From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.chen@freescale.com (Peter Chen) Date: Fri, 12 Jul 2013 16:25:01 +0800 Subject: [PATCH v12 06/13] usb: chipidea: add otg_cap attribute for otg capable In-Reply-To: <871u742o4u.fsf@ashishki-desk.ger.corp.intel.com> References: <1373524041-10482-1-git-send-email-peter.chen@freescale.com> <1373524041-10482-7-git-send-email-peter.chen@freescale.com> <871u742o4u.fsf@ashishki-desk.ger.corp.intel.com> Message-ID: <20130712082500.GA16202@nchen-desktop> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jul 12, 2013 at 11:12:01AM +0300, Alexander Shishkin wrote: > Peter Chen writes: > > > Since we need otgsc to know vbus's status at some chipidea > > controllers even it is peripheral-only mode. Besides, some > > SoCs (eg, AR9331 SoC) don't have otgsc register even > > the DCCPARAMS_DC and DCCPARAMS_HC are both 1 at CAP_DCCPARAMS. > > We inroduce otg_cap attribute to indicate if the controller > > is otg capable, defaultly, we follow the rule that if DCCPARAMS_DC > > and DCCPARAMS_HC are both 1 at CAP_DCCPARAMS are otg capable, but if there > > is exception, the platform can override it by device tree or platform data. > > > > Signed-off-by: Peter Chen > > --- > > [...] > > > diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h > > index 118bf66..0a906b4 100644 > > --- a/include/linux/usb/chipidea.h > > +++ b/include/linux/usb/chipidea.h > > @@ -7,6 +7,12 @@ > > > > #include > > > > +enum usb_otg_cap { > > + OTG_CAP_ATTR_IS_NOT_EXISTED = 0, > > + OTG_CAP_ATTR_IS_TRUE, > > + OTG_CAP_ATTR_IS_FALSE, > > +}; > > We don't really need all three, do we? We only need to know if the > controller *can't* do otg. The rest we can infer from dr_mode and > DCCPARAMS. So it can be another bit in flags rather than a separate > field in platdata. > In order to cover below two cases, I have no other idea. 1. For mips Soc (ARxxx), if dr_mode = otg and it is 1 for both mode at DCCPARAMS, It can switch role through proc or whatever, but NO otgsc register, it is NOT otg-capable. 2. For peripheral-only case at most chipidea controllers, the dr_mode = peripheral and it is 1 for both modes at DCCPARAMS, the otgsc can be visited, it is otg-capable. -- Best Regards, Peter Chen