From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chase Douglas Subject: Re: [PATCH v2] Documentation: Add evdev type and code definitions Date: Fri, 07 Jan 2011 17:15:17 -0500 Message-ID: <4D279075.4080503@canonical.com> References: <1294435695-16750-1-git-send-email-chase.douglas@canonical.com> <4D278E6B.7020002@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D278E6B.7020002@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Nikolai Kondrashov Cc: Dmitry Torokhov , Henrik Rydberg , Chris Bagwell , Peter Hutterer , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org On 01/07/2011 05:06 PM, Nikolai Kondrashov wrote: > On 01/08/2011 12:28 AM, Chase Douglas wrote: >> +* BTN_TOOL_: >> + - These codes are used in conjunction with input trackpads, tablets, and >> + touchscreens. These devices may be used with fingers, pens, or other tools. >> + When an event occurs and a tool is used, the corresponding BTN_TOOL_ >> + code should be set to a value of 1. When the tool is no longer interacting >> + with the input device, the BTN_TOOL_ code should be reset to 0. All >> + trackpads, tablets, and touchscreens should use at least one BTN_TOOL_ >> + code when events are generated. > > There are some tablets (namely UC-Logic ones), which do not indicate tool > proximity. Yet they may have both a pen and a mouse. They just send reports > with separate report IDs. Currently it is solved by using > HID_QUIRK_MULTI_INPUT and not sending any BTN_TOOL_* events. > > Should the documentation reflect the fact that some tablets do not send any > BTN_TOOL_* events, or should the drivers be updated to synthesise them? I think it should be stated more obviously that all evdev codes are optional except for specific cases, such as BTN_TOUCH for any type of touch device. My understanding is that BTN_TOOL_ is optional. Perhaps I should do something like the following for all the evdev codes: * : - Usage: Required|Optional|Required when ... etc. - > Note that in the latter case there will never be a BTN_TOOL_* with > zero value when the tool leaves the digitizing area, but only when the tools > are switched (if ever). Hmm.. That seems incorrect to me. Why wouldn't it follow the behavior outlined above? -- Chase