johann deneux wrote: > On 3/27/07, Jiri Slaby <[EMAIL PROTECTED]> wrote: > >> Ok, so how to deal with these devices? Does anybody have some idea? >> That's >> what I was talking about somewhere in the beginning of this thread, >> the raw >> values, because it seems too specific for letting kernel to cope with >> each >> of these devices separately, but there might be a better idea in >> somebody's >> head? But raw is ugly... >> > > What about adding a member to ff_effect which would be the number of the > motor? > We can't change the layout of ff_effect too much though, so we have to > find unused bits and put them to work.
Actually, having thought more about this, I'm beginning to believe Jiri's original FF_RAW approach could actually be a good option to add 3d effect support to the API. It would be similar to FF_CONSTANT but instead of angle+magnitude the force is defined as s16 per every axis (so it could actually be used with current drivers as well). Alternatively we could define FF_3D_CONSTANT as an usual FF_CONSTANT with an additional direction value, allowing a 3D force to be described using 2x direction and magnitude. Or we could define both ;) Howewer, if I understood correctly that the 3 values the phantom device takes are not really magnitudes along X, Y, Z, but some possibly unaligned motors specific to this device, we cannot really abstract the device motors into a 3D force effect. We could still add some FF_RAW type, however, but with the values representing motors instead of axes, with the exact function (direction) of each motor being left undefined in the API (unlike the FF_RAW type I was talking a few paragraphs ago, this type of course wouldn't be used at all by other drivers). > Another possibility is to get rid of "trigger" and replace it by __u8 > motor and some padding, since that's I-Force specific (are there other > drivers that implement that?). The goal of "trigger" is to start an > effect when a button is pressed, which can be done from userland > instead. It's not like we need micro-second latency when starting > effects. The generic PID driver implements that. I also think implementing the support in software for the devices not supporting triggers in hw could be quite easily done in ff-core.c or ff-memless.c. (I also don't know what the triggers are useful for) johann deneux also wrote in another message: > The > problem is to make an extension that does not duplicate the > capabilities of the existing API. We don't want to have two ways of > specifying the same effects. How is this a problem? -- Anssi Hannula - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
