From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Wed, 13 Feb 2013 08:52:20 -0800 Subject: Getting your opinion about the best place to put one specific device driver... In-Reply-To: <511B6140.90801@stericsson.com> References: <511A0F11.1050608@stericsson.com> <201302121454.10231.arnd@arndb.de> <511A6D1E.50705@stericsson.com> <201302121741.31494.arnd@arndb.de> <20130213094552.GD3073@tbergstrom-lnx.Nvidia.com> <511B6140.90801@stericsson.com> Message-ID: <20130213165219.GG7144@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Jean-Nicolas GRAUX [130213 01:52]: > Le 02/13/2013 10:45 AM, Peter De Schrijver a ?crit : > >>Correct, I try my best to avoid adding random stuff in there that might > >>need a generic interface later. Tony already pointed out the similarity > >>to the OMAP specific hwopbs feature, and whatever user interface we > >>introduce for one should be generic enough to work on the other one as > >>well, and ideally also on future ones to the degree that we can anticipate > >>them today. > >> > >>I like the idea of making the in-kernel configuration part of this a > >>pinctrl driver, which would already allow you to configure it through > >>a custom device tree and no user interface at all. > >> > >Having done significant work with the OMAP3 hwobs feature, you really want a > >userinterface. At least OMAP3 has limitations on which signal can be > >monitored on which hwobs pin. This means that depending on the measurements > >you want to do, you need to change the configuration. If you want to automate > >several measurements, having a user interface (eg using debugfs), makes things > >much easier. Also when using this for debugging, you probably will have to > >experiment with which signals to monitor to rootcause the problem. Also then > >having a userinterface will be much easier than modifying the devicetree > >and rebooting the system. > > > Yep, that's true. Yeah user space is the way to go for toggling the settings. For omap hwobs, that all should be pretty close doable via debugfs with pinctrl-single.c + the patches posted by Haojian to add debugfs write support. Regards, Tony