Implement SC520 timers
Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
diff --git a/lib_i386/timer.c b/lib_i386/timer.c
new file mode 100644
index 0000000..5cb1f54
--- /dev/null
+++ b/lib_i386/timer.c
@@ -0,0 +1,107 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/i8254.h>
+#include <asm/ibmpc.h>
+
+struct timer_isr_function {
+ struct timer_isr_function *next;
+ timer_fnc_t *isr_func;
+};
+
+static struct timer_isr_function *first_timer_isr = NULL;
+static volatile unsigned long system_ticks = 0;
+
+/*
+ * register_timer_isr() allows multiple architecture and board specific
+ * functions to be called every millisecond. Keep the execution time of
+ * each function as low as possible
+ */
+int register_timer_isr (timer_fnc_t *isr_func)
+{
+ struct timer_isr_function *new_func;
+ struct timer_isr_function *temp;
+ int flag;
+
+ new_func = malloc(sizeof(struct timer_isr_function));
+
+ if (new_func == NULL)
+ return 1;
+
+ new_func->isr_func = isr_func;
+ new_func->next = NULL;
+
+ /*
+ * Don't allow timer interrupts while the
+ * linked list is being modified
+ */
+ flag = disable_interrupts ();
+
+ if (first_timer_isr == NULL) {
+ first_timer_isr = new_func;
+ } else {
+ temp = first_timer_isr;
+ while (temp->next != NULL)
+ temp = temp->next;
+ temp->next = new_func;
+ }
+
+ if (flag)
+ enable_interrupts ();
+
+ return 0;
+}
+
+/*
+ * timer_isr() MUST be the registered interrupt handler for
+ */
+void timer_isr(void *unused)
+{
+ struct timer_isr_function *temp = first_timer_isr;
+
+ system_ticks++;
+
+ /* Execute each registered function */
+ while (temp != NULL) {
+ temp->isr_func ();
+ temp = temp->next;
+ }
+}
+
+void reset_timer (void)
+{
+ system_ticks = 0;
+}
+
+ulong get_timer (ulong base)
+{
+ return (system_ticks - base);
+}
+
+void set_timer (ulong t)
+{
+ system_ticks = t;
+}
