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-rw-r--r--src/generic/canbus.c133
-rw-r--r--src/generic/canbus.h6
-rw-r--r--src/stm32/can.c28
3 files changed, 94 insertions, 73 deletions
diff --git a/src/generic/canbus.c b/src/generic/canbus.c
index 80d0e462..9b8e0e54 100644
--- a/src/generic/canbus.c
+++ b/src/generic/canbus.c
@@ -82,80 +82,88 @@ console_sendf(const struct command_encoder *ce, va_list args)
/****************************************************************
- * CAN command handling
+ * CAN "admin" command handling
****************************************************************/
-static uint8_t receive_buf[192], receive_pos;
-DECL_CONSTANT("RECEIVE_WINDOW", ARRAY_SIZE(receive_buf));
+// Available commands and responses
+#define CANBUS_CMD_QUERY_UNASSIGNED 0x00
+#define CANBUS_CMD_SET_NODEID 0x01
+#define CANBUS_RESP_NEED_NODEID 0x20
-static void
-can_process_data(uint32_t id, uint32_t len, uint8_t *data)
+// Helper to verify a UUID in a command matches this chip's UUID
+static int
+can_check_uuid(uint32_t id, uint32_t len, uint8_t *data)
{
- int rpos = receive_pos;
- if (len > sizeof(receive_buf) - rpos)
- len = sizeof(receive_buf) - rpos;
- memcpy(&receive_buf[rpos], data, len);
- receive_pos = rpos + len;
+ return len >= 7 && memcmp(&data[1], canbus_uuid, sizeof(canbus_uuid)) == 0;
}
-// Helper to retry sending until successful
-static void
-canbus_send_blocking(uint32_t id, uint32_t len, uint8_t *data)
+// Helpers to encode/decode a CAN identifier to a 1-byte "nodeid"
+static int
+can_get_nodeid(void)
{
- for (;;) {
- int ret = canbus_send(id, len, data);
- if (ret >= 0)
- return;
- }
+ if (!canbus_assigned_id)
+ return 0;
+ return (canbus_assigned_id - 0x100) >> 1;
}
-
-static void
-can_process_ping(uint32_t id, uint32_t len, uint8_t *data)
+static uint32_t
+can_decode_nodeid(int nodeid)
{
- canbus_send_blocking(canbus_assigned_id + 1, 0, NULL);
+ return (nodeid << 1) + 0x100;
}
static void
-can_process_reset(uint32_t id, uint32_t len, uint8_t *data)
+can_process_query_unassigned(uint32_t id, uint32_t len, uint8_t *data)
{
- uint32_t reset_id = data[0] | (data[1] << 8);
- if (reset_id == canbus_assigned_id)
- canbus_reboot();
+ if (canbus_assigned_id)
+ return;
+ uint8_t send[8];
+ send[0] = CANBUS_RESP_NEED_NODEID;
+ memcpy(&send[1], canbus_uuid, sizeof(canbus_uuid));
+ // Send with retry
+ for (;;) {
+ int ret = canbus_send(CANBUS_ID_ADMIN_RESP, 7, send);
+ if (ret >= 0)
+ return;
+ }
}
static void
-can_process_uuid(uint32_t id, uint32_t len, uint8_t *data)
+can_id_conflict(void)
{
- if (canbus_assigned_id)
- return;
- canbus_send_blocking(CANBUS_ID_UUID_RESP, sizeof(canbus_uuid), canbus_uuid);
+ canbus_assigned_id = 0;
+ canbus_set_filter(canbus_assigned_id);
+ shutdown("Another CAN node assigned this ID");
}
static void
-can_process_set_id(uint32_t id, uint32_t len, uint8_t *data)
+can_process_set_nodeid(uint32_t id, uint32_t len, uint8_t *data)
{
- // compare my UUID with packet to check if this packet mine
- if (memcmp(&data[2], canbus_uuid, sizeof(canbus_uuid)) == 0) {
- canbus_assigned_id = data[0] | (data[1] << 8);
- canbus_set_filter(canbus_assigned_id);
+ if (len < 8)
+ return;
+ uint32_t newid = can_decode_nodeid(data[7]);
+ if (can_check_uuid(id, len, data)) {
+ if (newid != canbus_assigned_id) {
+ canbus_assigned_id = newid;
+ canbus_set_filter(canbus_assigned_id);
+ }
+ } else if (newid == canbus_assigned_id) {
+ can_id_conflict();
}
}
+// Handle an "admin" command
static void
can_process(uint32_t id, uint32_t len, uint8_t *data)
{
- if (id == canbus_assigned_id) {
- if (len)
- can_process_data(id, len, data);
- else
- can_process_ping(id, len, data);
- } else if (id == CANBUS_ID_UUID) {
- if (len)
- can_process_reset(id, len, data);
- else
- can_process_uuid(id, len, data);
- } else if (id==CANBUS_ID_SET) {
- can_process_set_id(id, len, data);
+ if (!len)
+ return;
+ switch (data[0]) {
+ case CANBUS_CMD_QUERY_UNASSIGNED:
+ can_process_query_unassigned(id, len, data);
+ break;
+ case CANBUS_CMD_SET_NODEID:
