From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 2/2] ARM: OMAP2+: Enable pinctrl dummy states Date: Tue, 11 Sep 2012 11:35:22 -0700 Message-ID: <20120911183522.GL23092@atomide.com> References: <1347385599-27558-1-git-send-email-mporter@ti.com> <1347385599-27558-3-git-send-email-mporter@ti.com> <20120911180306.GI23092@atomide.com> <20120911181540.GO27758@beef> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linux Kernel Mailing List , Grant Likely , AnilKumar , Linux SPI Devel List , Linux OMAP List , Linux ARM Kernel List To: Matt Porter Return-path: Content-Disposition: inline In-Reply-To: <20120911181540.GO27758@beef> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org Added Linus Walleij to Cc as well. * Matt Porter [120911 11:24]: > On Tue, Sep 11, 2012 at 11:03:06AM -0700, Tony Lindgren wrote: > > * Matt Porter [120911 10:46]: > > > Enable pinctrl dummy states for all OMAP platforms. This allows > > > drivers to be converted to pinctrl while still running on > > > platforms that do not provide pinctrl data. > > > > > > Signed-off-by: Matt Porter > > > --- > > > arch/arm/mach-omap2/devices.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c > > > index c00c689..577cd04 100644 > > > --- a/arch/arm/mach-omap2/devices.c > > > +++ b/arch/arm/mach-omap2/devices.c > > > @@ -17,6 +17,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > #include > > > > > > #include > > > @@ -631,6 +632,9 @@ static inline void omap_init_vout(void) {} > > > > > > static int __init omap2_init_devices(void) > > > { > > > + /* Enable dummy states for those platforms without pinctrl support */ > > > + pinctrl_provide_dummies(); > > > + > > > /* > > > * please keep these calls, and their implementations above, > > > * in alphabetical order so they're easier to sort through. > > > > Hmm I think this may need to be board specific. And may need to > > be board specific and depend on unpopulated device tree? > > If I run this on AM33xx with dummy states enabled, I'm able to override > that dummy state just fine with an appropriate pinctl/pinmux entry in my > DT data for spi. But do you get an error then if the desired pins are not found? If you do get an error, then sounds like it's OK to do. > Meanwhile on xM booting from board-omap3evm.c/!DT and debug enabled I > get the following: > > [ 1.837829] omap2_mcspi omap2_mcspi.1: no of_node; not parsing > pinctrl DT > [ 1.845214] omap2_mcspi omap2_mcspi.1: using pinctrl dummy state > (default) > [ 1.854278] omap2_mcspi omap2_mcspi.2: no of_node; not parsing > pinctrl DT > [ 1.861572] omap2_mcspi omap2_mcspi.2: using pinctrl dummy state > (default) > [ 1.870025] omap2_mcspi omap2_mcspi.3: no of_node; not parsing > pinctrl DT > [ 1.877288] omap2_mcspi omap2_mcspi.3: using pinctrl dummy state > (default) > [ 1.885681] omap2_mcspi omap2_mcspi.4: no of_node; not parsing > pinctrl DT > [ 1.892913] omap2_mcspi omap2_mcspi.4: using pinctrl dummy state > (default) > > which seems to cover things being informative enough about what is > going on. Are you wanting to see an explicit warning that the pinctrl > dummy state is in use when pinctrl data is not available? Well I think we should consider at least the following: 1. Always see warnings when device tree is populated with board-generic. If somebody wants to use bootloader only muxing with DT, they can patch in pinctrl_provide_dummies() somewhere. But let's assume we always want to see the warnings with board-generic.c and DT. 2. For legacy booting without DT, we should not see any warnings from pinctrl-single.c as it's DT based. 3. There may be other non-pinctrl drivers too that are not DT based, and in those cases we should see the warnings as well for in the non-DT case. > > For board-generic.c we always want to see the warnings. And some boards > > insist on doing all the muxing only in the bootloader. > > Which warnings are you saying we should see in the board-generic.c > case? Sure, there's plenty of cases where this will be unused due to > somebody setting all the muxes in the bootloader and then not using > pinctrl data. I'll have to doublecheck but I believe that case is also > fine as the -single driver can't override the dummy state if the DT has > no pinctrl data for the spi driver. Yeah I guess it's the case #1 above for board-generic.c. Regards, Tony