CAN filter- and mask-setting functions

1 files changed, 74 insertions, 7 deletions

diff --git a/fw/can.h b/fw/can.h
index 833a7c4..c9b3d4b 100644
--- a/fw/can.h
+++ b/fw/can.h
@@ -7,6 +7,7 @@
  *
  * Usage:
  *
+ * #include <stdbool.h>
  * #include <stdint.h>
  * #include "types.h"
  * #include "can.h"
@@ -17,14 +18,80 @@
 #define CAN_CS LATAbits.LATA5
 
 // Bit timings (CNF1, CNF2, CNF3)
-#define CAN_TIMINGS_10K 0xDE, 0xAD, 0x06 // BRP=30, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
-#define CAN_TIMINGS_20K 0xCF, 0xAD, 0x06 // BRP=15, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
-#define CAN_TIMINGS_50K 0xC6, 0xAD, 0x06 // BRP=6, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
-#define CAN_TIMINGS_100K 0xC3, 0xAD, 0x06 // BRP=3, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
-#define CAN_TIMINGS_125K 0xC4, 0x9A, 0x03 // BRP=4, PropSeg=3, PS1=4, PS2=4, SP=66.7%, SJW=4
-#define CAN_TIMINGS_250K 0xC2, 0x9A, 0x03 // BRP=2, PropSeg=3, PS1=4, PS2=4, SP=66.7%, SJW=4
-#define CAN_TIMINGS_500K 0xC1, 0x9A, 0x03 // BRP=1, PropSeg=3, PS1=4, PS2=4, SP=66.7, SJW=4
+#define CAN_TIMINGS_10K 0xDD, 0xAD, 0x06 // BRP=30, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
+#define CAN_TIMINGS_20K 0xCE, 0xAD, 0x06 // BRP=15, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
+#define CAN_TIMINGS_50K 0xC5, 0xAD, 0x06 // BRP=6, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
+#define CAN_TIMINGS_100K 0xC2, 0xAD, 0x06 // BRP=3, PropSeg=6, PS1=6, PS2=7, SP=65%, SJW=4
+#define CAN_TIMINGS_125K 0xC3, 0x9A, 0x03 // BRP=4, PropSeg=3, PS1=4, PS2=4, SP=66.7%, SJW=4
+#define CAN_TIMINGS_250K 0xC1, 0x9A, 0x03 // BRP=2, PropSeg=3, PS1=4, PS2=4, SP=66.7%, SJW=4
+#define CAN_TIMINGS_500K 0xC0, 0x9A, 0x03 // BRP=1, PropSeg=3, PS1=4, PS2=4, SP=66.7%, SJW=4
 #define CAN_TIMINGS_800K "800kbps unsupported" // not possible with 12MHz clock
 #define CAN_TIMINGS_1M "1Mbps unsupported" // not possible with 12MHz clock
 
+// MCP2515 modes of operation
+typedef enum {
+	CAN_MODE_NORMAL = 0x0,
+	CAN_MODE_SLEEP = 0x1,
+	CAN_MODE_LOOPBACK = 0x2,
+	CAN_MODE_LISTEN_ONLY = 0x3,
+	CAN_MODE_CONFIG = 0x4,
+} CanMode;
+
+// CAN identifier
+typedef struct {
+	enum {
+		CAN_ID_STD, // standard
+		CAN_ID_EXT, // extended
+	} type;
+	union {
+		U16 sid; // 11-bit standard ID
+		U32 eid; // 29-bit extended ID
+	};
+} CanId;
+
+// Initialize the MCP2515.
+// Initial mode is Config.
 void canInit(void);
+
+// Set the operating mode of the MCP2515.
+void canSetMode(CanMode mode);
+
+// Set the bit timing parameters (bitrate, etc.).
+// Pass one of the CAN_TIMINGS_x macros.
+// The MCP2515 must be in Config mode.
+void canSetBitTiming(U8 cnf1, U8 cnf2, U8 cnf3);
+
+// Enable/disable interrupts on the MCP2515's INT pin.
+void canIE(bool enable);
+
+// Set the message acceptance mask of RXB0.
+// The MCP2515 must be in Config mode.
+void canSetMask0(const CanId *mask);
+
+// Set the message acceptance mask of RXB1.
+// The MCP2515 must be in Config mode.
+void canSetMask0(const CanId *mask);
+
+// Set message acceptance filter 0 (RXB0).
+// The MCP2515 must be in Config mode.
+void canSetFilter0(const CanId *filter);
+
+// Set message acceptance filter 1 (RXB0).
+// The MCP2515 must be in Config mode.
+void canSetFilter1(const CanId *filter);
+
+// Set message acceptance filter 2 (RXB1).
+// The MCP2515 must be in Config mode.
+void canSetFilter2(const CanId *filter);
+
+// Set message acceptance filter 3 (RXB1).
+// The MCP2515 must be in Config mode.
+void canSetFilter3(const CanId *filter);
+
+// Set message acceptance filter 4 (RXB1).
+// The MCP2515 must be in Config mode.
+void canSetFilter4(const CanId *filter);
+
+// Set message acceptance filter 5 (RXB1).
+// The MCP2515 must be in Config mode.
+void canSetFilter5(const CanId *filter);