sllin: Added LIN frame cache and its configuration with CAN EFF frames.

diff --git a/sllin/sllin.c b/sllin/sllin.c
index 0be69d94e091ee11079b0d2bf2afe5971c914a1a..2570bee86a297a7a51276dcb49dc70f0a5981343 100644 (file)
--- a/sllin/sllin.c
+++ b/sllin/sllin.c
@@ -90,6 +90,7 @@ MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
 #define SLLIN_BUFF_DATA         3
 
 #define SLLIN_ID_MASK  0x3f
+#define SLLIN_ID_MAX   SLLIN_ID_MASK
 
 enum slstate {
        SLSTATE_IDLE = 0,
@@ -99,6 +100,21 @@ enum slstate {
        SLSTATE_RESPONSE_SENT,
 };
 
+struct sllin_conf_entry {
+       int dlc;                /* Length of data in LIN frame */
+#define SLLIN_CANFR_FLAGS_OFFS 6 /* Lower 6 bits in can_id correspond to LIN ID */
+/* Save configuration for particualr LIN ID */
+#define SLLIN_SRC_ID_CONF      (1 <<  SLLIN_CANFR_FLAGS_OFFS)
+/* Publisher of particular LIN response is SLLIN Master */
+#define SLLIN_SRC_MASTER       (1 << (SLLIN_CANFR_FLAGS_OFFS + 1))
+#define SLLIN_SRC_SLAVE                (1 << (SLLIN_CANFR_FLAGS_OFFS + 2))
+#define SLLIN_SLAVE_LOCAL      (1 << (SLLIN_CANFR_FLAGS_OFFS + 3))
+#define SLLIN_SLAVE_REMOTE     (1 << (SLLIN_CANFR_FLAGS_OFFS + 4))
+#define SLLIN_LOC_SLAVE_CACHE  (1 << (SLLIN_CANFR_FLAGS_OFFS + 5))
+       u32 frame_fl;           /* LIN frame flags */
+       u8 data[8];             /* LIN frame data payload */
+};
+
 struct sllin {
        int                     magic;
 
@@ -135,6 +151,9 @@ struct sllin {
        struct hrtimer          rx_timer;       /* RX timeout timer */
        ktime_t                 rx_timer_timeout; /* RX timeout timer value */
        struct sk_buff          *rec_skb;       /* Socket buffer with received CAN frame */
+
+       struct sllin_conf_entry linfr_cache[SLLIN_ID_MAX + 1]; /* List with configurations for
+                                               each of 0 to SLLIN_ID_MAX LIN IDs */
 };
 
 static struct net_device **sllin_devs;
@@ -450,6 +469,20 @@ static void sllin_receive_buf(struct tty_struct *tty,
 /*****************************************
  *  sllin message helper routines
  *****************************************/
+int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
+{
+       struct sllin_conf_entry *sce;
+       if (!(cf->can_id & SLLIN_SRC_ID_CONF))
+               return -1;
+
+       sce = &sl->linfr_cache[cf->can_id & SLLIN_ID_MASK];
+
+       sce->dlc = (sce->dlc > 8) ? 8 : cf->can_dlc;
+       sce->frame_fl = (cf->can_id & ~SLLIN_ID_MASK) & CAN_EFF_FLAG;
+       memcpy(sce->data, cf->data, cf->can_dlc);
+
+       return 0;
+}
 
 int sllin_setup_msg(struct sllin *sl, int mode, int id,
                unsigned char *data, int len)
@@ -658,12 +691,12 @@ int sllin_kwthread(void *ptr)
                if ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)) {
                        cf = (struct can_frame *)sl->rec_skb->data;
 
-                       /* We do care only about SFF frames */
-                       if (cf->can_id & CAN_EFF_FLAG)
-                               goto release_skb;
-
-                       if (cf->can_id & CAN_RTR_FLAG) {
-                               printk(KERN_INFO "%s: RTR CAN frame, ID = %x\n",
+                       /* "Configuration" frame */
+                       if (cf->can_id & CAN_EFF_FLAG) {
+                               sllin_configure_frame_cache(sl, cf);
+                       } 
+                       else if (cf->can_id & CAN_RTR_FLAG) {
+                               printk(KERN_INFO "%s: RTR SFF CAN frame, ID = %x\n",
                                        __FUNCTION__, cf->can_id & CAN_SFF_MASK);
                                if (sllin_setup_msg(sl, 0, 
                                        cf->can_id & CAN_SFF_MASK, NULL, 0) != -1) {
@@ -671,7 +704,7 @@ int sllin_kwthread(void *ptr)
                                        sl->data_to_send = false;
                                }
                        } else {
-                               printk(KERN_INFO "%s: NON-RTR CAN frame, ID = %x\n",
+                               printk(KERN_INFO "%s: NON-RTR SFF CAN frame, ID = %x\n",
                                        __FUNCTION__, (int)cf->can_id & CAN_SFF_MASK);
 
                                if (sllin_setup_msg(sl, 0, cf->can_id & CAN_SFF_MASK, 
@@ -681,7 +714,6 @@ int sllin_kwthread(void *ptr)
                                }
                        }
 
-               release_skb:
                        sl->dev->stats.tx_packets++;
                        sl->dev->stats.tx_bytes += cf->can_dlc;
                        clear_bit(SLF_MSGEVENT, &sl->flags);
@@ -828,7 +860,6 @@ static struct sllin *sll_alloc(dev_t line)
        }
 
        sl = netdev_priv(dev);
-
        /* Initialize channel control data */
        sl->magic = SLLIN_MAGIC;
        sl->dev = dev;