extcon: Add documentation for EXTCON_CHG_USB_SLOW/FAST

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@suse.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
[cw00.choi: Use the 'connector' expression instead of 'cable']
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index d57e524438410cbee8b4a1bdaa885e863aa91cc9..242157cad25d25810c283ddea0888b0f22be5ffe 100644 (file)
--- 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.
+ *
+ * The EXTCON_CHG_USB_SLOW connector can provide at least 500mA of
+ * current at 5V. The EXTCON_CHG_USB_FAST connector 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 */