| 1 | /*
|
|---|
| 2 | * Copyright (c) 2001-2004 Jakub Jermar
|
|---|
| 3 | * All rights reserved.
|
|---|
| 4 | *
|
|---|
| 5 | * Redistribution and use in source and binary forms, with or without
|
|---|
| 6 | * modification, are permitted provided that the following conditions
|
|---|
| 7 | * are met:
|
|---|
| 8 | *
|
|---|
| 9 | * - Redistributions of source code must retain the above copyright
|
|---|
| 10 | * notice, this list of conditions and the following disclaimer.
|
|---|
| 11 | * - Redistributions in binary form must reproduce the above copyright
|
|---|
| 12 | * notice, this list of conditions and the following disclaimer in the
|
|---|
| 13 | * documentation and/or other materials provided with the distribution.
|
|---|
| 14 | * - The name of the author may not be used to endorse or promote products
|
|---|
| 15 | * derived from this software without specific prior written permission.
|
|---|
| 16 | *
|
|---|
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|---|
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|---|
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|---|
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|---|
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|---|
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|---|
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|---|
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|---|
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|---|
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|---|
| 27 | */
|
|---|
| 28 |
|
|---|
| 29 | /** @addtogroup time
|
|---|
| 30 | * @{
|
|---|
| 31 | */
|
|---|
| 32 |
|
|---|
| 33 | /**
|
|---|
| 34 | * @file
|
|---|
| 35 | * @brief Active delay function.
|
|---|
| 36 | */
|
|---|
| 37 |
|
|---|
| 38 | #include <time/delay.h>
|
|---|
| 39 | #include <proc/thread.h>
|
|---|
| 40 | #include <typedefs.h>
|
|---|
| 41 | #include <cpu.h>
|
|---|
| 42 | #include <arch/asm.h>
|
|---|
| 43 | #include <arch.h>
|
|---|
| 44 |
|
|---|
| 45 | /** Delay the execution for the given number of microseconds (or slightly more).
|
|---|
| 46 | *
|
|---|
| 47 | * The delay is implemented as active delay loop.
|
|---|
| 48 | *
|
|---|
| 49 | * @param usec Number of microseconds to sleep.
|
|---|
| 50 | */
|
|---|
| 51 | void delay(uint32_t usec)
|
|---|
| 52 | {
|
|---|
| 53 | /*
|
|---|
| 54 | * The delay loop is calibrated for each and every CPU in the system.
|
|---|
| 55 | * If running in a thread context, it is therefore necessary to disable
|
|---|
| 56 | * thread migration. We want to do this in a lightweight manner.
|
|---|
| 57 | */
|
|---|
| 58 | if (THREAD)
|
|---|
| 59 | thread_migration_disable();
|
|---|
| 60 | asm_delay_loop(usec * CPU->delay_loop_const);
|
|---|
| 61 | if (THREAD)
|
|---|
| 62 | thread_migration_enable();
|
|---|
| 63 | }
|
|---|
| 64 |
|
|---|
| 65 | /** @}
|
|---|
| 66 | */
|
|---|
