1 files changed, 145 insertions, 0 deletions
diff --git a/nuttx/arch/z80/src/z8/z8_timerisr.c b/nuttx/arch/z80/src/z8/z8_timerisr.c
new file mode 100644
index 000000000..8ace6a677
--- /dev/null
+++ b/nuttx/arch/z80/src/z8/z8_timerisr.c
@@ -0,0 +1,145 @@
+/***************************************************************************
+ * arch/z80/src/z8/z8_timerisr.c
+ *
+ *   Copyright (C) 2008 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 <debug.h>
+
+#include <nuttx/arch.h>
+#include <ez8.h>
+
+#include "chip/chip.h"
+#include "clock_internal.h"
+#include "up_internal.h"
+
+/***************************************************************************
+ * Definitions
+ ***************************************************************************/
+
+/* System clock frequency value from ZDS target settings */
+
+extern ROM uint32 __user_frequency;
+#define _DEFCLK ((uint32)&__user_frequency)
+
+/***************************************************************************
+ * Private Types
+ ***************************************************************************/
+
+/***************************************************************************
+ * Private Functions
+ ***************************************************************************/
+
+/***************************************************************************
+ * Public Functions
+ ***************************************************************************/
+
+/***************************************************************************
+ * Function:  up_timerisr
+ *
+ * Description:
+ *   The timer ISR will perform a variety of services for various portions
+ *   of the system.
+ *
+ ***************************************************************************/
+
+int up_timerisr(int irq, uint32 *regs)
+{
+   /* Process timer interrupt */
+
+   sched_process_timer();
+   return 0;
+}
+
+/***************************************************************************
+ * Function:  up_timerinit
+ *
+ * Description:
+ *   This function is called during start-up to initialize the timer
+ *   interrupt.
+ *
+ ***************************************************************************/
+
+void up_timerinit(void)
+{
+  up_disable_irq(Z8_IRQ_SYSTIMER);
+
+  /* Write to the timer control register to disable the timer, configure
+   * the timer for continuous mode, and set up the pre-scale value for
+   * divide by 4.
+   */
+
+  putreg8( Z8_TIMERSCTL_DIV4 | Z8_TIMERSCTL_CONT, Z8_TIMER0_CTL);
+
+  /* Write to the timer high and low byte registers to set a starting
+   * count value (this effects only the first pass in continuous mode)
+   */
+
+  putreg16(0x0001, Z8_TIMER0_HL);
+
+  /* Write to the timer reload register to set the reload value.
+   *
+   * In continuous mode:
+   *
+   *   timer_period = reload_value x prescale / system_clock_frequency
+   * or
+   *   reload_value = (timer_period * system_clock_frequency) / prescale
+   *
+   * For system_clock_frequency=18.432MHz, timer_period=10mS, and prescale=4,
+   * then reload_value=46,080 - OR:
+   *
+   *   reload_value = system_clock_frequency / 400
+   */
+
+  putreg16(((uint32)_DEFCLK / 400), Z8_TIMER0_R);
+
+  /* Write to the timer control register to enable the timer and to
+   * initiate counting
+   */
+
+  putreg8((getreg8(Z8_TIMER0_CTL) | Z8_TIMERCTL_TEN), Z8_TIMER0_CTL);
+
+  /* Set the timer priority */
+
+  /* Attach and enable the timer interrupt (leaving at priority 0 */
+
+  irq_attach(Z8_IRQ_SYSTIMER, (xcpt_t)up_timerisr);
+  up_enable_irq(Z8_IRQ_SYSTIMER);
+}
+