]> rtime.felk.cvut.cz Git - linux-lin.git/blobdiff - sllin/sllin.c
sllin: Fix checksum mode decision
[linux-lin.git] / sllin / sllin.c
index c1cdcd10afc54853a80d70604a0cba6ba087b040..487b72ad337d2c64a411c60710889f8c2dac63d8 100644 (file)
@@ -62,6 +62,7 @@
 #include <linux/can.h>
 #include <linux/kthread.h>
 #include <linux/hrtimer.h>
+#include <linux/version.h>
 #include "linux/lin_bus.h"
 
 /* Should be in include/linux/tty.h */
@@ -113,6 +114,7 @@ enum slstate {
        SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
                                only (CAN frames from network stack
                                are not processed in this moment) */
+       SLSTATE_ID_RECEIVED,
        SLSTATE_RESPONSE_SENT,
 };
 
@@ -205,22 +207,31 @@ const unsigned char sllin_id_parity_table[] = {
  */
 static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
 {
-       struct ktermios old_termios;
+       struct ktermios old_termios, termios;
        int cflag;
 
        mutex_lock(&tty->termios_mutex);
 
-       old_termios = *(tty->termios);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
+       old_termios = termios = *(tty->termios);
+#else
+       old_termios = termios = tty->termios;
+#endif
 
        cflag = CS8 | CREAD | CLOCAL | HUPCL;
        cflag &= ~(CBAUD | CIBAUD);
        cflag |= BOTHER;
-       tty->termios->c_cflag = cflag;
-       tty->termios->c_oflag = 0;
-       tty->termios->c_lflag = 0;
+       termios.c_cflag = cflag;
+       termios.c_oflag = 0;
+       termios.c_lflag = 0;
 
        /* Enable interrupt when UART-Break or Framing error received */
-       tty->termios->c_iflag = BRKINT | INPCK;
+       termios.c_iflag = BRKINT | INPCK;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
+       *(tty->termios) = termios;
+#else
+       tty->termios = termios;
+#endif
 
        tty_encode_baud_rate(tty, speed, speed);
 
@@ -494,111 +505,6 @@ static void sllin_master_receive_buf(struct tty_struct *tty,
 }
 
 
-static void sllin_slave_receive_buf(struct tty_struct *tty,
-                             const unsigned char *cp, char *fp, int count)
-{
-       struct sllin *sl = (struct sllin *) tty->disc_data;
-       int lin_id;
-       struct sllin_conf_entry *sce;
-
-
-       /* Read the characters out of the buffer */
-       while (count--) {
-               if (fp && *fp++) {
-                       netdev_dbg(sl->dev, "sllin_slave_receive_buf char 0x%02x ignored "
-                               "due marker 0x%02x, flags 0x%lx\n",
-                               *cp, *(fp-1), sl->flags);
-
-                       /* 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) {
-                       netdev_dbg(sl->dev, "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
-
-                       /* We did not receive break (0x00) character */
-                       if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
-                               sl->rx_buff[sl->rx_cnt++] = 0x00;
-                       }
-
-                       if (sl->rx_cnt == SLLIN_BUFF_SYNC) {
-                               /* 'Duplicated' break character -- ignore */
-                               if (*cp == 0x00) {
-                                       cp++;
-                                       continue;
-                               }
-
-                               /* Wrong sync character */
-                               if (*cp != 0x55)
-                                       break;
-                       }
-
-                       sl->rx_buff[sl->rx_cnt++] = *cp++;
-               }
-
-               /* Header received */
-               if ((sl->header_received == false) && (sl->rx_cnt >= (SLLIN_BUFF_ID + 1))) {
-                       unsigned long flags;
-
-                       lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
-                       sce = &sl->linfr_cache[lin_id];
-
-                       spin_lock_irqsave(&sl->linfr_lock, flags);
-
-                       /* Is the length of data set in frame cache? */
-                       if (sce->frame_fl & LIN_CACHE_RESPONSE) {
-                               sl->rx_expect += sce->dlc;
-                               sl->rx_len_unknown = false;
-                       } else {
-                               sl->rx_expect += SLLIN_DATA_MAX + 1; /* + checksum */
-                               sl->rx_len_unknown = true;
-                       }
-                       spin_unlock_irqrestore(&sl->linfr_lock, flags);
-
-                       sl->header_received = true;
-
-                       sll_send_rtr(sl);
-                       continue;
-               }
-
-               /* Response received */
-               if ((sl->header_received == true) &&
-                       ((sl->rx_cnt >= sl->rx_expect) ||
-                       ((sl->rx_len_unknown == true) && (count == 0)))) {
-
-                       sll_bump(sl);
-                       netdev_dbg(sl->dev, "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;
-               }
-       }
-}
-
-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;
-       netdev_dbg(sl->dev, "sllin_receive_buf invoked, count = %u\n", count);
-
-       if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
-               return;
-
-       if (sl->lin_master)
-               sllin_master_receive_buf(tty, cp, fp, count);
-       else
-               sllin_slave_receive_buf(tty, cp, fp, count);
-
-}
-
 /*****************************************
  *  sllin message helper routines
  *****************************************/
@@ -609,7 +515,7 @@ static void sllin_receive_buf(struct tty_struct *tty,
  * @sl:
  * @err: Error flag to be sent.
  */
-void sllin_report_error(struct sllin *sl, int err)
+static void sllin_report_error(struct sllin *sl, int err)
 {
        switch (err) {
        case LIN_ERR_CHECKSUM:
@@ -694,7 +600,7 @@ static inline unsigned sllin_checksum(unsigned char *data, int length, int enhan
 #define SLLIN_STPMSG_CHCKSUM_CLS       (1 << 1)
 #define SLLIN_STPMSG_CHCKSUM_ENH       (1 << 2)
 
