drivers: display: ssd16xx: performance improvement

The driver writes the scan entry mode to the display controller on each
set_window call. Multiple calls to set_window can be needed to update
a single frame buffer in the controller.

There's a performance improvement by only setting the scan mode when
the orientation is changed (set_orientation, see previous commit)
and when the profile has changed.
For the latter the scan_mode is lost on the controller
due to a software reset.

Signed-off-by: Sven Depoorter <[email protected]>

Author: Snevzor

drivers/display/ssd16xx.c

@@ -453,12 +453,6 @@ static int ssd16xx_set_window(const struct device *dev,
 		return -EINVAL;
 	}
 
-	err = ssd16xx_write_cmd(dev, SSD16XX_CMD_ENTRY_MODE,
-				&data->scan_mode, sizeof(data->scan_mode));
-	if (err < 0) {
-		return err;
-	}
-
 	err = ssd16xx_set_ram_param(dev, x_start, x_end, y_start, y_end);
 	if (err < 0) {
 		return err;
@@ -895,6 +889,11 @@ static int ssd16xx_set_profile(const struct device *dev,
 		}
 	}
 
+	err = ssd16xx_write_uint8(dev, SSD16XX_CMD_ENTRY_MODE, data->scan_mode);
+	if (err < 0) {
+		return err;
+	}
+
 	data->profile = type;
 
 	return 0;