From 081218e24682be11668ec5218dcd8b49630d7a87 Mon Sep 17 00:00:00 2001
From: Jiri Vanek <vanekjir@fel.cvut.cz>
Date: Mon, 9 Apr 2012 17:17:30 +0200
Subject: [PATCH] Some bugs related with bit timing fixed.

---
 embedded/app/usbcan/lpc17xx_can.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/embedded/app/usbcan/lpc17xx_can.c b/embedded/app/usbcan/lpc17xx_can.c
index fd09804..7cd0f56 100644
--- a/embedded/app/usbcan/lpc17xx_can.c
+++ b/embedded/app/usbcan/lpc17xx_can.c
@@ -3,6 +3,8 @@
 static void CAN_configPin();
 static void CAN_setBusTiming(struct canchip_t *chip);
 
+#define MAX_TRANSMIT_WAIT_LOOPS 20
+
 //---------------------------------------------------------------------------------
 //---------------------------------------------------------------------------------
 
@@ -102,10 +104,20 @@ int lpc17xx_pre_write_config(struct canchip_t *chip, struct msgobj_t *obj,
 int lpc17xx_send_msg(struct canchip_t *chip, struct msgobj_t *obj,
 							struct canmsg_t *msg)
 {
-	
+	uint32_t i=0;	
+
 	// write transmission request
 	can_write_reg(chip, (CAN_CMR_TR | CAN_CMR_STB1), CAN_CMR_o); 
 
+	while (!(can_read_reg(chip, CAN_SR_o) & (1<<3))){
+		if(i++<MAX_TRANSMIT_WAIT_LOOPS)
+			continue;
+
+		// request command to abort transmission request
+		can_write_reg(chip, CAN_CMR_AT, CAN_CMR_o);
+		break;
+	}
+
 	return 0;
 }
 
@@ -186,6 +198,7 @@ void lpc17xx_irq_write_handler(struct canchip_t *chip, struct msgobj_t *obj)
 {
 	int cmd;
 
+
 	if(obj->tx_slot){
 		/* Do local transmitted message distribution if enabled */
 		if (processlocal){
@@ -357,14 +370,22 @@ void CAN_recv(struct canchip_t *chip, canmsg_t* msg){
 
 }
 
+
 void CAN_send(struct canchip_t *chip, canmsg_t* msg){
 
 	volatile uint32_t data;
 	volatile uint32_t can_tfi1;
-	uint32_t i;
+	uint32_t i=0;
 
 	// check status of TB1
-	while (!(can_read_reg(chip, CAN_SR_o) & CAN_SR_TBS1)){}	
+	while (!(can_read_reg(chip, CAN_SR_o) & CAN_SR_TBS1)){
+		if(i++<MAX_TRANSMIT_WAIT_LOOPS)
+			continue;
+
+		// request command to abort transmission request
+		can_write_reg(chip, CAN_CMR_AT, CAN_CMR_o);
+		return;
+	}	
 
 	can_tfi1 = can_read_reg(chip, CAN_TFI1_o);
 
-- 
2.39.2