Zephyr: Print more on command errors

When a command fails, notify the user of the failure and print out the
command help.  If the failure was a generic parameter error, then also
print out a readable string for that specific issue.

BRANCH=None
BUG=b:226595697
TEST=on skyrim, run accelrate with no parameters and observe a helpful
error print
22-03-31 10:00:38.085 ec:~$ accelrate
22-03-31 10:00:40.751 Wrong number of parameters
22-03-31 10:00:40.752 Read or write accelerometer ODR
22-03-31 10:00:40.755 Usage: accelrate id [data [roundup]]

Signed-off-by: Diana Z <dzigterman@chromium.org>
Change-Id: Ia490657ef4d8ac2a77590eb5930763f5d23660bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3564078
Reviewed-by: Wai-Hong Tam <waihong@google.com>
Commit-Queue: Wai-Hong Tam <waihong@google.com>

1 files changed, 30 insertions, 5 deletions

diff --git a/zephyr/shim/src/console.c b/zephyr/shim/src/console.c
index fb587e8fbc..1aa29c9d3c 100644
--- a/zephyr/shim/src/console.c
+++ b/zephyr/shim/src/console.c
@@ -185,9 +185,22 @@ void uart_shell_set_priority(int prio)
 	k_thread_priority_set(shell_zephyr->ctx->tid, shell_priority);
 }
 
+#ifdef CONFIG_SHELL_HELP
+static void print_console_help(char *name,
+			       const struct zephyr_console_command *command)
+{
+	if (command->help)
+		printk("%s\n", command->help);
+	if (command->argdesc)
+		printk("Usage: %s %s\n", name, command->argdesc);
+}
+#endif
+
 int zshim_run_ec_console_command(const struct zephyr_console_command *command,
 				 size_t argc, char **argv)
 {
+	int ret;
+
 	/*
 	 * The Zephyr shell only displays the help string and not
 	 * the argument descriptor when passing "-h" or "--help".  Mimic the
@@ -198,16 +211,28 @@ int zshim_run_ec_console_command(const struct zephyr_console_command *command,
 		if (!command->help && !command->argdesc)
 			break;
 		if (!strcmp(argv[i], "help")) {
-			if (command->help)
-				printk("%s\n", command->help);
-			if (command->argdesc)
-				printk("Usage: %s\n", command->argdesc);
+			print_console_help(argv[0], command);
 			return 0;
 		}
 	}
 #endif
 
-	return command->handler(argc, argv);
+	ret = command->handler(argc, argv);
+	if (ret == EC_SUCCESS)
+		return ret;
+
+	/* Print common parameter error conditions and help on error */
+	if (ret >= EC_ERROR_PARAM1 && ret < EC_ERROR_PARAM_COUNT)
+		printk("Parameter %d invalid\n", ret - EC_ERROR_PARAM1 + 1);
+	else if (ret == EC_ERROR_PARAM_COUNT)
+		printk("Wrong number of parameters\n");
+	else
+		printk("Command returned error: %d\n", ret);
+
+#ifdef CONFIG_SHELL_HELP
+	print_console_help(argv[0], command);
+#endif
+	return ret;
 }
 
 #if defined(CONFIG_CONSOLE_CHANNEL) && DT_NODE_EXISTS(DT_PATH(ec_console))