diff --git a/configs/stm32f103-minimum/src/stm32f103_minimum.h b/configs/stm32f103-minimum/src/stm32f103_minimum.h
index adabdbc3b03..9b2e62df14f 100644
--- a/configs/stm32f103-minimum/src/stm32f103_minimum.h
+++ b/configs/stm32f103-minimum/src/stm32f103_minimum.h
@@ -194,6 +194,18 @@ int stm32_qencoder_initialize(FAR const char *devpath, int timer);
 int stm32_rgbled_setup(void);
 #endif
 
+/************************************************************************************
+ * Name: stm32_mcp2515initialize
+ *
+ * Description:
+ *   Initialize and register the MCP2515 CAN driver.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_CAN_MCP2515
+int stm32_mcp2515initialize(FAR const char *devpath);
+#endif
+
 /************************************************************************************
  * Name: stm32_usbinitialize
  *
diff --git a/drivers/can/mcp2515.c b/drivers/can/mcp2515.c
index 8fe6e353644..50d4999e603 100644
--- a/drivers/can/mcp2515.c
+++ b/drivers/can/mcp2515.c
@@ -1298,6 +1298,7 @@ static void mcp2515_rxint(FAR struct can_dev_s *dev, bool enable)
   DEBUGASSERT(config);
 
   caninfo("CAN%d enable: %d\n", config->devid, enable);
+  UNUSED(config);
 
   /* Enable/disable the receive interrupts */
 
@@ -1670,6 +1671,7 @@ static int mcp2515_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
   caninfo("CAN%d\n", config->devid);
   caninfo("CAN%d ID: %d DLC: %d\n",
           config->devid, msg->cm_hdr.ch_id, msg->cm_hdr.ch_dlc);
+  UNUSED(config);
 
   /* That that FIFO elements were configured.
    *
@@ -1823,7 +1825,7 @@ static bool mcp2515_txready(FAR struct can_dev_s *dev)
 {
   FAR struct mcp2515_can_s *priv;
   uint8_t regval;
-  bool empty;
+  bool ready;
 
   DEBUGASSERT(dev);
   priv = dev->cd_priv;
@@ -1845,32 +1847,32 @@ static bool mcp2515_txready(FAR struct can_dev_s *dev)
   mcp2515_readregs(priv, MCP2515_TXB0CTRL, &regval, 1);
   if ((regval & TXBCTRL_TXREQ) == 0)
     {
-      empty = true;
+      ready = true;
     }
   else
     {
       mcp2515_readregs(priv, MCP2515_TXB1CTRL, &regval, 1);
       if ((regval & TXBCTRL_TXREQ) == 0)
         {
-          empty = true;
+          ready = true;
         }
      else
        {
          mcp2515_readregs(priv, MCP2515_TXB2CTRL, &regval, 1);
          if ((regval & TXBCTRL_TXREQ) == 0)
            {
-              empty = true;
+              ready = true;
            }
          else
            {
-             empty = false;
+             ready = false;
            }
        }
     }
 
   mcp2515_dev_unlock(priv);
 
-  return empty;
+  return ready;
 }
 
 /****************************************************************************
@@ -2241,7 +2243,8 @@ static int mcp2515_interrupt(FAR struct mcp2515_config_s *config, FAR void *arg)
         {
           /* Clear interrupt errors */
 
-          mcp2515_modifyreg(priv, MCP2515_CANINTF, MCP2515_ERROR_INTS, ~MCP2515_ERROR_INTS);
+          mcp2515_modifyreg(priv, MCP2515_CANINTF, MCP2515_ERROR_INTS,
+                            (uint8_t)~MCP2515_ERROR_INTS);
 
 #ifdef CONFIG_CAN_ERRORS
           /* Report errors */
@@ -2378,6 +2381,7 @@ static int mcp2515_hw_initialize(struct mcp2515_can_s *priv)
   uint8_t regval;
 
   caninfo("CAN%d\n", config->devid);
+  UNUSED(config);
 
   /* Setup CNF1 register */