Andy Shevchenko 29c2c6aa32 pinctrl: intel: Avoid potential glitches if pin is in GPIO mode
When consumer requests a pin, in order to be on the safest side,
we switch it first to GPIO mode followed by immediate transition
to the input state. Due to posted writes it's luckily to be a single
I/O transaction.

However, if firmware or boot loader already configures the pin
to the GPIO mode, user expects no glitches for the requested pin.
We may check if the pin is pre-configured and leave it as is
till the actual consumer toggles its state to avoid glitches.

Fixes: 7981c0015a ("pinctrl: intel: Add Intel Sunrisepoint pin controller and GPIO support")
Depends-on: f5a26acf01 ("pinctrl: intel: Initialize GPIO properly when used through irqchip")
Cc: stable@vger.kernel.org
Cc: fei.yang@intel.com
Reported-by: Oliver Barta <oliver.barta@aptiv.com>
Reported-by: Malin Jonsson <malin.jonsson@ericsson.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-10-21 15:41:19 +03:00
2019-09-13 17:21:38 +03:00
2019-09-30 10:35:40 -07:00

Linux kernel
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