From patchwork Sat Feb 6 18:02:08 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 77545 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o16I2RRh032646 for ; Sat, 6 Feb 2010 18:02:28 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755924Ab0BFSCZ (ORCPT ); Sat, 6 Feb 2010 13:02:25 -0500 Received: from smtp.nokia.com ([192.100.105.134]:25164 "EHLO mgw-mx09.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755858Ab0BFSCW (ORCPT ); Sat, 6 Feb 2010 13:02:22 -0500 Received: from esebh106.NOE.Nokia.com (esebh106.ntc.nokia.com [172.21.138.213]) by mgw-mx09.nokia.com (Switch-3.3.3/Switch-3.3.3) with ESMTP id o16I2H7U023886; Sat, 6 Feb 2010 12:02:18 -0600 Received: from vaebh104.NOE.Nokia.com ([10.160.244.30]) by esebh106.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.3959); Sat, 6 Feb 2010 20:02:16 +0200 Received: from mgw-sa02.ext.nokia.com ([147.243.1.48]) by vaebh104.NOE.Nokia.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959); Sat, 6 Feb 2010 20:02:16 +0200 Received: from maxwell.research.nokia.com (maxwell.research.nokia.com [172.21.50.162]) by mgw-sa02.ext.nokia.com (Switch-3.3.3/Switch-3.3.3) with ESMTP id o16I2EO2000455 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 6 Feb 2010 20:02:14 +0200 Received: from lanttu (unknown [192.168.239.74]) by maxwell.research.nokia.com (Postfix) with ESMTPS id 4F3367010D; Sat, 6 Feb 2010 20:02:14 +0200 (EET) Received: from sakke by lanttu with local (Exim 4.69) (envelope-from ) id 1Ndoyy-0005Ms-VU; Sat, 06 Feb 2010 20:02:13 +0200 From: Sakari Ailus To: linux-media@vger.kernel.org Cc: hans.verkuil@xs4all.nl, laurent.pinchart@ideasonboard.com, gururaj.nagendra@intel.com, david.cohen@nokia.com, iivanov@mm-sol.com, Sakari Ailus Subject: [PATCH 5/8] V4L: Events: Add backend Date: Sat, 6 Feb 2010 20:02:08 +0200 Message-Id: <1265479331-20595-5-git-send-email-sakari.ailus@maxwell.research.nokia.com> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <4B6DAE5A.5090508@maxwell.research.nokia.com> References: <4B6DAE5A.5090508@maxwell.research.nokia.com> X-OriginalArrivalTime: 06 Feb 2010 18:02:16.0285 (UTC) FILETIME=[8457C0D0:01CAA756] X-Nokia-AV: Clean Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Sat, 06 Feb 2010 18:02:28 +0000 (UTC) diff --git a/drivers/media/video/v4l2-event.c b/drivers/media/video/v4l2-event.c new file mode 100644 index 0000000..7ae763f --- /dev/null +++ b/drivers/media/video/v4l2-event.c @@ -0,0 +1,317 @@ +/* + * drivers/media/video/v4l2-event.c + * + * V4L2 events. + * + * Copyright (C) 2009 Nokia Corporation. + * + * Contact: Sakari Ailus + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include +#include + +#include + +/* In error case, return number of events *not* allocated. */ +int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n) +{ + struct v4l2_events *events = fh->events; + unsigned long flags; + + for (; n > 0; n--) { + struct v4l2_kevent *kev; + + kev = kzalloc(sizeof(*kev), GFP_KERNEL); + if (kev == NULL) + return n; + + spin_lock_irqsave(&fh->lock, flags); + list_add_tail(&kev->list, &events->free); + spin_unlock_irqrestore(&fh->lock, flags); + + } + + return n; +} +EXPORT_SYMBOL_GPL(v4l2_event_alloc); + +void v4l2_event_exit(struct v4l2_fh *fh) +{ + struct v4l2_events *events = fh->events; + + if (!events) + return; + + while (!list_empty(&events->free)) { + struct v4l2_kevent *kev; + + kev = list_first_entry(&events->free, + struct v4l2_kevent, list); + list_del(&kev->list); + + kfree(kev); + } + + while (!list_empty(&events->available)) { + struct v4l2_kevent *kev; + + kev = list_first_entry(&events->available, + struct v4l2_kevent, list); + list_del(&kev->list); + + kfree(kev); + } + + while (!list_empty(&events->subscribed)) { + struct v4l2_subscribed_event *sub; + + sub = list_first_entry(&events->subscribed, + struct v4l2_subscribed_event, list); + + list_del(&sub->list); + + kfree(sub); + } + + kfree(events); + fh->events = NULL; +} +EXPORT_SYMBOL_GPL(v4l2_event_exit); + +int v4l2_event_init(struct v4l2_fh *fh, unsigned int n) +{ + int ret; + + fh->events = kzalloc(sizeof(*fh->events), GFP_KERNEL); + if (fh->events == NULL) + return -ENOMEM; + + init_waitqueue_head(&fh->events->wait); + + INIT_LIST_HEAD(&fh->events->free); + INIT_LIST_HEAD(&fh->events->available); + INIT_LIST_HEAD(&fh->events->subscribed); + + ret = v4l2_event_alloc(fh, n); + if (ret < 0) + v4l2_event_exit(fh); + + return ret; +} +EXPORT_SYMBOL_GPL(v4l2_event_init); + +int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event) +{ + struct v4l2_events *events = fh->events; + struct v4l2_kevent *kev; + unsigned long flags; + + spin_lock_irqsave(&fh->lock, flags); + + if (list_empty(&events->available)) { + spin_unlock_irqrestore(&fh->lock, flags); + return -ENOENT; + } + + kev = list_first_entry(&events->available, struct v4l2_kevent, list); + list_del(&kev->list); + + kev->event.count = !list_empty(&events->available); + + spin_unlock_irqrestore(&fh->lock, flags); + + *event = kev->event; + + spin_lock_irqsave(&fh->lock, flags); + list_add(&kev->list, &events->free); + spin_unlock_irqrestore(&fh->lock, flags); + + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_event_dequeue); + +static struct v4l2_subscribed_event *__v4l2_kevent_subscribed( + struct v4l2_fh *fh, u32 type) +{ + struct v4l2_events *events = fh->events; + struct v4l2_subscribed_event *sev; + + list_for_each_entry(sev, &events->subscribed, list) { + if (sev->type == type) + return sev; + } + + return NULL; +} + +struct v4l2_subscribed_event *v4l2_event_subscribed( + struct v4l2_fh *fh, u32 type) +{ + struct v4l2_subscribed_event *sev; + unsigned long flags; + + spin_lock_irqsave(&fh->lock, flags); + + sev = __v4l2_kevent_subscribed(fh, type); + + spin_unlock_irqrestore(&fh->lock, flags); + + return sev; +} +EXPORT_SYMBOL_GPL(v4l2_event_subscribed); + +void v4l2_event_queue(struct video_device *vdev, struct v4l2_event *ev) +{ + struct v4l2_fh *fh; + unsigned long flags; + struct v4l2_fh *put_me = NULL; + + spin_lock_irqsave(&vdev->fhs.lock, flags); + + list_for_each_entry(fh, &vdev->fhs.list, list) { + struct v4l2_events *events = fh->events; + struct v4l2_kevent *kev; + + /* Is it subscribed? */ + if (!v4l2_event_subscribed(fh, ev->type)) + continue; + + /* Can we get the file handle? */ + if (v4l2_fh_get(vdev, fh)) + continue; + + /* List lock no longer required. */ + spin_unlock_irqrestore(&vdev->fhs.lock, flags); + + /* Put earlier v4l2_fh. */ + if (put_me) { + v4l2_fh_put(vdev, put_me); + put_me = NULL; + } + put_me = fh; + + /* Do we have any free events? */ + spin_lock_irqsave(&fh->lock, flags); + if (list_empty(&events->free)) { + spin_unlock_irqrestore(&fh->lock, flags); + spin_lock_irqsave(&vdev->fhs.lock, flags); + continue; + } + + /* Take one and fill it. */ + kev = list_first_entry(&events->free, struct v4l2_kevent, list); + list_del(&kev->list); + spin_unlock_irqrestore(&fh->lock, flags); + + kev->event = *ev; + + /* And add to the available list. */ + spin_lock_irqsave(&fh->lock, flags); + list_add_tail(&kev->list, &events->available); + spin_unlock_irqrestore(&fh->lock, flags); + + wake_up_all(&events->wait); + + spin_lock_irqsave(&vdev->fhs.lock, flags); + } + + spin_unlock_irqrestore(&vdev->fhs.lock, flags); + + /* Put final v4l2_fh if exists. */ + if (put_me) + v4l2_fh_put(vdev, put_me); +} +EXPORT_SYMBOL_GPL(v4l2_event_queue); + +int v4l2_event_pending(struct v4l2_fh *fh) +{ + struct v4l2_events *events = fh->events; + unsigned long flags; + int ret; + + spin_lock_irqsave(&fh->lock, flags); + ret = !list_empty(&events->available); + spin_unlock_irqrestore(&fh->lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(v4l2_event_pending); + +int v4l2_event_subscribe(struct v4l2_fh *fh, + struct v4l2_event_subscription *sub) +{ + struct v4l2_events *events = fh->events; + struct v4l2_subscribed_event *sev; + unsigned long flags; + int ret = 0; + + /* Allow subscribing to valid events only. */ + if (sub->type < V4L2_EVENT_PRIVATE_START) + switch (sub->type) { + default: + return -EINVAL; + } + + sev = kmalloc(sizeof(*sev), GFP_KERNEL); + if (!sev) + return -ENOMEM; + + spin_lock_irqsave(&fh->lock, flags); + + if (__v4l2_kevent_subscribed(fh, sub->type) != NULL) { + ret = -EBUSY; + goto out; + } + + INIT_LIST_HEAD(&sev->list); + sev->type = sub->type; + + list_add(&sev->list, &events->subscribed); + +out: + spin_unlock_irqrestore(&fh->lock, flags); + + if (ret) + kfree(sev); + + return ret; +} +EXPORT_SYMBOL_GPL(v4l2_event_subscribe); + +int v4l2_event_unsubscribe(struct v4l2_fh *fh, + struct v4l2_event_subscription *sub) +{ + struct v4l2_subscribed_event *sev; + unsigned long flags; + + spin_lock_irqsave(&fh->lock, flags); + + sev = __v4l2_kevent_subscribed(fh, sub->type); + + if (sev == NULL) { + spin_unlock_irqrestore(&fh->lock, flags); + return -EINVAL; + } + + list_del(&sev->list); + + spin_unlock_irqrestore(&fh->lock, flags); + + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe); diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c index 1728e1c..3bd40f8 100644 --- a/drivers/media/video/v4l2-fh.c +++ b/drivers/media/video/v4l2-fh.c @@ -24,6 +24,7 @@ #include #include +#include void v4l2_fh_new(struct video_device *vdev, struct v4l2_fh *fh) { @@ -54,6 +55,8 @@ void v4l2_fh_put(struct video_device *vdev, struct v4l2_fh *fh) spin_lock_irqsave(&vdev->fhs.lock, flags); list_del(&fh->list); spin_unlock_irqrestore(&vdev->fhs.lock, flags); + + v4l2_event_exit(fh); } EXPORT_SYMBOL_GPL(v4l2_fh_put); diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h new file mode 100644 index 0000000..580c9d4 --- /dev/null +++ b/include/media/v4l2-event.h @@ -0,0 +1,64 @@ +/* + * include/media/v4l2-event.h + * + * V4L2 events. + * + * Copyright (C) 2009 Nokia Corporation. + * + * Contact: Sakari Ailus + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#ifndef V4L2_EVENT_H +#define V4L2_EVENT_H + +#include +#include + +struct v4l2_fh; +struct video_device; + +struct v4l2_kevent { + struct list_head list; + struct v4l2_event event; +}; + +struct v4l2_subscribed_event { + struct list_head list; + u32 type; +}; + +struct v4l2_events { + wait_queue_head_t wait; + struct list_head subscribed; /* Subscribed events */ + struct list_head available; /* Dequeueable event */ + struct list_head free; /* Events ready for use */ +}; + +int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n); +int v4l2_event_init(struct v4l2_fh *fh, unsigned int n); +void v4l2_event_exit(struct v4l2_fh *fh); +int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event); +struct v4l2_subscribed_event *v4l2_event_subscribed( + struct v4l2_fh *fh, u32 type); +void v4l2_event_queue(struct video_device *vdev, struct v4l2_event *ev); +int v4l2_event_pending(struct v4l2_fh *fh); +int v4l2_event_subscribe(struct v4l2_fh *fh, + struct v4l2_event_subscription *sub); +int v4l2_event_unsubscribe(struct v4l2_fh *fh, + struct v4l2_event_subscription *sub); + +#endif /* V4L2_EVENT_H */ diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h index 51d6508..d9589c2 100644 --- a/include/media/v4l2-fh.h +++ b/include/media/v4l2-fh.h @@ -34,6 +34,7 @@ struct v4l2_fh { struct list_head list; atomic_t refcount; spinlock_t lock; + struct v4l2_events *events; /* events, pending and subscribed */ }; /* File handle related data for video_device. */