configs: MPC8548CDS: enable DM_I2C

[oweals/u-boot.git] / doc / README.commands

diff --git a/doc/README.commands b/doc/README.commands
index 1d29c4d91dddf9b1552f8b8f26aa5596a94f9077..4e9e8098fa81a8090fac38c0391815c5b6bfaa1f 100644 (file)
--- a/doc/README.commands
+++ b/doc/README.commands
@@ -28,10 +28,46 @@ comp:               Pointer to the completion function. May be NULL.
                entering the command arguments to complete the entry. Command
                completion is only available if CONFIG_AUTO_COMPLETE is defined.
 
+Sub-command definition
+----------------------
+
+Likewise an array of cmd_tbl_t holding sub-commands can be created using either
+of the following macros:
+
+* U_BOOT_CMD_MKENT(name, maxargs, repeatable, command, "usage", "help")
+* U_BOOT_CMD_MKENTCOMPLETE(name, maxargs, repeatable, command, "usage, "help",
+  comp)
+
+This table has to be evaluated in the command function of the main command, e.g.
+
+    static cmd_tbl_t cmd_sub[] = {
+        U_BOOT_CMD_MKENT(foo, CONFIG_SYS_MAXARGS, 1, do_foo, "", ""),
+        U_BOOT_CMD_MKENT(bar, CONFIG_SYS_MAXARGS, 1, do_bar, "", ""),
+    };
+
+    static int do_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+    {
+        cmd_tbl_t *cp;
+
+        if (argc < 2)
+                return CMD_RET_USAGE;
+
+        /* drop sub-command argument */
+        argc--;
+        argv++;
+
+        cp = find_cmd_tbl(argv[0], cmd_ut_sub, ARRAY_SIZE(cmd_sub));
+
+        if (cp)
+            return cp->cmd(cmdtp, flag, argc, argv);
+
+        return CMD_RET_USAGE;
+    }
+
 Command function
 ----------------
 
-The commmand function pointer has to be of type
+The command function pointer has to be of type
 int (*cmd)(struct cmd_tbl_s *cmdtp, int flag, int argc, const char *argv[]);
 
 cmdtp:         Table entry describing the command (see above).
@@ -47,9 +83,9 @@ argv:         Arguments.
 
 Allowable return value are:
 
-CMD_SUCCESS    The command was successfully executed.
+CMD_RET_SUCCESS        The command was successfully executed.
 
-CMD_FAILURE    The command failed.
+CMD_RET_FAILURE        The command failed.
 
 CMD_RET_USAGE  The command was called with invalid parameters. This value
                leads to the display of the usage string.