On Thu, Nov 11, 2010 at 1:38 PM, Henrik Rydberg <rydberg@xxxxxxxxxxx> wrote: > >> Are we going to do the tocuh and pen aribtration in input-mt.c? I need >> to understand this to make my patches. > > If the pen is implemented as just another contact, it will also be treated as > such, and arbitration becomes the same thing as single-pointer emulation. New questions occured when I think about input-mt.c. How are we going to pass MT_TOOL types and resolution to the userland? We need to pass MT_TOOL types to the userland since there would be different tools in the same slot array. Something like: input_report_key(input, MT_TOOL_PEN, prox); is needed. To do so, we need to enable them by a call to __set_bit(MT_TOOL_.... first. But, __set_bit wasn't meant for MT_TOOL_ since 0 (MT_TOOL_FINGER) and 1 (MT_TOOL_PEN) are used for KEY_RESERVED and KEY_ESC. One way to make this work is to increase MT_TOOL_FINGER from 0 to something like 0x2ff (we need to increase KEY_MAX as well). Luckily MT_TOOL_ is not in any of the existing HID drivers. Another solution could be to pass the tool type as ABS values since we have ABS_MT_TOOL_TYPE defined already: input_report_abs(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER); ......... input_set_abs_params(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER, MT_TOOL_PEN ....) . We need to add more MT tool types, such as MT_TOOL_AIRBRUSH...., for styli. Not sure if we want to go that far or not. I have thought about the resolution issue for a while. I didn't want to tocuh it since it affects all HID drivers. Resolution has been added to absinfo since kernel 2.6.31. But no kernel driver has passed resolution to the userland yet. We (linuxwacom project) still keep a resolution table in the X driver. Passing resolution to the userland from the kernel can get rid of those tables and avoid retrieving that information from HID descriptor. One simple way to support resolution is to add "int res" to input_set_abs_params(...). This means an interface change. All HID drivers that call input_set_abs_params() have to be updated. We could introduce a new input_set_abs_something so only those drivers that want to pass the resolution switch to the new routine. Maybe you guys have other suggestions? Ping -- 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
