Patch from "John M. Mills" <jmills@tga.com> with subsequent cleanup from

Ralf Corsepius <corsepiu@faw.uni-ulm.de> that adds initial Hitachi SH-2
support to RTEMS.  Ralf's comments are:

    Changes:
    ------
    1. SH-Port:
    * Many files renamed.
    * CONSOLE_DEVNAME  and MHZ defines removed from libcpu.
    * console.c moved to libbsp/sh/shared, build in libbsp/sh/<BSP>/console
      applying VPATH.
    * CONSOLE_DEVNAME made BSP-specific, replacement is defined in bsp.h
    * MHZ define replaced with HZ (extendent resolution) in custom/*.cfg
    * -DHZ=HZ  used in bspstart.c, only
    * Makefile variable HZ used in bsp-dependent directories only.

    2. SH1-Port
    * clock-driver rewritten to provide better resolution for odd CPU
      frequencies. This driver is only partially tested on hardware, ie.
      sightly experimental, but I don't expect severe problems with it.
    * Polling SCI-driver added. This driver is experimental and completly
      untested yet. Therefore it is not yet used for the console (/dev/console
      is still pointing to /dev/null, cf. gensh1/bsp.h).
    * minor changes to the timer driver
    * SH1 specific delay()/CPU_delay() now is implemented as a function

    3. SH2-Port
    * Merged
    * IMO, the code is still in its infancy. Therefore I have interspersed
      comments (FIXME) it for items which I think John should look after.
    * sci and console drivers partially rewritten and extended (John, I hope
      you don't mind).
    * Copyright notices are not yet adapted

