pinctrl: mediatek: questions about gpio/pinctrl/eint

[biao.huang@mediatek.com (biao huang)]

Hi Linus,

	We have two questions associate with mediatek pinctrl/gpio in linux
kernel to asking for your help.

	First, when user call GPIO API to control medaitek gpio, they should
call pinctrl API to set pinmux to mode 0 ahead, so this pin is function
as gpio. And this makes things a little complicated. Is there any simple
API can solve this problem? How about add pinmux setting in
gpio_request?

	Second, here is our request_irq flow in mkd eint driver:
request_irq --> mtk_pinctrl_irq_request_resources--> mtk_pmx_set_mode,
Normally, it'll set pinmux to eint mode (usually is mode 0) in
mtk_pmx_set_mode function. But for special case, such as iddig (connect
to usb), when iddig request_irq, it should set pinmux to iddig mode
(mode 2 in mt8163).
	Is there a better way than changing
        MTK_PIN(
                PINCTRL_PIN(16, "IDDIG"),
                NULL, "mt8173",
                MTK_EINT_FUNCTION(0, 16),
                MTK_FUNCTION(0, "GPIO16"),
                MTK_FUNCTION(1, "IDDIG"),
                MTK_FUNCTION(2, "CMFLASH"),
                MTK_FUNCTION(4, "PWM5")
        ),
	to
        MTK_PIN(
                PINCTRL_PIN(16, "IDDIG"),
                NULL, "mt8173",
                MTK_EINT_FUNCTION(2, 16),
                MTK_FUNCTION(0, "GPIO16"),
                MTK_FUNCTION(1, "IDDIG"),
                MTK_FUNCTION(2, "CMFLASH"),
                MTK_FUNCTION(4, "PWM5")
        ),
	in drivers/pinctrl/mediatek/pinctrl-mtk-mt8163.h?

	We are looking forward for your help, thanks very much!

Best Regards!
Yours,
Biao Huang