1 /**
2 * \file
3 *
4 * \brief Events implementation.
5 *
6 * Copyright (C) 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 CAUSEsD 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 #include <utils_event.h>
45 #include <utils_assert.h>
46 #include <string.h>
47
48 #define EVENT_WORD_BITS (sizeof(event_word_t) * 8)
49
50 static struct list_descriptor events;
51 static uint8_t subscribed[EVENT_MASK_SIZE];
52
event_subscribe(struct event * const event,const event_id_t id,event_cb_t cb)53 int32_t event_subscribe(struct event *const event, const event_id_t id, event_cb_t cb)
54 {
55 /* get byte and bit number of the given event in the event mask */
56 const uint8_t position = id >> 3;
57 const uint8_t mask = 1 << (id & 0x7);
58
59 ASSERT(event && cb && (id < EVENT_MAX_AMOUNT));
60
61 if (event->mask[position] & mask) {
62 return ERR_NO_CHANGE; /* Already subscribed */
63 }
64
65 if (!is_list_element(&events, event)) {
66 memset(event->mask, 0, EVENT_MASK_SIZE);
67 list_insert_as_head(&events, event);
68 }
69 event->cb = cb;
70 event->mask[position] |= mask;
71
72 subscribed[position] |= mask;
73
74 return ERR_NONE;
75 }
76
event_unsubscribe(struct event * const event,const event_id_t id)77 int32_t event_unsubscribe(struct event *const event, const event_id_t id)
78 {
79 /* get byte and bit number of the given event in the event mask */
80 const uint8_t position = id >> 3;
81 const uint8_t mask = 1 << (id & 0x7);
82 const struct event *current;
83 uint8_t i;
84
85 ASSERT(event && (id < EVENT_MAX_AMOUNT));
86
87 if (!(event->mask[position] & mask)) {
88 return ERR_NO_CHANGE; /* Already unsubscribed */
89 }
90
91 event->mask[position] &= ~mask;
92
93 /* Check if there are more subscribers */
94 for ((current = (const struct event *)list_get_head(&events)); current;
95 current = (const struct event *)list_get_next_element(current)) {
96 if (current->mask[position] & mask) {
97 break;
98 }
99 }
100 if (!current) {
101 subscribed[position] &= ~mask;
102 }
103
104 /* Remove event from the list. Can be unsave, document it! */
105 for (i = 0; i < ARRAY_SIZE(event->mask); i++) {
106 if (event->mask[i]) {
107 return ERR_NONE;
108 }
109 }
110 list_delete_element(&events, event);
111
112 return ERR_NONE;
113 }
114
event_post(const event_id_t id,const event_data_t data)115 void event_post(const event_id_t id, const event_data_t data)
116 {
117 /* get byte and bit number of the given event in the event mask */
118 const uint8_t position = id >> 3;
119 const uint8_t mask = 1 << (id & 0x7);
120 const struct event *current;
121
122 ASSERT((id < EVENT_MAX_AMOUNT));
123
124 if (!(subscribed[position] & mask)) {
125 return; /* No subscribers */
126 }
127
128 /* Find all subscribers */
129 for ((current = (const struct event *)list_get_head(&events)); current;
130 current = (const struct event *)list_get_next_element(current)) {
131 if (current->mask[position] & mask) {
132 current->cb(id, data);
133 }
134 }
135 }
136