-int sllin_setup_msg(struct sllin *sl, int mode, int id,
+static int sllin_setup_msg(struct sllin *sl, int mode, int id,
                unsigned char *data, int len)
 {
        if (id > LIN_ID_MASK)
@@ -736,7 +642,185 @@ static void sllin_reset_buffs(struct sllin *sl)
        sl->data_to_send = false;
 }
 
-int sllin_send_tx_buff(struct sllin *sl)
+/**
+ * sllin_rx_validate() -- Validate received frame, i,e. check checksum
+ *
+ * @sl:
+ */
+static int sllin_rx_validate(struct sllin *sl)
+{
+       unsigned long flags;
+       int actual_id;
+       int ext_chcks_fl;
+       int lin_dlc;
+       unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
+       struct sllin_conf_entry *sce;
+
+       actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+       sce = &sl->linfr_cache[actual_id];
+
+       spin_lock_irqsave(&sl->linfr_lock, flags);
+       lin_dlc = sce->dlc;
+       ext_chcks_fl = sce->frame_fl & LIN_CHECKSUM_EXTENDED;
+       spin_unlock_irqrestore(&sl->linfr_lock, flags);
+
+       if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
+               rec_chcksm) {
+
+               /* Type of checksum is configured for particular frame */
+               if (lin_dlc > 0) {
+                       return -1;
+               } else {
+                       if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
+                               !ext_chcks_fl) != rec_chcksm) {
+                               return -1;
+                       }
+               }
+       }
+
+       return 0;
+}
+
+static void sllin_slave_finish_rx_msg(struct sllin *sl)
+{
+       if (sllin_rx_validate(sl) == -1) {
+               netdev_dbg(sl->dev, "sllin: RX validation failed.\n");
+               sllin_report_error(sl, LIN_ERR_CHECKSUM);
+       } else {
+               /* Send CAN non-RTR frame with data */
+               netdev_dbg(sl->dev, "sllin: sending NON-RTR CAN frame with LIN payload.");
+               sll_bump(sl); /* send packet to the network layer */
+       }
+       /* 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;
+}
+
+static void sllin_slave_receive_buf(struct tty_struct *tty,
+                             const unsigned char *cp, char *fp, int count)
+{
+       struct sllin *sl = (struct sllin *) tty->disc_data;
+       int lin_id;
+       struct sllin_conf_entry *sce;
+
+
+       /* Read the characters out of the buffer */
+       while (count--) {
+               if (fp && *fp++) {
+                       /*
+                        * If we don't know the length of the current message
+                        * we received the break of the next message.
+                        * Evaluate the previous one before continuing
+                        */
+                       if (sl->rx_len_unknown == true)
+                       {
+                               hrtimer_cancel(&sl->rx_timer);
+                               sllin_slave_finish_rx_msg(sl);
+
+                               set_bit(SLF_RXEVENT, &sl->flags);
+                               wake_up(&sl->kwt_wq);
+                       }
+
+                       netdev_dbg(sl->dev, "sllin_slave_receive_buf char 0x%02x ignored "
+                               "due marker 0x%02x, flags 0x%lx\n",
+                               *cp, *(fp-1), sl->flags);
+
+                       /* 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) {
+                       netdev_dbg(sl->dev, "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
+
+                       /* We did not receive break (0x00) character */
+                       if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+                               sl->rx_buff[sl->rx_cnt++] = 0x00;
+                       }
+
+                       if (sl->rx_cnt == SLLIN_BUFF_SYNC) {
+                               /* 'Duplicated' break character -- ignore */
+                               if (*cp == 0x00) {
+                                       cp++;
+                                       continue;
+                               }
+
+                               /* Wrong sync character */
+                               if (*cp != 0x55)
+                                       break;
+                       }
+
+                       sl->rx_buff[sl->rx_cnt++] = *cp++;
+               }
+
+               /* Header received */
+               if ((sl->header_received == false) && (sl->rx_cnt >= (SLLIN_BUFF_ID + 1))) {
+                       unsigned long flags;
+
+                       lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+                       sce = &sl->linfr_cache[lin_id];
+
+                       spin_lock_irqsave(&sl->linfr_lock, flags);
+
+                       sl->lin_state = SLSTATE_ID_RECEIVED;
+                       /* Is the length of data set in frame cache? */
+                       if (sce->frame_fl & LIN_CACHE_RESPONSE) {
+                               sl->rx_expect += sce->dlc + 1; /* + checksum */
+                               sl->rx_len_unknown = false;
+                               set_bit(SLF_MSGEVENT, &sl->flags);
+                               wake_up(&sl->kwt_wq);
+                       } else {
+                               sl->rx_expect += SLLIN_DATA_MAX + 1; /* + checksum */
+                               sl->rx_len_unknown = true;
+                       }
+                       spin_unlock_irqrestore(&sl->linfr_lock, flags);
+
+                       sl->header_received = true;
+
+                       hrtimer_start(&sl->rx_timer,
+                               ktime_add(ktime_get(), sl->rx_timer_timeout),
+                               HRTIMER_MODE_ABS);
+                       sll_send_rtr(sl);
+                       continue;
+               }
+
+               /* Response received */
+               if ((sl->header_received == true) &&
+                       ((sl->rx_cnt >= sl->rx_expect))) {
+
+                       hrtimer_cancel(&sl->rx_timer);
+                       netdev_dbg(sl->dev, "Received LIN header & LIN response. "
+                                       "rx_cnt = %u, rx_expect = %u\n", sl->rx_cnt,
+                                       sl->rx_expect);
+                       sllin_slave_finish_rx_msg(sl);
+
+                       set_bit(SLF_RXEVENT, &sl->flags);
+                       wake_up(&sl->kwt_wq);
+               }
+       }
+}
+
+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;
+       netdev_dbg(sl->dev, "sllin_receive_buf invoked, count = %u\n", count);
+
+       if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
+               return;
+
+       if (sl->lin_master)
+               sllin_master_receive_buf(tty, cp, fp, count);
+       else
+               sllin_slave_receive_buf(tty, cp, fp, count);
+
+}
+
+static int sllin_send_tx_buff(struct sllin *sl)
 {
        struct tty_struct *tty = sl->tty;
        int remains;
@@ -795,7 +879,7 @@ error_in_write:
 }
 
