1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup CANBus
*
* @brief Controller Area Network (CAN) Bus Implementation
*
*/
/*
* Copyright (C) 2022 Prashanth S <fishesprashanth@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _DEV_CAN_CAN_QUEUE_H
#define _DEV_CAN_CAN_QUEUE_H
#include <rtems/imfs.h>
#include <rtems/thread.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <dev/can/can-msg.h>
#include <dev/can/can.h>
/**
* @defgroup Controller Area Network (CAN) Driver
*
* @ingroup RTEMSDeviceDrivers
*
* @brief Controller Area Network (CAN) bus and device driver support.
*
* @{
*/
/**
* @defgroup CANBus CAN Bus Driver
*
* @ingroup CAN
*
* @{
*/
/**
* @brief Create CAN tx buffers.
*
* @param[in] bus Bus control structure.
*
* @retval 0 Successful operation.
* @retval >0 error number in case of an error.
*/
static rtems_status_code can_bus_create_tx_buffers(struct can_bus *bus);
/**
* @brief Free CAN tx buffers.
*
* @param[in] bus Bus control structure.
*
*/
static void can_bus_free_tx_buffers(struct can_bus *bus);
/**
* @brief Check for atleast one empty CAN tx buffer.
*
* @param[in] bus Bus control structure.
*
* @retval true If atleast one CAN buffer is empty.
* @retval false If no CAN buffer is empty.
*/
static bool can_bus_tx_buf_is_empty(struct can_bus *bus);
/**
* @brief Get a produced tx buffer to transmit from the tx fifo.
*
* @param[in] bus Bus control structure.
*
* @retval can_msg Pointer to can_msg structure buffer.
* @retval NULL If no can_msg buffer.
*/
static struct can_msg *can_bus_tx_get_data_buf(struct can_bus *bus);
/**
* @brief Get a empty tx buffer.
*
* @param[in] bus Bus control structure.
*
* @retval can_msg Pointer to can_msg structure buffer.
* @retval NULL If no empty can_msg buffer.
*/
static struct can_msg *can_bus_tx_get_empty_buf(struct can_bus *bus);
/**
* @brief Creates tx buffers for the CAN bus driver.
*
* @param[in] bus Bus control structure.
*
* @retval rtems_status_code
*/
static rtems_status_code can_bus_create_tx_buffers(struct can_bus *bus)
{
bus->tx_fifo.pbuf = (struct can_msg *)malloc(CAN_TX_BUF_COUNT *
sizeof(struct can_msg));
if (bus->tx_fifo.pbuf == NULL) {
CAN_ERR("can_create_tx_buffers: malloc failed\n");
return RTEMS_NO_MEMORY;
}
bus->tx_fifo.empty_count = CAN_TX_BUF_COUNT;
return RTEMS_SUCCESSFUL;
}
/**
* @brief Free tx buffers for the CAN bus driver.
*
* @param[in] bus Bus control structure.
*
*/
static void can_bus_free_tx_buffers(struct can_bus *bus)
{
free(bus->tx_fifo.pbuf);
}
/**
* @brief Check if there is atleast one tx buffer in the CAN
* bus driver.
*
* @param[in] bus Bus control structure.
*
* @retval true - If there is at least one free tx buffer.
* false - If there is no free tx buffer.
*/
static bool can_bus_tx_buf_is_empty(struct can_bus *bus)
{
if (bus->tx_fifo.empty_count == 0) {
return false;
}
return true;
}
/**
* @brief To get a can_msg tx buf which contains valid data to send in
* in the CAN bus.
*
* Note: freeing the returned data buf is done in the same function,
* So the returned buffer should be sent before releasing the
* lock acquired while calling this function.
*
* @param[in] bus Bus control structure.
*
* @retval *can_msg - If there is atleast one tx buffer to send in the CAN bus.
* NULL - If there is no valid tx buffer.
*/
static struct can_msg *can_bus_tx_get_data_buf(struct can_bus *bus)
{
struct can_msg *msg = NULL;
if (bus->tx_fifo.empty_count == CAN_TX_BUF_COUNT ||
bus->tx_fifo.tail >= CAN_TX_BUF_COUNT) {
CAN_DEBUG_BUF("can_bus_tx_get_data_buf: All buffers are empty\n");
return NULL;
}
msg = &bus->tx_fifo.pbuf[bus->tx_fifo.tail];
bus->tx_fifo.empty_count++;
bus->tx_fifo.tail = (bus->tx_fifo.tail + 1) % CAN_TX_BUF_COUNT;
return msg;
}
/**
* @brief To get a can_msg tx buf which is empty (contains no valid data).
*
* Note: marking the returned buf valid is done in the same function
* So a valid CAN message should be copied to the returned buffer before
* releasing the lock acquired while calling this function.
*
* @param[in] bus Bus control structure.
*
* @retval *can_msg - If there is atleast one empty tx buffer.
* NULL - If there is no empty tx buffer.
*/
static struct can_msg *can_bus_tx_get_empty_buf(struct can_bus *bus)
{
struct can_msg *msg = NULL;
/* Check whether there is a empty CAN msg buffer */
if (can_bus_tx_buf_is_empty(bus) == false) {
CAN_DEBUG_BUF("can_bus_tx_get_empty_buf: No empty buffer\n");
return NULL;
}
bus->tx_fifo.empty_count--;
/* tx_fifo.head always points to a empty buffer if there is atleast one */
msg = &bus->tx_fifo.pbuf[bus->tx_fifo.head];
bus->tx_fifo.head = (bus->tx_fifo.head + 1) % CAN_TX_BUF_COUNT;
return msg;
}
/** @} */ /* end of CAN device driver */
/** @} */
#endif /*_DEV_CAN_CAN_QUEUE_H */
|
