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/**
 * CAN Interface. This is a general high-level interface for CAN communication.
 * Underlying CAN controllers are abstracted by this interface, so the
 * application needs not work directly against the CAN controllers.
 *
 * @date    2006-10-28
 *
 * @author  Jimmy Myhrman
 * @author  Martin Thomas
 *  
 */
 
/*-----------------------------------------------------------------------------
 * Includes
 *---------------------------------------------------------------------------*/
#include <string.h>
#include <can.h>
#include "timebase.h"
 
 
#ifdef CAN_CONTROLLER_MCP2515
    #include "mcp2515.h"
#else
    #error No CAN controller specified! Edit can_cfg.h !
#endif
 
 
/*-----------------------------------------------------------------------------
 * Functions
 *---------------------------------------------------------------------------*/
 
/**
 * Initializes the CAN interface.
 *
 * @param bitrate
 *      The bitrate that should be used.
 * @return
 *      CAN_OK if initialization was successful.
 *      CAN_FAILINIT otherwise.
 */
CanReturn_t CanInit(const CanBitrate_t bitrate) {
 
#ifdef CAN_CONTROLLER_MCP2515
    if (mcp2515_init(bitrate) != MCP2515_OK) {
        return CAN_FAILINIT;
    }
    if (mcp2515_setCANCTRL_Mode(MODE_NORMAL) != MCP2515_OK) {
        return CAN_FAILINIT;
    }
    return CAN_OK;
#endif
 
    return CAN_FAILINIT;
   
}
 
 
/**
 * Sends a CAN message. If the CAN controller is busy, the message will be
 * copied to an internal transmission queue and transmitted later.
 *
 * @param msg
 *      Pointer to the CAN message storage buffer.
 * @return
 *      CAN_OK if the message was successfully sent (or put in queue).
 *      CAN_FAILTX if the controller is busy AND the transmission queue is full.
 */
CanReturn_t CanSend(CanMessage_t* msg) {
 
#ifdef CAN_CONTROLLER_MCP2515
    uint8_t res, txbuf_n;
    res = mcp2515_getNextFreeTXBuf(&txbuf_n); // info = addr.
    if (res == MCP_ALLTXBUSY) {
        return CAN_FAILTX;
    }
    mcp2515_write_canMsg(txbuf_n, msg);
    mcp2515_start_transmit(txbuf_n);
    return CAN_OK;
#endif
 
}
 
 
/**
 * Pulls a message from the internal CAN interface reception queue. Unless this queue
 * is empty, a CAN message is moved from the queue into the message storage provided
 * by the calling function.
 *
 * @param msg
 *      Pointer to the message storage buffer.
 * @return
 *      CAN_OK if a received message was successfully copied into the buffer.
 *      CAN_NOMSG if there are no received messages available.
 */
CanReturn_t CanReceive(CanMessage_t *msg) {
   
#ifdef CAN_CONTROLLER_MCP2515
    uint8_t stat, res;
    stat = mcp2515_readStatus();
    if (stat & MCP_STAT_RX0IF) {
        // Msg in Buffer 0
        mcp2515_read_canMsg( MCP_RXBUF_0, msg);
        mcp2515_modifyRegister(MCP_CANINTF, MCP_RX0IF, 0);
        res = CAN_OK;
    }
    else if (stat & MCP_STAT_RX1IF) {
        // Msg in Buffer 1
        mcp2515_read_canMsg( MCP_RXBUF_1, msg);
        mcp2515_modifyRegister(MCP_CANINTF, MCP_RX1IF, 0);
        res = CAN_OK;
    }
    else {
        res = CAN_NOMSG;
    }  
    return res;
#endif
 
}
 
 
/**
 * Checks if there are any received CAN messages waiting in the reception queue.
 *
 * @return
 *      CAN_MSGAVAIL if there are messages available.
 *      CAN_NOMSG if the queue is empty.
 */
CanReturn_t CanReceiveAvailable(void) {
   
