From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VtJMQ-0001l1-PP for barebox@lists.infradead.org; Wed, 18 Dec 2013 15:48:35 +0000 From: Sascha Hauer Date: Wed, 18 Dec 2013 16:48:10 +0100 Message-Id: <1387381690-6088-1-git-send-email-s.hauer@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] poller: Allow to call functions asynchronously To: barebox@lists.infradead.org Sometimes execution of a function has to be delayed, for example when a backlight can only be turned on when the picture has stabilized. To help in such situations add a convenience function around the poller stuff to call a function after a delay. Signed-off-by: Sascha Hauer --- common/poller.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/poller.h | 14 +++++++++++++- 2 files changed, 71 insertions(+), 1 deletion(-) diff --git a/common/poller.c b/common/poller.c index 0583a53..496636d 100644 --- a/common/poller.c +++ b/common/poller.c @@ -11,24 +11,82 @@ #include #include #include +#include static LIST_HEAD(poller_list); static int poller_active; int poller_register(struct poller_struct *poller) { + if (poller->registered) + return -EBUSY; + list_add_tail(&poller->list, &poller_list); + poller->registered = 1; return 0; } int poller_unregister(struct poller_struct *poller) { + if (!poller->registered) + return -ENODEV; + list_del(&poller->list); + poller->registered = 0; return 0; } +static void poller_async_callback(struct poller_struct *poller) +{ + struct poller_async *pa = container_of(poller, struct poller_async, poller); + + if (get_time_ns() < pa->end) + return; + + pa->fn(pa->ctx); + pa->fn = NULL; + poller_unregister(&pa->poller); +} + +/* + * Cancel an outstanding asynchronous function call + * + * @pa the poller that has been scheduled + * + * Cancel an outstanding function call. Returns 0 if the call + * has actually been cancelled or -ENODEV when the call wasn't + * scheduled. + * + */ +int poller_async_cancel(struct poller_async *pa) +{ + return poller_unregister(&pa->poller); +} + +/* + * Call a function asynchronously + * + * @pa the poller to be used + * @delay The delay in nanoseconds + * @fn The function to call + * @ctx context pointer passed to the function + * + * This calls the passed function after a delay of delay_ns. Returns + * a pointer which can be used as a cookie to cancel a scheduled call. + */ +int poller_call_async(struct poller_async *pa, uint64_t delay_ns, + void (*fn)(void *), void *ctx) +{ + pa->ctx = ctx; + pa->poller.func = poller_async_callback; + pa->end = get_time_ns() + delay_ns; + pa->fn = fn; + + return poller_register(&pa->poller); +} + void poller_call(void) { struct poller_struct *poller, *tmp; diff --git a/include/poller.h b/include/poller.h index dc98155..cda5b57 100644 --- a/include/poller.h +++ b/include/poller.h @@ -12,13 +12,25 @@ struct poller_struct { void (*func)(struct poller_struct *poller); - + int registered; struct list_head list; }; int poller_register(struct poller_struct *poller); int poller_unregister(struct poller_struct *poller); +struct poller_async; + +struct poller_async { + struct poller_struct poller; + void (*fn)(void *); + void *ctx; + uint64_t end; +}; + +int poller_call_async(struct poller_async *pa, uint64_t delay_ns, + void (*fn)(void *), void *ctx); +int poller_async_cancel(struct poller_async *pa); #ifdef CONFIG_POLLER void poller_call(void); -- 1.8.5.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox