl-moore.o:pinctrl-moore.c:(.text+0x7d0): first defined here
drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.o: In function `mtk_eint_find_irq':
pinctrl-mtk-common-v2.c:(.text+0x13c): multiple definition of `mtk_eint_find_irq'

Fixes: e46df235b4e6 ("pinctrl: mediatek: refactor EINT related code for all MediaTek pinctrl can fit")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: mediatek: remove unused fields in struct mtk_eint_hw

The .name field has been not being used in existent code logic, so
it's better that we remove them all.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: mediatek: refactor EINT related code for all MediaTek pinctrl can fit

This patch is in preparation for adding EINT support to MT7622 pinctrl,
and the refactoring doesn't alter any existent logic.

A reason we have to refactor EINT code pieces into a generic way is that
currently, they're tightly coupled with a certain type of MediaTek pinctrl
would cause a grown in a very bad way as there is different types of
pinctrl devices getting to join.

Therefore, it is an essential or urgent thing that EINT code pieces are
refactored to eliminate any dependencies across GPIO and EINT as possible.

Additional structure mtk_eint_[xt, hw, regs] are being introduced for
indicating how maps being designed between GPIO and EINT hw number, how to
set and get GPIO state for a certain EINT pin, what characteristic on a
EINT device is present on various SoCs.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>