Fix error in calculating baud rate generation value

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1524 42af7a65-404d-4744-a932-0658087f49c3

arch/z80/src/ez80/Make.defs

@@ -50,7 +50,7 @@ CHIP_ASRCS	+= ez80f91_init.asm
 endif
 
 CHIP_SSRCS	= 
-CHIP_CSRCS	= ez80_initialstate.c ez80_irq.c ez80_copystate.c \
+CHIP_CSRCS	= ez80_clock.c ez80_initialstate.c ez80_irq.c ez80_copystate.c \
 		  ez80_schedulesigaction.c ez80_sigdeliver.c ez80_timerisr.c \
 		  ez80_lowuart.c ez80_serial.c ez80_registerdump.c
 ifeq ($(CONFIG_ARCH_CHIP_EZ80F91),y)

arch/z80/src/ez80/chip.h

@@ -67,7 +67,7 @@
 #endif
 
 /************************************************************************************
- * Public Function Prototypes
+ * Public Data
  ************************************************************************************/
 
 #ifndef __ASSEMBLY__
@@ -78,7 +78,13 @@ extern "C" {
 #define EXTERN extern
 #endif
 
-#undef EXTERN
+EXTERN uint32 ez80_systemclock;
+
+/************************************************************************************
+ * Public Function Prototypes
+ ************************************************************************************/
+
+ #undef EXTERN
 #ifdef __cplusplus
 }
 #endif

arch/z80/src/ez80/ez80_clock.c

@@ -0,0 +1,65 @@
+/****************************************************************************
+ * arch/z80/src/ez80/ez80_clock.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include "arch/board/board.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+uint32 ez80_systemclock = EZ80_SYS_CLK_FREQ;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/

arch/z80/src/ez80/ez80_lowuart.c

@@ -57,9 +57,6 @@
 
 /* The system clock frequency is defined in the linkcmd file */
 
-extern unsigned long SYS_CLK_FREQ;
-#define _DEFCLK ((unsigned long)&SYS_CLK_FREQ)
-
 #ifdef CONFIG_UART0_SERIAL_CONSOLE
 #  define ez80_inp(offs)     inp((EZ80_UART0_BASE+(offs)))
 #  define ez80_outp(offs,val) outp((EZ80_UART0_BASE+(offs)), (val))
@@ -115,7 +112,7 @@ extern unsigned long SYS_CLK_FREQ;
 #ifndef CONFIG_SUPPRESS_UART_CONFIG
 static void ez80_setbaud(void)
 {
-  uint24 brg_divisor;
+  uint32 brg_divisor;
   ubyte lctl;
 
   /* The resulting BAUD and depends on the system clock frequency and the
@@ -128,7 +125,7 @@ static void ez80_setbaud(void)
    * BRG_Divisor = SYSTEM_CLOCK_FREQUENCY / 16 / BAUD
    */
 
-   brg_divisor = ( _DEFCLK + (CONFIG_UART_BAUD << 3)) / (CONFIG_UART_BAUD << 4);
+   brg_divisor = (ez80_systemclock + (CONFIG_UART_BAUD << 3)) / (CONFIG_UART_BAUD << 4);
 
    /* Set the DLAB bit to enable access to the BRG registers */
 

arch/z80/src/ez80/ez80_serial.c

@@ -62,11 +62,6 @@
  * Definitions
  ****************************************************************************/
 
-/* The system clock frequency is defined in the linkcmd file */
-
-extern unsigned long SYS_CLK_FREQ;
-#define _DEFCLK ((unsigned long)&SYS_CLK_FREQ)
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -291,7 +286,7 @@ static inline void ez80_waittxready(struct ez80_dev_s *priv)
 
 static inline void ez80_setbaud(struct ez80_dev_s *priv, uint24 baud)
 {
-  uint24 brg_divisor;
+  uint32 brg_divisor;
   ubyte lctl;
 
   /* The resulting BAUD and depends on the system clock frequency and the
@@ -304,7 +299,7 @@ static inline void ez80_setbaud(struct ez80_dev_s *priv, uint24 baud)
    * BRG_Divisor = SYSTEM_CLOCK_FREQUENCY / 16 / BAUD
    */
 
-   brg_divisor = ( _DEFCLK + (baud << 3)) / (baud << 4);
+   brg_divisor = (ez80_systemclock + (baud << 3)) / (baud << 4);
 
    /* Set the DLAB bit to enable access to the BRG registers */
 

configs/ez80f910200zco/include/board.h

@@ -44,6 +44,10 @@
  * Definitions
  ****************************************************************************/
 
+/* Clocking */
+
+#define EZ80_SYS_CLK_FREQ           50000000
+
 /* LED pattern definitions                 ON                OFF            */
 
 #define LED_STARTED                 0  /*  '0'               N/A            */