diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index 0cc35da52..ca5bfff04 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -1358,7 +1358,7 @@ static int32_t ch341_set_baudrate (cdch_interface_t* p_cdc, uint32_t baud_rate,
    * inverted.
    */
   if ( p_cdc->ch34x.version > 0x27 ) {
-    val = (val | BIT(7));
+    val = (val | TU_BIT(7));
   }
 
   return ch341_write_reg ( p_cdc, CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER, val, complete_cb, user_data );
diff --git a/src/class/cdc/serial/ch34x.h b/src/class/cdc/serial/ch34x.h
index 94e18b252..4a5e61bbd 100644
--- a/src/class/cdc/serial/ch34x.h
+++ b/src/class/cdc/serial/ch34x.h
@@ -29,7 +29,7 @@
 
 #include <stdint.h>
 
-#define BIT(nr) ( (uint32_t)1 << (nr) )
+//#define BIT(nr) ( (uint32_t)1 << (nr) )
 
 #define CH34X_BUFFER_SIZE 2
 
@@ -93,20 +93,17 @@
 #define CH341_LCR_CS6          0x01
 #define CH341_LCR_CS5          0x00
 
-#define CH341_QUIRK_LIMITED_PRESCALER BIT(0)
-#define CH341_QUIRK_SIMULATE_BREAK  BIT(1)
+#define CH341_QUIRK_LIMITED_PRESCALER TU_BIT(0)
+#define CH341_QUIRK_SIMULATE_BREAK  TU_BIT(1)
 
 #define CH341_CLKRATE   48000000
 #define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact)))
 #define CH341_MIN_RATE(ps)  (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512))
 
 /* Supported range is 46 to 3000000 bps. */
-#define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
+#define CH341_MIN_BPS TU_DIV_CEIL(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
 #define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2))
 
-#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
-#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
-
 // error codes
 #define EINVAL    22  /* Invalid argument */
 
diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h
index caeb5f2ef..1f08ce4ed 100644
--- a/src/common/tusb_common.h
+++ b/src/common/tusb_common.h
@@ -37,6 +37,7 @@
 #define TU_ARRAY_SIZE(_arr)   ( sizeof(_arr) / sizeof(_arr[0]) )
 #define TU_MIN(_x, _y)        ( ( (_x) < (_y) ) ? (_x) : (_y) )
 #define TU_MAX(_x, _y)        ( ( (_x) > (_y) ) ? (_x) : (_y) )
+#define TU_DIV_CEIL(n, d)     (((n) + (d) - 1) / (d))
 
 #define TU_U16(_high, _low)   ((uint16_t) (((_high) << 8) | (_low)))
 #define TU_U16_HIGH(_u16)     ((uint8_t) (((_u16) >> 8) & 0x00ff))