From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: Pinmux bindings proposal V2 Date: Mon, 30 Jan 2012 18:29:06 -0800 Message-ID: <20120131022906.GH9339@atomide.com> References: <20120124012038.GT22818@atomide.com> <74CDBE0F657A3D45AFBB94109FB122FF178CB81EDB@HQMAIL01.nvidia.com> <20120125000407.GU22818@atomide.com> <74CDBE0F657A3D45AFBB94109FB122FF178CB82433@HQMAIL01.nvidia.com> <20120127020832.GJ29812@atomide.com> <20120127065752.GB32740@S2101-09.ap.freescale.net> <20120127170545.GH13504@atomide.com> <20120130015607.GA10470@S2101-09.ap.freescale.net> <20120130172042.GE9339@atomide.com> <20120131013215.GB24681@S2101-09.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20120131013215.GB24681-rvtDTF3kK1ictlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Shawn Guo Cc: Dong Aisheng , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org" , "Sascha Hauer (s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org)" , "kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org" , "cjb-2X9k7bc8m7Mdnm+yROfE0A@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org * Shawn Guo [120130 16:49]: > On Mon, Jan 30, 2012 at 09:20:42AM -0800, Tony Lindgren wrote: > > * Shawn Guo [120129 17:13]: > > > On Fri, Jan 27, 2012 at 09:05:45AM -0800, Tony Lindgren wrote: > ... > > > > Wouldn't it be cleaner to just clk_get esdhc_clk during init, then > > > > do clk_set_rate on it to toggle the rates? > > > > > > > It's not an init-time switch but run-time one. That said, > > > sdhci_ops.set_clock will be called during run-time. > > > > Right, basically you don't want to do clk_get or pinmux_get during > > runtime, you do that once one during init. Then do clk_set_rate or > > whaterver during runtime. > > > > Is there anything stopping from implementing sdhci_ops.set_rate > > using clock framework and clk_set_rate in this case BTW? > > > We are doing this exactly for clk, and trying to figure out how to > handle pinctrl here. I do not see how we can do pinmux_get at > init-time and pinmux_set_whatever at run-time. The pinmux API does > not work that way. Hmm OK I see what you mean. Maybe we should have something like pinmux_get/set_function to change the mux without having to do pinmux_put and pinmux_get during runtime? As long as the locking is per pin that should be safe to do. > > > > > > So I'd rather stay out of random named states for > > > > > > the pins coming from device tree; If we still need them, they should > > > > > > be common bindings rather than things like "xyz_clock_hack". > > > > > > > > > > > The binding defines the syntax, and I do not see the necessity to > > > > > force the particular state name, which is really pinctrl client > > > > > device specific. > > > > > > > > Do you have some other custom pin state example other than the > > > > clock rate change example above? > > > > > > > I have another case PM related. To aggressively save power, the pins > > > configured for particular function during active mode need to be > > > muxed on gpio mode and output 0 in low-power mode. > > > > OK, but basically only a small subset of pins of the total pins? > > > Actually, all pins used by the block. That's still a fraction of the total pins on the SoC that need dynamic remuxing, right? Regards, Tony