Input: omap-keypad - fix idle configuration to not block SoC idle states
authorTony Lindgren <tony@atomide.com>
Tue, 4 Dec 2018 21:52:49 +0000 (13:52 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 13 Jan 2019 09:00:57 +0000 (10:00 +0100)
commit6989cedd762f2e1b9062f2c20f19528f9116badc
treeddbeeb38a4114e2046f097871ac0fa3b0f60ac9d
parentbbed2ced931009ba45ff32e8abdef8523548fd9b
Input: omap-keypad - fix idle configuration to not block SoC idle states

[ Upstream commit e2ca26ec4f01486661b55b03597c13e2b9c18b73 ]

With PM enabled, I noticed that pressing a key on the droid4 keyboard will
block deeper idle states for the SoC. Let's fix this by using IRQF_ONESHOT
and stop constantly toggling the device OMAP4_KBD_IRQENABLE register as
suggested by Dmitry Torokhov <dmitry.torokhov@gmail.com>.

From the hardware point of view, looks like we need to manage the registers
for OMAP4_KBD_IRQENABLE and OMAP4_KBD_WAKEUPENABLE together to avoid
blocking deeper SoC idle states. And with toggling of OMAP4_KBD_IRQENABLE
register now gone with IRQF_ONESHOT, also the SoC idle state problem is
gone during runtime. We still also need to clear OMAP4_KBD_WAKEUPENABLE in
omap4_keypad_close() though to pair it with omap4_keypad_open() to prevent
blocking deeper SoC idle states after rmmod omap4-keypad.

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/input/keyboard/omap4-keypad.c