-- pinctrl: When present, must have one state named "sleep"
- and one state named "default"
-- clocks: When present, must refer to exactly one clock named
+- pinctrl: When present, must have one state named "default",
+ and may contain a second name named "sleep". The former
+ state sets up pins for ordinary operation whereas
+ the latter state will put the associated pins to sleep
+ when the UART is unused
+- clocks: When present, the first clock listed must correspond to
+ the clock named UARTCLK on the IP block, i.e. the clock
+ to the external serial line, whereas the second clock
+ must correspond to the PCLK clocking the internal logic
+ of the block. Just listing one clock (the first one) is
+ deprecated.
+- clocks-names: When present, the first clock listed must be named
+ "uartclk" and the second clock listed must be named