Merge branch 'master' of ssh://rtime.felk.cvut.cz/lisovros/pcan_lin into experiments

diff --git a/sllin/sllin.c b/sllin/sllin.c
index 459ae9f58eabd8b8ee1706e7aa5d551e9413132d..c914a4a5ea755eeb9b2ee886f71684e911b19bc8 100644 (file)
--- a/sllin/sllin.c
+++ b/sllin/sllin.c
@@ -146,6 +146,10 @@ struct sllin {
        char                    id_to_send;     /* there is ID to be sent */
        char                    data_to_send;   /* there are data to be sent */
        char                    resp_len_known; /* Length of the response is known */
+       char                    header_received;/* In Slave mode, set when header was already
+                                                  received */
+       char                    rx_len_unknown; /* We are not sure how much data will be sent to us --
+                                                  we just guess the length */
 
        unsigned long           flags;          /* Flag values/ mode etc     */
 #define SLF_INUSE              0               /* Channel in use            */
@@ -258,9 +262,17 @@ static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
  */
 static void sll_bump(struct sllin *sl)
 {
+       int len = sl->rx_cnt - SLLIN_BUFF_DATA - 1; /* without checksum */
+       len = (len < 0) ? 0 : len;
+
        sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK,
-               sl->rx_buff + SLLIN_BUFF_DATA,
-               sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */
+               sl->rx_buff + SLLIN_BUFF_DATA, len);
+}
+
+static void sll_send_rtr(struct sllin *sl)
+{
+       sllin_send_canfr(sl, (sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK) |
+               CAN_RTR_FLAG, NULL, 0);
 }
 
 /*
@@ -419,13 +431,18 @@ static void sll_setup(struct net_device *dev)
 /******************************************
   Routines looking at TTY side.
  ******************************************/
+#define SLL_RESPONSE_RECEIVED          ((sl->header_received == true) && \
+                                        ((sl->rx_cnt >= sl->rx_expect) || \
+                                        ((sl->rx_len_unknown == true) && (count == 0))))
+
+#define SLL_HEADER_RECEIVED            ((sl->header_received == false) && \
+                                        (sl->rx_cnt >= (SLLIN_BUFF_ID + 1)))
 
 static void sllin_receive_buf(struct tty_struct *tty,
                              const unsigned char *cp, char *fp, int count)
 {
        struct sllin *sl = (struct sllin *) tty->disc_data;
-
-       pr_debug("sllin: sllin_receive_buf invoked\n");
+       pr_debug("sllin: sllin_receive_buf invoked, count = %u\n", count);
 
        if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
                return;
@@ -433,41 +450,80 @@ static void sllin_receive_buf(struct tty_struct *tty,
        /* Read the characters out of the buffer */
        while (count--) {
                if (fp && *fp++) {
-                       if (sl->rx_cnt > SLLIN_BUFF_BREAK) {
-                               set_bit(SLF_ERROR, &sl->flags);
-
-                               pr_debug("sllin: sllin_receive_buf char 0x%02x ignored "
-                                       "due marker 0x%02x, flags 0x%lx\n",
-                                       *cp, *(fp-1), sl->flags);
+                       pr_debug("sllin: sllin_receive_buf char 0x%02x ignored "
+                               "due marker 0x%02x, flags 0x%lx\n",
+                               *cp, *(fp-1), sl->flags);
 
-                               if (sl->lin_master == true) {
-                                       wake_up(&sl->kwt_wq);
-                                       return;
-                               }
-
-                               cp++;
-                               continue;
+                       if (sl->lin_master == true) { /* Report error */
+                               set_bit(SLF_ERROR, &sl->flags);
+                               wake_up(&sl->kwt_wq);
+                               return;
+                       } else { /* Received Break */
+                               sl->rx_cnt = 0;
+                               sl->rx_expect = SLLIN_BUFF_ID + 1;
+                               sl->rx_len_unknown = false; /* We do know exact length of the header */
+                               sl->header_received = false;
                        }
                }
 
-               if (sl->rx_cnt < SLLIN_BUFF_LEN) {
 #ifndef BREAK_BY_BAUD
-                       /* We didn't receive Break character */
-                       if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
-                               sl->rx_buff[sl->rx_cnt++] = 0x00;
-                       }
+               /* We didn't receive Break character -- fake it! */
+               if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+                       pr_debug("sllin: LIN_RX[%d]: 0x00\n", sl->rx_cnt);
+                       sl->rx_buff[sl->rx_cnt++] = 0x00;
+               }
 #endif
+               if (sl->rx_cnt < SLLIN_BUFF_LEN) {
                        pr_debug("sllin: LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
                        sl->rx_buff[sl->rx_cnt++] = *cp++;
                }
-       }
 
-       if (sl->rx_cnt >= sl->rx_expect) {
-               set_bit(SLF_RXEVENT, &sl->flags);
-               wake_up(&sl->kwt_wq);
-               pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
-       } else {
-               pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
+               if (sl->lin_master == true) {
+                       if (SLL_RESPONSE_RECEIVED) {
+                               set_bit(SLF_RXEVENT, &sl->flags);
+                               wake_up(&sl->kwt_wq);
+                               pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
+                       } else {
+                               pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
+                       }
+               } else { /* LIN slave */
+                       int lin_id;
+                       struct sllin_conf_entry *sce;
+
+                       pr_debug("sllin: rx_cnt = %u; header_received = %u\n",
+                                       sl->rx_cnt, sl->header_received);
+
+                       if (SLL_HEADER_RECEIVED) {
+                               lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+                               sce = &sl->linfr_cache[lin_id];
+
+                               /* Is the length of data set in frame cache? */
+                               if (sce->frame_fl & LIN_LOC_SLAVE_CACHE) {
+                                       sl->rx_expect += sce->dlc;
+                                       sl->rx_len_unknown = false;
+                               } else {
+                                       sl->rx_expect += SLLIN_DATA_MAX + 1; /* + checksum */
+                                       sl->rx_len_unknown = true;
+                               }
+
+                               sl->header_received = true;
+                               sll_send_rtr(sl);
+                               continue;
+                       }
+
+                       if (SLL_RESPONSE_RECEIVED) {
+                               sll_bump(sl);
+                               pr_debug("sllin: Received LIN header & LIN response. "
+                                               "rx_cnt = %u, rx_expect = %u\n", sl->rx_cnt,
+                                               sl->rx_expect);
+
+                               /* Prepare for reception of new header */
+                               sl->rx_cnt = 0;
+                               sl->rx_expect = SLLIN_BUFF_ID + 1;
+                               sl->rx_len_unknown = false; /* We do know exact length of the header */
+                               sl->header_received = false;
+                       }
+               }
        }
 }
 
@@ -488,7 +544,7 @@ void sllin_report_error(struct sllin *sl, int err)
                        sl->dev->stats.rx_crc_errors++;
                        break;
 
-               case LIN_ERR_RX_TIMEOUT:                
+               case LIN_ERR_RX_TIMEOUT:
                        sl->dev->stats.rx_errors++;
                        break;
 
@@ -1130,6 +1186,12 @@ static int sllin_open(struct tty_struct *tty)
        if (!test_bit(SLF_INUSE, &sl->flags)) {
                /* Perform the low-level SLLIN initialization. */
                sl->lin_master = master;
+#ifdef DEBUG
+               if (master)
+                       pr_debug("sllin: Configured as MASTER\n");
+               else
+                       pr_debug("sllin: Configured as SLAVE\n");
+#endif
 
                sllin_reset_buffs(sl);