On Mon, Feb 16, 2009 at 01:09:00PM -0500, Mike Murphy wrote: > On Mon, Feb 16, 2009 at 11:13 AM, Greg KH <greg@xxxxxxxxx> wrote: > ... > > > > The bigger question is why are you using a struct kobject in the first > > place? As you are a device, just use a struct device. What are you > > trying to do in sysfs here to make you want to use a "raw" kobject in a > > driver? > > > > thanks, > > > > greg k-h > > > > The purpose of the struct xpad_data (which contains the struct > kobject) is to expose parameters that can be read and/or tweaked at > runtime. At the moment, the adjustable parameters are the size of the > dead zone around the center of the stick, and the choice of whether to > map to a square axis. Read-only data include a unique identifier for > each pad (wireless) and an indication as to whether the wireless pad > is actually connected. Then hang those parameters off the struct device you already have. > The idea behind this interface is to enable a future userspace > application, likely using HAL and D-BUS, to receive events whenever a > wireless pad connects, and to identify the particular pad in question > (specifically, the unique ID of the pad). The user could then, for > example, have a different dead zone size for each pad, based upon the > actual manufacturing variations in the sticks on that pad (some appear > more precise at centering than others). Ideally, this functionality > could be designed in a "common" way so that the userspace code could > eventually work with other, non-xpad gaming devices. Have you documented them in Documentation/ABI? > I didn't use a struct device because of the existing struct usb_xpad > that was created on a per-gamepad basis (not necessarily per device, > as the wireless 360 adapter is one physical device but exposes 4 > gamepads by exposing 4 logical devices [and then each gamepad, in > turn, is technically a USB hub that can have other stuff > attached...]). Put it on the logical device, as given to you. > I tried not to break existing functionality. Additionally, struct > usb_xpad contains two device pointers: one to the actual USB device, > and one to an input device (see source of the in-tree xpad.c). So I > followed your kobject.txt documentation and samples to create a new > object whose sole purpose in life is to expose the sysfs interface, > without interfering with the existing device entries in the driver. > I'm not sure I see a clean way to use a single struct device here.... Put it on the input device, which is what is the per-device thing. It's much simpler than creating a new struct kobject. You can even create a subdirectory for your attributes if you use an attribute group (which you should be doing anyway, it's much simpler that way.) And document the attributes please. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