#ifdef CAN_CONTROLLER_MCP2515
    uint8_t res;
    res = mcp2515_readStatus(); // RXnIF in Bit 1 and 0
    if ( res & MCP_STAT_RXIF_MASK ) {
        return CAN_MSGAVAIL;
    }
    else {
        return CAN_NOMSG;
    }
#endif
 
}
 
 
/*
 * Checks Controller-Error-State.
 *
 * @return
 *      CAN_OK if the controller is OK.
 *      CAN_CTRLERROR if errors have occured.
 * @todo
 *      Styr upp denna funktion lite bättre.
 */
CanReturn_t CanCheckError(void) {
   
#ifdef CAN_CONTROLLER_MCP2515
    uint8_t eflg = mcp2515_readRegister(MCP_EFLG);
    if (eflg & MCP_EFLG_ERRORMASK) {
        return CAN_CTRLERROR;
    }
    else {
        return CAN_OK;
    }
#endif
 
}
 

Rev 59	Rev 63
1	/**	1	/**
2	* CAN Interface. This is a general high-level interface for CAN communication.	2	* CAN Interface. This is a general high-level interface for CAN communication.
3	* Underlying CAN controllers are abstracted by this interface, so the	3	* Underlying CAN controllers are abstracted by this interface, so the
4	* application needs not work directly against the CAN controllers.	4	* application needs not work directly against the CAN controllers.
5	*	5	*
6	* @date 2006-10-28	6	* @date 2006-10-28
7	*	7	*
8	* @author Jimmy Myhrman	8	* @author Jimmy Myhrman
9	* @author Martin Thomas	9	* @author Martin Thomas
10	*	10	*
11	*/	11	*/
12		12
13	/*-----------------------------------------------------------------------------	13	/*-----------------------------------------------------------------------------
14	* Includes	14	* Includes
15	---------------------------------------------------------------------------/	15	---------------------------------------------------------------------------/
16	#include <string.h>	16	#include <string.h>
17	#include <can.h>	17	#include <can.h>
18	#include "timebase.h"	18	#include "timebase.h"
19		19
20		20
21	#ifdef CAN_CONTROLLER_MCP2515	21	#ifdef CAN_CONTROLLER_MCP2515
22	#include "mcp2515.h"	22	#include "mcp2515.h"
23	#else	23	#else
24	#error No CAN controller specified! Edit can_cfg.h !	24	#error No CAN controller specified! Edit can_cfg.h !
25	#endif	25	#endif
26		26
27		27
28	/*-----------------------------------------------------------------------------	28	/*-----------------------------------------------------------------------------
29	* Functions	29	* Functions
30	---------------------------------------------------------------------------/	30	---------------------------------------------------------------------------/
31		31
32	/**	32	/**
33	* Initializes the CAN interface.	33	* Initializes the CAN interface.
34	*	34	*
35	* @param bitrate	35	* @param bitrate
36	* The bitrate that should be used.	36	* The bitrate that should be used.
37	* @return	37	* @return
38	* CAN_OK if initialization was successful.	38	* CAN_OK if initialization was successful.
39	* CAN_FAILINIT otherwise.	39	* CAN_FAILINIT otherwise.
40	*/	40	*/
41	CanReturn_t CanInit(const CanBitrate_t bitrate) {	41	CanReturn_t CanInit(const CanBitrate_t bitrate) {
42		42
43	#ifdef CAN_CONTROLLER_MCP2515	43	#ifdef CAN_CONTROLLER_MCP2515
44	if (mcp2515_init(bitrate) != MCP2515_OK) {	44	if (mcp2515_init(bitrate) != MCP2515_OK) {
45	return CAN_FAILINIT;	45	return CAN_FAILINIT;
46	}	46	}
47	if (mcp2515_setCANCTRL_Mode(MODE_NORMAL) != MCP2515_OK) {	47	if (mcp2515_setCANCTRL_Mode(MODE_NORMAL) != MCP2515_OK) {
48	return CAN_FAILINIT;	48	return CAN_FAILINIT;
49	}	49	}
50	return CAN_OK;	50	return CAN_OK;
51	#endif	51	#endif
52		52
53	return CAN_FAILINIT;	53	return CAN_FAILINIT;
54		54
55	}	55	}
56		56
57		57
58	/**	58	/**
59	* Sends a CAN message. If the CAN controller is busy, the message will be	59	* Sends a CAN message. If the CAN controller is busy, the message will be
60	* copied to an internal transmission queue and transmitted later.	60	* copied to an internal transmission queue and transmitted later.
61	*	61	*
62	* @param msg	62	* @param msg
63	* Pointer to the CAN message storage buffer.	63	* Pointer to the CAN message storage buffer.
64	* @return	64	* @return
65	* CAN_OK if the message was successfully sent (or put in queue).	65	* CAN_OK if the message was successfully sent (or put in queue).
66	* CAN_FAILTX if the controller is busy AND the transmission queue is full.	66	* CAN_FAILTX if the controller is busy AND the transmission queue is full.
67	*/	67	*/
68	CanReturn_t CanSend(~~const~~ CanMessage_t* msg) {	68	CanReturn_t CanSend(CanMessage_t* msg) {
69		69
70	#ifdef CAN_CONTROLLER_MCP2515	70	#ifdef CAN_CONTROLLER_MCP2515
71	uint8_t res, txbuf_n;	71	uint8_t res, txbuf_n;
72	res = mcp2515_getNextFreeTXBuf(&txbuf_n); // info = addr.	72	res = mcp2515_getNextFreeTXBuf(&txbuf_n); // info = addr.
73	if (res == MCP_ALLTXBUSY) {	73	if (res == MCP_ALLTXBUSY) {
74	return CAN_FAILTX;	74	return CAN_FAILTX;
75	}	75	}
76	mcp2515_write_canMsg(txbuf_n, msg);	76	mcp2515_write_canMsg(txbuf_n, msg);
77	mcp2515_start_transmit(txbuf_n);	77	mcp2515_start_transmit(txbuf_n);
78	return CAN_OK;	78	return CAN_OK;
79	#endif	79	#endif
80		80
81	}	81	}
82		82
83		83
84	/**	84	/**
85	* Pulls a message from the internal CAN interface reception queue. Unless this queue	85	* Pulls a message from the internal CAN interface reception queue. Unless this queue
86	* is empty, a CAN message is moved from the queue into the message storage provided	86	* is empty, a CAN message is moved from the queue into the message storage provided
87	* by the calling function.	87	* by the calling function.
88	*	88	*
89	* @param msg	89	* @param msg
90	* Pointer to the message storage buffer.	90	* Pointer to the message storage buffer.
91	* @return	91	* @return
92	* CAN_OK if a received message was successfully copied into the buffer.	92	* CAN_OK if a received message was successfully copied into the buffer.
93	* CAN_NOMSG if there are no received messages available.	93	* CAN_NOMSG if there are no received messages available.
94	*/	94	*/
95	CanReturn_t CanReceive(CanMessage_t *msg) {	95	CanReturn_t CanReceive(CanMessage_t *msg) {
96		96
97	#ifdef CAN_CONTROLLER_MCP2515	97	#ifdef CAN_CONTROLLER_MCP2515
98	uint8_t stat, res;	98	uint8_t stat, res;
99	stat = mcp2515_readStatus();	99	stat = mcp2515_readStatus();
100	if (stat & MCP_STAT_RX0IF) {	100	if (stat & MCP_STAT_RX0IF) {
101	// Msg in Buffer 0	101	// Msg in Buffer 0
102	mcp2515_read_canMsg( MCP_RXBUF_0, msg);	102	mcp2515_read_canMsg( MCP_RXBUF_0, msg);
103	mcp2515_modifyRegister(MCP_CANINTF, MCP_RX0IF, 0);	103	mcp2515_modifyRegister(MCP_CANINTF, MCP_RX0IF, 0);
104	res = CAN_OK;	104	res = CAN_OK;
105	}	105	}
106	else if (stat & MCP_STAT_RX1IF) {	106	else if (stat & MCP_STAT_RX1IF) {
107	// Msg in Buffer 1	107	// Msg in Buffer 1
108	mcp2515_read_canMsg( MCP_RXBUF_1, msg);	108	mcp2515_read_canMsg( MCP_RXBUF_1, msg);
109	mcp2515_modifyRegister(MCP_CANINTF, MCP_RX1IF, 0);	109	mcp2515_modifyRegister(MCP_CANINTF, MCP_RX1IF, 0);
110	res = CAN_OK;	110	res = CAN_OK;
111	}	111	}
112	else {	112	else {
113	res = CAN_NOMSG;	113	res = CAN_NOMSG;
114	}	114	}
115	return res;	115	return res;
116	#endif	116	#endif
117		117
118	}	118	}
119		119
120		120
121	/**	121	/**
122	* Checks if there are any received CAN messages waiting in the reception queue.	122	* Checks if there are any received CAN messages waiting in the reception queue.
123	*	123	*
124	* @return	124	* @return
125	* CAN_MSGAVAIL if there are messages available.	125	* CAN_MSGAVAIL if there are messages available.
126	* CAN_NOMSG if the queue is empty.	126	* CAN_NOMSG if the queue is empty.
127	*/	127	*/
128	CanReturn_t CanReceiveAvailable(void) {	128	CanReturn_t CanReceiveAvailable(void) {
129		129
130	#ifdef CAN_CONTROLLER_MCP2515	130	#ifdef CAN_CONTROLLER_MCP2515
131	uint8_t res;	131	uint8_t res;
132	res = mcp2515_readStatus(); // RXnIF in Bit 1 and 0	132	res = mcp2515_readStatus(); // RXnIF in Bit 1 and 0
133	if ( res & MCP_STAT_RXIF_MASK ) {	133	if ( res & MCP_STAT_RXIF_MASK ) {
134	return CAN_MSGAVAIL;	134	return CAN_MSGAVAIL;
135	}	135	}
136	else {	136	else {
137	return CAN_NOMSG;	137	return CAN_NOMSG;
138	}	138	}
139	#endif	139	#endif
140		140
141	}	141	}
142		142
143		143
144	/*	144	/*
145	* Checks Controller-Error-State.	145	* Checks Controller-Error-State.
146	*	146	*
147	* @return	147	* @return
148	* CAN_OK if the controller is OK.	148	* CAN_OK if the controller is OK.
149	* CAN_CTRLERROR if errors have occured.	149	* CAN_CTRLERROR if errors have occured.
150	* @todo	150	* @todo
151	* Styr upp denna funktion lite bättre.	151	* Styr upp denna funktion lite bättre.
152	*/	152	*/
153	CanReturn_t CanCheckError(void) {	153	CanReturn_t CanCheckError(void) {
154		154
155	#ifdef CAN_CONTROLLER_MCP2515	155	#ifdef CAN_CONTROLLER_MCP2515
156	uint8_t eflg = mcp2515_readRegister(MCP_EFLG);	156	uint8_t eflg = mcp2515_readRegister(MCP_EFLG);
157	if (eflg & MCP_EFLG_ERRORMASK) {	157	if (eflg & MCP_EFLG_ERRORMASK) {
158	return CAN_CTRLERROR;	158	return CAN_CTRLERROR;
159	}	159	}
160	else {	160	else {
161	return CAN_OK;	161	return CAN_OK;
162	}	162	}
163	#endif	163	#endif
164		164
165	}	165	}
166		166

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