| What:		/sys/devices/platform/<phy-name>/role | 
 | Date:		October 2016 | 
 | KernelVersion:	4.10 | 
 | Contact:	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 
 | Description: | 
 | 		This file can be read and write. | 
 | 		The file can show/change the phy mode for role swap of usb. | 
 |  | 
 | 		Write the following strings to change the mode: | 
 | 		 "host" - switching mode from peripheral to host. | 
 | 		 "peripheral" - switching mode from host to peripheral. | 
 |  | 
 | 		Read the file, then it shows the following strings: | 
 | 		 "host" - The mode is host now. | 
 | 		 "peripheral" - The mode is peripheral now. |