From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: Pinmux bindings proposal
Date: Wed, 18 Jan 2012 07:32:56 -0800 [thread overview]
Message-ID: <20120118153256.GB22818@atomide.com> (raw)
In-Reply-To: <CAAQ0ZWTtYz3Lg7=Xz29m07j_k8yA95hn6cyk92SAJ4iGJRT_gw@mail.gmail.com>
* Shawn Guo <shawn.guo@linaro•org> [120118 05:57]:
> On 18 January 2012 22:13, Tony Lindgren <tony@atomide•com> wrote:
> > Hi,
> >
> > * Grant Likely <grant.likely@secretlab•ca> [120116 09:55]:
> >> On Fri, Jan 13, 2012 at 12:39:42PM -0800, Stephen Warren wrote:
> >> > ? ? ? ? ? ? ? ? pinmux =
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"default" &pmx_sdhci_active>
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"suspend" &pmx_sdhci_suspend>;
> >> >
> >> > ? ? ? ? ? ? ? ? /* 1:n example: */
> >> > ? ? ? ? ? ? ? ? pinmux =
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"default" &pmx_sdhci_mux_a>
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"default" &pmx_sdhci_pincfg_a>
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"suspend" &pmx_sdhci_mux_a>
> >> > ? ? ? ? ? ? ? ? ? ? ? ? <"suspend" &pmx_sdhci_pincfg_a_suspend>;
> >>
> >>
> >> Yeah, don't do this. ?Mixing phandle, string and cell values in a
> >> property gets messy and could become troublesome to parse. ?I've
> >> backed away from it in the clk binding.
> >
> > Yup, that's because the string is embedded directly into the mixed
> > mode array and will likely make the following data unaligned. That
> > means it's extremely flakey to parse, and will lead into horrible
> > errors if you have typos in the .dts file.. Tried that and gave up
> > on it.
> >
> > I think I've found a way to avoid using names at all, assuming we set
> > each pin as a phandle for the drivers to use :)
> >
> The problem with doing that is we will have to represent each pin as a
> node in device tree. For imx6q case, we have 197 pins. Doing so will
> bloat the device tree.
Sure there's some overhead. I've got it working with 220 pins, it's
not too bad as threre's not much string parsing involved.
I don't have all the devices mapping the pins though. The .dtb for
omap4 is about 25k now.
If we wanted to avoid adding phandles for each pin, then we could do:
serial at 0x48020000 {
compatible = "ti,8250";
reg = <0x48020000 0x100>;
reg-shift = <2>;
interrupts = <106>;
/* controller, offset, value */
pins = <&mux1 0xabcd 0x10
&mux1 0xabcf 0x0>;
};
But then the .dts file becomes an unreadable matrix unless we have
a preprocessor..
Regards,
Tony
next prev parent reply other threads:[~2012-01-18 15:32 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-13 20:39 Pinmux bindings proposal Stephen Warren
2012-01-14 7:09 ` Shawn Guo
2012-01-17 18:47 ` Stephen Warren
2012-01-18 3:32 ` Shawn Guo
2012-01-18 19:00 ` Stephen Warren
2012-01-16 12:50 ` Dong Aisheng-B29396
2012-01-17 8:23 ` Shawn Guo
2012-01-17 9:46 ` Dong Aisheng-B29396
2012-01-17 14:13 ` Shawn Guo
2012-01-17 19:32 ` Stephen Warren
2012-01-18 3:44 ` Dong Aisheng-B29396
2012-01-18 4:47 ` Shawn Guo
2012-01-18 19:24 ` Stephen Warren
2012-01-17 19:28 ` Stephen Warren
2012-01-18 11:06 ` Dong Aisheng-B29396
2012-01-20 20:28 ` Stephen Warren
2012-01-27 12:00 ` Linus Walleij
2012-01-27 16:58 ` Stephen Warren
2012-01-17 19:21 ` Stephen Warren
2012-01-18 4:01 ` Shawn Guo
2012-01-18 9:32 ` Dong Aisheng-B29396
2012-01-17 19:09 ` Stephen Warren
2012-01-18 7:24 ` Dong Aisheng-B29396
2012-01-18 19:42 ` Stephen Warren
2012-01-16 18:28 ` Grant Likely
2012-01-18 14:13 ` Tony Lindgren
2012-01-18 14:30 ` Shawn Guo
2012-01-18 15:32 ` Tony Lindgren [this message]
2012-01-18 16:29 ` Tony Lindgren
2012-01-18 20:22 ` Grant Likely
2012-01-18 20:20 ` Grant Likely
2012-01-19 10:31 ` Tony Lindgren
2012-01-18 20:02 ` Stephen Warren
2012-01-19 10:57 ` Tony Lindgren
2012-01-20 20:50 ` Stephen Warren
2012-01-23 20:13 ` Tony Lindgren
2012-01-23 22:54 ` Stephen Warren
2012-01-27 13:11 ` Linus Walleij
2012-01-18 12:16 ` Thomas Abraham
2012-01-18 19:52 ` Stephen Warren
2012-01-19 17:01 ` Tony Lindgren
2012-01-19 13:10 ` Thomas Abraham
2012-01-19 16:56 ` Tony Lindgren
2012-01-19 17:38 ` Thomas Abraham
2012-01-19 18:20 ` Tony Lindgren
2012-01-19 18:38 ` Thomas Abraham
2012-01-20 10:05 ` Tony Lindgren
2012-01-20 16:17 ` Thomas Abraham
2012-01-20 17:53 ` Tony Lindgren
2012-01-21 1:38 ` Thomas Abraham
2012-01-20 21:15 ` Stephen Warren
2012-01-20 21:11 ` Stephen Warren
2012-01-21 1:27 ` Thomas Abraham
2012-01-23 22:43 ` Stephen Warren
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