initial commit of lk (little kernel) project
diff --git a/platform/omap5912/timer.c b/platform/omap5912/timer.c
new file mode 100644
index 0000000..72659f1
--- /dev/null
+++ b/platform/omap5912/timer.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <sys/types.h>
+#include <err.h>
+#include <kernel/thread.h>
+#include <debug.h>
+#include <platform.h>
+#include <platform/interrupts.h>
+#include <platform/timer.h>
+#include <platform/omap5912.h>
+#include "platform_p.h"
+
+static time_t system_time = 0;
+
+static time_t tick_interval;
+static uint32_t ticks_per_interval;
+static platform_timer_callback t_callback;
+static void *callback_arg;
+
+status_t platform_set_periodic_timer(platform_timer_callback callback, void *arg, time_t interval)
+{
+ enter_critical_section();
+
+ t_callback = callback;
+ callback_arg = arg;
+ tick_interval = interval;
+ ticks_per_interval = interval * 32768 / 1000; // interval is in ms
+
+ OS_TIMER_CTRL_REG = 0; // stop it
+ OS_TIMER_TICK_VALUE_REG = ticks_per_interval;
+ OS_TIMER_CTRL_REG = (1<<3) | (1<<2) | (1<<1) | (1<<0);
+
+ exit_critical_section();
+
+ return NO_ERROR;
+}
+
+time_t current_time(void)
+{
+ time_t t;
+ uint32_t delta_ticks;
+ uint32_t delta_ticks2;
+
+retry:
+ delta_ticks = OS_TIMER_TICK_COUNTER_REG;
+ t = system_time;
+ delta_ticks2 = OS_TIMER_TICK_COUNTER_REG;
+ if (delta_ticks2 > delta_ticks)
+ goto retry;
+
+ t += ((ticks_per_interval - delta_ticks2) * tick_interval) / ticks_per_interval;
+
+ return t;
+}
+
+bigtime_t current_time_hires(void)
+{
+ time_t t;
+ uint32_t delta_ticks;
+ uint32_t delta_ticks2;
+
+retry:
+ delta_ticks = OS_TIMER_TICK_COUNTER_REG;
+ t = system_time;
+ delta_ticks2 = OS_TIMER_TICK_COUNTER_REG;
+ if (delta_ticks2 > delta_ticks)
+ goto retry;
+
+ t += ((ticks_per_interval - delta_ticks2) * tick_interval) / ticks_per_interval;
+
+ return t * 1000ULL;
+}
+
+
+static enum handler_return os_timer_tick(void *arg)
+{
+ system_time += tick_interval;
+// dprintf("os_timer_tick %d\n", system_time);
+
+ return t_callback(callback_arg, system_time);
+}
+
+void platform_init_timer(void)
+{
+ OS_TIMER_CTRL_REG = 0; // stop the timer if it's already running
+
+ register_int_handler(IRQ_OS_TIMER, &os_timer_tick, NULL);
+ unmask_interrupt(IRQ_OS_TIMER, NULL);
+}
+