Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759262Ab0HDVTW (ORCPT ); Wed, 4 Aug 2010 17:19:22 -0400 Received: from gate.lvk.cs.msu.su ([158.250.17.1]:57592 "EHLO mail.lvk.cs.msu.su" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759072Ab0HDVS4 (ORCPT ); Wed, 4 Aug 2010 17:18:56 -0400 X-Spam-ASN: From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: "Nikita V\. Youshchenko" , linuxpps@ml.enneenne.com, Rodolfo Giometti , john stultz , Alexander Gordeev , Andrew Morton , Tejun Heo , Joonwoo Park Subject: [PATCHv3 08/16] pps: add async PPS event handler Date: Thu, 5 Aug 2010 01:06:45 +0400 Message-Id: <0d66f8eea2d28b57485ff703e5332c56fde1ee04.1280952801.git.lasaine@lvk.cs.msu.su> X-Mailer: git-send-email 1.7.1 In-Reply-To: References: X-AV-Checked: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8043 Lines: 264 This handler should be called from an IRQ handler. It uses per-device workqueue internally. Signed-off-by: Alexander Gordeev --- drivers/pps/clients/pps-ktimer.c | 2 +- drivers/pps/clients/pps-ldisc.c | 2 +- drivers/pps/kapi.c | 95 ++++++++++++++++++++++++++++++++++++-- drivers/pps/pps.c | 14 +++++- include/linux/pps_kernel.h | 16 ++++++- 5 files changed, 119 insertions(+), 10 deletions(-) diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c index 9d27239..61d0800 100644 --- a/drivers/pps/clients/pps-ktimer.c +++ b/drivers/pps/clients/pps-ktimer.c @@ -47,7 +47,7 @@ static void pps_ktimer_event(unsigned long ptr) dev_info(pps->dev, "PPS event at %lu\n", jiffies); - pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL); + pps_event_irq(pps, &ts, PPS_CAPTUREASSERT, NULL); mod_timer(&ktimer, jiffies + HZ); } diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index d7e1a27..3e64042 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -40,7 +40,7 @@ static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status, ts = &__ts; /* Now do the PPS event report */ - pps_event(pps, ts, status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, + pps_event_irq(pps, ts, status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, NULL); dev_dbg(pps->dev, "PPS %s at %lu\n", status ? "assert" : "clear", diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index 041c27e..d5f18ce 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -31,9 +31,19 @@ #include /* + * Global variables + */ + +/* PPS event workqueue */ +struct workqueue_struct *pps_event_workqueue; + +/* * Local functions */ +static void assert_work_func(struct work_struct *work); +static void clear_work_func(struct work_struct *work); + static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) { ts->nsec += offset->nsec; @@ -107,6 +117,9 @@ struct pps_device *pps_register_source(struct pps_source_info *info, init_waitqueue_head(&pps->queue); spin_lock_init(&pps->lock); + INIT_WORK(&pps->assert_work, assert_work_func); + INIT_WORK(&pps->clear_work, clear_work_func); + /* Create the char device */ err = pps_register_cdev(pps); if (err < 0) { @@ -148,11 +161,12 @@ EXPORT_SYMBOL(pps_unregister_source); * @event: the event type * @data: userdef pointer * - * This function is used by each PPS client in order to register a new - * PPS event into the system (it's usually called inside an IRQ handler). + * This function is used by PPS clients in order to register a new + * PPS event into the system. It should not be called from an IRQ + * handler. Use pps_event_irq instead. * - * If an echo function is associated with the PPS device it will be called - * as: + * If an echo function is associated with the PPS device it will be + * called as: * pps->info.echo(pps, event, data); */ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, @@ -222,3 +236,76 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, spin_unlock_irqrestore(&pps->lock, flags); } EXPORT_SYMBOL(pps_event); + +/* Async event handlers */ + +static void assert_work_func(struct work_struct *work) +{ + struct pps_device *pps = container_of(work, + struct pps_device, assert_work); + + pps_event(pps, &pps->assert_work_ts, PPS_CAPTUREASSERT, + pps->assert_work_data); +} + +static