drm/panel: Change dlen from u16 to u8

U8_MAX payload length can meet most requirements

Change-Id: I77e5780bde72b4229ab36d961dc7498f7c78a468
Signed-off-by: WeiYong Bi <bivvy.bi@rock-chips.com>

Author: bivvy

Documentation/devicetree/bindings/display/panel/simple-panel.txt

@@ -24,13 +24,13 @@ Optional properties when compatible is a dsi devices:
 - panel-init-sequence: A byte stream formed by simple multiple dcs packets.
 	byte 0: dcs data type
 	byte 1: wait number of specified ms after dcs command transmitted
-	byte 2, 3: 16 bits length in network byte order
-	byte 4 and beyond: number byte of payload
+	byte 2: packet payload length
+	byte 3 and beyond: number byte of payload
 - panel-exit-sequence: A byte stream formed by simple multiple dcs packets.
 	byte 0: dcs data type
 	byte 1: wait number of specified ms after dcs command transmitted
-	byte 2, 3: 16 bits length in network byte order
-	byte 4 and beyond: number byte of payload
+	byte 2: packet payload length
+	byte 3 and beyond: number byte of payload
 
 Example:
 
@@ -64,16 +64,16 @@ Or:
 		dsi,lanes = <4>;
 
 		panel-init-sequence = [
-			39 00 00 10 b1 6c 15 15 24 E4 11 f1 80 e4
-				    d7 23 80 c0 d2 58
+			39 00 10 b1 6c 15 15 24 E4 11 f1 80 e4
+				 d7 23 80 c0 d2 58
 			...
-			05 78 00 01 11
-			05 00 00 01 29
+			05 78 01 11
+			05 00 01 29
 		];
 
 		panel-exit-sequence = [
-			05 00 00 01 28
-			05 78 00 01 10
+			05 00 01 28
+			05 78 01 10
 		];
 
 		display-timings {

drivers/gpu/drm/panel/panel-simple.c

@@ -41,7 +41,7 @@
 struct dsi_ctrl_hdr {
 	u8 dtype;	/* data type */
 	u8 wait;	/* ms */
-	u16 dlen;	/* payload len */
+	u8 dlen;	/* payload len */
 } __packed;
 
 struct dsi_cmd_desc {
@@ -151,7 +151,6 @@ static int panel_simple_dsi_parse_dcs_cmds(struct device *dev,
 	cnt = 0;
 	while (len > sizeof(*dchdr)) {
 		dchdr = (struct dsi_ctrl_hdr *)bp;
-		dchdr->dlen = ntohs(dchdr->dlen);
 
 		if (dchdr->dlen > len) {
 			dev_err(dev, "%s: error, len=%d", __func__,