[PATCH] extcon: Add documentation for EXTCON_CHG_USB_SLOW/FAST

[Baolin Wang]

Currently there are no documentation for EXTCON_CHG_USB_SLOW/FAST
charger connector. These names don't mean much and no guide to tell
users how to use it, thus try to add documentation to make them clear.

Suggested-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
 include/linux/extcon.h |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 0020123..ceec1f0 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -53,6 +53,10 @@
  * the USB connector, which means EXTCON_CHG_USB_SDP should always
  * appear together with EXTCON_USB. The same as ACA charger connector,
  * EXTCON_CHG_USB_ACA would normally appear with EXTCON_USB_HOST.
+ *
+ * A cable of type EXTCON_CHG_USB_SLOW can provide at least 500mA of
+ * current at 5V. A cable of type EXTCON_CHG_USB_FAST can provide at
+ * least 1A of current at 5V.
  */
 #define EXTCON_CHG_USB_SDP	5	/* Standard Downstream Port */
 #define EXTCON_CHG_USB_DCP	6	/* Dedicated Charging Port */
-- 
1.7.9.5