bsps/powerpc: Move dec clock driver to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

bsps/powerpc/shared/dev/clock-ppc-dec.c

@@ -0,0 +1,266 @@
+/**
+ *  @brief Clock Tick Device Driver
+ *
+ *  This routine utilizes the Decrementer Register common to the PPC family.
+ *
+ *  The tick frequency is directly programmed to the configured number of
+ *  microseconds per tick.
+ */
+
+/*
+ *  COPYRIGHT (c) 1989-2014.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may in
+ *  the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ *
+ *  Modified to support the MPC750.
+ *  Modifications Copyright (c) 1999 Eric Valette valette@crf.canon.fr
+ */
+
+#include <rtems.h>
+#include <rtems/libio.h>
+#include <rtems/clockdrv.h>
+#include <stdlib.h>                     /* for atexit() */
+#include <assert.h>
+#include <libcpu/c_clock.h>
+#include <libcpu/cpuIdent.h>
+#include <libcpu/spr.h>
+#include <rtems/bspIo.h>                /* for printk() */
+#include <libcpu/powerpc-utility.h>
+#include <rtems/timecounter.h>
+#include <rtems/score/percpu.h>
+
+#include <bspopts.h>   /* for CLOCK_DRIVER_USE_FAST_IDLE */
+
+SPR_RW(BOOKE_TCR)
+SPR_RW(BOOKE_TSR)
+SPR_RW(BOOKE_DECAR)
+
+extern int BSP_connect_clock_handler (void);
+
+/*
+ *  Clock ticks since initialization
+ */
+volatile uint32_t   Clock_driver_ticks;
+
+/*
+ *  This is the value programmed into the count down timer.
+ */
+static uint32_t   Clock_Decrementer_value;
+
+static struct timecounter Clock_TC;
+
+static uint32_t Clock_Get_timecount(struct timecounter *tc)
+{
+  return ppc_time_base();
+}
+
+void clockOff(void* unused)
+{
+  rtems_interrupt_level l;
+
+  if ( ppc_cpu_is_bookE() ) {
+    rtems_interrupt_disable(l);
+    _write_BOOKE_TCR(_read_BOOKE_TCR() & ~BOOKE_TCR_DIE);
+    rtems_interrupt_enable(l);
+  } else {
+    /*
+     * Nothing to do as we cannot disable all interrupts and
+     * the decrementer interrupt enable is MSR_EE
+     */
+  }
+}
+
+void clockOn(void* unused)
+{
+  rtems_interrupt_level l;
+
+  PPC_Set_decrementer( Clock_Decrementer_value );
+
+  if ( ppc_cpu_is_bookE() ) {
+    _write_BOOKE_DECAR( Clock_Decrementer_value );
+
+    rtems_interrupt_disable(l);
+
+    /* clear pending/stale irq */
+    _write_BOOKE_TSR( BOOKE_TSR_DIS );
+    /* enable */
+    _write_BOOKE_TCR( _read_BOOKE_TCR() | BOOKE_TCR_DIE );
+
+    rtems_interrupt_enable(l);
+
+  }
+}
+
+static void clockHandler(void)
+{
+  #if (CLOCK_DRIVER_USE_FAST_IDLE == 1)
+    rtems_interrupt_level level;
+    uint32_t tb;
+
+    rtems_interrupt_disable(level);
+
+    tb = ppc_time_base();
+    rtems_timecounter_tick();
+
+    while ( _Thread_Heir == _Thread_Executing && _Thread_Executing->is_idle ) {
+      tb += Clock_Decrementer_value;
+      ppc_set_time_base( tb );
+      rtems_timecounter_tick();
+    }
+
+    rtems_interrupt_enable(level);
+  #else
+    rtems_timecounter_tick();
+  #endif
+}
+
+static void (*clock_handler)(void);
+
+/*
+ *  Clock_isr
+ *
+ *  This is the clock tick interrupt handler.
