New files from Ralf Corsepius <corsepiu@faw.uni-ulm.de>. His comments:

    * c/src/exec/score/tools/sh - NEW DIRECTORY - contains shgen
    Most of it should be self-explanatory. I am a little bit concerned about
    host-dependent features (getopt, floating point libraries). This
    shouldn't disturb much now, as this tool should be compileable on all
    gnu-based hosts and is only applicable for the sh. But in case somebody
    complains, we may need to add autoconf checks or even restructurize
    parts of rtems (IMO, rtems needs to be restructurized - remember the
    "turning rtems upside down" issue).

1 files changed, 157 insertions, 0 deletions

diff --git a/tools/cpu/sh/sci.c b/tools/cpu/sh/sci.c
new file mode 100644
index 0000000000..58be0e68bf
--- /dev/null
+++ b/tools/cpu/sh/sci.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (c) 1998 Ralf Corsepius (corsepiu@faw.uni-ulm.de)
+ *
+ * See the file COPYING for copyright notice.
+ */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "sci.h"
+
+/*
+   n .. baudrate generator source 0,1,2,3
+   
+   N .. BRR setting (0..255)
+   
+   Phi .. processor baud rate
+   
+   B .. bitrate
+ */
+
+typedef struct sci_tab {
+  unsigned int  B ;
+  unsigned int  n ;
+  int 		N ;
+  double        err ;
+  } sci_tab_t ;
+
+static unsigned int bitrate [] = {
+  50,
+  75,
+  110,
+  134,
+  150,
+  200,
+  300,
+  600,
+  1200,
+  1800,
+  2400,
+  4800,
+  9600,
+  19200,
+  38400,
+  57600,
+  115200,
+  230400,
+  460800
+};
+
+static sci_tab_t test_array[4] ;
+
+static void Compute( 
+  unsigned int n, 
+  unsigned int B, 
+  unsigned int Phi,
+  struct sci_tab *entry )
+{
+  int    a = ( 32 << ( 2 * n ) ) * B ;
+  
+  entry->n = n ;
+  entry->B = B ;
+  entry->N = rint( ( Phi / a ) - 1.0 ) ;
+
+  if ( ( entry->N > 0 ) && ( entry->N < 256 ) ) 
+    entry->err = 
+      ( ( Phi / ( (entry->N + 1) * a ) - 1.0 ) * 100.0 );
+  else
+    entry->err = 100.0 ;
+}
+
+static sci_tab_t *SelectN( 
+  unsigned int 	B,
+  double 	Phi )
+{
+  unsigned int i ;
+  struct sci_tab* best = NULL ;
+    
+  for ( i = 0 ; i < 4 ; i++ )
+  { 
+    double err ;
+    
+    Compute( i, B, Phi, &test_array[i] );
+    err = fabs( test_array[i].err );
+
+    if ( best )
+    {
+      if ( err < fabs( best->err ) )
+        best = &test_array[i] ;
+    }
+    else
+      best = &test_array[i] ;
+  }
+
+  return best ; 
+}
+
+int shgen_gensci(
+  FILE		*file,
+  double	Phi ) /* Processor frequency [Hz] */
+{
+  unsigned int i ;
+
+  fprintf( file, 
+    "/*\n * Bitrate table for the serial devices (sci) of the SH at %.3f MHz\n"
+    " */\n\n", Phi / 1000000.0 );
+  fprintf( file,
+    "/*\n"
+    " * n     .. SMR bits 0,1 : baud rate generator clock source\n"
+    " * N     .. BRR bits 0..7: setting for baud rate generator\n"
+    " * error .. percentual error to nominal bitrate\n"
+    " *   Hitachi's HW manual recommends bitrates with an error less than 1%%\n"
+    " *   We experienced values less than 2%% to be stable\n"
+    " */\n\n" );
+  fprintf( file, "#include <termios.h>\n\n" );
+  fprintf( file, 
+    "static struct sci_bitrate_t {\n"
+    "  unsigned char n ;\n"
+    "  unsigned char N ;\n"
+    "} _sci_bitrates[] = {\n"
+    "/*  n    N      error */\n" );
+  
+  for ( i = 0 ; i < sizeof(bitrate)/sizeof(int) ; i++ )
+  {
+    struct sci_tab* best = SelectN( bitrate[i], Phi );
+
+    if ( i > 0 )
+      fprintf( file, ",\n" );
+    fprintf( file, "  { %1d, %3d } /* %+7.2f%% ; B%d */",
+      best->n,
+      best->N,
+      best->err,
+      best->B );
+  }
+
+  fprintf( file, "\n};\n\n" );
+
+  fprintf( file, 
+    "int _sci_get_brparms( \n"
+    "  tcflag_t      cflag,\n"
+    "  unsigned char *smr,\n"
+    "  unsigned char *brr )\n"
+    "{\n"
+    "  unsigned int offset ;\n\n"
+    "  offset = ( cflag & ( CBAUD & ~CBAUDEX ) )\n"
+    "    + ( ( cflag & CBAUDEX ) ? B38400 : 0 );\n"
+    "  if ( offset == 0 ) return -1 ;\n"
+    "  offset-- ;\n\n"
+    "  *smr &= ~0x03;\n"
+    "  *smr |= _sci_bitrates[offset].n;\n"
+    "  *brr =  _sci_bitrates[offset].N;\n\n"
+    "  return 0;\n"
+    "}\n" );
+    
+  return 0 ;
+}