1 files changed, 163 insertions, 0 deletions

diff --git a/firmware/target/hosted/ypr0/kernel-ypr0.c b/firmware/target/hosted/ypr0/kernel-ypr0.c
new file mode 100644
index 0000000000..bcf2cee583
--- /dev/null
+++ b/firmware/target/hosted/ypr0/kernel-ypr0.c
@@ -0,0 +1,163 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (c) 2010 Thomas Martitz
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+
+#include <time.h>
+#include <signal.h>
+#include <errno.h>
+#include <unistd.h>
+#include <pthread.h>
+#include "config.h"
+#include "system.h"
+#include "button.h"
+#include "audio.h"
+#include "panic.h"
+#include "timer.h"
+
+
+static pthread_cond_t wfi_cond = PTHREAD_COND_INITIALIZER;
+static pthread_mutex_t wfi_mtx = PTHREAD_MUTEX_INITIALIZER;
+/*
+ * call tick tasks and wake the scheduler up */
+void timer_signal(union sigval arg)
+{
+    (void)arg;
+    call_tick_tasks();
+    interrupt();
+}
+
+/*
+ * wait on the sem which the signal handler posts to save cpu time (aka sleep)
+ *
+ * other mechanisms could use them as well */
+void wait_for_interrupt(void)
+{
+    pthread_cond_wait(&wfi_cond, &wfi_mtx);
+}
+
+/*
+ * Wakeup the kernel, if sleeping (shall not be called from a signal handler) */
+void interrupt(void)
+{
+    pthread_cond_signal(&wfi_cond);
+}
+
+
+/*
+ * setup a hrtimer to send a signal to our process every tick
+ */
+union sigval tick_arg = {
+    .sival_int = 0,
+};
+
+void tick_start(unsigned int interval_in_ms)
+{
+    int ret = 0;
+    timer_t timerid;
+    struct itimerspec ts;
+    sigevent_t sigev;
+
+    /* initializing in the declaration causes some weird warnings */
+    memset(&sigev, 0, sizeof(sigevent_t));
+    sigev.sigev_notify = SIGEV_THREAD,
+    sigev.sigev_notify_function = timer_signal;
+
+    ts.it_value.tv_sec = ts.it_interval.tv_sec = 0;
+    ts.it_value.tv_nsec = ts.it_interval.tv_nsec = interval_in_ms*1000*1000;
+
+    /* add the timer */
+    ret |= timer_create(CLOCK_REALTIME, &sigev, &timerid);
+    ret |= timer_settime(timerid, 0, &ts, NULL);
+
+    /* Grab the mutex already now and leave it to this thread. We don't
+     * care about race conditions when signaling the condition (because
+     * they are not critical), but a mutex is necessary due to the API */
+    pthread_mutex_lock(&wfi_mtx);
+
+    if (ret != 0)
+        panicf("%s(): %s\n", __func__, strerror(errno));
+}
+
+#define cycles_to_microseconds(cycles) \
+    ((int)((1000000*cycles)/TIMER_FREQ))
+
+
+static timer_t timer_tid;
+static int timer_prio = -1;
+void (*global_unreg_callback)(void);
+void (*global_timer_callback)(void);
+
+static void timer_cb(union sigval arg)
+{
+    (void)arg;
+    if (global_timer_callback)
+        global_timer_callback();
+}
+
+bool timer_register(int reg_prio, void (*unregister_callback)(void),
+                    long cycles, void (*timer_callback)(void))
+{
+    int ret = 0;
+    struct itimerspec ts;
+    sigevent_t sigev;
+    long in_us = cycles_to_microseconds(cycles);
+
+    if (reg_prio <= timer_prio || in_us <= 0)
+        return false;
+
+    if (timer_prio >= 0 && global_unreg_callback)
+        global_unreg_callback();
+
+    /* initializing in the declaration causes some weird warnings */
+    memset(&sigev, 0, sizeof(sigevent_t));
+    sigev.sigev_notify = SIGEV_THREAD,
+    sigev.sigev_notify_function = timer_cb;
+
+    ts.it_value.tv_sec = ts.it_interval.tv_sec = in_us / 1000000;
+    ts.it_value.tv_nsec = ts.it_interval.tv_nsec = (in_us%1000000)*1000;
+
+    /* add the timer */
+    ret |= timer_create(CLOCK_REALTIME, &sigev, &timer_tid);
+    ret |= timer_settime(timer_tid, 0, &ts, NULL);
+
+    global_timer_callback = timer_callback;
+    global_unreg_callback = unregister_callback;
+    timer_prio = reg_prio;
+
+    return ret == 0;
+}
+
+bool timer_set_period(long cycles)
+{
+    struct itimerspec ts;
+    long in_us = cycles_to_microseconds(cycles);
+    ts.it_value.tv_sec = ts.it_interval.tv_sec = in_us / 1000000;
+    ts.it_value.tv_nsec = ts.it_interval.tv_nsec = (in_us%1000000)*1000;
+
+    return timer_settime(timer_tid, 0, &ts, NULL) == 0;
+}
+
+void timer_unregister(void)
+{
+    timer_delete(timer_tid);
+    timer_prio = -1;
+}
+