From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suman Anna Subject: Re: [PATCHv5 03/15] hwspinlock/core: maintain a list of registered hwspinlock banks Date: Thu, 3 Jul 2014 12:28:46 -0500 Message-ID: <53B592CE.2010001@ti.com> References: <1398904476-26200-1-git-send-email-s-anna@ti.com> <1398904476-26200-4-git-send-email-s-anna@ti.com> <53B47621.6090307@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ohad Ben-Cohen Cc: Mark Rutland , Kumar Gala , Tony Lindgren , Josh Cartwright , Bjorn Andersson , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-arm List-Id: devicetree@vger.kernel.org Hi Ohad, On 07/03/2014 02:00 AM, Ohad Ben-Cohen wrote: > Hi Suman, > > On Thu, Jul 3, 2014 at 12:14 AM, Suman Anna wrote: >>> I'm not sure we need this patch. >> >> This patch is needed if we use the controller-phandle + args specifier >> for requesting hwlocks by a client, as we need to translate >> controller-phandle to the corresponding hwspinlock_device. >> >> Looks like we still don't have a closure on the semantics of how >> clients have to request a lock in DT. You are suggesting something like >> hwlocks = ; >> >> whereas this patch is built to support based on comments from >> DT-maintainers, >> hwlocks = , > lock-specifier2>...; > > I'm actually ok with this suggestion and haven't suggested otherwise. OK, thanks for confirming and sorry for the misinterpretation. > > All I propose is that we add the base_id property to the controller > node (as you have done in the subsequent patches), and then drivers > will be able to infer the global lock id from the DT data by adding > the controller's base_id to the lock specifier. OK, but we would still require this function to lookup the registered device from the controller-phandle to retrieve the base_id. Do note that the hwspinlock core currently only maintains the registered locks in an integrated radix tree, but not the registered hwspinlock banks themselves. regards Suman > Controllers with non standard lock indexing may use an xlate() method > if needed but frankly this is fictional right now. We can start > without this, and add it later when needed, as this doesn't affect the > DT data. > > With the global lock id in hand, drivers could simply use the existing > hwspin_lock_request_specific API to obtain a specific lock, and then > we don't need this patch. > > Thanks, > Ohad. > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html