struct tty_struct *tty;
struct net_device *dev;
- char ifname[IFNAMSIZ];
-
/* Per-channel lock */
spinlock_t lock;
*/
atomic_t refcount;
+ /* Stop the channel on hardware failure.
+ * Once this is true, nothing will be sent to the TTY.
+ */
+ bool hw_failure;
+
/* TTY TX helpers */
struct work_struct tx_work; /* Flushes TTY TX buffer */
unsigned char txbuf[32];
static DEFINE_SPINLOCK(elmcan_discdata_lock);
+static inline void elm327_hw_failure(struct elmcan *elm);
+
/************************************************************************
{
int actual;
+ if (elm->hw_failure) {
+ return;
+ }
+
memcpy(elm->txbuf, buf, len);
/* Order of next two lines is *very* important.
*/
set_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
actual = elm->tty->ops->write(elm->tty, elm->txbuf, len);
+ if (actual < 0) {
+ netdev_err(elm->dev, "Failed to write to tty %s.\n", elm->tty->name);
+ elm327_hw_failure(elm);
+ return;
+ }
+
elm->txleft = len - actual;
elm->txhead = elm->txbuf + actual;
}
/************************************************************************
- * ELM327: Panic handler *
+ * ELM327: "Panic" handler *
* *
* (assumes elm->lock taken) *
************************************************************************/
-static inline void elm327_panic(struct elmcan *elm)
+/* 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;
- frame.can_id = CAN_ERR_FLAG | CAN_ERR_RESTARTED;
+ memset(&frame, 0, sizeof(frame));
+ frame.can_id = CAN_ERR_FLAG;
frame.can_dlc = CAN_ERR_DLC;
+ frame.data[5] = 'R';
+ frame.data[6] = 'I';
+ frame.data[7] = 'P';
elm327_feed_frame_to_netdev(elm, &frame);
- pr_err("ELM327 misbehaved. Re-initializing.\n");
+ netdev_err(elm->dev, "ELM327 misbehaved. "
+ "Blocking further communication.\n");
- elm->can.can_stats.restarts++;
- elm327_init(elm);
+ elm->hw_failure = true;
+ can_bus_off(elm->dev);
}
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;
switch(len) {
case 17:
if (!memcmp(elm->rxbuf, "UNABLE TO CONNECT", 17)) {
- pr_err("The ELM327 reported UNABLE TO CONNECT. Please check your setup.\n");
+ netdev_err(elm->dev, "The ELM327 reported UNABLE TO CONNECT. Please check your setup.\n");
}
break;
case 11:
break;
case 5:
if (!memcmp(elm->rxbuf, "ERR", 3)) {
- pr_err("The ELM327 reported an ERR%c%c. Please power it off and on again.\n",
+ netdev_err(elm->dev, "The ELM327 reported an ERR%c%c. Please power it off and on again.\n",
elm->rxbuf[3], elm->rxbuf[4]);
frame.can_id |= CAN_ERR_CRTL;
}
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));
elm->next_init_cmd++;
if (!(*elm->next_init_cmd)) {
clear_bit(ELM_TODO_INIT, &elm->cmds_todo);
- pr_info("%s: Initialization finished.\n", elm->dev->name);
+ netdev_info(elm->dev, "Initialization finished.\n");
}
/* Some chips are unreliable and need extra time after
*/
elm->state = ELM_NOTINIT;
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);
/* Line exceeds buffer. It's probably all garbage.
* Did we even connect at the right baud rate?
*/
- pr_err("RX buffer overflow. Faulty ELM327 connected?\n");
- elm327_panic(elm);
+ netdev_err(elm->dev, "RX buffer overflow. Faulty ELM327 connected?\n");
+ elm327_hw_failure(elm);
+ return;
} else if (len == elm->rxfill) {
if (elm->state == ELM_RECEIVING
&& elm->rxbuf[elm->rxfill - 1] == ELM327_READY_CHAR) {
* (takes elm->lock) *
************************************************************************/
-static int elmcan_netdev_init(struct net_device *dev)
-{
- struct elmcan *elm = netdev_priv(dev);
-
- /* Copy the interface name here, so the SIOCGIFNAME case in
- * elmcan_ldisc_ioctl() doesn't race against unregister_candev().
