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>

2 files changed, 18 insertions, 1 deletions

diff --git a/include/cedit.h b/include/cedit.h
index fe10e6c829c..2970965b5f6 100644
--- a/include/cedit.h
+++ b/include/cedit.h
@@ -97,4 +97,17 @@ int cedit_write_settings_env(struct expo *exp, bool verbose);
  */
 int cedit_read_settings_env(struct expo *exp, bool verbose);
 
+/**
+ * cedit_write_settings_cmos() - Write settings to CMOS RAM
+ *
+ * Write settings to the defined places in CMOS RAM
+ *
+ * @exp: Expo to write settings from
+ * @dev: UCLASS_RTC device containing space for this information
+ * Returns 0 if OK, -ve on error
+ * @verbose: true to print a summary at the end
+ */
+int cedit_write_settings_cmos(struct expo *exp, struct udevice *dev,
+			      bool verbose);
+
 #endif /* __CEDIT_H */
diff --git a/include/expo.h b/include/expo.h
index da151074d20..a2b3a71c159 100644
--- a/include/expo.h
+++ b/include/expo.h
@@ -187,6 +187,8 @@ enum scene_obj_flags_t {
  * @type: Type of this object
  * @dim: Dimensions for this object
  * @flags: Flags for this object
+ * @bit_length: Number of bits used for this object in CMOS RAM
+ * @start_bit: Start bit to use for this object in CMOS RAM
  * @sibling: Node to link this object to its siblings
  */
 struct scene_obj {
@@ -195,7 +197,9 @@ struct scene_obj {
 	uint id;
 	enum scene_obj_t type;
 	struct scene_dim dim;
-	int flags;
+	u8 flags;
+	u8 bit_length;
+	u16 start_bit;
 	struct list_head sibling;
 };