pinctrl: clarify idle vs sleep states

This pure documentation fix tries to align the "idle" and
"sleep" pin states to the idle and suspend states from
runtime PM.

Cc: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/pinctrl/pinctrl-state.h

@@ -6,13 +6,18 @@
  * @PINCTRL_STATE_DEFAULT: the state the pinctrl handle shall be put
  *	into as default, usually this means the pins are up and ready to
  *	be used by the device driver. This state is commonly used by
- *	hogs to configure muxing and pins at boot.
+ *	hogs to configure muxing and pins at boot, and also as a state
+ *	to go into when returning from sleep and idle in
+ *	.pm_runtime_resume() or ordinary .resume() for example.
  * @PINCTRL_STATE_IDLE: the state the pinctrl handle shall be put into
- *	when the pins are idle. Could typically be set from a
- *	pm_runtime_suspend() operation.
+ *	when the pins are idle. This is a state where the system is relaxed
+ *	but not fully sleeping - some power may be on but clocks gated for
+ *	example. Could typically be set from a pm_runtime_suspend() or
+ *	pm_runtime_idle() operation.
  * @PINCTRL_STATE_SLEEP: the state the pinctrl handle shall be put into
- *	when the pins are sleeping. Could typically be set from a
- *	common suspend() function.
+ *	when the pins are sleeping. This is a state where the system is in
+ *	its lowest sleep state. Could typically be set from an
+ *	ordinary .suspend() function.
  */
 #define PINCTRL_STATE_DEFAULT "default"
 #define PINCTRL_STATE_IDLE "idle"