void clear_work_func(struct work_struct *work) +{ + struct pps_device *pps = container_of(work, + struct pps_device, clear_work); + + pps_event(pps, &pps->clear_work_ts, PPS_CAPTURECLEAR, + pps->clear_work_data); +} + +/* pps_event_irq - register a PPS event for deffered handling using + * workqueue + * + * @pps: the PPS device + * @ts: the event timestamp + * @event: the event type + * @data: userdef pointer + * + * This function is used by PPS clients in order to register a new + * PPS event into the system. It should be called from an IRQ handler + * only. + * + * If an echo function is associated with the PPS device it will be + * called as: + * pps->info.echo(pps, event, data); + */ +void pps_event_irq(struct pps_device *pps, struct pps_event_time *ts, + int event, void *data) +{ + /* check event type */ + BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); + + if (event & PPS_CAPTUREASSERT) { + if (work_pending(&pps->assert_work)) { + dev_err(pps->dev, "deferred assert edge work haven't" + " been handled within a second\n"); + /* FIXME: do something more intelligent + * then just exit */ + } else { + /* now we can copy data safely */ + pps->assert_work_ts = *ts; + pps->assert_work_data = data; + + queue_work(pps_event_workqueue, &pps->assert_work); + } + } + if (event & PPS_CAPTURECLEAR) { + if (work_pending(&pps->clear_work)) { + dev_err(pps->dev, "deferred clear edge work haven't" + " been handled within a second\n"); + /* FIXME: do something more intelligent + * then just exit */ + } else { + /* now we can copy data safely */ + pps->clear_work_ts = *ts; + pps->clear_work_data = data; + + queue_work(pps_event_workqueue, &pps->clear_work); + } + } +} +EXPORT_SYMBOL(pps_event_irq); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index d81f13b..81adb33 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -319,18 +319,26 @@ void pps_unregister_cdev(struct pps_device *pps) static void __exit pps_exit(void) { - class_destroy(pps_class); unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + class_destroy(pps_class); + destroy_workqueue(pps_event_workqueue); } static int __init pps_init(void) { int err; + pps_event_workqueue = create_rt_workqueue("pps"); + if (!pps_event_workqueue) { + pr_err("pps: failed to create workqueue\n"); + return -ENOMEM; + } + pps_class = class_create(THIS_MODULE, "pps"); if (!pps_class) { pr_err("pps: failed to allocate class\n"); - return -ENOMEM; + err = -ENOMEM; + goto destroy_workqueue; } pps_class->dev_attrs = pps_attrs; @@ -348,6 +356,8 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); +destroy_workqueue: + destroy_workqueue(pps_event_workqueue); return err; } diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 1e0f249..5af0498 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -26,6 +26,7 @@ #include #include #include +#include /* * Global defines @@ -70,6 +71,13 @@ struct pps_device { struct device *dev; struct fasync_struct *async_queue; /* fasync method */ spinlock_t lock; + + struct work_struct assert_work; + struct work_struct clear_work; + struct pps_event_time assert_work_ts; + struct pps_event_time clear_work_ts; + void *assert_work_data; + void *clear_work_data; }; /* @@ -78,6 +86,8 @@ struct pps_device { extern struct device_attribute pps_attrs[]; +extern struct workqueue_struct *pps_event_workqueue; + /* * Exported functions */ @@ -87,8 +97,10 @@ extern struct pps_device *pps_register_source( extern void pps_unregister_source(struct pps_device *pps); extern int pps_register_cdev(struct pps_device *pps); extern void pps_unregister_cdev(struct pps_device *pps); -extern void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, - void *data); +extern void pps_event(struct pps_device *pps, + struct pps_event_time *ts, int event, void *data); +extern void pps_event_irq(struct pps_device *pps, + struct pps_event_time *ts, int event, void *data); static inline void timespec_to_pps_ktime(struct pps_ktime *kt, struct timespec ts) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/