On Fri, Sep 18, 2009 at 10:56:01AM -0300, Henrique de Moraes Holschuh wrote: > On Thu, 17 Sep 2009, Dmitry Torokhov wrote: > > On Thu, Sep 17, 2009 at 02:57:07PM -0300, Henrique de Moraes Holschuh wrote: > > > On Wed, 16 Sep 2009, Rick L. Vinyard, Jr. wrote: > > > > The M* keys are intended to provide a quick way to switch between key > > > > mappings, with each mode having their own user-defined mappings. > > > > > > What I'd do in this case would be this: > > > > > > 1. Initially have the M* level-shift keys assigned KEY_RESERVED > > > > > > 2. Have a big enough keymap to map all keys in all M*-level shift states > > > possible. > > > > > > Eg: > > > START OF KEYMAP > > > M* keys > > > 1st set of G* keys > > > 2nd set of G* keys > > > 3rd set of G* keys... > > > ... > > > last set of G* keys > > > END OF KEYMAP > > > > > > 3. Have the driver special-process M* level-shift keys *as long as they are > > > still set to KEY_RESERVED* to select which part of the keymap is used to > > > translate the other keys. Note that this likely means pressing a M* key > > > would be transparent to userspace in this case, i.e. no events would be > > > issued when a M* key is doing a level shift. > > > > > > So, you'd be able to set all mappings you want in the driver, and the M* > > > keys would do what they're expected to do without any userland help at all, > > > but you'd still be able to program the M* keys to be normal keys if you > > > want. > > > > > > Of course, this assumes you don't do chording on multiple M* keys to end up > > > with a huge number of keymaps :p > > > > Actually I think that the device should just emit KEY_PROG1..KEY_PROG4 > > for the M keys and have userspace daemon load alternate keymaps on the > > fly in resaponse to KEY_PROGx. The device is just a set of completely > > generic buttons... User will have to tell the kernel what to map them > > to. > > It would work, but it is a big trip through userspace. If quickly pressing > M#+G# is a common use pattern (and it will be, for gaming), i.e. you often > want to access quickly a function on one level then another on a different > level, asking userspace to upload a new keymap to switch levels at every M# > press is going to be way too racy. I'd say it should be pretty quick, compared to what a game needs to do to render a single frame. -- Dmitry -- 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
