[PATCH 2/4] pinctrl: Add skew-delay pin config and bindings

Some pin controllers (such as the Gemini) can control the
expected clock skew and output delay on certain pins with a
sub-nanosecond granularity. This is typically done by shunting
in a number of double inverters in front of or behind the pin.
Make it possible to configure this with a generic binding.

Cc: devicetree at vger.kernel.org
Signed-off-by: Linus Walleij <redacted>
---
 Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt | 4 ++++
 drivers/pinctrl/pinconf-generic.c                              | 2 ++
 include/linux/pinctrl/pinconf-generic.h                        | 5 +++++
 3 files changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index 4483cc31e531..ad9bbbba36e9 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt

@@ -271,6 +271,10 @@ output-high		- set the pin to output mode with high level
 sleep-hardware-state	- indicate this is sleep related state which will be programmed
 			  into the registers for the sleep state.
 slew-rate		- set the slew rate
+skew-delay		- this affects the expected clock skew on input pins
+			  and the delay before latching a value to an output
+			  pin. Typically indicates how many double-inverters are
+			  used to delay the signal.