Chanwoo, On 06/10/15 15:12, Chanwoo Choi wrote: > Roger, > > On 2015년 10월 06일 20:49, Roger Quadros wrote: >> Hi, >> >> On 06/10/15 14:21, Chanwoo Choi wrote: >>> The SDP (Standard Downstream Port) is one of various USB Charging ports. >>> The SDP >>> supports both the data transmission and the charging through USB connector >>> at >>> the same time. So, the EXTCON framework defines two connector type for USB >>> SDP >>> connector as following: >>> - EXTCON_USB means the USB cable for data transmission. >>> - EXTCON_CHG_USB means the USB charger cable for battery charging. >>> >>> This patch add the support of EXTCON_CHG_USB when USB SDP is attached or >>> detached. >> >> I didn't understand why this change is needed. SDP, EXTCON_USB and >> EXTCON_CHG_USB >> are the same thing. no? > > As you knew, SDP support both data transmission and charging > through one port at the same time. Also, On patch1 of this patch-set, > I add the prefix to clarify both attribute and meaning of external connector > as following: > - EXTCON_CHG_* mean the charger connector. > > So, there are three possible naming approach for USB SDP. > > Approach 1. > - EXTCON_USB /* SDP for both data transmission and charging */ > > Approach 2. > - EXTCON_USB /* SDP for data transmission */ > - EXTCON_CHG_USB /* SDP for charging */
This only adds confusion. There is only one cable that will always do both jobs so no point in using 2 names for it. > > Approach 3. > - EXTCON_CHG_USB /* SDP for both data transmission and charging */ > > It is not fixed about name. I want to discuss what is proper name for USB SDP. I do not have any preference over 1 or 3. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
