From patchwork Fri May 15 16:52:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Pietrasiewicz X-Patchwork-Id: 11552599 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C797A697 for ; Fri, 15 May 2020 16:53:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 97CDA2073E for ; Fri, 15 May 2020 16:53:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jI/h0h5J" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97CDA2073E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=9a91A5IKLRbp5HBu1vFYUquGRKyklIjoa4KQxkjSfoI=; b=jI/h0h5JBviuZVMQGFWP2jwejj tSNR73J7vke8nJd28EkLg0so2enltudNiaGuNBxia8UGvhcZrOrnUXB61lsPpEeYwXkbVZHERUmsy pnQ5HQ1UQO2EvWRfUQXUTjzZWE3jG28MVn6esY9QB5LUu4MPNs0MLSycj574ezOpa3825vM2rWAET geYVyEiq1p7SP2F9K+75T/BGIxqukBTrqa9VHHLpFhOBKBYjmXaGvR+YD9+o7GP1COCnn9UOVERiY 64blAxJ2l1IFGqliprTTsVYnPXXNLSO/v9sdZW5giUYQL8mGx8W3N1lUxGiTY8s9sOdLnYaGYS3GX 5MekNvSw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jZda1-0000Gk-JK; Fri, 15 May 2020 16:53:01 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jZdZr-00008g-V5 for linux-arm-kernel@lists.infradead.org; Fri, 15 May 2020 16:52:58 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: andrzej.p) with ESMTPSA id 2F1C42A32FD From: Andrzej Pietrasiewicz To: linux-input@vger.kernel.org, linux-acpi@vger.kernel.org, linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, patches@opensource.cirrus.com, ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org Subject: [PATCHv2 6/7] Input: Add "inhibited" property Date: Fri, 15 May 2020 18:52:37 +0200 Message-Id: <20200515165237.28906-1-andrzej.p@collabora.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200515164943.28480-1-andrzej.p@collabora.com> References: <20200515164943.28480-1-andrzej.p@collabora.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200515_095252_283744_5AF59EFA X-CRM114-Status: GOOD ( 22.94 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nick Dyer , Laxman Dewangan , Peter Meerwald-Stadler , kernel@collabora.com, Fabio Estevam , Lars-Peter Clausen , Krzysztof Kozlowski , Jonathan Hunter , Kukjin Kim , NXP Linux Team , Sylvain Lemieux , Len Brown , Michael Hennerich , Sascha Hauer , Henrique de Moraes Holschuh , Vladimir Zapolskiy , Hans de Goede , Barry Song , Ferruh Yigit , Patrik Fimml , Dmitry Torokhov , "Rafael J . Wysocki" , Andrzej Pietrasiewicz , Thierry Reding , Sangwon Jee , Pengutronix Kernel Team , Hartmut Knaack , Shawn Guo , Jonathan Cameron MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Patrik Fimml Userspace might want to implement a policy to temporarily disregard input from certain devices, including not treating them as wakeup sources. An example use case is a laptop, whose keyboard can be folded under the screen to create tablet-like experience. The user then must hold the laptop in such a way that it is difficult to avoid pressing the keyboard keys. It is therefore desirable to temporarily disregard input from the keyboard, until it is folded back. This obviously is a policy which should be kept out of the kernel, but the kernel must provide suitable means to implement such a policy. This patch adds a sysfs interface for exactly this purpose. To implement the said interface it adds an "inhibited" property to struct input_dev and two optional methods - inhibit() and uninhibit(), and effectively creates four states a device can be in: closed uninhibited, closed inhibited, open uninhibited, open inhibited. It also defers calling driver's ->open() and ->close() to until they are actually needed, e.g. it makes no sense to prepare the underlying device for generating events (->open()) if the device is inhibited. uninhibit closed <------------ closed uninhibited ------------> inhibited | ^ inhibit | ^ 1st | | 1st | | open | | open | | | | | | | | last | | last | | close | | close v | uninhibit v | open <------------ open uninhibited ------------> inhibited The top inhibit/uninhibit transition happens when users == 0. The bottom inhibit/uninhibit transition happens when users > 0. The left open/close transition happens when !inhibited. The right open/close transition happens when inhibited. Due to all transitions being serialized with dev->mutex, it is impossible to have "diagonal" transitions between closed uninhibited and open inhibited or between open uninhibited and closed inhibited. open() and close() - if provided - are called in both inhibit and uninhibit paths. Please note that close() does not return a value, so if your driver might need failing inhibiting, you need to provide inhibit() so that it returns a value to check. It is drivers' responsibility to implement their inhibiting capability in terms of whatever is suitable in their context, be it open/close, inhibit/uninhibit or a combination of both. The drivers should also ensure that they properly interact with suspend/resume and PM runtime, because most likely a side effect of inhibiting a device should be its going into low power mode. Properly inhibiting a device means to prevent it from being a wakeup source, so drivers should also take care of that. Signed-off-by: Patrik Fimml Co-developed-by: Andrzej