Extend examples/can so that it can be used in other contexts

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4489 7fd9a85b-ad96-42d3-883c-3090e2eb8679

5 files changed, 59 insertions, 6 deletions

diff --git a/apps/ChangeLog.txt b/apps/ChangeLog.txt
index eb8cab8617..ae4e5ec546 100755
--- a/apps/ChangeLog.txt
+++ b/apps/ChangeLog.txt
@@ -204,3 +204,7 @@
 	  allows NSH to be used on boards that have USB but no serial connectors.
 
 6.17 2012-xx-xx Gregory Nutt <gnutt@nuttx.org>
+
+	* apps/examples/can:  Add conditional compilation so that the test can be
+	  configured to only send messages or to only receive messages.  This will
+	  let the test work in other modes than simple loopback testing.
diff --git a/apps/examples/README.txt b/apps/examples/README.txt
index 86edc6e339..54cbec978b 100644
--- a/apps/examples/README.txt
+++ b/apps/examples/README.txt
@@ -110,6 +110,13 @@ examples/can
       built-in, the default is 32.  Otherwise messages are sent and received
       indefinitely.
 
+  The default behavior assumes loopback mode.  Messages are sent, then read
+  and verified.  The behavior can be altered for other kinds of testing where
+  the test only sends or received (but does not verify) can messages.
+
+   CONFIG_EXAMPLES_CAN_READONLY - Only receive messages
+   CONFIG_EXAMPLES_CAN_WRITEONLY - Only send messages
+
 examples/cdcacm
 ^^^^^^^^^^^^^^^
 
diff --git a/apps/examples/can/can.h b/apps/examples/can/can.h
index 0b781c6692..53a6b63ea0 100644
--- a/apps/examples/can/can.h
+++ b/apps/examples/can/can.h
@@ -65,6 +65,8 @@
  *   collected and the program terminates.  Default:  If built as an NSH
  *   built-in, the default is 32.  Otherwise messages are sent and received
  *   indefinitely.
+ * CONFIG_EXAMPLES_CAN_READONLY - Only receive messages
+ * CONFIG_EXAMPLES_CAN_WRITEONLY - Only send messages
  */
 
 #ifndef CONFIG_CAN
diff --git a/apps/examples/can/can_main.c b/apps/examples/can/can_main.c
index 27e19b1564..c7b0859ba5 100644
--- a/apps/examples/can/can_main.c
+++ b/apps/examples/can/can_main.c
@@ -57,6 +57,19 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+#if defined(CONFIG_EXAMPLES_CAN_READONLY)
+#  undef CONFIG_EXAMPLES_CAN_WRITEONLY
+#  undef CONFIG_EXAMPLES_CAN_READWRITE
+#  define CAN_OFLAGS O_RDONLY
+#elif defined(CONFIG_EXAMPLES_CAN_WRITEONLY)
+#  undef CONFIG_EXAMPLES_CAN_READWRITE
+#  define CAN_OFLAGS O_WRONLY
+#else
+#  undef CONFIG_EXAMPLES_CAN_READWRITE
+#  define CONFIG_EXAMPLES_CAN_READWRITE 1
+#  define CAN_OFLAGS O_RDWR
+#endif
+
 #ifdef CONFIG_CAN_EXTID
 #  define MAX_ID (1 << 29)
 #else
@@ -101,20 +114,27 @@
 
 int MAIN_NAME(int argc, char *argv[])
 {
+#ifndef CONFIG_EXAMPLES_CAN_READONLY
   struct can_msg_s txmsg;
-  struct can_msg_s rxmsg;
-  size_t msgsize;
-  ssize_t nbytes;
 #ifdef CONFIG_CAN_EXTID
   uint32_t msgid;
 #else
   uint16_t msgid;
 #endif
+  int msgdlc;
   uint8_t msgdata;
+#endif
+
+#ifndef CONFIG_EXAMPLES_CAN_WRITEONLY
+  struct can_msg_s rxmsg;
+#endif
+
+  size_t msgsize;
+  ssize_t nbytes;
 #if defined(CONFIG_NSH_BUILTIN_APPS) || defined(CONFIG_EXAMPLES_CAN_NMSGS)
   long nmsgs;
 #endif
-  int msgdlc;
+
   int fd;
   int errval = 0;
   int ret;
@@ -151,7 +171,7 @@ int MAIN_NAME(int argc, char *argv[])
   /* Open the CAN device for reading */
 
   message(MAIN_STRING "Hardware initialized. Opening the CAN device\n");
-  fd = open(CONFIG_EXAMPLES_CAN_DEVPATH, O_RDWR);
+  fd = open(CONFIG_EXAMPLES_CAN_DEVPATH, CAN_OFLAGS);
   if (fd < 0)
     {
       message(MAIN_STRING "open %s failed: %d\n",
@@ -164,9 +184,11 @@ int MAIN_NAME(int argc, char *argv[])
    * on each pass.
    */
 
+#ifndef CONFIG_EXAMPLES_CAN_READONLY
   msgdlc  = 1;
   msgid   = 1;
   msgdata = 0;
+#endif
 
 #if defined(CONFIG_NSH_BUILTIN_APPS)
   for (; nmsgs > 0; nmsgs--)
@@ -184,6 +206,7 @@ int MAIN_NAME(int argc, char *argv[])
 
     /* Construct the next TX message */
 
+#ifndef CONFIG_EXAMPLES_CAN_READONLY
     txmsg.cm_hdr.ch_id    = msgid;
     txmsg.cm_hdr.ch_rtr   = false;
     txmsg.cm_hdr.ch_dlc   = msgdlc;
@@ -207,8 +230,14 @@ int MAIN_NAME(int argc, char *argv[])
         goto errout_with_dev;
       }
 
+#ifndef CONFIG_EXAMPLES_CAN_READWRITE
+    message("  ID: %4d DLC: %d\n", msgid, msgdlc);
+#endif
+#endif
+
     /* Read the RX message */
 
+#ifndef CONFIG_EXAMPLES_CAN_WRITEONLY
     msgsize = sizeof(struct can_msg_s);
     nbytes = read(fd, &rxmsg, msgsize);
     if (nbytes < CAN_MSGLEN(0) || nbytes > msgsize)
@@ -218,8 +247,14 @@ int MAIN_NAME(int argc, char *argv[])
         goto errout_with_dev;
       }
 
+#ifndef CONFIG_EXAMPLES_CAN_READWRITE
+    message("  ID: %4d DLC: %d\n", rxmsg.cm_hdr.id, rxmsg.cm_hdr.dlc);
+#endif
+#endif
+
     /* Verify that the received messages are the same */
 
+#ifdef CONFIG_EXAMPLES_CAN_READWRITE
     if (memcmp(&txmsg.cm_hdr, &rxmsg.cm_hdr, sizeof(struct can_hdr_s)) != 0)
       {
         message("ERROR: Sent header does not match received header:\n");
@@ -245,9 +280,11 @@ int MAIN_NAME(int argc, char *argv[])
     /* Report success */
   
     message("  ID: %4d DLC: %d -- OK\n", msgid, msgdlc);
+#endif
 
     /* Set up for the next pass */
 
+#ifndef CONFIG_EXAMPLES_CAN_READONLY
     msgdata += msgdlc;
  
     if (++msgid >= MAX_ID)
@@ -259,6 +296,7 @@ int MAIN_NAME(int argc, char *argv[])
       {
         msgdlc = 1;
       }
+#endif
   }
 
 errout_with_dev:
diff --git a/nuttx/configs/pic32-starterkit/README.txt b/nuttx/configs/pic32-starterkit/README.txt
index ffbffde783..5b71bc1525 100644
--- a/nuttx/configs/pic32-starterkit/README.txt
+++ b/nuttx/configs/pic32-starterkit/README.txt
@@ -1168,6 +1168,8 @@ Where <subdir> is one of the following:
       nsh> msconn
 
     NOTE:  This modification is experimental and does not yet
-    work properly!  However, the configuration is worth remembering
+    work properly!  My hunch is that the USB device driver won't
+    support MSC -- probably because the required MSC stall
+    handling. However, this configuration is worth remembering
     for future USB MSC testing.