--- zzzz-none-000/linux-3.10.107/drivers/input/joystick/zhenhua.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/input/joystick/zhenhua.c	2021-02-04 17:41:59.000000000 +0000
@@ -47,9 +47,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/bitrev.h>
 #include <linux/input.h>
 #include <linux/serio.h>
-#include <linux/init.h>
 
 #define DRIVER_DESC	"RC transmitter with 5-byte Zhen Hua protocol joystick driver"
 
@@ -73,16 +73,6 @@
 	char phys[32];
 };
 
-
-/* bits in all incoming bytes needs to be "reversed" */
-static int zhenhua_bitreverse(int x)
-{
-	x = ((x & 0xaa) >> 1) | ((x & 0x55) << 1);
-	x = ((x & 0xcc) >> 2) | ((x & 0x33) << 2);
-	x = ((x & 0xf0) >> 4) | ((x & 0x0f) << 4);
-	return x;
-}
-
 /*
  * zhenhua_process_packet() decodes packets the driver receives from the
  * RC transmitter. It updates the data accordingly.
@@ -121,7 +111,7 @@
 		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */
 
 	if (zhenhua->idx < ZHENHUA_MAX_LENGTH)
-		zhenhua->data[zhenhua->idx++] = zhenhua_bitreverse(data);
+		zhenhua->data[zhenhua->idx++] = bitrev8(data);
 
 	if (zhenhua->idx == ZHENHUA_MAX_LENGTH) {
 		zhenhua_process_packet(zhenhua);