On Wednesday 20 April 2011 08:39:59 Arend van Spriel wrote: > On Tue, 19 Apr 2011 16:02:57 +0200, Greg KH <greg@xxxxxxxxx> wrote: > > > Please don't use a platform device, unless there is no other way for > > your device to work. For this device, you are connected to the PCI bus, > > so a platform device does not make sense at all. > > Hi Greg, > > This is only true for a particular usage model. There are two models as > shown below: > > 1) PCI(e) card > ........... > +----------+ : x y z : x, y, and z are cores. > | uC |__________:___|_|_| : > | | PCI-bus : axi-bus : > +----------+ :.........: > bcm chipset > > 2) SoC > ............... > : uC x y z : > : |____|_|_| : > : axi-bus : > :.............: > bcm chipset > > Your statement is true for 1) but in usage model 2) there is no PCI bus. > Also you refer to the chipset when you say 'device'. In the axi bus type > each individual core is registered as a device in the linux device tree. I guess what Greg was referring to is having platform devices for x/y/z here. In case 2, you might still need to have a platform_device for the combination of the three IP cores if they make up one logical device. As mentioned in my reply, it depends a lot on what these cores actually are, e.g. whether you might want to have only one of them active in a given system to drive a specific functionality, or if you always need all three of them. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
