On Fri, Jan 18, 2013 at 5:56 PM, Hartmut Knaack <knaack.h@xxxxxx> wrote: > Hi, > I've built myself a joystick adapter (project website: http://www.hexagons.de/index.php/USB_Joystickadapter), which has the purpose of connecting up to 2 Atari style joysticks (the ones with db9 connectors, found on 80's home computers like C64, Amiga,...) via USB. Current situation is: on Windows XP, 2 joystick devices get created with 2 axis and 2 buttons each (as intended); while on Linux, just one joystick device (/dev/input/js0) gets created, but with 4 axis and 4 buttons. > This device provides one interface with one Interrupt-in Endpoint. The division into two joystick devices is done using an HID descriptor [1] with two configurations and the REPORT_ID tag. > What I would like to know is, is there a problem in the Linux HID parser, or is its behavior intentional and those composite devices more like a dirty solution around the standards? Hi, well, currently, the HID parser does not split the different reportID into several devices. It's a known limitation and we are working on it (at least we already saw problems with that), but it will not make it in 3.9 I think. The solution that works for now is to use several usb interfaces. The usb layer splits the different interfaces, so it will give you 2 different HID devices. Oh, and if you want to contribute to split the device in the HID parser under Linux, you are welcome as well :) Cheers, Benjamin > Thanks > > Hartmut Knaack > > [1] > char usbHidReportDescriptor[102] PROGMEM = { > > // Joystick Port 1 > > 0x05, 0x01, // USAGE_PAGE (Generic Desktop) > 0x09, 0x04, // USAGE (Joystick) > 0xa1, 0x01, // COLLECTION (Application) > 0x85, 0x01, // REPORT_ID (1) > 0x09, 0x01, // USAGE (Pointer) > 0xa1, 0x00, // COLLECTION (Physical) > 0x09, 0x30, // USAGE (X) > 0x09, 0x31, // USAGE (Y) > 0x15, 0x00, // LOGICAL_MINIMUM (0) > 0x26, 0xff, 0x00, // LOGICAL_MAXIMUM (255) > 0x75, 0x08, // REPORT_SIZE (8) > 0x95, 0x02, // REPORT_COUNT (2) > 0x81, 0x02, // INPUT (Data,Var,Abs) > 0xc0, // END_COLLECTION > 0x05, 0x09, // USAGE_PAGE (Button) > 0x19, 0x01, // USAGE_MINIMUM (Button 1) > 0x29, 0x02, // USAGE_MAXIMUM (Button 2) > 0x15, 0x00, // LOGICAL_MINIMUM (0) > 0x25, 0x01, // LOGICAL_MAXIMUM (1) > 0x75, 0x01, // REPORT_SIZE (1) > 0x95, 0x02, // REPORT_COUNT (2) > 0x81, 0x02, // INPUT (Data,Var,Abs) > 0x75, 0x06, // REPORT_SIZE (6) > 0x95, 0x01, // REPORT_COUNT (1) > 0x81, 0x03, // INPUT (Constant,Var,Abs) > 0xc0, // END_COLLECTION > > // Joystick Port 2 > > 0x05, 0x01, // USAGE_PAGE (Generic Desktop) > 0x09, 0x04, // USAGE (Joystick) > 0xa1, 0x01, // COLLECTION (Application) > 0x85, 0x02, // REPORT_ID (2) > 0x09, 0x01, // USAGE (Pointer) > 0xa1, 0x00, // COLLECTION (Physical) > 0x09, 0x30, // USAGE (X) > 0x09, 0x31, // USAGE (Y) > 0x15, 0x00, // LOGICAL_MINIMUM (0) > 0x26, 0xff, 0x00, // LOGICAL_MAXIMUM (255) > 0x75, 0x08, // REPORT_SIZE (8) > 0x95, 0x02, // REPORT_COUNT (2) > 0x81, 0x02, // INPUT (Data,Var,Abs) > 0xc0, // END_COLLECTION > 0x05, 0x09, // USAGE_PAGE (Button) > 0x19, 0x01, // USAGE_MINIMUM (Button 1) > 0x29, 0x02, // USAGE_MAXIMUM (Button 2) > 0x15, 0x00, // LOGICAL_MINIMUM (0) > 0x25, 0x01, // LOGICAL_MAXIMUM (1) > 0x75, 0x01, // REPORT_SIZE (1) > 0x95, 0x02, // REPORT_COUNT (2) > 0x81, 0x02, // INPUT (Data,Var,Abs) > 0x75, 0x06, // REPORT_SIZE (6) > 0x95, 0x01, // REPORT_COUNT (1) > 0x81, 0x03, // INPUT (Constant,Var,Abs) > 0xc0 // END_COLLECTION > }; > -- > 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 -- 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
