Add framework for I2C tools

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3923 42af7a65-404d-4744-a932-0658087f49c3

7 files changed, 987 insertions, 0 deletions

diff --git a/apps/system/i2c/Makefile b/apps/system/i2c/Makefile
new file mode 100644
index 000000000..d6c09cf13
--- /dev/null
+++ b/apps/system/i2c/Makefile
@@ -0,0 +1,95 @@
+############################################################################
+# apps/system/i2c
+#
+#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name NuttX nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+-include $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+# I2C tool
+
+ASRCS	=
+CSRCS	= i2c_detect.c i2c_dump.c i2c_get.c i2c_main.c i2c_set.c
+
+
+AOBJS		= $(ASRCS:.S=$(OBJEXT))
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+ifeq ($(WINTOOL),y)
+  BIN		= "${shell cygpath -w  $(APPDIR)/libapps$(LIBEXT)}"
+else
+  BIN		= "$(APPDIR)/libapps$(LIBEXT)"
+endif
+
+ROOTDEPPATH	= --dep-path .
+VPATH		= 
+
+# Build targets
+
+all:	.built
+.PHONY: context .depend depend clean distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	@( for obj in $(OBJS) ; do \
+		$(call ARCHIVE, $(BIN), $${obj}); \
+	done ; )
+	@touch .built
+
+context:
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) \
+	  $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	@rm -f *.o *~ .*.swp .built
+	$(call CLEAN)
+
+distclean: clean
+	@rm -f Make.dep .depend
+
+-include Make.dep
+
diff --git a/apps/system/i2c/i2c_detect.c b/apps/system/i2c/i2c_detect.c
new file mode 100644
index 000000000..30e0560aa
--- /dev/null
+++ b/apps/system/i2c/i2c_detect.c
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * apps/system/i2c/i2c_detect.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "i2ctool.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_detect
+ ****************************************************************************/
+
+int cmd_detect(FAR void *handle, int argc, char **argv)
+{
+  return OK;
+}
diff --git a/apps/system/i2c/i2c_dump.c b/apps/system/i2c/i2c_dump.c
new file mode 100644
index 000000000..e910c3bc1
--- /dev/null
+++ b/apps/system/i2c/i2c_dump.c
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * apps/system/i2c/i2c_dump.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "i2ctool.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_dump
+ ****************************************************************************/
+
+int cmd_dump(FAR void *handle, int argc, char **argv)
+{
+  return OK;
+}
diff --git a/apps/system/i2c/i2c_get.c b/apps/system/i2c/i2c_get.c
new file mode 100644
index 000000000..9e98705cc
--- /dev/null
+++ b/apps/system/i2c/i2c_get.c
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * apps/system/i2c/i2c_get.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "i2ctool.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_get
+ ****************************************************************************/
+
+int cmd_get(FAR void *handle, int argc, char **argv)
+{
+  return OK;
+}
diff --git a/apps/system/i2c/i2c_main.c b/apps/system/i2c/i2c_main.c
new file mode 100644
index 000000000..286319db5
--- /dev/null
+++ b/apps/system/i2c/i2c_main.c
@@ -0,0 +1,458 @@
+/****************************************************************************
+ * apps/system/i2c/i2c_main.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "i2ctool.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Are we using the NuttX console for I/O?  Or some other character device? */
+
+#ifdef CONFIG_I2CTOOL_INDEV
+#  define INFD(p)      ((p)->ss_infd)
+#  define INSTREAM(p)  ((p)->ss_instream)
+#else
+#  define INFD(p)      0
+#  define INSTREAM(p)  stdin
+#endif
+
+#ifdef CONFIG_I2CTOOL_OUTDEV
+#  define OUTFD(p)     ((p)->ss_outfd)
+#  define OUTSTREAM(p) ((p)->ss_outstream)
+#else
+#  define OUTFD(p)     1
+#  define OUTSTREAM(p) stdout
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct i2ctool_s
+{
+  /* Output streams */
+
+#ifdef CONFIG_I2CTOOL_OUTDEV
+  int    ss_outfd;     /* Output file descriptor */
+  FILE  *ss_outstream; /* Output stream */
+#endif
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int cmd_help(FAR void *handle, int argc, char **argv);
+static int cmd_unrecognized(FAR void *handle, int argc, char **argv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+ 
+struct i2ctool_s g_i2ctool;
+
+static const struct cmdmap_s g_i2ccmds[] =
+{
+  { "?",        cmd_help,     1, 1, NULL },
