bdinfo: Show information about the serial port

It is useful to see the detailed setting of the serial port, e.g. to
allow setting up earlycon or console for Linux. Add this output to the
'bdinfo' command.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: squashed in 20230716033929.253357-2-sjg@chromium.org]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/cmd/bdinfo.c b/cmd/bdinfo.c
index 365357c..dab73f1 100644
--- a/cmd/bdinfo.c
+++ b/cmd/bdinfo.c
@@ -13,6 +13,7 @@
 #include <lmb.h>
 #include <mapmem.h>
 #include <net.h>
+#include <serial.h>
 #include <video.h>
 #include <vsprintf.h>
 #include <asm/cache.h>
@@ -113,6 +114,25 @@
 	}
 }
 
+static void print_serial(struct udevice *dev)
+{
+	struct serial_device_info info;
+	int ret;
+
+	if (!dev || !IS_ENABLED(CONFIG_DM_SERIAL))
+		return;
+
+	ret = serial_getinfo(dev, &info);
+	if (ret)
+		return;
+
+	bdinfo_print_num_l("serial addr", info.addr);
+	bdinfo_print_num_l(" width", info.reg_width);
+	bdinfo_print_num_l(" shift", info.reg_shift);
+	bdinfo_print_num_l(" offset", info.reg_offset);
+	bdinfo_print_num_l(" clock", info.clock);
+}
+
 int do_bdinfo(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	struct bd_info *bd = gd->bd;
@@ -151,6 +171,7 @@
 		if (IS_ENABLED(CONFIG_OF_REAL))
 			printf("devicetree  = %s\n", fdtdec_get_srcname());
 	}
+	print_serial(gd->cur_serial_dev);
 
 	arch_print_bdinfo();