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 ;
+}