can: isotp: Add CAN-FD support to ISO-TP

include/zephyr/canbus/isotp.h

@@ -11,8 +11,8 @@
  * ISO-TP is a transport protocol for CAN (Controller Area Network)
  */
 
-#ifndef ZEPHYR_INCLUDE_ISOTP_H_
-#define ZEPHYR_INCLUDE_ISOTP_H_
+#ifndef ZEPHYR_INCLUDE_CANBUS_ISOTP_H_
+#define ZEPHYR_INCLUDE_CANBUS_ISOTP_H_
 
 /**
  * @brief CAN ISO-TP Protocol
@@ -34,10 +34,16 @@
  * DLC     Data length code
  * FC      Flow Control
  * FF      First Frame
+ * SF      Single Frame
  * FS      Flow Status
  * AE      Address Extension
+ * SN      Sequence Number
+ * ST      Separation time
  * SA      Source Address
  * TA      Target Address
+ * RX_DL   CAN RX LL data size
+ * TX_DL   CAN TX LL data size
+ * PCI     Process Control Information
  */
 
 /*
@@ -147,6 +153,12 @@ extern "C" {
 /** Message uses extended (29-bit) CAN ID */
 #define ISOTP_MSG_IDE BIT(2)
 
+/** Message uses CAN-FD format (FDF) */
+#define ISOTP_MSG_FDF BIT(3)
+
+/** Message uses CAN-FD Baud Rate Switch (BRS). Only valid in combination with ``ISOTP_MSG_FDF``. */
+#define ISOTP_MSG_BRS BIT(4)
+
 /** @} */
 
 /**
@@ -167,6 +179,17 @@ struct isotp_msg_id {
 	};
 	/** ISO-TP extended address (if used) */
 	uint8_t ext_addr;
+	/**
+	 * ISO-TP frame data length (TX_DL for TX address or RX_DL for RX address).
+	 *
+	 * Valid values are 8 for classical CAN or 8, 12, 16, 20, 24, 32, 48 and 64 for CAN-FD.
+	 *
+	 * 0 will be interpreted as 8 or 64 (if ISOTP_MSG_FDF is set).
+	 *
+	 * The value for incoming transmissions (RX_DL) is determined automatically based on the
+	 * received first frame and does not need to be set during initialization.
+	 */
+	uint8_t dl;
 	/** Flags. @see @ref ISOTP_MSG_FLAGS. */
 	uint8_t flags;
 };
@@ -459,4 +482,4 @@ struct isotp_recv_ctx {
 }
 #endif
 
-#endif /* ZEPHYR_INCLUDE_ISOTP_H_ */
+#endif /* ZEPHYR_INCLUDE_CANBUS_ISOTP_H_ */

samples/subsys/canbus/isotp/Kconfig

@@ -22,4 +22,12 @@ config SAMPLE_RX_THREAD_PRIORITY
 	help
 	  Priority used for the RX threads.
 
+config SAMPLE_CAN_FD_MODE
+	bool "Use CAN-FD"
+	select CAN_FD_MODE
+
+config ISOTP_RX_BUF_COUNT
+	default 4 if SAMPLE_CAN_FD_MODE
+	default 2
+
 source "Kconfig.zephyr"

samples/subsys/canbus/isotp/prj.conf

@@ -4,9 +4,5 @@ CONFIG_CAN=y
 CONFIG_CAN_MAX_FILTER=8
 
 CONFIG_ISOTP=y
-CONFIG_ISOTP_RX_BUF_COUNT=2
-#A frame has 7 bytes payload, we are using a BS of 8 and need one char for the
-#string termination (7 * 8 + 1 = 57)
-CONFIG_ISOTP_RX_BUF_SIZE=57
-#We have two receiving contexts that are bound to a single address.
+# We have two receiving contexts that are bound to a single address.
 CONFIG_ISOTP_RX_SF_FF_BUF_COUNT=2

samples/subsys/canbus/isotp/sample.yaml

@@ -14,3 +14,19 @@ tests:
       type: one_line
       regex:
         - "(.*)Got 247 bytes in total"
+  sample.subsys.canbus.isotp.fd:
+    tags:
+      - can
+      - isotp
+    depends_on: can
+    extra_configs:
+      - CONFIG_SAMPLE_LOOPBACK_MODE=y
+      - CONFIG_SAMPLE_CAN_FD_MODE=y
+    platform_allow:
+      - native_posix
+      - native_posix_64
+    harness: console
+    harness_config:
+      type: one_line
+      regex:
+        - "(.*)Got 247 bytes in total"

samples/subsys/canbus/isotp/src/main.c

@@ -12,15 +12,29 @@ const struct isotp_fc_opts fc_opts_0_5 = {.bs = 0, .stmin = 5};
 
