From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 4/4] Documentation: Add device tree bindings for Freescale FTM PWM Date: Mon, 26 Aug 2013 14:01:17 -0600 Message-ID: <521BB40D.7040001@wwwdotorg.org> References: <1377054462-6283-1-git-send-email-Li.Xiubo@freescale.com> <1377054462-6283-5-git-send-email-Li.Xiubo@freescale.com> <1473340.OXSHEp7d4P@flatron> <1DD289F6464F0949A2FCA5AA6DC23F827D2244@039-SN2MPN1-013.039d.mgd.msft.net> <20130822062610.GR31036@pengutronix.de> <20130823073612.GB3535@ulmo> <5217B807.7020800@wwwdotorg.org> <1DD289F6464F0949A2FCA5AA6DC23F827E11AC@039-SN2MPN1-012.039d.mgd.msft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1DD289F6464F0949A2FCA5AA6DC23F827E11AC@039-SN2MPN1-012.039d.mgd.msft.net> Sender: linux-kernel-owner@vger.kernel.org To: Xiubo Li-B47053 Cc: Thierry Reding , Tomasz Figa , Guo Shawn-R65073 , "grant.likely@linaro.org" , "linux@arm.linux.org.uk" , "rob@landley.net" , "ian.campbell@citrix.com" , "mark.rutland@arm.com" , "pawel.moll@arm.com" , "rob.herring@calxeda.com" , "linux-arm-kernel@lists.infradead.org" , "linux-pwm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linus.walleij@linaro.org" List-Id: devicetree@vger.kernel.org On 08/25/2013 11:35 PM, Xiubo Li-B47053 wrote: >> Subject: Re: [PATCH 4/4] Documentation: Add device tree bindings for ... >>> Why do you need to manipulate the pinctrl to en/disable a channel? >> >> This is because in Vybrid VF610 TOWER board, there are 4 leds, and each >> led's one point(diode's positive pole) is connected to 3.3V, and the >> other point is connected to pwm's one channel. When the 4 pinctrls are >> configured as enable at the same time, the 4 pinctrls is low valtage, and >> the 4 leds will be lighted up as default, then when you enable/disable >> one led will effects others. >> >> These pinctrls are belong to pwm, and I don't think led or other customer >> could control them directly. >> So, here I authorize the 4 pinctrls to each channel controls. >> > " > For the reason above, I have to control the pinctrls separately. > > If all the pinctrls set as default state, the 8 pinctrls must be controlled together. > And the 4 leds will all be lighted up as default and will influence each other. Sorry, that still doesn't make much sense. Either way though, having separate pinctrl setup for a single device isn't going to work. You'll either need to have all combinations of 4 (8?) PWMs represented as pinctrl states(!), or register separate PWM devices so that they get independant pinctrl states.