On 23/10/2015 15:41, Måns Rullgård wrote: > Marc Gonzalez wrote: > >> On 22/10/2015 16:02, Mans Rullgard wrote: >> >>> This adds a binding for the Aurora VLSI NB8800 Ethernet controller >>> using the "aurora,nb8800" compatible string. When used in Sigma >>> Designs chips a few additional control registers are available. >>> This variant is indicated by the "sigma,smp8640-ethernet" compatible >>> string. >>> >>> Signed-off-by: Mans Rullgard <mans@xxxxxxxxx> >>> --- >>> .../devicetree/bindings/net/aurora,nb8800.txt | 26 ++++++++++++++++++++++ >>> 1 file changed, 26 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/net/aurora,nb8800.txt >>> >>> diff --git a/Documentation/devicetree/bindings/net/aurora,nb8800.txt b/Documentation/devicetree/bindings/net/aurora,nb8800.txt >>> new file mode 100644 >>> index 0000000..c19f615 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/net/aurora,nb8800.txt >>> @@ -0,0 +1,26 @@ >>> +* Aurora VLSI AU-NB8800 Ethernet controller >>> + >>> +Required properties: >>> +- compatible: Should be "aurora,nb8800", "sigma,smp8640-ethernet" >>> + The latter indicates presence of extra features added by Sigma Designs. >> >> I've been meaning to ask a noob question to the devicetree group >> about how names for compatible strings are chosen. >> >> Sigma Designs has two active SoC families, Tango3 (which consists of >> about a dozen MIPS-based SoCs, typically named SMP86xx) and Tango4 >> (a few ARM-based SoCs, typically named SMP87xx). I should note that >> there is no SMP8640 SoC AFAIK, rather SMP864x is a Tango3 sub-family >> (I could locate 42,43,44,45,46). >> >> AFAIK, all our SoCs are using the same Aurora NB8800 Ethernet MAC, >> along with the extra features. I find it odd to use a specific SoC >> model to refer to this device, instead of a more generic name. >> (It's weird having to mention smp8640 in the tango4 DT.) > > I picked 8640 since all 8640 or higher chips are compatible (863x chips > (tango2) are not). Some of the later versions have additional extra > features, but they all work with the basic driver. > > There also appear to be some differences (bug fixes?) between 8643 and > 8759 (the ones I have) not documented anywhere. I'm trying to locate someone who would know these kinds of details. >> Would it be possible to have a compatible string which makes it >> clear that it is an Aurora MAC with vendor-specific tweaks? >> Something like "sigma,aurora-nb8800-mac" ? > > This doesn't indicate which Sigma modifications are present. If the > driver is at some point modified to take advantage of features/fixes in > newer chips, it's good to have a naming scheme that can accommodate > that. > > For the SMP8759 devicetree, one could set the compatible list to > "sigma,smp8759-ethernet", "sigma,smp8640-ethernet", "aurora,nb8800" > indicating the exact device even if the driver currently doesn't care, > that it is compatible with the 8640 baseline, and finally the plain > aurora as a last fallback. I will update my vantage-1172 DT accordingly. >> I thought one had to specify also whether the device sent "edge" >> or "level" IRQs? > > Depends on the interrupt controller. This is just an example. Sorry for the noise. (I thought edge/level was a device property, as in "I'll just pulse that IRQ, or I'll hold it until someone asks me to shut up.") Regards. -- 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
