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mbed library sources. Supersedes mbed-src.
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Diff: targets/TARGET_NXP/TARGET_LPC15XX/can_api.c
- Revision:
- 156:95d6b41a828b
- Parent:
- 149:156823d33999
--- a/targets/TARGET_NXP/TARGET_LPC15XX/can_api.c Thu Jan 05 10:51:54 2017 +0000
+++ b/targets/TARGET_NXP/TARGET_LPC15XX/can_api.c Mon Jan 16 15:03:32 2017 +0000
@@ -23,7 +23,8 @@
#include <string.h>
/* Handy defines */
-#define MSG_OBJ_MAX 32
+#define RX_MSG_OBJ_COUNT 31
+#define TX_MSG_OBJ_COUNT 1
#define DLC_MAX 8
#define ID_STD_MASK 0x07FF
@@ -56,6 +57,12 @@
#define CANIFn_CMDMSK_RD (0UL << 7)
#define CANIFn_CMDREQ_BUSY (1UL << 15)
+#define CANSTAT_TXOK (1 << 3) // Transmitted a message successfully This bit must be reset by the CPU. It is never reset by the CAN controller.
+#define CANSTAT_RXOK (1 << 4) // Received a message successfully This bit must be reset by the CPU. It is never reset by the CAN controller.
+#define CANSTAT_EPASS (1 << 5) // Error passive
+#define CANSTAT_EWARN (1 << 6) // Warning status
+#define CANSTAT_BOFF (1 << 7) // Busoff status
+
#define CANCNTL_INIT (1 << 0) // Initialization
#define CANCNTL_IE (1 << 1) // Module interrupt enable
#define CANCNTL_SIE (1 << 2) // Status change interrupt enable
@@ -74,6 +81,16 @@
static uint32_t can_irq_id = 0;
static can_irq_handler irq_handler;
+#define IRQ_ENABLE_TX (1 << 0)
+#define IRQ_ENABLE_RX (1 << 1)
+#define IRQ_ENABLE_EW (1 << 2)
+#define IRQ_ENABLE_EP (1 << 3)
+#define IRQ_ENABLE_BE (1 << 4)
+#define IRQ_ENABLE_STATUS (IRQ_ENABLE_TX | IRQ_ENABLE_RX)
+#define IRQ_ENABLE_ERROR (IRQ_ENABLE_EW | IRQ_ENABLE_EP | IRQ_ENABLE_BE)
+#define IRQ_ENABLE_ANY (IRQ_ENABLE_STATUS | IRQ_ENABLE_ERROR)
+static uint32_t enabled_irqs = 0;
+
static inline void can_disable(can_t *obj) {
LPC_C_CAN0->CANCNTL |= 0x1;
}
@@ -139,7 +156,7 @@
}
}
- if (handle > 0 && handle < 32) {
+ if (handle > 0 && handle <= 32) {
if (format == CANExtended) {
// Mark message valid, Direction = TX, Extended Frame, Set Identifier and mask everything
LPC_C_CAN0->CANIF1_ARB1 = (id & 0xFFFF);
@@ -153,7 +170,7 @@
}
// Use mask, single message object and set DLC
- LPC_C_CAN0->CANIF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_EOB | CANIFn_MCTRL_RXIE | (DLC_MAX & 0xF);
+ LPC_C_CAN0->CANIF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_EOB | (DLC_MAX & 0xF);
// Transfer all fields to message object
LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_MASK | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL;
@@ -169,7 +186,41 @@
}
static inline void can_irq() {
- irq_handler(can_irq_id, IRQ_RX);
+ uint32_t intid = LPC_C_CAN0->CANINT & 0xFFFF;
+
+ if (intid == 0x8000) {
+ uint32_t status = LPC_C_CAN0->CANSTAT;
+ // Note that since it's impossible to tell which specific status caused
+ // the interrupt to fire, this just fires them all.
+ // In particular, EWARN is not mutually exclusive with the others and
+ // may fire multiple times with other status transitions, including
+ // transmit and receive completion (if enabled). Ignoring EWARN with a
+ // priority system (i.e. blocking EWARN interrupts if EPASS or BOFF is
+ // set) may discard some EWARN interrupts.
+ if (status & CANSTAT_BOFF) {
+ if (enabled_irqs & IRQ_ENABLE_BE) {
+ irq_handler(can_irq_id, IRQ_BUS);
+ }
+ }
+ if (status & CANSTAT_EPASS) {
+ if (enabled_irqs & IRQ_ENABLE_EP) {
+ irq_handler(can_irq_id, IRQ_PASSIVE);
+ }
+ }
+ if (status & CANSTAT_EWARN) {
+ if (enabled_irqs & IRQ_ENABLE_EW) {
+ irq_handler(can_irq_id, IRQ_ERROR);
+ }
+ }
+ if ((status & CANSTAT_RXOK) != 0) {
+ LPC_C_CAN0->CANSTAT &= ~CANSTAT_RXOK;
+ irq_handler(can_irq_id, IRQ_RX);
+ }
+ if ((status & CANSTAT_TXOK) != 0) {
+ LPC_C_CAN0->CANSTAT &= ~CANSTAT_TXOK;
+ irq_handler(can_irq_id, IRQ_TX);
+ }
+ }
}
// Register CAN object's irq handler
@@ -187,13 +238,53 @@
// Clear or set a irq
void can_irq_set(can_t *obj, CanIrqType type, uint32_t enable) {
+ uint32_t mask_enable;
+ switch (type) {
+ case IRQ_RX:
+ mask_enable = IRQ_ENABLE_RX;
+ break;
+ case IRQ_TX:
+ mask_enable = IRQ_ENABLE_TX;
+ break;
+ case IRQ_BUS:
+ mask_enable = IRQ_ENABLE_BE;
+ break;
+ case IRQ_PASSIVE:
+ mask_enable = IRQ_ENABLE_EP;
+ break;
+ case IRQ_ERROR:
+ mask_enable = IRQ_ENABLE_EW;
+ break;
+ default:
+ return;
+ }
+
+ if (enable) {
+ enabled_irqs = enabled_irqs | mask_enable;
+ } else {
+ enabled_irqs = enabled_irqs & ~mask_enable;
+ }
+
// Put CAN in Reset Mode and enable interrupt
can_disable(obj);
- if (enable == 0) {
- LPC_C_CAN0->CANCNTL &= ~(1UL << 1 | 1UL << 2);
+ if (!(enabled_irqs & IRQ_ENABLE_ANY)) {
+ LPC_C_CAN0->CANCNTL &= ~(1UL << 1 | 1UL << 2 | 1UL << 3);
} else {
- LPC_C_CAN0->CANCNTL |= 1UL << 1 | 1UL << 2;
+ LPC_C_CAN0->CANCNTL |= 1UL << 1;
+ // Use status interrupts instead of message interrupts to avoid
+ // stomping over potential filter configurations.
