/* ELM327 based CAN interface driver (tty line discipline)
*
* This driver started as a derivative of linux/drivers/net/can/slcan.c
- * and my thanks go to the original authors for their inspiration, even
- * after almost none of their code is left.
+ * and my thanks go to the original authors for their inspiration.
*
* elmcan.c Author : Max Staudt <max-linux@enpas.org>
* slcan.c Author : Oliver Hartkopp <socketcan@hartkopp.net>
u8 rxbuf[ELM327_SIZE_RXBUF];
u8 txbuf[ELM327_SIZE_TXBUF] ____cacheline_aligned;
- /* TTY buffer accounting */
- struct work_struct tx_work; /* Flushes TTY TX buffer */
- u8 *txhead; /* Next TX byte */
- unsigned txleft; /* Bytes left to TX */
- int rxfill; /* Bytes already RX'd in buffer */
+ /* Per-channel lock */
+ spinlock_t lock;
/* TTY and netdev devices that we're bridging */
struct tty_struct *tty;
struct net_device *dev;
- /* Per-channel lock */
- spinlock_t lock;
+ /* TTY buffer accounting */
+ struct work_struct tx_work; /* Flushes TTY TX buffer */
+ u8 *txhead; /* Next TX byte */
+ size_t txleft; /* Bytes left to TX */
+ int rxfill; /* Bytes already RX'd in buffer */
/* State machine */
enum {
{
int written;
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
if (elm->uart_side_failure)
return;
memcpy(elm->txbuf, buf, len);
+ /* Order of next two lines is *very* important.
+ * When we are sending a little amount of data,
+ * the transfer may be completed inside the ops->write()
+ * routine, because it's running with interrupts enabled.
+ * In this case we *never* got WRITE_WAKEUP event,
+ * if we did not request it before write operation.
+ * 14 Oct 1994 Dmitry Gorodchanin.
+ */
+ set_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
written = elm->tty->ops->write(elm->tty, elm->txbuf, len);
if (written < 0) {
netdev_err(elm->dev,
elm->txleft = len - written;
elm->txhead = elm->txbuf + written;
-
- if (elm->txleft)
- set_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
}
/* Take the ELM327 out of almost any state and back into command mode.
*/
static void elm327_kick_into_cmd_mode(struct elmcan *elm)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
if (elm->state != ELM327_STATE_GETDUMMYCHAR &&
elm->state != ELM327_STATE_GETPROMPT) {
/* Schedule a CAN frame and necessary config changes to be sent to the TTY. */
static void elm327_send_frame(struct elmcan *elm, struct can_frame *frame)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
/* Schedule any necessary changes in ELM327's CAN configuration */
if (elm->can_frame_to_send.can_id != frame->can_id) {
static void elm327_init(struct elmcan *elm)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
elm->state = ELM327_STATE_NOTINIT;
elm->can_frame_to_send.can_id = 0x7df; /* ELM327 HW default */
static void elm327_feed_frame_to_netdev(struct elmcan *elm,
struct sk_buff *skb)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
if (!netif_running(elm->dev))
return;
struct can_frame *frame;
struct sk_buff *skb;
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
elm->uart_side_failure = true;
+ clear_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
+
elm->can.can_stats.bus_off++;
netif_stop_queue(elm->dev);
elm->can.state = CAN_STATE_BUS_OFF;
struct can_frame *frame;
struct sk_buff *skb;
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
skb = alloc_can_err_skb(elm->dev, &frame);
if (!skb)
int datastart;
int i;
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
skb = alloc_can_skb(elm->dev, &frame);
if (!skb)
static void elm327_parse_line(struct elmcan *elm, size_t len)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
/* Skip empty lines */
if (!len)
}
/* Regular parsing */
- if (elm->state == ELM327_STATE_RECEIVING
- && elm327_parse_frame(elm, len)) {
+ if (elm->state == ELM327_STATE_RECEIVING &&
+ elm327_parse_frame(elm, len)) {
/* Parse an error line. */
elm327_parse_error(elm, len);
*/
char local_txbuf[sizeof("0102030405060708\r")];
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
if (!elm->cmds_todo) {
/* Enter CAN monitor mode */
elm->state = ELM327_STATE_RECEIVING;
/* We will be in the default state once this command is
- * send, so enable the TX packet queue.
