cmd: add serial console support for the cls command

Currently the cls command does not support the serial console

The screen can be cleared in the video uclass, the colored frame buffer
console, and the serial console by sending the same escape sequence.
This reduces the cls command to a single printf() statement on most
boards.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/cmd/cls.c b/cmd/cls.c
index eab4e69..bdeb497 100644 (file)
--- a/cmd/cls.c
+++ b/cmd/cls.c
@@ -11,17 +11,23 @@
 #include <lcd.h>
 #include <video.h>
 
+#define CSI "\x1b["
+
 static int do_video_clear(struct cmd_tbl *cmdtp, int flag, int argc,
                          char *const argv[])
 {
-#if defined(CONFIG_DM_VIDEO)
-       struct udevice *dev;
+       __maybe_unused struct udevice *dev;
 
+       /*  Send clear screen and home */
+       printf(CSI "2J" CSI "1;1H");
+#if defined(CONFIG_DM_VIDEO)
+#if !defined(CONFIG_VIDEO_ANSI)
        if (uclass_first_device_err(UCLASS_VIDEO, &dev))
                return CMD_RET_FAILURE;
 
        if (video_clear(dev))
                return CMD_RET_FAILURE;
+#endif
 #elif defined(CONFIG_CFB_CONSOLE)
        video_clear();
 #elif defined(CONFIG_LCD)