tools: env: allow to print U-Boot version

The fw_env utility family has a default environment compiled in
which ties it quite strongly to the U-Boot source/config it has
been built with. Allow to display the U-Boot version it has been
built with using the -v/--version argument.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
diff --git a/tools/env/fw_env_main.c b/tools/env/fw_env_main.c
index 6e278ca..0b90637 100644
--- a/tools/env/fw_env_main.c
+++ b/tools/env/fw_env_main.c
@@ -34,6 +34,7 @@
 #include <stdlib.h>
 #include <sys/file.h>
 #include <unistd.h>
+#include <version.h>
 #include "fw_env_private.h"
 #include "fw_env.h"
 
@@ -48,6 +49,7 @@
 	{"script", required_argument, NULL, 's'},
 	{"noheader", required_argument, NULL, 'n'},
 	{"lock", required_argument, NULL, 'l'},
+	{"version", no_argument, NULL, 'v'},
 	{NULL, 0, NULL, 0}
 };
 
@@ -67,6 +69,7 @@
 		"Print variables from U-Boot environment\n"
 		"\n"
 		" -h, --help           print this help.\n"
+		" -v, --version        display version\n"
 #ifdef CONFIG_ENV_AES
 		" -a, --aes            aes key to access environment\n"
 #endif
@@ -85,6 +88,7 @@
 		"Modify variables in U-Boot environment\n"
 		"\n"
 		" -h, --help           print this help.\n"
+		" -v, --version        display version\n"
 #ifdef CONFIG_ENV_AES
 		" -a, --aes            aes key to access environment\n"
 #endif
@@ -123,7 +127,7 @@
 	env_opts.config_file = CONFIG_FILE;
 #endif
 
-	while ((c = getopt_long(argc, argv, ":a:c:l:h", long_options, NULL)) !=
+	while ((c = getopt_long(argc, argv, ":a:c:l:h:v", long_options, NULL)) !=
 	       EOF) {
 		switch (c) {
 		case 'a':
@@ -145,6 +149,10 @@
 			do_printenv ? usage_printenv() : usage_env_set();
 			exit(EXIT_SUCCESS);
 			break;
+		case 'v':
+			fprintf(stderr, "Compiled with " U_BOOT_VERSION "\n");
+			exit(EXIT_SUCCESS);
+			break;
 		default:
 			/* ignore unknown options */
 			break;
@@ -162,7 +170,7 @@
 
 	parse_common_args(argc, argv);
 
-	while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
+	while ((c = getopt_long(argc, argv, "a:c:ns:l:h:v", long_options, NULL))
 		!= EOF) {
 		switch (c) {
 		case 'n':
@@ -189,7 +197,7 @@
 
 	parse_common_args(argc, argv);
 
-	while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
+	while ((c = getopt_long(argc, argv, "a:c:ns:l:h:v", long_options, NULL))
 		!= EOF) {
 		switch (c) {
 		case 's':