On Fri, Jan 10, 2014 at 02:45:50PM -0500, Jason Cooper wrote: > > IMHO the compatible string should represent a specific HW/SW ABI. So > > you need a unique compatible string for every variation of that ABI. > > My concern is that we tend to do things like "marvell,orion-sata" for > the first version of the IP block we can work with. orion5x, kirkwood, > dove, and armada 370/xp all use that compatible string to refer to that > IP block. Right, absent guidance from the originators of the IP block that is sort of all we are left with. But something like 'marvell,orion-sata' is just a label to describe the ABI implemented by the HW on that particular chip. > Given that we look at it as 'and newer', '...-a0-i2c' would mean no > offloading until we introduce '-b0-i2c'. Or am I mis-understanding what > you're saying? I would stop thinking of this in terms of 'is newer' / 'is older'. marvell,orion-sata means any HW that implements the same ABI as the orion chip. When we get a different chip that has a compatible, but extended ABI we introduce a new label: compatible = "marvell,foobar-sata", "marvell,orion-sata"; And if we get one that has a very similar, but incompatible ABI, we still introduce a new label: compatible = "marvell,foobar2-sata"; And everything works properly. > > We already have a compatible string defined for the ABI that B0 > > presents. > > So 'mv78230-i2c' is newer than 'mv78230-a0-i2c', or are you referring to > something else? 'mv78230-i2c' is the name that was picked to describe the ABI that works as-documented in the manual 'mv78230-a0-i2c' is the name that was picked to describe the ABI that works as-implemented in the A0 chip :) There is no newer/older, they are just two different ABIs. I guess it turns out that 'mv78230-a0-i2c' is a strict compatible subset of 'mv78230-i2c' - but that doesn't really make a difference. The 'mv78230-i2c' driver is guarenteed avaialble in all places where the 'mv78230-a0-i2c' driver would be available. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