- */
- memcpy(elm->ifname, dev->name, IFNAMSIZ);
-
- return 0;
-}
-
/* Netdevice DOWN -> UP routine */
static int elmcan_netdev_open(struct net_device *dev)
{
int err;
spin_lock_bh(&elm->lock);
+ if (elm->hw_failure) {
+ netdev_err(elm->dev, "Refusing to open interface after "
+ "a hardware fault has been detected.\n");
+ spin_unlock_bh(&elm->lock);
+ return -EIO;
+ }
+
if (elm->tty == NULL) {
spin_unlock_bh(&elm->lock);
return -ENODEV;
goto out;
if (!netif_running(dev)) {
- pr_warn("%s: xmit: iface is down\n", dev->name);
+ netdev_warn(elm->dev, "xmit: iface is down.\n");
goto out;
}
* See Documentation/networking/netdevices.txt
*/
spin_lock(&elm->lock);
+
+ /* We shouldn't get here after a hardware fault:
+ * can_bus_off() calls netif_carrier_off()
+ */
+ BUG_ON(elm->hw_failure);
+
if (elm->tty == NULL
|| elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
spin_unlock(&elm->lock);
}
static const struct net_device_ops elmcan_netdev_ops = {
- .ndo_init = elmcan_netdev_init,
.ndo_open = elmcan_netdev_open,
.ndo_stop = elmcan_netdev_close,
.ndo_start_xmit = elmcan_netdev_start_xmit,
/* Read the characters out of the buffer */
while (count-- && elm->rxfill < sizeof(elm->rxbuf)) {
if (fp && *fp++) {
- pr_err("Error in received character stream. Check your wiring.");
+ netdev_err(elm->dev, "Error in received character stream. Check your wiring.");
spin_lock_bh(&elm->lock);
- elm327_panic(elm);
+ elm327_hw_failure(elm);
spin_unlock_bh(&elm->lock);
put_elm(elm);
}
if (count >= 0) {
- pr_err("Receive buffer overflowed. Bad chip or wiring?");
+ netdev_err(elm->dev, "Receive buffer overflowed. Bad chip or wiring?");
spin_lock_bh(&elm->lock);
- elm327_panic(elm);
+ elm327_hw_failure(elm);
spin_unlock_bh(&elm->lock);
put_elm(elm);
ssize_t actual;
spin_lock_bh(&elm->lock);
- /* First make sure we're connected. */
+ if (elm->hw_failure) {
+ spin_unlock_bh(&elm->lock);
+ return;
+ }
+
if (!elm->tty || !netif_running(elm->dev)) {
spin_unlock_bh(&elm->lock);
return;
actual = elm->tty->ops->write(elm->tty, elm->txhead, elm->txleft);
if (actual < 0) {
- pr_err("Failed to write to tty for %s.\n", elm->dev->name);
- elm327_panic(elm);
+ netdev_err(elm->dev, "Failed to write to tty %s.\n", elm->tty->name);
+ elm327_hw_failure(elm);
+ spin_unlock_bh(&elm->lock);
+ return;
}
elm->txleft -= actual;
-/* 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 */
struct elmcan *elm = get_elm(tty);
unsigned int tmp;
- /* First make sure we're connected. */
if (!elm)
return -EINVAL;
switch (cmd) {
case SIOCGIFNAME:
- tmp = strlen(elm->ifname) + 1;
- if (copy_to_user((void __user *)arg, elm->ifname, tmp)) {
+ tmp = strlen(elm->dev->name) + 1;
+ if (copy_to_user((void __user *)arg, elm->dev->name, tmp)) {
put_elm(elm);
return -EFAULT;
}
projects / elmcan.git / blobdiff