+ * sent, so enable the TX packet queue.
*/
netif_wake_queue(elm->dev);
/* Reconfigure ELM327 step by step as indicated by elm->cmds_todo */
if (test_bit(ELM327_TX_DO_INIT, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "%s",
- *elm->next_init_cmd);
+ "%s",
+ *elm->next_init_cmd);
elm->next_init_cmd++;
if (!(*elm->next_init_cmd)) {
} else if (test_and_clear_bit(ELM327_TX_DO_SILENT_MONITOR, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATCSM%i\r",
- !(!(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)));
+ "ATCSM%i\r",
+ !(!(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)));
} else if (test_and_clear_bit(ELM327_TX_DO_RESPONSES, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATR%i\r",
- !(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY));
+ "ATR%i\r",
+ !(elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY));
} else if (test_and_clear_bit(ELM327_TX_DO_CAN_CONFIG, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATPC\r");
+ "ATPC\r");
set_bit(ELM327_TX_DO_CAN_CONFIG_PART2, &elm->cmds_todo);
} else if (test_and_clear_bit(ELM327_TX_DO_CAN_CONFIG_PART2, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATPB%04X\r",
- elm->can_config);
+ "ATPB%04X\r",
+ elm->can_config);
} else if (test_and_clear_bit(ELM327_TX_DO_CANID_29BIT_HIGH, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATCP%02X\r",
- (frame->can_id & CAN_EFF_MASK) >> 24);
+ "ATCP%02X\r",
+ (frame->can_id & CAN_EFF_MASK) >> 24);
} else if (test_and_clear_bit(ELM327_TX_DO_CANID_29BIT_LOW, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATSH%06X\r",
- frame->can_id & CAN_EFF_MASK & ((1 << 24) - 1));
+ "ATSH%06X\r",
+ frame->can_id & CAN_EFF_MASK & ((1 << 24) - 1));
} else if (test_and_clear_bit(ELM327_TX_DO_CANID_11BIT, &elm->cmds_todo)) {
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATSH%03X\r",
- frame->can_id & CAN_SFF_MASK);
+ "ATSH%03X\r",
+ frame->can_id & CAN_SFF_MASK);
} else if (test_and_clear_bit(ELM327_TX_DO_CAN_DATA, &elm->cmds_todo)) {
if (frame->can_id & CAN_RTR_FLAG) {
* Some chips don't send them at all.
*/
snprintf(local_txbuf, sizeof(local_txbuf),
- "ATRTR\r");
+ "ATRTR\r");
} else {
/* Send a regular CAN data frame */
int i;
for (i = 0; i < frame->len; i++) {
snprintf(&local_txbuf[2 * i], sizeof(local_txbuf),
- "%02X",
- frame->data[i]);
+ "%02X",
+ frame->data[i]);
}
snprintf(&local_txbuf[2 * i], sizeof(local_txbuf),
- "\r");
+ "\r");
}
elm->drop_next_line = 1;
elm->state = ELM327_STATE_RECEIVING;
/* We will be in the default state once this command is
- * send, so enable the TX packet queue.
+ * sent, so enable the TX packet queue.
*/
netif_wake_queue(elm->dev);
}
static void elm327_drop_bytes(struct elmcan *elm, size_t i)
{
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
memmove(&elm->rxbuf[0], &elm->rxbuf[i], ELM327_SIZE_RXBUF - i);
elm->rxfill -= i;
size_t len;
int i;
- lockdep_assert_held(elm->lock);
+ lockdep_assert_held(&elm->lock);
switch (elm->state) {
case ELM327_STATE_NOTINIT:
elm327_uart_side_failure(elm);
spin_unlock_bh(&elm->lock);
return;
- } else {
- elm->txleft -= written;
- elm->txhead += written;
}
+
+ elm->txleft -= written;
+ elm->txhead += written;
}
if (!elm->txleft) {
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