pinctrl: generic: Add bi-directional and output-enable

Add bi-directional and output-enable pin configuration properties.

bi-directional allows to specify when a pin shall operate in input and
output mode at the same time. This is particularly useful in platforms
where input and output buffers have to be manually enabled.

output-enable is just syntactic sugar to specify that a pin shall
operate in output mode, ignoring the provided argument.
This pairs with input-enable pin configuration option.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 7620eb1..279e3c5 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -42,6 +42,8 @@
  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
  *	impedance to VDD). If the argument is != 0 pull-up is enabled,
  *	if it is 0, pull-up is total, i.e. the pin is connected to VDD.
+ * @PIN_CONFIG_BIDIRECTIONAL: the pin will be configured to allow simultaneous
+ *	input and output operations.
  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
  *	collector) which means it is usually wired with other output ports
  *	which are then pulled up with an external resistor. Setting this
@@ -96,6 +98,7 @@ enum pin_config_param {
 	PIN_CONFIG_BIAS_PULL_DOWN,
 	PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
 	PIN_CONFIG_BIAS_PULL_UP,
+	PIN_CONFIG_BIDIRECTIONAL,
 	PIN_CONFIG_DRIVE_OPEN_DRAIN,
 	PIN_CONFIG_DRIVE_OPEN_SOURCE,
 	PIN_CONFIG_DRIVE_PUSH_PULL,