+ *
+ *  Input parameters:
+ *    vector - vector number
+ *
+ *  Output parameters:  NONE
+ *
+ *  Return values:      NONE
+ *
+ */
+void clockIsr(void *unused)
+{
+  int decr;
+
+  /*
+   *  The driver has seen another tick.
+   */
+  do {
+    register uint32_t flags;
+
+    rtems_interrupt_disable(flags);
+      __asm__ volatile (
+	"mfdec %0; add %0, %0, %1; mtdec %0"
+	: "=&r"(decr)
+	: "r"(Clock_Decrementer_value)
+      );
+    rtems_interrupt_enable(flags);
+
+    Clock_driver_ticks += 1;
+    /*
+     *  Real Time Clock counter/timer is set to automatically reload.
+     */
+    clock_handler();
+  } while ( decr < 0 );
+}
+
+/*
+ *  Clock_isr_bookE
+ *
+ *  This is the clock tick interrupt handler
+ *  for bookE CPUs. For efficiency reasons we
+ *  provide a separate handler rather than
+ *  checking the CPU type each time.
+ */
+void clockIsrBookE(void *unused)
+{
+  /* Note: TSR bit has already been cleared in the exception handler */
+
+  /*
+   *  The driver has seen another tick.
+   */
+
+  Clock_driver_ticks += 1;
+
+  /*
+   *  Real Time Clock counter/timer is set to automatically reload.
+   */
+  clock_handler();
+}
+
+int clockIsOn(void* unused)
+{
+  uint32_t   msr_value;
+
+  _CPU_MSR_GET( msr_value );
+
+  if ( ppc_cpu_is_bookE() && ! (_read_BOOKE_TCR() & BOOKE_TCR_DIE) )
+    msr_value = 0;
+
+  if (msr_value & MSR_EE) return 1;
+
+  return 0;
+}
+
+/*
+ *  Clock_exit
+ *
+ *  This routine allows the clock driver to exit by masking the interrupt and
+ *  disabling the clock's counter.
+ */
+void Clock_exit( void )
+{
+  (void) BSP_disconnect_clock_handler ();
+}
+
+/*
+ *  Clock_initialize
+ *
+ *  This routine initializes the clock driver.
+ */
+rtems_device_driver Clock_initialize(
+  rtems_device_major_number major,
+  rtems_device_minor_number minor,
+  void *pargp
+)
+{
+  rtems_interrupt_level l,tcr;
+
+  Clock_Decrementer_value = (BSP_bus_frequency/BSP_time_base_divisor)*
+            rtems_configuration_get_milliseconds_per_tick();
+
+  /* set the decrementer now, prior to installing the handler
+   * so no interrupts will happen in a while.
+   */
+  PPC_Set_decrementer( (unsigned)-1 );
+
+  /* On a bookE CPU the decrementer works differently. It doesn't
+   * count past zero but we can enable auto-reload :-)
+   */
+  if ( ppc_cpu_is_bookE() ) {
+
+    rtems_interrupt_disable(l);
+
+      tcr  = _read_BOOKE_TCR();
+      tcr |= BOOKE_TCR_ARE;
+      tcr &= ~BOOKE_TCR_DIE;
+      _write_BOOKE_TCR(tcr);
+
+    rtems_interrupt_enable(l);
+  }
+
+  Clock_TC.tc_get_timecount = Clock_Get_timecount;
+  Clock_TC.tc_counter_mask = 0xffffffff;
+  Clock_TC.tc_frequency = (UINT64_C(1000) * BSP_bus_frequency) / BSP_time_base_divisor;
+  Clock_TC.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
+  rtems_timecounter_install(&Clock_TC);
+
+  /*
+   * If a decrementer exception was pending, it is cleared by
+   * executing the default (nop) handler at this point;
+   * The next exception will then be taken by our clock handler.
+   * Clock handler installation initializes the decrementer to
+   * the correct value.
+   */
+  clock_handler = clockHandler;
+  if (!BSP_connect_clock_handler ()) {
+    printk("Unable to initialize system clock\n");
+    rtems_fatal_error_occurred(1);
+  }
+
+  return RTEMS_SUCCESSFUL;
+} /* Clock_initialize */