 #ifdef BREAK_BY_BAUD
-int sllin_send_break(struct sllin *sl)
+static int sllin_send_break(struct sllin *sl)
 {
        struct tty_struct *tty = sl->tty;
        unsigned long break_baud;
@@ -820,7 +904,7 @@ int sllin_send_break(struct sllin *sl)
 }
 #else /* BREAK_BY_BAUD */
 
-int sllin_send_break(struct sllin *sl)
+static int sllin_send_break(struct sllin *sl)
 {
        struct tty_struct *tty = sl->tty;
        int retval;
@@ -866,63 +950,31 @@ static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
 {
        struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
 
-       sllin_report_error(sl, LIN_ERR_RX_TIMEOUT);
-       set_bit(SLF_TMOUTEVENT, &sl->flags);
+       if (sl->lin_master) {
+               sllin_report_error(sl, LIN_ERR_RX_TIMEOUT);
+               set_bit(SLF_TMOUTEVENT, &sl->flags);
+       } else {
+               sllin_slave_finish_rx_msg(sl);
+               set_bit(SLF_RXEVENT, &sl->flags);
+       }
        wake_up(&sl->kwt_wq);
 
        return HRTIMER_NORESTART;
 }
 
-/**
- * sllin_rx_validate() -- Validate received frame, i,e. check checksum
- *
- * @sl:
- */
-static int sllin_rx_validate(struct sllin *sl)
-{
-       unsigned long flags;
-       int actual_id;
-       int ext_chcks_fl;
-       int lin_dlc;
-       unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
-       struct sllin_conf_entry *sce;
-
-       actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
-       sce = &sl->linfr_cache[actual_id];
-
-       spin_lock_irqsave(&sl->linfr_lock, flags);
-       lin_dlc = sce->dlc;
-       ext_chcks_fl = sce->frame_fl & LIN_CHECKSUM_EXTENDED;
-       spin_unlock_irqrestore(&sl->linfr_lock, flags);
-
-       if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
-               rec_chcksm) {
-
-               /* Type of checksum is configured for particular frame */
-               if (lin_dlc > 0) {
-                       return -1;
-               } else {
-                       if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
-                               !ext_chcks_fl) != rec_chcksm) {
-                               return -1;
-                       }
-               }
-       }
-
-       return 0;
-}
-
 /*****************************************
  *  sllin_kwthread - kernel worker thread
  *****************************************/
 
-int sllin_kwthread(void *ptr)
+static int sllin_kwthread(void *ptr)
 {
        struct sllin *sl = (struct sllin *)ptr;
        struct tty_struct *tty = sl->tty;
        struct sched_param schparam = { .sched_priority = 40 };
        int tx_bytes = 0; /* Used for Network statistics */
-
+       unsigned long flags;
+       int lin_id;
+       struct sllin_conf_entry *sce;
 
        netdev_dbg(sl->dev, "sllin_kwthread started.\n");
        sched_setscheduler(current, SCHED_FIFO, &schparam);
@@ -950,7 +1002,8 @@ int sllin_kwthread(void *ptr)
                        test_bit(SLF_TMOUTEVENT, &sl->flags) ||
                        test_bit(SLF_ERROR, &sl->flags) ||
                        (((sl->lin_state == SLSTATE_IDLE) ||
-                               (sl->lin_state == SLSTATE_RESPONSE_WAIT))
+                               (sl->lin_state == SLSTATE_RESPONSE_WAIT) ||
+                               (sl->lin_state == SLSTATE_ID_RECEIVED))
                                && test_bit(SLF_MSGEVENT, &sl->flags)));
 
                if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
@@ -994,7 +1047,6 @@ int sllin_kwthread(void *ptr)
 
                        /* SFF RTR CAN frame -> LIN header */
                        if (cf->can_id & CAN_RTR_FLAG) {
-                               unsigned long flags;
                                struct sllin_conf_entry *sce;
 
                                netdev_dbg(sl->dev, "%s: RTR SFF CAN frame, ID = %x\n",
@@ -1143,6 +1195,56 @@ slstate_response_wait:
                        sl->lin_state = SLSTATE_IDLE;
                        break;
 
+               case SLSTATE_ID_RECEIVED:
+                       lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+                       sce = &sl->linfr_cache[lin_id];
+                       spin_lock_irqsave(&sl->linfr_lock, flags);
+
+                       if ((sce->frame_fl & LIN_CACHE_RESPONSE)
+                                       && (sce->dlc > 0)
+                                       && (test_bit(SLF_MSGEVENT, &sl->flags))) {
+                               int mode;
+
+                               netdev_dbg(sl->dev, "Sending LIN response from linfr_cache\n");
+
+                               lin_data = sce->data;
+                               lin_dlc = sce->dlc;
+                               if (lin_dlc > SLLIN_DATA_MAX)
+                                       lin_dlc = SLLIN_DATA_MAX;
+                               memcpy(lin_data_buff, lin_data, lin_dlc);
+                               lin_data = lin_data_buff;
+                               tx_bytes = lin_dlc;
+
+                               mode = SLLIN_STPMSG_RESPONLY;
+                               if (sce->frame_fl & LIN_CHECKSUM_EXTENDED)
+                                       mode |= SLLIN_STPMSG_CHCKSUM_ENH;
+
+                               if (sllin_setup_msg(sl, mode, lin_id & LIN_ID_MASK,
+                                       lin_data, lin_dlc) != -1) {
+
+                                       sl->rx_expect = sl->tx_lim;
+                                       sl->data_to_send = true;
+                                       sl->dev->stats.tx_packets++;
+                                       sl->dev->stats.tx_bytes += tx_bytes;
+                                       sl->resp_len_known = true;
+
+                                       if (!sl->lin_master) {
+                                               sl->tx_cnt = SLLIN_BUFF_DATA;
+                                       }
+                                       sllin_send_tx_buff(sl);
+                               }
+
+                               clear_bit(SLF_MSGEVENT, &sl->flags);
+                               kfree_skb(sl->tx_req_skb);
+                               netif_wake_queue(sl->dev);
+                               hrtimer_start(&sl->rx_timer,
+                                       ktime_add(ktime_get(), sl->rx_timer_timeout),
+                                       HRTIMER_MODE_ABS);
+                       }
+                       spin_unlock_irqrestore(&sl->linfr_lock, flags);
+                       sl->lin_state = SLSTATE_IDLE;
+                       break;
+
                case SLSTATE_RESPONSE_SENT:
 slstate_response_sent:
                        if (sl->rx_cnt < sl->tx_lim)