expo: cedit: Support writing settings to CMOS RAM

Add a command to write cedit settings to CMOS RAM so that it can be
preserved across a reboot. This uses a simple bit-encoding, where each
field has a 'bit position' and a 'bit length' in the schema.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/cmd/cedit.c b/cmd/cedit.c
index b2548f44b57..95d5c22c2f7 100644
--- a/cmd/cedit.c
+++ b/cmd/cedit.c
@@ -10,6 +10,7 @@
 #include <abuf.h>
 #include <cedit.h>
 #include <command.h>
+#include <dm.h>
 #include <expo.h>
 #include <fs.h>
 #include <malloc.h>
@@ -176,6 +177,39 @@ static int do_cedit_read_env(struct cmd_tbl *cmdtp, int flag, int argc,
 	return 0;
 }
 
+static int do_cedit_write_cmos(struct cmd_tbl *cmdtp, int flag, int argc,
+			       char *const argv[])
+{
+	struct udevice *dev;
+	bool verbose = false;
+	int ret;
+
+	if (check_cur_expo())
+		return CMD_RET_FAILURE;
+
+	if (argc > 1 && !strcmp(argv[1], "-v")) {
+		verbose = true;
+		argc--;
+		argv++;
+	}
+
+	if (argc > 1)
+		ret = uclass_get_device_by_name(UCLASS_RTC, argv[1], &dev);
+	else
+		ret = uclass_first_device_err(UCLASS_RTC, &dev);
+	if (ret) {
+		printf("Failed to get RTC device: %dE\n", ret);
+		return CMD_RET_FAILURE;
+	}
+
+	if (cedit_write_settings_cmos(cur_exp, dev, verbose)) {
+		printf("Failed to write settings to CMOS\n");
+		return CMD_RET_FAILURE;
+	}
+
+	return 0;
+}
+
 static int do_cedit_run(struct cmd_tbl *cmdtp, int flag, int argc,
 			char *const argv[])
 {
@@ -209,6 +243,7 @@ static char cedit_help_text[] =
 	"cedit write_fdt <i/f> <dev[:part]> <filename>    - write settings\n"
 	"cedit read_env [-v]                              - read settings from env vars\n"
 	"cedit write_env [-v]                             - write settings to env vars\n"
+	"cedit write_cmos [-v] [dev]                      - write settings to CMOS RAM\n"
 	"cedit run                                        - run config editor";
 #endif /* CONFIG_SYS_LONGHELP */
 
@@ -218,5 +253,6 @@ U_BOOT_CMD_WITH_SUBCMDS(cedit, "Configuration editor", cedit_help_text,
 	U_BOOT_SUBCMD_MKENT(write_fdt, 5, 1, do_cedit_write_fdt),
 	U_BOOT_SUBCMD_MKENT(read_env, 2, 1, do_cedit_read_env),
 	U_BOOT_SUBCMD_MKENT(write_env, 2, 1, do_cedit_write_env),
+	U_BOOT_SUBCMD_MKENT(write_cmos, 2, 1, do_cedit_write_cmos),
 	U_BOOT_SUBCMD_MKENT(run, 1, 1, do_cedit_run),
 );