On Tue, Nov 23, 2010 at 2:30 PM, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > On Tue, Nov 23, 2010 at 12:48:07PM -0800, Ping Cheng wrote: >> Hi all, >> >> I am not going to write a patch for this request before I get the >> permission for the new tool type. It affects all touch screen devices >> (under drivers/input/touchscreen) that support both pen and touch. >> >> Right now, in the user land, BTN_TOUCH is used to indicate a single >> touch events. BTN_TOUCH and !BTN_TOOL_PEN >> (http://udev.sourcearchive.com/documentation/161-1/input__id_8c-source.html) >> are used to determine if the device is a touch screen device or not a >> pen. With both pen and touch on the same logical port (serial touch >> screen with pen and touch enabled, refer to wacom_w8001.c), BTN_TOUCH >> and !BTN_TOOL_PEN will always be false, which indicates a >> non-touchscreen device. That is wrong. >> >> Unless we have other means to tell the user land a device is a >> touchscreen, BTN_TOUCH with !BTN_TOOL_PEN won't do the job for us. >> >> I've already had a value for the new type: >> >> +#define BTN_TOOL_TOUCH 0x149 >> >> This new type resolves the confusion we had for the existing serial >> pen and touch enabled touchscreen devices. Considering we are merging >> the two logical ports for USB devices, the new type is required for >> the future USB touchscreen support as well. > > How is BTN_TOOL_TOUCH is different from BTN_TOOL_FINGER? Good question. BTN_TOOL_FINGER is used for touchpad or trackpad, or whichever term that works for you. It indicates a relative cursor movement. The touch screen needs to translate the (x,y) events into absolute movement. That's why none of those touchscreen drivers use BTN_TOOL_FINGER so far. Any more questions ;)? 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
