From 0747f5816c680502f9b8a314795fd341d0ce6166 Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
Date: Tue, 16 May 2023 10:58:06 +0200
Subject: [PATCH] sys/shell: Add coreclk command to shell_cmd_sys

The coreclk shell command now prints the CPU frequency in Hz, which
can be useful for boards with RC generated CPU frequency (e.g.
RP2040, FE310, or MPS430Fx1xx MCUs allow this) which may quite a bit
off the target frequency.
---
 makefiles/pseudomodules.inc.mk |  1 +
 sys/shell/cmds/Kconfig         |  5 +++++
 sys/shell/cmds/coreclk.c       | 36 ++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 sys/shell/cmds/coreclk.c

diff --git a/makefiles/pseudomodules.inc.mk b/makefiles/pseudomodules.inc.mk
index 639e804fbb..24f3228f02 100644
--- a/makefiles/pseudomodules.inc.mk
+++ b/makefiles/pseudomodules.inc.mk
@@ -448,6 +448,7 @@ PSEUDOMODULES += shell_cmd_benchmark_udp
 PSEUDOMODULES += shell_cmd_ccn-lite-utils
 PSEUDOMODULES += shell_cmd_conn_can
 PSEUDOMODULES += shell_cmd_cord_ep
+PSEUDOMODULES += shell_cmd_coreclk
 PSEUDOMODULES += shell_cmd_cryptoauthlib
 PSEUDOMODULES += shell_cmd_dfplayer
 PSEUDOMODULES += shell_cmd_fib
diff --git a/sys/shell/cmds/Kconfig b/sys/shell/cmds/Kconfig
index e43852bdc4..794bca53d0 100644
--- a/sys/shell/cmds/Kconfig
+++ b/sys/shell/cmds/Kconfig
@@ -308,6 +308,11 @@ config MODULE_SHELL_CMD_SYS
     default y if MODULE_SHELL_CMDS_DEFAULT
     depends on MODULE_SHELL_CMDS
 
+config MODULE_SHELL_CMD_CORECLK
+    bool "Shell command printing the CPU frequency"
+    default n
+    depends on MODULE_SHELL_CMDS
+
 config MODULE_SHELL_CMD_VFS
     bool "Commands for the VFS module (ls, vfs)"
     default y if MODULE_SHELL_CMDS_DEFAULT
diff --git a/sys/shell/cmds/coreclk.c b/sys/shell/cmds/coreclk.c
new file mode 100644
index 0000000000..cc9c563341
--- /dev/null
+++ b/sys/shell/cmds/coreclk.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2023 Otto-von-Guericke Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     sys_shell_commands
+ * @{
+ *
+ * @file
+ * @brief       Shell command printing the CPU frequency
+ *
+ * @author      Marian Buschsieweke <marian.buschsieweke@ovgu.de>
+ *
+ * @}
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "clk.h"
+#include "shell.h"
+
+static int _coreclk(int argc, char **argv)
+{
+    (void)argc;
+    (void)argv;
+    printf("core clock: %" PRIu32 " Hz\n", coreclk());
+    return 0;
+}
+
+SHELL_COMMAND(coreclk, "Print the CPU frequency", _coreclk);