From patchwork Wed Dec 5 00:42:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Hutterer X-Patchwork-Id: 10712851 X-Patchwork-Delegate: jikos@jikos.cz Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CEAE413BF for ; Wed, 5 Dec 2018 00:43:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCBBF2CA49 for ; Wed, 5 Dec 2018 00:43:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B14432CA62; Wed, 5 Dec 2018 00:43:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EC9162CA49 for ; Wed, 5 Dec 2018 00:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726744AbeLEAnB (ORCPT ); Tue, 4 Dec 2018 19:43:01 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:45003 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726731AbeLEAnA (ORCPT ); Tue, 4 Dec 2018 19:43:00 -0500 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 2E2BDCB5; Tue, 4 Dec 2018 19:42:59 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Tue, 04 Dec 2018 19:42:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=who-t.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=fm1; bh=El/5AD1IxDyIY e1C6QEB3WZxrJCG31Xg0m6pkSD0av8=; b=L7006ckOtlK93TnS8WTw4XmN8M/Vg nbAqH7kFKwoL25+BS/bXsX9Madro17o8L2fpMbXRFVteBy8q5PCqdgGP7zgAuVrV 59B+8Lm7Ixx/OdHOO4Vi38Gz3t9QuZcgxC7Z+hrid2lZBgs2BQdwrhtBk2PDpBfi q3uRUQ/Hxrg3odnuN8Fy71A+pkhEbI2O/EeRU26mZb4roYLzXnnADR5q7E3No88b KXBqJ5OpsTm3lC8FAYN6AmzsuLk3z7EfutBr6fpO9Ecf5+dV0ZAufbAKETieHP8/ 2vPMGkSyzCOMiFUZjnY13yF+7OCFkapGLJT65UEz4YmbiAhot8RgbT4BA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=El/5AD1IxDyIYe1C6QEB3WZxrJCG31Xg0m6pkSD0av8=; b=gpOFRZuT 9o5hj53VnAF/wQcOeaxOm/4gOc2U+bUtow3r7Tr4336hl5vJdI+JRqOOxbDUJZWv zOgo53w1zP6dpRiTZQK6ruV4MfiYvlzX8M9le4Hpo1XVCMgjNtwvMXCuf31Js7tA wIO2WTP+HOYgiKP8NsBTWvwJgrbfiMrPqG4GMyP9I2BZH4bvHexWB7QV4YfdMs5F J6adNDukEqKtzWHuqujRTH0igtFaMKzN1ayl5nE3RKi0sALCwQCHx3O4Qn9SCl4K w78d2JOa3AMCe2r7c0fZVJOH2EWULX1oGPJyULNiG3t1pNmCVogtxsNIZ/5GiQPM N8q+aZyJP/PMBw== X-ME-Sender: X-ME-Proxy: Received: from jelly.home.gateway (167-179-166-29.a7b3a6.bne.nbn.aussiebb.net [167.179.166.29]) by mail.messagingengine.com (Postfix) with ESMTPA id A038CE48FA; Tue, 4 Dec 2018 19:42:55 -0500 (EST) From: Peter Hutterer To: linux-input@vger.kernel.org Cc: Dmitry Torokhov , Jiri Kosina , Harry Cutts , torvalds@linux-foundation.org, Nestor Lopez Casado , linux-kernel@vger.kernel.org, Benjamin Tissoires Subject: [PATCH v3 3/8] HID: core: process the Resolution Multiplier Date: Wed, 5 Dec 2018 10:42:23 +1000 Message-Id: <20181205004228.10714-4-peter.hutterer@who-t.net> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181205004228.10714-1-peter.hutterer@who-t.net> References: <20181205004228.10714-1-peter.hutterer@who-t.net> MIME-Version: 1.0 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The Resolution Multiplier is a feature report that modifies the value of Usages within the same Logical Collection. If the multiplier is set to anything but 1, the hardware reports (value * multiplier) for the same amount of physical movement, i.e. the value we receive in the kernel is pre-multiplied. The hardware may either send a single (value * multiplier), or by sending multiplier as many reports with the same value, or a combination of these two options. For example, when the Microsoft Sculpt Ergonomic mouse Resolution Multiplier is set to 12, the Wheel sends out 12 for every detent but AC Pan sends out a value of 3 at 4 times the frequency. The effective multiplier is based on the physical min/max of the multiplier field, a logical min/max of [0,1] with a physical min/max of [1,8] means the multiplier is either 1 or 8. The Resolution Multiplier was introduced for high-resolution scrolling in Windows Vista and is commonly used on Microsoft mice. The recommendation for the Resolution Multiplier is to default to 1 for backwards compatibility. This patch adds an arbitrary upper limit at 255. The only known use case for the Resolution Multiplier is for scroll wheels