+ can_process_set_nodeid(id, len, data);
+ break;
}
}
@@ -172,6 +180,19 @@ canbus_notify_rx(void)
sched_wake_task(&canbus_rx_wake);
}
+static uint8_t receive_buf[192], receive_pos;
+DECL_CONSTANT("RECEIVE_WINDOW", ARRAY_SIZE(receive_buf));
+
+static void
+can_process_data(uint32_t id, uint32_t len, uint8_t *data)
+{
+ int rpos = receive_pos;
+ if (len > sizeof(receive_buf) - rpos)
+ len = sizeof(receive_buf) - rpos;
+ memcpy(&receive_buf[rpos], data, len);
+ receive_pos = rpos + len;
+}
+
void
canbus_rx_task(void)
{
@@ -185,7 +206,12 @@ canbus_rx_task(void)
int ret = canbus_read(&id, data);
if (ret < 0)
break;
- can_process(id, ret, data);
+ if (id && id == canbus_assigned_id)
+ can_process_data(id, ret, data);
+ if (id && id == canbus_assigned_id + 1)
+ can_id_conflict();
+ else if (id == CANBUS_ID_ADMIN)
+ can_process(id, ret, data);
}
// Check for a complete message block and process it
@@ -210,13 +236,18 @@ DECL_TASK(canbus_rx_task);
****************************************************************/
void
+command_get_canbus_id(uint32_t *args)
+{
+ sendf("canbus_id canbus_uuid=%.*s canbus_nodeid=%u"
+ , sizeof(canbus_uuid), canbus_uuid, can_get_nodeid());
+}
+DECL_COMMAND_FLAGS(command_get_canbus_id, HF_IN_SHUTDOWN, "get_canbus_id");
+
+void
canbus_set_uuid(void *uuid)
{
memcpy(canbus_uuid, uuid, sizeof(canbus_uuid));
canbus_notify_rx();
-
- // Send initial message
- can_process_uuid(0, 0, NULL);
}
void
diff --git a/src/generic/canbus.h b/src/generic/canbus.h
index 3a3283ca..d9c330b3 100644
--- a/src/generic/canbus.h
+++ b/src/generic/canbus.h
@@ -3,16 +3,14 @@
#include <stdint.h> // uint32_t
-#define CANBUS_ID_UUID 0x321
-#define CANBUS_ID_SET 0x322
-#define CANBUS_ID_UUID_RESP 0x323
+#define CANBUS_ID_ADMIN 0x3f0
+#define CANBUS_ID_ADMIN_RESP 0x3f1
#define CANBUS_UUID_LEN 6
// callbacks provided by board specific code
int canbus_read(uint32_t *id, uint8_t *data);
int canbus_send(uint32_t id, uint32_t len, uint8_t *data);
void canbus_set_filter(uint32_t id);
-void canbus_reboot(void);
// canbus.c
void canbus_notify_tx(void);
diff --git a/src/stm32/can.c b/src/stm32/can.c
index c4d45f9c..867bbfd7 100644
--- a/src/stm32/can.c
+++ b/src/stm32/can.c
@@ -159,43 +159,35 @@ canbus_send(uint32_t id, uint32_t len, uint8_t *data)
return len;
}
-#define CAN_FILTER_NUMBER 0
-
// Setup the receive packet filter
void
canbus_set_filter(uint32_t id)
{
- uint32_t filternbrbitpos = 1 << CAN_FILTER_NUMBER;
-
/* Select the start slave bank */
SOC_CAN->FMR |= CAN_FMR_FINIT;
/* Initialisation mode for the filter */
SOC_CAN->FA1R = 0;
- uint32_t idadmin = CANBUS_ID_UUID;
- SOC_CAN->sFilterRegister[CAN_FILTER_NUMBER].FR1 = idadmin << (5 + 16);
- SOC_CAN->sFilterRegister[CAN_FILTER_NUMBER].FR2 = id << (5 + 16);
+ uint32_t mask = CAN_RI0R_STID | CAN_TI0R_IDE | CAN_TI0R_RTR;
+ SOC_CAN->sFilterRegister[0].FR1 = CANBUS_ID_ADMIN << CAN_RI0R_STID_Pos;
+ SOC_CAN->sFilterRegister[0].FR2 = mask;
+ SOC_CAN->sFilterRegister[1].FR1 = (id + 1) << CAN_RI0R_STID_Pos;
+ SOC_CAN->sFilterRegister[1].FR2 = mask;
+ SOC_CAN->sFilterRegister[2].FR1 = id << CAN_RI0R_STID_Pos;
+ SOC_CAN->sFilterRegister[2].FR2 = mask;
- /* Identifier list mode for the filter */
- SOC_CAN->FM1R = filternbrbitpos;
/* 32-bit scale for the filter */
- SOC_CAN->FS1R = filternbrbitpos;
+ SOC_CAN->FS1R = (1<<0) | (1<<1) | (1<<2);
/* FIFO 0 assigned for the filter */
SOC_CAN->FFA1R = 0;
/* Filter activation */
- SOC_CAN->FA1R = filternbrbitpos;
+ SOC_CAN->FA1R = (1<<0) | (id ? (1<<1) | (1<<2) : 0);
/* Leave the initialisation mode for the filter */
SOC_CAN->FMR &= ~CAN_FMR_FINIT;
}
-void
-canbus_reboot(void)
-{
- NVIC_SystemReset();
-}
-
// This function handles CAN global interrupts
void
CAN_IRQHandler(void)
@@ -292,7 +284,7 @@ can_init(void)
;
/*##-2- Configure the CAN Filter #######################################*/
- canbus_set_filter(CANBUS_ID_SET);
+ canbus_set_filter(0);
/*##-3- Configure Interrupts #################################*/
armcm_enable_irq(CAN_IRQHandler, CAN_RX0_IRQn, 0);