On Thu, Jun 14, 2012 at 07:57:32PM +0100, Lee Jones wrote: > On 14/06/12 19:36, Mark Brown wrote: >> On Wed, Jun 13, 2012 at 01:28:17PM +0100, Lee Jones wrote: >> >>> Device Tree. However, we have just as much control by keeping them >>> in separate structs in the C file and selecting the right one using >>> the compatible sting. >> >> You're not understanding Linus' point. The compatible string isn't >> useful here because properties like the maximum clock rate of the bus >> depend on the board design, not the silicon. The controller may be >> perfectly happy to run at a given rate but other devices on the bus or >> the electrical engineering of the PCB itself may restrict this further. > > And you're not understanding mine. ;) > > You can have multiple compatible strings for a single driver. Which one > you reference from the Device Tree will dictate which group of settings > are used, including variation of clock rates. However, if you list these settings separately, rather than selecting them based on a compatible string, it means when other board designs come along, you don't have to modify the kernel code to provide yet another compatible to settings translation in the code - you can keep all that information entirely within DT with no kernel code mods. I thought that was partly the point of DT... -- 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