where the multiplier has to be a fraction of 120 to work with Windows. Signed-off-by: Peter Hutterer --- Changes since v1, v2: - expanded the commit message with more detail drivers/hid/hid-core.c | 170 +++++++++++++++++++++++++++++++++++++++++ include/linux/hid.h | 5 ++ 2 files changed, 175 insertions(+) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 43d488a45120..f41d5fe51abe 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -294,6 +294,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign field->usage[i].collection_index = parser->local.collection_index[j]; field->usage[i].usage_index = i; + field->usage[i].resolution_multiplier = 1; } field->maxusage = usages; @@ -947,6 +948,167 @@ struct hid_report *hid_validate_values(struct hid_device *hid, } EXPORT_SYMBOL_GPL(hid_validate_values); +static int hid_calculate_multiplier(struct hid_device *hid, + struct hid_field *multiplier) +{ + int m; + __s32 v = *multiplier->value; + __s32 lmin = multiplier->logical_minimum; + __s32 lmax = multiplier->logical_maximum; + __s32 pmin = multiplier->physical_minimum; + __s32 pmax = multiplier->physical_maximum; + + /* + * "Because OS implementations will generally divide the control's + * reported count by the Effective Resolution Multiplier, designers + * should take care not to establish a potential Effective + * Resolution Multiplier of zero." + * HID Usage Table, v1.12, Section 4.3.1, p31 + */ + if (lmax - lmin == 0) + return 1; + /* + * Handling the unit exponent is left as an exercise to whoever + * finds a device where that exponent is not 0. + */ + m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin); + if (unlikely(multiplier->unit_exponent != 0)) { + hid_warn(hid, + "unsupported Resolution Multiplier unit exponent %d\n", + multiplier->unit_exponent); + } + + /* There are no devices with an effective multiplier > 255 */ + if (unlikely(m == 0 || m > 255 || m < -255)) { + hid_warn(hid, "unsupported Resolution Multiplier %d\n", m); + m = 1; + } + + return m; +} + +static void hid_apply_multiplier_to_field(struct hid_device *hid, + struct hid_field *field, + struct hid_collection *multiplier_collection, + int effective_multiplier) +{ + struct hid_collection *collection; + struct hid_usage *usage; + int i; + + /* + * If multiplier_collection is NULL, the multiplier applies + * to all fields in the report. + * Otherwise, it is the Logical Collection the multiplier applies to + * but our field may be in a subcollection of that collection. + */ + for (i = 0; i < field->maxusage; i++) { + usage = &field->usage[i]; + + collection = &hid->collection[usage->collection_index]; + while (collection && collection != multiplier_collection) + collection = collection->parent; + + if (collection || multiplier_collection == NULL) + usage->resolution_multiplier = effective_multiplier; + + } +} + +static void hid_apply_multiplier(struct hid_device *hid, + struct hid_field *multiplier) +{ + struct hid_report_enum *rep_enum; + struct hid_report *rep; + struct hid_field *field; + struct hid_collection *multiplier_collection; + int effective_multiplier; + int i; + + /* + * "The Resolution Multiplier control must be contained in the same + * Logical Collection as the control(s) to which it is to be applied. + * If no Resolution Multiplier is defined, then the Resolution + * Multiplier defaults to 1. If more than one control exists in a + * Logical Collection, the Resolution Multiplier is associated with + * all controls in the collection. If no Logical Collection is + * defined, the Resolution Multiplier is associated with all + * controls in the report." + * HID Usage Table, v1.12, Section 4.3.1, p30 + * + * Thus, search from the current collection upwards until we find a + * logical collection. Then search all fields for that same parent + * collection. Those are the fields the multiplier applies to. + * + * If we have more than one multiplier, it will overwrite the + * applicable fields later. + */ + multiplier_collection = &hid->collection[multiplier->usage->collection_index]; + while (multiplier_collection && + multiplier_collection->type != HID_COLLECTION_LOGICAL) + multiplier_collection = multiplier_collection->parent; + + effective_multiplier = hid_calculate_multiplier(hid, multiplier); + + rep_enum = &hid->report_enum[HID_INPUT_REPORT]; + list_for_each_entry(rep, &rep_enum->report_list, list) { + for (i = 0; i < rep->maxfield; i++) { + field = rep->field[i]; + hid_apply_multiplier_to_field(hid, field, + multiplier_collection, + effective_multiplier); + } + } +} + +/* + * hid_setup_resolution_multiplier - set up all resolution multipliers + * + * @device: hid device + * + * Search for all Resolution Multiplier Feature Reports and apply their + * value to all matching Input items. This only updates the internal struct + * fields. + * + * The Resolution Multiplier is applied by the hardware. If the multiplier + * is anything other than 1, the hardware will send pre-multiplied events + * so that the same physical interaction generates an accumulated + * accumulated_value = value * * multiplier + * This may be achieved by sending + * - "value * multiplier" for each event, or + * - "value" but "multiplier" times as frequently, or + * - a combination of the above + * The only guarantee is that the same physical interaction always generates + * an accumulated 'value * multiplier'. + * + * This function must be called before any event processing and after + * any SetRequest to the Resolution Multiplier. + */ +void hid_setup_resolution_multiplier(struct hid_device *hid) +{ + struct hid_report_enum *rep_enum; + struct hid_report *rep; + struct hid_usage *usage; + int i, j; + + rep_enum = &hid->report_enum[HID_FEATURE_REPORT]; + list_for_each_entry(rep, &rep_enum->report_list, list) { + for (i = 0; i < rep->maxfield; i++) { + /* Ignore if report count is out of bounds. */ + if (rep->field[i]->report_count < 1) + continue; + + for (j = 0; j < rep->field[i]->maxusage; j++) { + usage = &rep->field[i]->usage[j]; + if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER) + hid_apply_multiplier(hid, + rep->field[i]); + } + } + } +} +EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier); + /** * hid_open_report - open a driver-specific device report * @@ -1043,9 +1205,17 @@ int hid_open_report(struct hid_device *device) hid_err(device, "unbalanced delimiter at end of report description\n"); goto err; } + + /* + * fetch initial values in case the device's + * default multiplier isn't the recommended 1 + */ + hid_setup_resolution_multiplier(device); + kfree(parser->collection_stack); vfree(parser); device->status |= HID_STAT_PARSED; + return 0; } } diff --git a/include/linux/hid.h b/include/linux/hid.h index fdfda898656c..fd8d860365a4 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -219,6 +219,7 @@ struct hid_item { #define HID_GD_VBRZ 0x00010045 #define HID_GD_VNO 0x00010046 #define HID_GD_FEATURE 0x00010047 +#define HID_GD_RESOLUTION_MULTIPLIER 0x00010048 #define HID_GD_SYSTEM_CONTROL 0x00010080 #define HID_GD_UP 0x00010090 #define HID_GD_DOWN 0x00010091 @@ -437,6 +438,8 @@ struct hid_usage { unsigned hid; /* hid usage code */ unsigned collection_index; /* index into collection array */ unsigned usage_index; /* index into usage array */ + __s8 resolution_multiplier;/* Effective Resolution Multiplier + (HUT v1.12, 4.3.1), default: 1 */ /* hidinput data */ __u16 code; /* input driver code */ __u8 type; /* input driver type */ @@ -894,6 +897,8 @@ struct hid_report *hid_validate_values(struct hid_device *hid, unsigned int type, unsigned int id, unsigned int field_index, unsigned int report_counts); + +void hid_setup_resolution_multiplier(struct hid_device *hid); int hid_open_report(struct hid_device *device); int hid_check_keys_pressed(struct hid_device *hid); int hid_connect(struct hid_device *hid, unsigned int connect_mask);