From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 4/4] usb: phy: twl4030: test ID resistance to see if charger is present. Date: Mon, 2 Mar 2015 22:04:44 +0100 Message-ID: <20150302210444.GI13270@amd> References: <20150224033730.31400.78200.stgit@notabene.brown> <20150224034037.31400.48003.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150224034037.31400.48003.stgit@notabene.brown> Sender: linux-kernel-owner@vger.kernel.org To: NeilBrown Cc: Tony Lindgren , Felipe Balbi , Kishon Vijay Abraham I , linux-omap@vger.kernel.org, lkml , GTA04 owners List-Id: linux-omap@vger.kernel.org On Tue 2015-02-24 14:40:37, NeilBrown wrote: > If an 'A' plug is inserted, ID should be pulled to ground. > If a 'B' plug, then ID should be floating. > > If an Accessory Charger Adapter is inserted, then ID will > be neither grounded nor floating. In this case tell the > USB subsystem that it is an A plug, and the battery > charging subsystem that it is a charger. > Fortunately, this will treat the Openmoko charger (and > other similar chargers) as a charger. > > Signed-off-by: NeilBrown I guess signed-off-by should be "real name", so I'd add a space.. Acked-by: Pavel Machek > --- a/drivers/phy/phy-twl4030-usb.c > +++ b/drivers/phy/phy-twl4030-usb.c > @@ -596,9 +596,31 @@ static irqreturn_t twl4030_usb_irq(int irq, void *_twl) > struct twl4030_usb *twl = _twl; > enum omap_musb_vbus_id_status status; > bool status_changed = false; > + bool found_charger = false; > > status = twl4030_usb_linkstat(twl); > > + if (status == OMAP_MUSB_ID_GROUND || > + status == OMAP_MUSB_VBUS_VALID) { > + /* We should check the resistance on the ID pin. > + * If not a Ground or Floating, then this is > + * likely a charger "charger.", and I guess kernel comments should have /* on separate line. So it will draw .5A from the charger? 1A? 2A? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html