1 /**
2 * \file
3 *
4 * \brief Global interrupt management for SAM D20, SAM3 and SAM4 (NVIC based)
5 *
6 * Copyright (c) 2012-2015 Atmel Corporation. All rights reserved.
7 *
8 * \asf_license_start
9 *
10 * \page License
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright notice,
16 * this list of conditions and the following disclaimer.
17 *
18 * 2. Redistributions in binary form must reproduce the above copyright notice,
19 * this list of conditions and the following disclaimer in the documentation
20 * and/or other materials provided with the distribution.
21 *
22 * 3. The name of Atmel may not be used to endorse or promote products derived
23 * from this software without specific prior written permission.
24 *
25 * 4. This software may only be redistributed and used in connection with an
26 * Atmel microcontroller product.
27 *
28 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
29 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
31 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
32 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
36 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 *
40 * \asf_license_stop
41 *
42 */
43 /*
44 * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
45 */
46
47 #include "interrupt_sam_nvic.h"
48
49 #if !defined(__DOXYGEN__)
50 /* Deprecated - global flag to determine the global interrupt state. Required by
51 * QTouch library, however new applications should use cpu_irq_is_enabled()
52 * which probes the true global interrupt state from the CPU special registers.
53 */
54 volatile bool g_interrupt_enabled = true;
55 #endif
56
cpu_irq_enter_critical(void)57 void cpu_irq_enter_critical(void)
58 {
59 if (cpu_irq_critical_section_counter == 0) {
60 if (cpu_irq_is_enabled()) {
61 cpu_irq_disable();
62 cpu_irq_prev_interrupt_state = true;
63 } else {
64 /* Make sure the to save the prev state as false */
65 cpu_irq_prev_interrupt_state = false;
66 }
67
68 }
69
70 cpu_irq_critical_section_counter++;
71 }
72
cpu_irq_leave_critical(void)73 void cpu_irq_leave_critical(void)
74 {
75 /* Check if the user is trying to leave a critical section when not in a critical section */
76 Assert(cpu_irq_critical_section_counter > 0);
77
78 cpu_irq_critical_section_counter--;
79
80 /* Only enable global interrupts when the counter reaches 0 and the state of the global interrupt flag
81 was enabled when entering critical state */
82 if ((cpu_irq_critical_section_counter == 0) && (cpu_irq_prev_interrupt_state)) {
83 cpu_irq_enable();
84 }
85 }
86
87