+  { "detect",   cmd_detect,   1, 1, NULL },
+  { "dump",     cmd_dump,     1, 1, NULL },
+  { "get",      cmd_get,      1, 1, NULL },
+  { "help",     cmd_help,     1, 1, NULL },
+  { "set",      cmd_set,      1, 1, NULL },
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* Common, message formats */
+
+const char g_syntax[]            = "i2ctool: %s: syntax error\n";
+const char g_fmtargrequired[]    = "i2ctool: %s: missing required argument(s)\n";
+const char g_fmtarginvalid[]     = "i2ctool: %s: argument invalid\n";
+const char g_fmtargrange[]       = "i2ctool: %s: value out of range\n";
+const char g_fmtcmdnotfound[]    = "i2ctool: %s: command not found\n";
+const char g_fmtnosuch[]         = "i2ctool: %s: no such %s: %s\n";
+const char g_fmttoomanyargs[]    = "i2ctool: %s: too many arguments\n";
+const char g_fmtdeepnesting[]    = "i2ctool: %s: nesting too deep\n";
+const char g_fmtcontext[]        = "i2ctool: %s: not valid in this context\n";
+const char g_fmtcmdfailed[]      = "i2ctool: %s: %s failed: %d\n";
+const char g_fmtcmdoutofmemory[] = "i2ctool: %s: out of memory\n";
+const char g_fmtinternalerror[]  = "i2ctool: %s: Internal error\n";
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_help
+ ****************************************************************************/
+
+static int cmd_help(FAR void *handle, int argc, char **argv)
+{
+  const struct cmdmap_s *ptr;
+
+  i2ctool_printf(handle, "Usage: i2ctool <cmd> [arguments]\n");
+  i2ctool_printf(handle, "Where <cmd> is one of:\n");
+  for (ptr = g_i2ccmds; ptr->cmd; ptr++)
+    {
+      if (ptr->usage)
+        {
+          i2ctool_printf(handle, "  %s %s\n", ptr->cmd, ptr->usage);
+        }
+      else
+        {
+          i2ctool_printf(handle, "  %s\n", ptr->cmd);
+        }
+    }
+
+  i2ctool_printf(handle, "NOTES:\n");
+#ifndef CONFIG_DISABLE_ENVIRON
+  i2ctool_printf(handle, "- An environment variable like $PATH may be used for any argument.\n");
+#endif
+  i2ctool_printf(handle, "- Arguments are persistent.  For example, once the I2C address is\n");
+  i2ctool_printf(handle, "  specified, that address will be re-used until it changes.\n");
+  i2ctool_printf(handle, "WARNING:\n");
+  i2ctool_printf(handle, "- The I2C detect command may have bad side effects on your I2C devices.\n");
+  i2ctool_printf(handle, "  Use only at your own risk.\n");
+  return OK;
+}
+
+/****************************************************************************
+ * Name: cmd_unrecognized
+ ****************************************************************************/
+
+static int cmd_unrecognized(FAR void *handle, int argc, char **argv)
+{
+  i2ctool_printf(handle, g_fmtcmdnotfound, argv[0]);
+  return ERROR;
+}
+
+/****************************************************************************
+ * Name: i2c_execute
+ ****************************************************************************/
+
+static int i2c_execute(FAR void *handle, int argc, char *argv[])
+{
+   const struct cmdmap_s *cmdmap;
+   const char            *cmd;
+   cmd_t                  handler = cmd_unrecognized;
+   int                    ret;
+
+   /* The form of argv is:
+    *
+    * argv[0]:      The command name.  This is argv[0] when the arguments
+    *               are, finally, received by the command vtblr
+    * argv[1]:      The beginning of argument (up to MAX_ARGUMENTS)
+    * argv[argc]:   NULL terminating pointer
+    */
+
+   cmd = argv[0];
+
+   /* See if the command is one that we understand */
+
+   for (cmdmap = g_i2ccmds; cmdmap->cmd; cmdmap++)
+     {
+       if (strcmp(cmdmap->cmd, cmd) == 0)
+         {
+           /* Check if a valid number of arguments was provided.  We
+            * do this simple, imperfect checking here so that it does
+            * not have to be performed in each command.
+            */
+
+           if (argc < cmdmap->minargs)
+             {
+               /* Fewer than the minimum number were provided */
+
+               i2ctool_printf(handle, g_fmtargrequired, cmd);
+               return ERROR;
+             }
+           else if (argc > cmdmap->maxargs)
+             {
+               /* More than the maximum number were provided */
+
+               i2ctool_printf(handle, g_fmttoomanyargs, cmd);
+               return ERROR;
+             }
+           else
+             {
+               /* A valid number of arguments were provided (this does
+                * not mean they are right).
+                */
+
+               handler = cmdmap->handler;
+               break;
+             }
+         }
+     }
+
+   ret = handler(handle, argc, argv);
+   return ret;
+}
+
+/****************************************************************************
+ * Name: i2c_argument
+ ****************************************************************************/
+
+FAR char *i2c_argument(FAR void *handle, int argc, char *argv[], int *pindex)
+{
+  FAR char *arg;
+  int  index = *pindex;
+
+  /* If we are at the end of the arguments with nothing, then return NULL */
+
+  if (index >= argc)
+    {
+      return NULL;
+    }
+
+  /* Get the return parameter */
+
+  arg     = argv[index];
+  *pindex = index + 1;
+
+#ifndef CONFIG_DISABLE_ENVIRON
+  /* Check for references to environment variables */
+
+  if (arg[0] == '$')
+    {
+      /* Return the value of the environment variable with this name */
+
+      FAR char *value = getenv(arg+1);
+      if (value)
+        {
+          return value;
+        }
+      else
+        {
+          return (FAR char*)"";
+        }
+    }
+#endif
+
+  /* Return the next argument. */
+
+  return arg;
+}
+
+/****************************************************************************
+ * Name: i2c_parse
+ ****************************************************************************/
+
+int i2c_parse(FAR void *handle, int argc, char *argv[])
+{
+  FAR char *newargs[MAX_ARGUMENTS+1];
+  FAR char *cmd;
+  int       nargs;
+  int       index;
+
+  /* Initialize parser state */
+
+  memset(argv, 0, MAX_ARGUMENTS*sizeof(FAR char *));
+
+  /* Parse out the command, skipping the first argument (the program name)*/
+
+  index = 1;
+  cmd = i2c_argument(handle, argc, argv, &index);
+
+  /* Check if any command was provided */
+
+  if (!cmd)
+    {
+      /* An empty line is not an error and an unprocessed command cannot
+       * generate an error, but neither should they change the last
+       * command status.
+       */
+
+      return cmd_help(handle, 0, NULL);
+    }
+
+  /* Parse all of the arguments following the command name. */
+
+  newargs[0] = cmd;
+  for (nargs = 1; nargs < MAX_ARGUMENTS; nargs++)
+    {
+      newargs[nargs] = i2c_argument(handle, argc, argv, &index);
+      if (!newargs[nargs])
+        {
+          break;
+        }
+    }
+  newargs[nargs] = NULL;
+
+  /* Then execute the command */
+
+  return i2c_execute(handle, nargs, newargs);
+}
+
+/****************************************************************************
+ * Name: i2c_setup
+ ****************************************************************************/
+
+static inline int i2c_setup(void)
+{
+  /* Initialize the output stream */
+
+#ifdef CONFIG_I2CTOOL_OUTDEV
+  g_i2ctool.ss_outfd = open(CONFIG_I2CTOOL_OUTDEV, O_WRONLY);
+  if (g_i2ctool.ss_outfd < 0)
+    {
+      fprintf(stderr, g_fmtcmdfailed, "open", errno);
+      return ERROR;
+    }
+
+  /* Create a standard C stream on the console device */
+
+  g_i2ctool.ss_outstream = fdopen(g_i2ctool.ss_outfd, "w");
+  if (!g_i2ctool.ss_outstream)
+    {
+      fprintf(stderr, g_fmtcmdfailed, "fdopen", errno);
+      return ERROR;
+    }
+#endif
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: i2c_teardown
+ *
+ * Description:
+ *   Close the output stream if it is not the standard output stream.
+ *
+ ****************************************************************************/
+
+static void i2c_teardown(void)
+{
+  fflush(OUTSTREAM(&g_i2ctool));
+
+#ifdef CONFIG_I2CTOOL_OUTDEV
+  fclose(g_i2ctool.ss_outstream);
+#endif
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: i2c_main
+ ****************************************************************************/
+
+#ifdef CONFIG_I2CTOOL_BUILTIN
+#  define MAIN_NAME i2c_main
+#  define MAIN_NAME_STRING "i2c_main"
+#else
+#  define MAIN_NAME user_start
+#  define MAIN_NAME_STRING "user_start"
+#endif
+
+int MAIN_NAME(int argc, char *argv[])
+{
+  /* Parse process the command line */
+
+  i2c_setup();
+  (void)i2c_parse((FAR void *)&g_i2ctool, argc, argv);
+
+  i2c_teardown();
+  return OK;
+}
+
+/****************************************************************************
+ * Name: i2ctool_printf
+ *
+ * Description:
+ *   Print a string to the currently selected stream.
+ *
+ ****************************************************************************/
+
+int i2ctool_printf(FAR void *handle, const char *fmt, ...)
+{
+#ifdef CONFIG_I2CTOOL_OUTDEV
+  FAR struct i2ctool_s *pstate = (FAR struct i2ctool_s *)handle;
+#endif
+  va_list ap;
+  int     ret;
+
+  va_start(ap, fmt);
+  ret = vfprintf(OUTSTREAM(pstate), fmt, ap);
+  va_end(ap);
+ 
+  return ret;
+}
+
+/****************************************************************************
+ * Name: i2ctool_write
+ *
+ * Description:
+ *   write a buffer to the currently selected stream.
+ *
+ ****************************************************************************/
+
+ssize_t i2ctool_write(FAR void *handle, FAR const void *buffer, size_t nbytes)
+{
+#ifdef CONFIG_I2CTOOL_OUTDEV
+  FAR struct i2ctool_s *pstate = (FAR struct i2ctool_s *)handle;
+#endif
+  ssize_t ret;
+
+  /* Write the data to the output stream */
+
+  ret = fwrite(buffer, 1, nbytes, OUTSTREAM(pstate));
+  if (ret < 0)
+    {
+      dbg("[%d] Failed to send buffer: %d\n", OUTFD(pstate), errno);
+    }
+  return ret;
+}
+
diff --git a/apps/system/i2c/i2c_set.c b/apps/system/i2c/i2c_set.c
new file mode 100644
index 000000000..501eca9c5
--- /dev/null
+++ b/apps/system/i2c/i2c_set.c
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * apps/system/i2c/i2c_set.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "i2ctool.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_set
+ ****************************************************************************/
+
+int cmd_set(FAR void *handle, int argc, char **argv)
+{
+  return OK;
+}
diff --git a/apps/system/i2c/i2ctool.h b/apps/system/i2c/i2ctool.h
new file mode 100644
index 000000000..36726c7dc
--- /dev/null
+++ b/apps/system/i2c/i2ctool.h
@@ -0,0 +1,118 @@
+/****************************************************************************
+ * apps/system/i2c/i2ctool.h
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_SYSTEM_I2C_I2CTOOLS_H
+#define __APPS_SYSTEM_I2C_I2CTOOLS_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/* This is the maximum number of arguments that will be accepted for a command */
+
+#define MAX_ARGUMENTS 6
+
+/* Maximum size of one command line */
+
+#define MAX_LINELEN 80
+
+/* Output is via printf but can be changed using this macro */
+
+#ifdef CONFIG_CPP_HAVE_VARARGS
+# define i2c_output(v, fmt...) printf(v, ##fmt)
+#else
+# define i2c_output            printf
+#endif
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+typedef int  (*cmd_t)(FAR void *handle, int argc, char **argv);
+
+struct cmdmap_s
+{
+  const char *cmd;        /* Name of the command */
+  cmd_t       handler;    /* Function that handles the command */
+  uint8_t     minargs;    /* Minimum number of arguments (including command) */
+  uint8_t     maxargs;    /* Maximum number of arguments (including command) */
+  const char *usage;      /* Usage instructions for 'help' command */
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+extern const char g_syntax[];
+extern const char g_fmtargrequired[];
+extern const char g_fmtarginvalid[];
+extern const char g_fmtargrange[];
+extern const char g_fmtcmdnotfound[];
+extern const char g_fmtnosuch[];
+extern const char g_fmttoomanyargs[];
+extern const char g_fmtcmdfailed[];
+extern const char g_fmtcmdoutofmemory[];
+extern const char g_fmtinternalerror[];
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/* Message handler */
+
+ssize_t i2ctool_write(FAR void *handle, FAR const void *buffer, size_t nbytes);
+int i2ctool_printf(FAR void *handle, const char *fmt, ...);
+
+/* Command handlers */
+
+extern int cmd_detect(FAR void *handle, int argc, char **argv);
+extern int cmd_dump(FAR void *handle, int argc, char **argv);
+extern int cmd_get(FAR void *handle, int argc, char **argv);
+extern int cmd_set(FAR void *handle, int argc, char **argv);
+
+#endif /* __APPS_SYSTEM_I2C_I2CTOOLS_H */