Pietrasiewicz Signed-off-by: Andrzej Pietrasiewicz --- drivers/input/input.c | 136 ++++++++++++++++++++++++++++++++++++++---- include/linux/input.h | 8 +++ 2 files changed, 134 insertions(+), 10 deletions(-) diff --git a/drivers/input/input.c b/drivers/input/input.c index 41377bfa142d..5b859a178c11 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -367,8 +367,13 @@ static int input_get_disposition(struct input_dev *dev, static void input_handle_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { - int disposition = input_get_disposition(dev, type, code, &value); + int disposition; + /* filter-out events from inhibited devices */ + if (dev->inhibited) + return; + + disposition = input_get_disposition(dev, type, code, &value); if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN) add_input_randomness(type, code, value); @@ -612,7 +617,7 @@ int input_open_device(struct input_handle *handle) handle->open++; - if (dev->users++) { + if (dev->users++ || dev->inhibited) { /* * Device is already opened, so we can exit immediately and * report success. @@ -660,6 +665,14 @@ int input_flush_device(struct input_handle *handle, struct file *file) } EXPORT_SYMBOL(input_flush_device); +static inline void input_stop(struct input_dev *dev) +{ + if (dev->poller) + input_dev_poller_stop(dev->poller); + if (dev->close) + dev->close(dev); +} + /** * input_close_device - close input device * @handle: handle through which device is being accessed @@ -675,13 +688,8 @@ void input_close_device(struct input_handle *handle) __input_release_device(handle); - if (!--dev->users) { - if (dev->poller) - input_dev_poller_stop(dev->poller); - - if (dev->close) - dev->close(dev); - } + if (!dev->inhibited && !--dev->users) + input_stop(dev); if (!--handle->open) { /* @@ -1416,12 +1424,49 @@ static ssize_t input_dev_show_properties(struct device *dev, } static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL); +static int input_inhibit(struct input_dev *dev); +static int input_uninhibit(struct input_dev *dev); + +static ssize_t inhibited_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct input_dev *input_dev = to_input_dev(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", input_dev->inhibited); +} + +static ssize_t inhibited_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t len) +{ + struct input_dev *input_dev = to_input_dev(dev); + ssize_t rv; + bool inhibited; + + if (strtobool(buf, &inhibited)) + return -EINVAL; + + if (inhibited) + rv = input_inhibit(input_dev); + else + rv = input_uninhibit(input_dev); + + if (rv != 0) + return rv; + + return len; +} + +static DEVICE_ATTR_RW(inhibited); + static struct attribute *input_dev_attrs[] = { &dev_attr_name.attr, &dev_attr_phys.attr, &dev_attr_uniq.attr, &dev_attr_modalias.attr, &dev_attr_properties.attr, + &dev_attr_inhibited.attr, NULL }; @@ -1703,6 +1748,77 @@ void input_reset_device(struct input_dev *dev) } EXPORT_SYMBOL(input_reset_device); +static int input_inhibit(struct input_dev *dev) +{ + int ret = 0; + + mutex_lock(&dev->mutex); + + if (dev->inhibited) + goto out; + + if (dev->users) { + if (dev->inhibit) { + ret = dev->inhibit(dev); + if (ret) + goto out; + } + input_stop(dev); + } + + spin_lock_irq(&dev->event_lock); + input_dev_release_keys(dev); + input_dev_toggle(dev, false); + spin_unlock_irq(&dev->event_lock); + + dev->inhibited = true; + +out: + mutex_unlock(&dev->mutex); + return ret; +} + +static int input_uninhibit(struct input_dev *dev) +{ + int ret = 0; + + mutex_lock(&dev->mutex); + + if (!dev->inhibited) + goto out; + + if (dev->users) { + if (dev->open) { + ret = dev->open(dev); + if (ret) + goto toggle; + } + if (dev->uninhibit) { + ret = dev->uninhibit(dev); + if (ret) { + if (dev->close) + dev->close(dev); + goto toggle; + } + } + if (dev->poller) + input_dev_poller_start(dev->poller); + } + + dev->inhibited = false; + +toggle: + if (!dev->inhibited) { + spin_lock_irq(&dev->event_lock); + input_dev_toggle(dev, true); + spin_unlock_irq(&dev->event_lock); + } + +out: + mutex_unlock(&dev->mutex); + return ret; +} + #ifdef CONFIG_PM_SLEEP static int input_dev_suspend(struct device *dev) { @@ -2131,7 +2247,7 @@ bool input_device_enabled(struct input_dev *dev) { lockdep_assert_held(&dev->mutex); - return dev->users > 0; + return !dev->inhibited && dev->users > 0; } EXPORT_SYMBOL_GPL(input_device_enabled); diff --git a/include/linux/input.h b/include/linux/input.h index eda4587dba67..8d0dcfaeaf6f 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -127,6 +127,9 @@ enum input_clock_type { * and needs not be explicitly unregistered or freed. * @timestamp: storage for a timestamp set by input_set_timestamp called * by a driver + * @inhibit: makes the device ignore all input + * @uninhibit: undoes the effect of inhibit + * @inhibited: indicates that the input device is inhibited */ struct input_dev { const char *name; @@ -201,6 +204,11 @@ struct input_dev { bool devres_managed; ktime_t timestamp[INPUT_CLK_MAX]; + + int (*inhibit)(struct input_dev *dev); + int (*uninhibit)(struct input_dev *dev); + + bool inhibited; }; #define to_input_dev(d) container_of(d, struct input_dev, dev)