From patchwork Wed Jul 10 23:04:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atif Niyaz X-Patchwork-Id: 11039091 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 93D2614F6 for ; Wed, 10 Jul 2019 23:04:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7730B287E7 for ; Wed, 10 Jul 2019 23:04:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 67C512883B; Wed, 10 Jul 2019 23:04:16 +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=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL 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 C3CED287E7 for ; Wed, 10 Jul 2019 23:04:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727458AbfGJXEP (ORCPT ); Wed, 10 Jul 2019 19:04:15 -0400 Received: from mail-pf1-f201.google.com ([209.85.210.201]:46246 "EHLO mail-pf1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726708AbfGJXEP (ORCPT ); Wed, 10 Jul 2019 19:04:15 -0400 Received: by mail-pf1-f201.google.com with SMTP id g21so2229002pfb.13 for ; Wed, 10 Jul 2019 16:04:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=ZtSCYRHrfuqeQFIWIan5FMIhgUsXnRQXRzmzNcRVTvA=; b=JqyQFu/936dQlgKHtsm7+vkRRQ2FEGjcK3zyQ9FtJTEogsQurFNSrSQfqiihOFvzgu Rtc9EflergHRlqVhiQVuq4nVY6xEROwEZtJS2dBlrVKGjSCsqJmnesNfSlGsIw1jEyJ+ 5UQ6ljtGbHhdwtwJzNUMXzuKU9OQpDDcfuvGpOQmTm429CJovYJNlxYoWAlDZqKWBBoX MYYrRFAtRJu1HRDuUNOSq5MO5o+EFmKQKJG5XDs2iM/kKNvBrIWDyE62CzhcMZBqp2CK pwjyNgBO8PHHICfiCD5KEfHRr7Is0xnKFyALCSFmVBjzMr9Iqkam5xNclyDDqCyTK8/k kvsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=ZtSCYRHrfuqeQFIWIan5FMIhgUsXnRQXRzmzNcRVTvA=; b=iwAO9E/DaO8x29zbnHZcw4jmyAFiMDb47KzRGD27gXAlkXBpLZcx8pPM0geVDLXpNF LF1Fee3oYfOWzqS6tPL4JutgjWcn7IHln7Jc8rSdpp8skEVt9JqFrYe3b7IbhS4f9621 FHN+I9k1g/5tXcPszqDzFgXgSxND82h7xYLVO/tn41oXAJOjMnheB1Jwpxo3O6aOWLP3 wD9z1BDCSJaQJisEitQnmWYWo/ZwpPBJraEt+h3rj4EP0i9VSPAF23kJMRj/p3PkY65W l7mit7Rknf2t1qlv4I7e2C/prFpeAzfLDppS4HYQv8ByRcfbPRNs5ZtARemLHvr4mSFO hcYQ== X-Gm-Message-State: APjAAAUzBdWwwkfYIhIGypwsDH2WsHQLfYYdZ2bV8+DgITFIlt2mTGZU mrO3ZuxL2rHL2+zg53H+WwZzfxgURn4Up6M= X-Google-Smtp-Source: APXvYqz9nxqbgKTcnIyVtM9Cf2IExoluezUtYMDtu1yz90v1LYMQi3QOULdrycwXTXmb6qiPPCYRQd+1ZiwieEk= X-Received: by 2002:a63:d748:: with SMTP id w8mr764999pgi.157.1562799854045; Wed, 10 Jul 2019 16:04:14 -0700 (PDT) Date: Wed, 10 Jul 2019 16:04:10 -0700 Message-Id: <20190710230410.9386-1-atifniyaz@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH] input: API for Setting a Timestamp from a Driver From: Atif Niyaz To: Dmitry Torokhov Cc: Atif Niyaz , Siarhei Vishniakou , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Atif Niyaz 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 Currently, evdev stamps time with timestamps acquired in evdev_events. However, this timestamping may not be accurate in terms of measuring when the actual event happened. This API allows any 3rd party driver to be able to call input_set_timestamp, and provide a timestamp that can be utilized in order to provide a more accurate sense of time for the event Signed-off-by: Atif Niyaz --- drivers/input/evdev.c | 42 ++++++++++++++++-------------------------- drivers/input/input.c | 17 +++++++++++++++++ include/linux/input.h | 38 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 71 insertions(+), 26 deletions(-) diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 867c2cfd0038..a331efa0a3f6 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -25,13 +25,6 @@ #include #include "input-compat.h" -enum evdev_clock_type { - EV_CLK_REAL = 0, - EV_CLK_MONO, - EV_CLK_BOOT, - EV_CLK_MAX -}; - struct evdev { int open; struct input_handle handle; @@ -53,7 +46,7 @@ struct evdev_client { struct fasync_struct *fasync; struct evdev *evdev; struct list_head node; - unsigned int clk_type; + input_clk_t clk_type; bool revoked; unsigned long *evmasks[EV_CNT]; unsigned int bufsize; @@ -150,16 +143,18 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type) static void __evdev_queue_syn_dropped(struct evdev_client *client) { struct input_event ev; - ktime_t time; struct timespec64 ts; + ktime_t *time = input_get_timestamp(client->evdev->handle.dev); - time = client->clk_type == EV_CLK_REAL ? - ktime_get_real() : - client->clk_type == EV_CLK_MONO ? - ktime_get() : - ktime_get_boottime(); + switch (client->clk_type) { + case INPUT_CLK_REAL: + case INPUT_CLK_MONO: + ts = ktime_to_timespec64(time[client->clk_type]); + break; + default: + ts = ktime_to_timespec64(time[INPUT_CLK_BOOT]); + } - ts = ktime_to_timespec64(time); ev.input_event_sec = ts.tv_sec; ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC; ev.type = EV_SYN; @@ -185,21 +180,21 @@ static void evdev_queue_syn_dropped(struct evdev_client *client) spin_unlock_irqrestore(&client->buffer_lock, flags); } -static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid) +static int evdev_set_clk_type(struct evdev_client *client, clockid_t clkid) { unsigned long flags; - unsigned int clk_type; + input_clk_t clk_type; switch (clkid) { case CLOCK_REALTIME: - clk_type = EV_CLK_REAL; + clk_type = INPUT_CLK_REAL; break; case CLOCK_MONOTONIC: - clk_type = EV_CLK_MONO; + clk_type = INPUT_CLK_MONO; break; case CLOCK_BOOTTIME: - clk_type = EV_CLK_BOOT; + clk_type = INPUT_CLK_BOOT; break; default: return -EINVAL; @@ -307,12 +302,7 @@ static void evdev_events(struct input_handle *handle, { struct evdev *evdev = handle->private; struct evdev_client *client; - ktime_t ev_time[EV_CLK_MAX]; - - ev_time[EV_CLK_MONO] = ktime_get(); - ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]); - ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO], - TK_OFFS_BOOT); + ktime_t *ev_time = input_get_timestamp(handle->dev); rcu_read_lock(); diff --git a/drivers/input/input.c b/drivers/input/input.c index 7f3c5fcb9ed6..ae8b0ee58120 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -1894,6 +1894,23 @@ void input_free_device(struct input_dev *dev) } EXPORT_SYMBOL(input_free_device); +/** + * input_get_timestamp - get timestamp for input events + * @dev: input device to get timestamp from + * + * A valid timestamp is a timestamp of non-zero value. + */ +ktime_t *input_get_timestamp(struct input_dev *dev) +{ + const ktime_t invalid_timestamp = ktime_set(0, 0); + + if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], ktime_zero)) { + input_set_timestamp(dev, ktime_get()); + } + return dev->timestamp; +} +EXPORT_SYMBOL(input_get_timestamp); + /** * input_set_capability - mark device as capable of a certain event * @dev: device that is capable of emitting or accepting event diff --git a/include/linux/input.h b/include/linux/input.h index 510e78558c10..3929b62ccbe5 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -33,6 +33,14 @@ struct input_value { __s32 value; }; +enum input_clock_type { + INPUT_CLK_REAL = 0, + INPUT_CLK_MONO, + INPUT_CLK_BOOT, + INPUT_CLK_MAX +}; +typedef enum input_clock_type input_clk_t; + /** * struct input_dev - represents an input device * @name: name of the device @@ -114,6 +122,8 @@ struct input_value { * @vals: array of values queued in the current frame * @devres_managed: indicates that devices is managed with devres framework * and needs not be explicitly unregistered or freed. + * @timestamp: storage for a timestamp set by input_set_timestamp called + * by a driver */ struct input_dev { const char *name; @@ -184,6 +194,8 @@ struct input_dev { struct input_value *vals; bool devres_managed; + + ktime_t timestamp[INPUT_CLK_MAX]; }; #define to_input_dev(d) container_of(d, struct input_dev, dev) @@ -382,6 +394,32 @@ void input_close_device(struct input_handle *); int input_flush_device(struct input_handle *handle, struct file *file); +/** + * input_set_timestamp - set timestamp for input events + * @dev: input device to set timestamp for + * @timestamp: the time at which the event has occurred + * in CLOCK_MONOTONIC + * + * This function is intended to provide to the input system a more + * accurate time of when an event actually occurred. The driver should + * call this function as soon as a timestamp is acquired ensuring + * clock conversions in input_set_timestamp are done correctly. + * + * The system entering a suspend between timestamp acquisition and + * calling input_set_timestamp can result in inaccurate conversions. + * + */ +static inline void input_set_timestamp(struct input_dev *dev, + ktime_t timestamp) +{ + dev->timestamp[INPUT_CLK_MONO] = timestamp; + dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp); + dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any( + timestamp, TK_OFFS_BOOT); +} + +ktime_t *input_get_timestamp(struct input_dev *dev); + void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value); void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value);