common: command: Expose a generic helper to auto-complete sub commands

Some commands have a table of sub-commands. With minor adjustments,
complete_cmdv() is able to provide auto-completion for sub-commands
(it's just about passing the table of commands instead of taking the
global one).
We rename this function into complete_subcmd() and implement
complete_cmdv() as a wrapper around complete_subcmdv().
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: NTom Rini <trini@konsulko.com>

common/command.c

@@ -161,11 +161,11 @@ int var_complete(int argc, char * const argv[], char last_char, int maxv, char *
 
 /*************************************************************************************/
 
-static int complete_cmdv(int argc, char * const argv[], char last_char, int maxv, char *cmdv[])
+int complete_subcmdv(cmd_tbl_t *cmdtp, int count, int argc,
+		     char * const argv[], char last_char,
+		     int maxv, char *cmdv[])
 {
 #ifdef CONFIG_CMDLINE
-	cmd_tbl_t *cmdtp = ll_entry_start(cmd_tbl_t, cmd);
-	const int count = ll_entry_count(cmd_tbl_t, cmd);
 	const cmd_tbl_t *cmdend = cmdtp + count;
 	const char *p;
 	int len, clen;
@@ -193,7 +193,7 @@ static int complete_cmdv(int argc, char * const argv[], char last_char, int maxv
 
 	/* more than one arg or one but the start of the next */
 	if (argc > 1 || last_char == '\0' || isblank(last_char)) {
-		cmdtp = find_cmd(argv[0]);
+		cmdtp = find_cmd_tbl(argv[0], cmdtp, count);
 		if (cmdtp == NULL || cmdtp->complete == NULL) {
 			cmdv[0] = NULL;
 			return 0;
@@ -238,6 +238,18 @@ static int complete_cmdv(int argc, char * const argv[], char last_char, int maxv
 #endif
 }
 
+static int complete_cmdv(int argc, char * const argv[], char last_char,
+			 int maxv, char *cmdv[])
+{
+#ifdef CONFIG_CMDLINE
+	return complete_subcmdv(ll_entry_start(cmd_tbl_t, cmd),
+				ll_entry_count(cmd_tbl_t, cmd), argc, argv,
+				last_char, maxv, cmdv);
+#else
+	return 0;
+#endif
+}
+
 static int make_argv(char *s, int argvsz, char *argv[])
 {
 	int argc = 0;

include/command.h

@@ -54,6 +54,9 @@ int _do_help (cmd_tbl_t *cmd_start, int cmd_items, cmd_tbl_t * cmdtp, int
 	      flag, int argc, char * const argv[]);
 cmd_tbl_t *find_cmd(const char *cmd);
 cmd_tbl_t *find_cmd_tbl (const char *cmd, cmd_tbl_t *table, int table_len);
+int complete_subcmdv(cmd_tbl_t *cmdtp, int count, int argc,
+		     char * const argv[], char last_char, int maxv,
+		     char *cmdv[]);
 
 extern int cmd_usage(const cmd_tbl_t *cmdtp);