From d9bd95200f3252c141653a2e83f7580b00a4782d Mon Sep 17 00:00:00 2001 From: ChromeOS Developer Date: Sat, 22 Mar 2014 13:56:42 -0700 Subject: [PATCH] cortex-m: Add task_wait_event_mask() helper function BUG=chrome-os-partner:27180 BRANCH=rambi TEST=Tested indirectly via subsequent patches to use this call in the adc and i2c handlers for the lm4. Change-Id: I53501fdf47d606ea6c7705facb66e945e25d9745 Signed-off-by: Dave Parker Reviewed-on: https://chromium-review.googlesource.com/191300 Reviewed-by: Vincent Palatin Reviewed-by: Randall Spangler --- core/cortex-m/task.c | 29 +++++++++++++++++++++++++++++ include/task.h | 21 ++++++++++++++++++++- 2 files changed, 49 insertions(+), 1 deletion(-) diff --git a/core/cortex-m/task.c b/core/cortex-m/task.c index 5e309ef4cb..5d2f967693 100644 --- a/core/cortex-m/task.c +++ b/core/cortex-m/task.c @@ -380,6 +380,35 @@ uint32_t task_wait_event(int timeout_us) return __wait_evt(timeout_us, TASK_ID_IDLE); } +uint32_t task_wait_event_mask(uint32_t event_mask, int timeout_us) +{ + uint64_t deadline = get_time().val + timeout_us; + uint32_t events = 0; + int time_remaining_us = timeout_us; + + /* Add the timer event to the mask so we can indicate a timeout */ + event_mask |= TASK_EVENT_TIMER; + + while (!(events & event_mask)) { + /* Collect events to re-post later */ + events |= __wait_evt(time_remaining_us, TASK_ID_IDLE); + + time_remaining_us = deadline - get_time().val; + if (timeout_us > 0 && time_remaining_us <= 0) { + /* Ensure we return a TIMER event if we timeout */ + events |= TASK_EVENT_TIMER; + break; + } + } + + /* Re-post any other events collected */ + if (events & ~event_mask) + atomic_or(task_get_event_bitmap(task_get_current()), + events & ~event_mask); + + return events & event_mask; +} + void task_enable_irq(int irq) { CPU_NVIC_EN(irq / 32) = 1 << (irq % 32); diff --git a/include/task.h b/include/task.h index 723c6f0ad6..6b10c649b1 100644 --- a/include/task.h +++ b/include/task.h @@ -95,9 +95,28 @@ uint32_t *task_get_event_bitmap(task_id_t tskid); * @param timeout_us If > 0, sets a timer to produce the TASK_EVENT_TIMER * event after the specified micro-second duration. * - * @return The bitmap of received events. */ + * @return The bitmap of received events. + */ uint32_t task_wait_event(int timeout_us); +/** + * Wait for any event included in an event mask. + * + * If one or more events are already pending, returns immediately. Otherwise, + * it de-schedules the calling task and wakes up the next one in the priority + * order. Automatically clears the bitmap of received events before returning + * the events which are set. + * + * @param event_mask Bitmap of task events to wait for. + * + * @param timeout_us If > 0, sets a timer to produce the TASK_EVENT_TIMER + * event after the specified micro-second duration. + * + * @return The bitmap of received events. Includes + * TASK_EVENT_TIMER if the timeout is reached. + */ +uint32_t task_wait_event_mask(uint32_t event_mask, int timeout_us); + /** * Prints the list of tasks. *