docs: Import documentation from source-code inline comments.

The inline docs (prefixed with /// in .c files) have been converted to
RST format and put in the docs subdirectory.

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/tutorial/power_ctrl.rst b/docs/tutorial/power_ctrl.rst
new file mode 100644
index 000000000..877b7cd7e
--- /dev/null
+++ b/docs/tutorial/power_ctrl.rst
@@ -0,0 +1,13 @@
+Power control
+=============
+
+:meth:`pyb.wfi` is used to reduce power consumption while waiting for an
+event such as an interrupt.  You would use it in the following situation::
+
+    while True:
+        do_some_processing()
+        pyb.wfi()
+
+Control the frequency using :meth:`pyb.freq`::
+
+    pyb.freq(30000000) # set CPU frequency to 30MHz