 const struct isotp_msg_id rx_addr_8_0 = {
 	.std_id = 0x80,
+#ifdef CONFIG_SAMPLE_CAN_FD_MODE
+	.flags = ISOTP_MSG_FDF | ISOTP_MSG_BRS,
+#endif
 };
 const struct isotp_msg_id tx_addr_8_0 = {
 	.std_id = 0x180,
+#ifdef CONFIG_SAMPLE_CAN_FD_MODE
+	.dl = 64,
+	.flags = ISOTP_MSG_FDF | ISOTP_MSG_BRS,
+#endif
 };
 const struct isotp_msg_id rx_addr_0_5 = {
 	.std_id = 0x01,
+#ifdef CONFIG_SAMPLE_CAN_FD_MODE
+	.flags = ISOTP_MSG_FDF | ISOTP_MSG_BRS,
+#endif
 };
 const struct isotp_msg_id tx_addr_0_5 = {
 	.std_id = 0x101,
+#ifdef CONFIG_SAMPLE_CAN_FD_MODE
+	.dl = 64,
+	.flags = ISOTP_MSG_FDF | ISOTP_MSG_BRS,
+#endif
 };
 
 const struct device *can_dev;
@@ -49,8 +63,6 @@ void rx_8_0_thread(void *arg1, void *arg2, void *arg3)
 	ARG_UNUSED(arg3);
 	int ret, rem_len, received_len;
 	struct net_buf *buf;
-	static uint8_t rx_buffer[7];
-
 
 	ret = isotp_bind(&recv_ctx_8_0, can_dev,
 			 &tx_addr_8_0, &rx_addr_8_0,
@@ -71,19 +83,11 @@ void rx_8_0_thread(void *arg1, void *arg2, void *arg3)
 				break;
 			}
 
-			received_len += buf->len;
-			if (net_buf_tailroom(buf) >= 1) {
-				net_buf_add_u8(buf, '\0');
-				printk("%s", buf->data);
-			} else if (buf->len == 6) {
-				/* First frame does not have tailroom.*/
-				memcpy(rx_buffer, buf->data, 6);
-				rx_buffer[6] = '\0';
-				printk("%s", rx_buffer);
-			} else {
-				printk("No tailroom for string termination\n");
+			while (buf != NULL) {
+				received_len += buf->len;
+				printk("%.*s", buf->len, buf->data);
+				buf = net_buf_frag_del(NULL, buf);
 			}
-			net_buf_unref(buf);
 		} while (rem_len);
 		printk("Got %d bytes in total\n", received_len);
 	}
@@ -142,13 +146,13 @@ int main(void)
 		return 0;
 	}
 
-#ifdef CONFIG_SAMPLE_LOOPBACK_MODE
-	ret = can_set_mode(can_dev, CAN_MODE_LOOPBACK);
+	can_mode_t mode = (IS_ENABLED(CONFIG_SAMPLE_LOOPBACK_MODE) ? CAN_MODE_LOOPBACK : 0) |
+			  (IS_ENABLED(CONFIG_SAMPLE_CAN_FD_MODE) ? CAN_MODE_FD : 0);
+	ret = can_set_mode(can_dev, mode);
 	if (ret != 0) {
-		printk("CAN: Failed to set loopback mode [%d]", ret);
+		printk("CAN: Failed to set mode [%d]", ret);
 		return 0;
 	}
-#endif /* CONFIG_SAMPLE_LOOPBACK_MODE */
 
 	ret = can_start(can_dev);
 	if (ret != 0) {

subsys/canbus/isotp/Kconfig

@@ -5,6 +5,7 @@
 
 menuconfig ISOTP
 	bool "ISO-TP Transport [EXPERIMENTAL]"
+	depends on CAN
 	select NET_BUF
 	select POLL
 	select EXPERIMENTAL
@@ -74,11 +75,12 @@ config ISOTP_RX_BUF_COUNT
 
 config ISOTP_RX_BUF_SIZE
 	int "Size of one buffer data block"
+	default 63 if CAN_FD_MODE
 	default 56
 	help
 	  This value defines the size of a single block in the pool. The number of
 	  blocks is given by ISOTP_RX_BUF_COUNT. To be efficient use a multiple of
-	  CAN_DL - 1 (for classic can : 8 - 1 = 7).
+	  CAN_MAX_DLEN - 1 (for classic CAN : 8 - 1 = 7, for CAN-FD : 64 - 1 = 63).
 
 config ISOTP_RX_SF_FF_BUF_COUNT
 	int "Number of SF and FF data buffers for receiving data"
@@ -87,7 +89,7 @@ config ISOTP_RX_SF_FF_BUF_COUNT
 	  This buffer is used for first and single frames. It is extra because the
 	  buffer has to be ready for the first reception in isr context and therefor
 	  is allocated when binding.
-	  Each buffer will occupy CAN_DL - 1 byte + header (sizeof(struct net_buf))
+	  Each buffer will occupy CAN_MAX_DLEN - 1 byte + header (sizeof(struct net_buf))
 	  amount of data.
 
 config ISOTP_USE_TX_BUF