/* Called when we're out of ideas and just want it all to end. */
static inline void elm327_hw_failure(struct elmcan *elm)
{
- struct can_frame frame = {0};
+ struct can_frame frame;
+ memset(&frame, 0, sizeof(frame));
frame.can_id = CAN_ERR_FLAG;
frame.can_dlc = CAN_ERR_DLC;
frame.data[5] = 'R';
static void elm327_parse_error(struct elmcan *elm, int len)
{
- struct can_frame frame = {0};
+ struct can_frame frame;
+ memset(&frame, 0, sizeof(frame));
frame.can_id = CAN_ERR_FLAG;
frame.can_dlc = CAN_ERR_DLC;
static int elm327_parse_frame(struct elmcan *elm, int len)
{
- struct can_frame frame = {0};
+ struct can_frame frame;
int hexlen;
int datastart;
int i;
+ memset(&frame, 0, sizeof(frame));
+
/* Find first non-hex and non-space character:
* - In the simplest case, there is none.
* - For RTR frames, 'R' is the first non-hex character.
{
if (elm->cmds_todo) {
struct can_frame *frame = &elm->can_frame;
- char txbuf[20];
+ char local_txbuf[20];
if (test_bit(ELM_TODO_INIT, &elm->cmds_todo)) {
elm327_send(elm, *elm->next_init_cmd, strlen(*elm->next_init_cmd));
elm327_kick_into_cmd_mode(elm);
return;
+
} else if (test_and_clear_bit(ELM_TODO_SILENT_MONITOR, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATCSM%i\r", !(!(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)));
+ sprintf(local_txbuf, "ATCSM%i\r",
+ !(!(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)));
+
} else if (test_and_clear_bit(ELM_TODO_RESPONSES, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATR%i\r", !(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY));
+ sprintf(local_txbuf, "ATR%i\r",
+ !(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY));
+
} else if (test_and_clear_bit(ELM_TODO_CAN_CONFIG, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATPB%04X\r", elm->can_config);
+ sprintf(local_txbuf, "ATPB%04X\r",
+ elm->can_config);
+
} else if (test_and_clear_bit(ELM_TODO_CANID_29BIT_HIGH, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATCP%02X\r", (frame->can_id & CAN_EFF_MASK) >> 24);
+ sprintf(local_txbuf, "ATCP%02X\r",
+ (frame->can_id & CAN_EFF_MASK) >> 24);
+
} else if (test_and_clear_bit(ELM_TODO_CANID_29BIT_LOW, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATSH%06X\r", frame->can_id & CAN_EFF_MASK & ((1 << 24) - 1));
+ sprintf(local_txbuf, "ATSH%06X\r",
+ frame->can_id & CAN_EFF_MASK & ((1 << 24) - 1));
+
} else if (test_and_clear_bit(ELM_TODO_CANID_11BIT, &elm->cmds_todo)) {
- snprintf(txbuf, sizeof(txbuf), "ATSH%03X\r", frame->can_id & CAN_SFF_MASK);
+ sprintf(local_txbuf, "ATSH%03X\r",
+ frame->can_id & CAN_SFF_MASK);
+
} else if (test_and_clear_bit(ELM_TODO_CAN_DATA, &elm->cmds_todo)) {
if (frame->can_id & CAN_RTR_FLAG) {
- snprintf(txbuf, sizeof(txbuf), "ATRTR\r");
+ /* Send an RTR frame. Their DLC is fixed.
+ * Some chips don't send them at all.
+ */
+ sprintf(local_txbuf, "ATRTR\r");
} else {
+ /* Send a regular CAN data frame */
int i;
for (i = 0; i < frame->can_dlc; i++) {
- sprintf(&txbuf[2*i], "%02X", frame->data[i]);
+ sprintf(&local_txbuf[2*i], "%02X",
+ frame->data[i]);
}
- sprintf(&txbuf[2*i], "\r");
+ sprintf(&local_txbuf[2*i], "\r");
}
elm->drop_next_line = 1;
elm->state = ELM_RECEIVING;
}
- elm327_send(elm, txbuf, strlen(txbuf));
+ elm327_send(elm, local_txbuf, strlen(local_txbuf));
} else {
/* Enter CAN monitor mode */
elm327_send(elm, "ATMA\r", 5);
-/* Some fake bit timings to allow bitrate setting */
-static const struct can_bittiming_const elmcan_bittiming_const = {
- .name = "elmcan",
- .tseg1_min = 1,
- .tseg1_max = 1,
- .tseg2_min = 0,
- .tseg2_max = 0,
- .sjw_max = 1,
- .brp_min = 1,
- .brp_max = 500,
- .brp_inc = 1,
+/* ELM327 can only handle bitrates that are integer divisors of 500 kHz,
+ * or 7/8 of that. Divisors are 1 to 64.
+ * Currently we don't implement support for 7/8 rates.
+ */
+static const u32 elmcan_bitrate_const[64] = {
+ 7812, 7936, 8064, 8196, 8333, 8474, 8620, 8771,
+ 8928, 9090, 9259, 9433, 9615, 9803, 10000, 10204,
+ 10416, 10638, 10869, 11111, 11363, 11627, 11904, 12195,
+ 12500, 12820, 13157, 13513, 13888, 14285, 14705, 15151,
+ 15625, 16129, 16666, 17241, 17857, 18518, 19230, 20000,
+ 20833, 21739, 22727, 23809, 25000, 26315, 27777, 29411,
+ 31250, 33333, 35714, 38461, 41666, 45454, 50000, 55555,
+ 62500, 71428, 83333, 100000, 125000, 166666, 250000, 500000
};
+/* Dummy function to claim we're changing the bitrate.
+ * We actually do this when opening the net device.
+ */
+static int elmcan_do_set_bittiming(struct net_device *netdev)
+{
+ return 0;
+}
+
+
/*
* Open the high-level part of the elmcan channel.
* This function is called by the TTY module when the
/* Configure CAN metadata */
elm->can.state = CAN_STATE_STOPPED;
- elm->can.clock.freq = 1000000;
- elm->can.bittiming_const = &elmcan_bittiming_const;
+ elm->can.bitrate_const = elmcan_bitrate_const;
+ elm->can.bitrate_const_cnt = ARRAY_SIZE(elmcan_bitrate_const);
+ elm->can.do_set_bittiming = elmcan_do_set_bittiming;
elm->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY;
/* Configure netlink interface */
projects / elmcan.git / blobdiff