Compatibles for i2c muxes nxp,pca954x and ti,tca954x

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi!

Texas has apparently made copies for some of the NXP devices
handled by the drivers/i2c/muxes/i2c-mux-pca954x.c driver.

How is that best handled?

I see e.g. that arch/arm/boot/dts/vf610-zii-dev-rev-{b,c}.dts has
this snippet:

&i2c2 {
	tca9548@70 {
		compatible = "nxp,pca9548";

Which indicates that it really is a Texas chip sitting there, but that
someone did not bother to state that explicitly.

As I see it, there are two levels to this.

1. Update the above to be

		compatible = "ti,tca9548a", "nxp,pca9548";

   and rely on the secondary compatible to be matched with the driver.

2. Also update the driver to recognize the "ti,tca9548a" compatible.

There are also "ti,tca9543a", "ti,tca9544a", "ti,tca9545a" and
"ti,tca9546a" to consider (but no "ti,tca9542a" or "ti,tca9547a").

AFAIU, the Texas chips are completely compatible from the driver
point of view.

Step 1 above is probably a bugfix, should someone find some
unexpected incompatibility in the future. Without differentiating
the compatibles now, there's just no way to handle that in a future
driver.

But is step 2 needed/desired until such a time that differences between
the chips are found? How is this situation handled elsewhere?

Cheers,
peda
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux