binman: Add a way to obtain the version

Add a -V option which shows the version number of binman. For now this
just uses a local 'version' file. Once the tool is packaged in some way
we can figure out an approach that suits.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/cmdline.py b/tools/binman/cmdline.py
index 14ec95c..2229316 100644
--- a/tools/binman/cmdline.py
+++ b/tools/binman/cmdline.py
@@ -5,7 +5,9 @@
 
 """Command-line parser for binman"""
 
+import argparse
 from argparse import ArgumentParser
+import state
 
 def make_extract_parser(subparsers):
     """make_extract_parser: Make a subparser for the 'extract' command
@@ -26,6 +28,32 @@
     extract_parser.add_argument('-U', '--uncompressed', action='store_true',
         help='Output raw uncompressed data for compressed entries')
 
+
+#pylint: disable=R0903
+class BinmanVersion(argparse.Action):
+    """Handles the -V option to binman
+
+    This reads the version information from a file called 'version' in the same
+    directory as this file.
+
+    If not present it assumes this is running from the U-Boot tree and collects
+    the version from the Makefile.
+
+    The format of the version information is three VAR = VALUE lines, for
+    example:
+
+        VERSION = 2022
+        PATCHLEVEL = 01
+        EXTRAVERSION = -rc2
+    """
+    def __init__(self, nargs=0, **kwargs):
+        super().__init__(nargs=nargs, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        parser._print_message(f'Binman {state.GetVersion()}\n')
+        parser.exit()
+
+
 def ParseArgs(argv):
     """Parse the binman command-line arguments
 
@@ -59,6 +87,7 @@
     parser.add_argument('-v', '--verbosity', default=1,
         type=int, help='Control verbosity: 0=silent, 1=warnings, 2=notices, '
         '3=info, 4=detail, 5=debug')
+    parser.add_argument('-V', '--version', nargs=0, action=BinmanVersion)
 
     subparsers = parser.add_subparsers(dest='cmd')
     subparsers.required = True
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 6be0037..6a36e8f 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -4661,6 +4661,26 @@
             str(e.exception),
             "Not enough space in '.*u_boot_binman_embed_sm' for data length.*")
 
+    def testVersion(self):
+        """Test we can get the binman version"""
+        version = '(unreleased)'
+        self.assertEqual(version, state.GetVersion(self._indir))
+
+        with self.assertRaises(SystemExit):
+            with test_util.capture_sys_output() as (_, stderr):
+                self._DoBinman('-V')
+        self.assertEqual('Binman %s\n' % version, stderr.getvalue())
+
+        # Try running the tool too, just to be safe
+        result = self._RunBinman('-V')
+        self.assertEqual('Binman %s\n' % version, result.stderr)
+
+        # Set up a version file to make sure that works
+        version = 'v2025.01-rc2'
+        tools.WriteFile(os.path.join(self._indir, 'version'), version,
+                        binary=False)
+        self.assertEqual(version, state.GetVersion(self._indir))
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/tools/binman/state.py b/tools/binman/state.py
index 9e5b8a3..af0a65e 100644
--- a/tools/binman/state.py
+++ b/tools/binman/state.py
@@ -16,6 +16,8 @@
 from patman import tools
 from patman import tout
 
+OUR_PATH = os.path.dirname(os.path.realpath(__file__))
+
 # Map an dtb etype to its expected filename
 DTB_TYPE_FNAME = {
     'u-boot-spl-dtb': 'spl/u-boot-spl.dtb',
@@ -515,3 +517,19 @@
 
     for name, seconds in duration.items():
         print('%10s: %10.1fms' % (name, seconds * 1000))
+
+def GetVersion(path=OUR_PATH):
+    """Get the version string for binman
+
+    Args:
+        path: Path to 'version' file
+
+    Returns:
+        str: String version, e.g. 'v2021.10'
+    """
+    version_fname = os.path.join(path, 'version')
+    if os.path.exists(version_fname):
+        version = tools.ReadFile(version_fname, binary=False)
+    else:
+        version = '(unreleased)'
+    return version