On Tue, Dec 12, 2017 at 07:01:34AM +0000, Takashi Matsuzawa wrote: > Hello. > Thank you very much for your comment. > > > Since USB OTG FSM has not been accepted by industry during last ten years, > > we decide > > to give up maintaining OTG FSM at Linux kernel. For role switch use case, > > please use > > /sys/../role instead, see below commit for detail: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git/commit/drivers/usb/chipidea/core.c?h=ci-for-usb- > next&id=a932a8041ff9941a244619555f1c75ecf299f662 > > I am still learning so just point me to existing memo / notes which I should > look into, before go furher. > > 1) HNP aware devices > > That means it does not work (or will not work) with HNP-aware device anymore, > or I can expect that it still works when I enable CONFIG_USB_OTG and > CONFIG_USB_OTG_FSM?
Afaik, there is no fully HNP aware device, if you know any, please tell me. > > 2) role I/F. > > As for the role I/F. > I tried like below and confirmed that the role value changes gadget <-> host. > And new bus is added can see on lsusb output, when I change the role from > gadget to host. > > echo host > /sys/bus/platform/devices/ci_hdrc.0/role > > However, I am still confused since it does not more. > Say, I have two boards A and B connected with C-C cable. > And by command like above, I set A host role and B gadget role, and also load > mass storage driver on B. > > I expect to see on B is enumerated as mass storage device attached to the > newly added bus on A, but I cannot see it on lsusb output. > Not sure I am missing / skipping steps. Maybe vbus is not there or the gadget does not pull DP up correctly. > > 3) USB-C lines > > As for USB-C receptacle on my board, I can see the following. In my case I > am just trying to use it in place of old one (micro-A/B receptacle), but I > wonder if I further need kernel configuration specific to TYPEC. > For your hardware, I don't think you need. > board cable > ---- ---- > USB_OTG_DP - Dp1/Dp2 > USB_OTG_DN - Dn1/Dn2 > USB_OTG_ID - CC1/CC2 > You said the role has switched successfully, it is not related Type-C issue, it is the controller driver issue, please focus on if vbus is there and if the gadget pull DP up. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