+ if (enabled_irqs & IRQ_ENABLE_STATUS) {
+ LPC_C_CAN0->CANCNTL |= 1UL << 2;
+ } else {
+ LPC_C_CAN0->CANCNTL &= ~(1UL << 2);
+ }
+ if (enabled_irqs & IRQ_ENABLE_ERROR) {
+ LPC_C_CAN0->CANCNTL |= 1UL << 3;
+ } else {
+ LPC_C_CAN0->CANCNTL &= ~(1UL << 3);
+ }
}
+
// Take it out of reset...
can_enable(obj);
@@ -280,9 +371,9 @@
LPC_C_CAN0->CANIF1_ARB2 = 0;
LPC_C_CAN0->CANIF1_MCTRL = 0;
- for ( i = 0; i < MSG_OBJ_MAX; i++ ) {
+ for ( i = 1; i <= RX_MSG_OBJ_COUNT; i++ ) {
// Transfer arb and control fields to message object
- LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL | CANIFn_CMDMSK_TXRQST;
+ LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL;
// Start Transfer to given message number
LPC_C_CAN0->CANIF1_CMDREQ = (i & 0x3F);
@@ -297,6 +388,33 @@
return 1;
}
+int can_config_txmsgobj(can_t *obj) {
+ uint16_t i = 0;
+
+ // Make sure the interface is available
+ while ( LPC_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY );
+
+ // Mark message valid, Direction = TX, Don't care about anything else
+ LPC_C_CAN0->CANIF1_ARB1 = 0;
+ LPC_C_CAN0->CANIF1_ARB2 = CANIFn_ARB2_DIR;
+ LPC_C_CAN0->CANIF1_MCTRL = 0;
+
+ for ( i = RX_MSG_OBJ_COUNT + 1; i <= (TX_MSG_OBJ_COUNT + RX_MSG_OBJ_COUNT); i++ )
+ {
+ // Transfer arb and control fields to message object
+ LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL;
+ // In a union with CANIF1_CMDMSK_R
+
+ // Start Transfer to given message number
+ LPC_C_CAN0->CANIF1_CMDREQ = i & 0x3F;
+
+ // Wait until transfer to message ram complete - TODO: maybe not block??
+ while( LPC_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY );
+ }
+
+ return 1;
+}
+
void can_init(can_t *obj, PinName rd, PinName td) {
// Enable power and clock
@@ -320,6 +438,8 @@
// Initialize RX message object
can_config_rxmsgobj(obj);
+ // Initialize TX message object
+ can_config_txmsgobj(obj);
}
void can_free(can_t *obj) {
@@ -345,11 +465,26 @@
}
int can_write(can_t *obj, CAN_Message msg, int cc) {
- uint16_t msgnum = 0;
// Make sure controller is enabled
can_enable(obj);
+ // Find first message object that isn't pending to send
+ uint16_t msgnum = 0;
+ uint32_t txPending = (LPC_C_CAN0->CANTXREQ1 & 0xFF) | (LPC_C_CAN0->CANTXREQ2 << 16);
+ uint16_t i = 0;
+ for(i = RX_MSG_OBJ_COUNT; i < 32; i++) {
+ if ((txPending & (1 << i)) == 0) {
+ msgnum = i+1;
+ break;
+ }
+ }
+
+ // If no messageboxes are available, stop and return failure
+ if (msgnum == 0) {
+ return 0;
+ }
+
// Make sure the interface is available
while ( LPC_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY );
@@ -405,7 +540,7 @@
if (handle == 0) {
uint32_t newdata = LPC_C_CAN0->CANND1 | (LPC_C_CAN0->CANND2 << 16);
// Find first free messagebox
- for (i = 0; i < 32; i++) {
+ for (i = 0; i < RX_MSG_OBJ_COUNT; i++) {
if (newdata & (1 << i)) {
handle = i+1;
break;
@@ -413,7 +548,7 @@
}
}
- if (handle > 0 && handle < 32) {
+ if (handle > 0 && handle <= 32) {
// Wait until message interface is free
while ( LPC_C_CAN0->CANIF2_CMDREQ & CANIFn_CMDREQ_BUSY );
@@ -462,6 +597,9 @@
LPC_SYSCON->PRESETCTRL1 &= ~(1UL << 7);
LPC_C_CAN0->CANSTAT = 0;
can_config_rxmsgobj(obj);
+ can_config_txmsgobj(obj);
+
+ can_enable(obj); // clears a bus-off condition if necessary
}
unsigned char can_rderror(can_t *obj) {