From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753843AbaEUWms (ORCPT ); Wed, 21 May 2014 18:42:48 -0400 Received: from host171.canaca.com ([67.55.55.225]:53425 "EHLO host171.canaca.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753342AbaEUWmq (ORCPT ); Wed, 21 May 2014 18:42:46 -0400 Message-ID: <77e93715d28deb2ec0508f9326f9102f.squirrel@mungewell.org> In-Reply-To: <537D28E3.3000401@logitech.com> References: <1398524543-15012-1-git-send-email-madcatxster@devoid-pointer.net> <2965006.XKYHWj9YzJ@sigyn> <537B9FAE.9070602@logitech.com> <10859911.6zyzadbfH9@sigyn> <537BCB63.1020200@logitech.com> <537D28E3.3000401@logitech.com> Date: Wed, 21 May 2014 18:42:40 -0400 Subject: Re: [PATCH v4 01/24] input: Add ff-memless-next module From: simon@mungewell.org To: "Roland Bosa" Cc: "Elias Vanderstuyft" , =?iso-8859-1?Q?=22Michal_Mal=C3=BD=22?= , "Dmitry Torokhov" , "HID CORE LAYER" , "linux-kernel@vger.kernel.org" , "Jiri Kosina" , "Anssi Hannula" , "Simon Wood" User-Agent: SquirrelMail/1.4.22 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - host171.canaca.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - mungewell.org X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> But 2 Spring effects with different offsets and non-zero effective >> force can't be combined into a single slot (without streaming them >> with Constant force), right? > > Yes - you cannot *download* two springs to a single slot. You need to > choose (allocate) one of them. The winner gets the slot. The losers go > somewhere else (they might get discarded, they might get simulated). In reverse engineering, I thought that a single slot could hold two rotational angles/points (at which a springs would start) and that that the direction could be set so that both acting in the same direction with different forces. -- Byte 2 - 0x_1 Byte 3 - Clockwise angle, nominally on left (0x00..0xFF - 0x00 is fully left) Byte 4 - Anti-Clockwise angle, nominally on right(0x00..0xFF) Byte 5 - L/R Proportion force, upper nibble clockwise + lower nibble anti-clockwise (each 0x0..0xF) Byte 6 - Reverse Direction; upper nibble clockwise + lower nibble anti-clockwise (each 0x0..0x1) Byte 7 - Force (0x00..0xFF) -- Ie. turning from fully left (00) with no force, you could hit a 'weak' spring (at 40) and then a 'stronger' spring (at 80). So to some degree you /can/ merge springs... but I'm not saying that you should :-). Simon