1 files changed, 19 insertions, 1 deletions
diff --git a/include/hw/char/imx_serial.h b/include/hw/char/imx_serial.h
index b823f94519..65f0e97c76 100644
--- a/include/hw/char/imx_serial.h
+++ b/include/hw/char/imx_serial.h
@@ -21,12 +21,16 @@
 #include "hw/sysbus.h"
 #include "chardev/char-fe.h"
 #include "qom/object.h"
+#include "qemu/fifo32.h"
 
 #define TYPE_IMX_SERIAL "imx.serial"
 OBJECT_DECLARE_SIMPLE_TYPE(IMXSerialState, IMX_SERIAL)
 
+#define FIFO_SIZE       32
+
 #define URXD_CHARRDY    (1<<15)   /* character read is valid */
 #define URXD_ERR        (1<<14)   /* Character has error */
+#define URXD_OVRRUN     (1<<13)   /* 32nd character in RX FIFO */
 #define URXD_FRMERR     (1<<12)   /* Character has frame error */
 #define URXD_BRK        (1<<11)   /* Break received */
 
@@ -65,11 +69,13 @@ OBJECT_DECLARE_SIMPLE_TYPE(IMXSerialState, IMX_SERIAL)
 #define UCR1_TXMPTYEN   (1<<6)    /* Tx Empty Interrupt Enable */
 #define UCR1_UARTEN     (1<<0)    /* UART Enable */
 
+#define UCR2_ATEN       (1<<3)    /* Ageing Timer Enable */
 #define UCR2_TXEN       (1<<2)    /* Transmitter enable */
 #define UCR2_RXEN       (1<<1)    /* Receiver enable */
 #define UCR2_SRST       (1<<0)    /* Reset complete */
 
 #define UCR4_DREN       BIT(0)    /* Receive Data Ready interrupt enable */
+#define UCR4_OREN       BIT(1)    /* Overrun interrupt enable */
 #define UCR4_TCEN       BIT(3)    /* TX complete interrupt enable */
 #define UCR4_WKEN       BIT(7)    /* WAKE interrupt enable */
 
@@ -78,13 +84,25 @@ OBJECT_DECLARE_SIMPLE_TYPE(IMXSerialState, IMX_SERIAL)
 #define UTS1_TXFULL     (1<<4)
 #define UTS1_RXFULL     (1<<3)
 
+#define TL_MASK         0x3f
+
+ /* Bit time in nanoseconds assuming maximum baud rate of 115200 */
+#define BIT_TIME_NS     8681
+
+/* Assume 8 bits per character */
+#define NUM_BITS        8
+
+/* Ageing timer triggers after 8 characters */
+#define AGE_DURATION_NS (8 * NUM_BITS * BIT_TIME_NS)
+
 struct IMXSerialState {
     /*< private >*/
     SysBusDevice parent_obj;
 
     /*< public >*/
     MemoryRegion iomem;
-    int32_t readbuff;
+    QEMUTimer ageing_timer;
+    Fifo32 rx_fifo;
 
     uint32_t usr1;
     uint32_t usr2;