1 files changed, 208 insertions, 0 deletions

diff --git a/c/src/lib/libcpu/sh/sh7045/timer/timer.c b/c/src/lib/libcpu/sh/sh7045/timer/timer.c
new file mode 100644
index 0000000000..029c0bec94
--- /dev/null
+++ b/c/src/lib/libcpu/sh/sh7045/timer/timer.c
@@ -0,0 +1,208 @@
+/*
+ *  timer for the Hitachi SH 704X 
+ *
+ *  This file manages the benchmark timer used by the RTEMS Timing Test
+ *  Suite.  Each measured time period is demarcated by calls to
+ *  Timer_initialize() and Read_timer().  Read_timer() usually returns
+ *  the number of microseconds since Timer_initialize() exitted.
+ *
+ *  NOTE: It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and
+ *           Bernd Becker (becker@faw.uni-ulm.de)
+ *
+ *  COPYRIGHT (c) 1997-1998, FAW Ulm, Germany
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ *  COPYRIGHT (c) 1998.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+
+#include <rtems/score/sh_io.h>
+#include <rtems/score/iosh7045.h>
+
+/*
+ *  We use a Phi/4 timer
+ */
+#define SCALE (Timer_MHZ/4)
+
+#define MTU1_STARTMASK 	0xfd
+#define MTU1_SYNCMASK 	0xfd
+#define MTU1_MODEMASK 	0xc0
+#define MTU1_TCRMASK 	0x01
+#define MTU1_TIORMASK 	0x88
+#define MTU1_STAT_MASK 	0xf8
+#define MTU1_TIERMASK 	0xfc
+#define IPRC_MTU1_MASK	0xfff0
+
+#ifndef MTU1_PRIO
+#define MTU1_PRIO 15
+#endif
+
+#define MTU1_VECTOR 86
+
+rtems_isr timerisr();
+
+static rtems_unsigned32 Timer_interrupts;
+
+rtems_boolean Timer_driver_Find_average_overhead;
+
+static rtems_unsigned32 Timer_MHZ ;
+
+void Timer_initialize( void )
+{
+  rtems_unsigned8  temp8;
+  rtems_unsigned16 temp16;
+  rtems_unsigned32 level;
+  rtems_isr	   *ignored;
+
+  Timer_MHZ = rtems_cpu_configuration_get_clicks_per_second() / 1000000 ;
+  
+  /*
+   *  Timer has never overflowed.  This may not be necessary on some
+   *  implemenations of timer but ....
+   */
+
+  Timer_interrupts /* .i */ = 0;
+  _CPU_ISR_Disable( level);
+
+  /*
+   *  Somehow start the timer
+   */
+  /* stop Timer 1  */
+  temp8 = read8( MTU_TSTR) & MTU1_STARTMASK;
+  write8( temp8, MTU_TSTR);
+
+  /* initialize counter 1 */
+  write16( 0, MTU_TCNT1);
+
+  /* Timer 1 is independent of other timers */
+  temp8 = read8( MTU_TSYR) & MTU1_SYNCMASK;
+  write8( temp8, MTU_TSYR);
+
+  /* Timer 1, normal mode */
+  temp8 = read8( MTU_TMDR1) & MTU1_MODEMASK;
+  write8( temp8, MTU_TMDR1);
+
+  /* x0000000
+   * |||||+++--- Internal Clock
+   * |||++------ Count on rising edge
+   * |++-------- disable TCNT clear
+   * +---------- don`t care
+   */
+  write8( MTU1_TCRMASK, MTU_TCR1);
+
+  /* gra and grb are not used */
+  write8( MTU1_TIORMASK, MTU_TIOR1);
+
+  /* reset all status flags */
+  temp8 = read8( MTU_TSR1) & MTU1_STAT_MASK;
+  write8( temp8, MTU_TSR1);
+
+  /* enable overflow interrupt */
+  write8( MTU1_TIERMASK, MTU_TIER1);
+
+  /* set interrupt priority */
+  temp16 = read16( INTC_IPRC) & IPRC_MTU1_MASK;
+  temp16 |= MTU1_PRIO;
+  write16( temp16, INTC_IPRC);
+
+  /* initialize ISR */
+  _CPU_ISR_install_raw_handler( MTU1_VECTOR, timerisr, &ignored );
+  _CPU_ISR_Enable( level);
+
+  /* start timer 1 */
+  temp8 = read8( MTU_TSTR) | ~MTU1_STARTMASK;
+  write8( temp8, MTU_TSTR);
+}
+
+/*
+ *  The following controls the behavior of Read_timer().
+ *
+ *  AVG_OVERHEAD is the overhead for starting and stopping the timer.  It
+ *  is usually deducted from the number returned.
+ *
+ *  LEAST_VALID is the lowest number this routine should trust.  Numbers
+ *  below this are "noise" and zero is returned.
+ */
+
+#define AVG_OVERHEAD      1  /* It typically takes X.X microseconds */
+                             /* (Y countdowns) to start/stop the timer. */
+                             /* This value is in microseconds. */
+#define LEAST_VALID       0 /* 20 */ /* Don't trust a clicks value lower than this */
+
+int Read_timer( void )
+{
+  rtems_unsigned32 clicks;
+  rtems_unsigned32 total ;
+  /*
+   *  Read the timer and see how many clicks it has been since we started.
+   */
+  
+
+  clicks = read16( MTU_TCNT1);   /* XXX: read some HW here */
+  
+  /*
+   *  Total is calculated by taking into account the number of timer overflow
+   *  interrupts since the timer was initialized and clicks since the last
+   *  interrupts.
+   */
+
+  total = clicks + Timer_interrupts * 65536 ;
+
+  if ( Timer_driver_Find_average_overhead )
+    return total / SCALE;          /* in XXX microsecond units */
+  else 
+  {
+    if ( total < LEAST_VALID )
+      return 0;            /* below timer resolution */
+  /*
+   *  Somehow convert total into microseconds
+   */
+    return (total / SCALE - AVG_OVERHEAD) ;
+  }
+}
+
+/*
+ *  Empty function call used in loops to measure basic cost of looping
+ *  in Timing Test Suite.
+ */
+
+rtems_status_code Empty_function( void )
+{
+  return RTEMS_SUCCESSFUL;
+}
+
+void Set_find_average_overhead(
+  rtems_boolean find_flag
+)
+{
+  Timer_driver_Find_average_overhead = find_flag;
+}
+
+/* Timer 1 is used */
+
+#pragma interrupt
+void timerisr( void )
+{
+  unsigned8 temp8;
+
+  /* reset the flags of the status register */
+  temp8 = read8( MTU_TSR1) & MTU1_STAT_MASK;
+  write8( temp8, MTU_TSR1);
+
+  Timer_interrupts += 1;
+}