On Wed, Jan 18, 2012 at 07:32:56AM -0800, Tony Lindgren wrote:

* Shawn Guo [off-list ref] [120118 05:57]:

quoted

On 18 January 2012 22:13, Tony Lindgren [off-list ref] wrote:

quoted

Hi,

* Grant Likely [off-list ref] [120116 09:55]:

quoted

On Fri, Jan 13, 2012 at 12:39:42PM -0800, Stephen Warren wrote:

quoted

? ? ? ? ? ? ? ? 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..

One node per pin does get excessive in a hurry.  I prefer the one node
per pin controller.  Tools can be written to make writing the
definition easier.

g.