Hello Dmitry, Dmitry Torokhov wrote: > On Thu, Apr 16, 2009 at 08:22:34AM +0200, Heiko Schocher wrote: >> Hello, >> >> I maybe get a projekt, where I have 2 PS/2 ports (a keyboard and a mousse) >> connected to one UART and the multiplexing is done by a PIC. >> >> I searched in actual 2.6 Kernel sources for such a solution, but >> couln;t find one. Overlooked I something? >> >> For 2.4er Kernel there was such a driver, see >> >> http://git.denx.de/?p=linuxppc_2_4_devel.git;a=blob;f=drivers/char/ps2mult.c >> >> but, I think, this is no longer portable to 2.6. >> >> So, thats why I am here and want to ask the experts how to solve >> this problem in a mainline acceptable way, before I make a hack, >> that never has a chance to go in mainline. >> >> Some suggestions from me (maybe they are all bad) >> >> I looked in drivers/input/serio/serio.c and could think of adding >> the multiplexing in serio_interrupt(), and call serio_driver specific >> serio->drv->interrupt functions, when I know, which byte come from >> which device. But, if I see it right, I can only add one "struct >> serio_driver *drv;" driver to one serio port, so it is not possible >> to handle 2 or more devices over one serio port :-( >> Maybe we enhance this too ... ? >> >> Or I make a combinated (keyboard/mousse) driver which uses one >> serio port ... but I think thats a bad idea, also no idea, in which >> directory i have to add such a driver. >> >> So I think it would nice to have the possibility to add more than >> one serio_driver to a serio_port and add a "multiplexer" layer ... >> but I am new to the input layer, so I ask the experts. >> >> Hopefully I just missed something in actual code, and there is >> better/easier way? ;-) >> > > You need to create 2 serio ports in your driver and have it send data > into appropriate port, depending on what device it came from. If you > take a look at i8042 driver it does exactly that. We have 1 serio port > for keyboard and eithe 1 or 4 AUX serio ports. In i8042_interrupt we > check the status bit to figure to which serio port incoming byte should > be routed and act accordingly. Ah, thanks for this hint :-) OK, so I have to write a serial driver for the uart on my hardware, and add this in drivers/serio, right? Hmm.. spontaneous I think (maybe it is a bad thought), what do you think to the following approach: I didn;t want to write a new serio driver for my uart (mpc5200 internal PSC Uart), because there is a working tty driver for this, and the multi- plexing functionality is just a protocoll ... so I think of using the drivers/serio/serport.c and add this "multiplexing" functionality to the serport.c driver ... is this worth about to think? this should be a more general approach then writting a special serial driver for "my" UART ... what do you think? > Hope this helps. of course, thanks! bye Heiko -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
