tot: Time-out timer module

This is a crude time-out timer, designed to be ticked along by the
systick timer then polled in the main loop.

git-svn-id: https://svn.code.sf.net/p/freetel/code@2423 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/stm32/inc/tot.h b/codec2-dev/stm32/inc/tot.h
new file mode 100644 (file)
index 0000000..ad635b0
--- /dev/null
+++ b/codec2-dev/stm32/inc/tot.h
@@ -0,0 +1,115 @@
+#ifndef _TOT_H
+#define _TOT_H
+/*!
+ * Time-out timer.
+ *
+ * This is a simple time-out timer for ensuring a maximum transmission
+ * time is observed.  The time-out timer is configured with a total time
+ * in "ticks", which get counted down in an interrupt.
+ *
+ * When the "warning" level is reached, a flag is repeatedly set permit
+ * triggering of LEDs/sounds to warn the user that time is nearly up.
+ *
+ * Upon timeout, a separate flag is set to indicate timeout has taken
+ * place.
+ *
+ * Author Stuart Longland <me@vk4msl.id.au>
+ * Copyright (C) 2015 FreeDV project.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.  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 Lesser General Public
+ * License along with this program; if not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+
+/*!
+ * Time-out timer state machine
+ */
+struct tot_t {
+       /*!
+        * Number of ticks remaining, if non-zero, transmission is
+        * in progress.
+        */
+       uint32_t        remaining;
+       /*!
+        * Number of ticks remaining, before next warning.
+        */
+       uint32_t        warn_remain;
+       /*!
+        * Timeout timer tick period.  Used to reset the ticks counter.
+        */
+       uint32_t        tick_period;
+       /*!
+        * Number of ticks between the remaining warnings.
+        */
+       uint16_t        remain_warn_ticks;
+       /*!
+        * Event tick timer.  Used to slow down the source timer.
+        */
+       uint16_t        ticks;
+       /*!
+        * Event flags.
+        */
+       uint16_t        event;
+};
+
+/*!
+ * Time-out timer has been started.
+ */
+#define        TOT_EVT_START           (1 << 0)
+
+/*!
+ * Start of warning period reached.
+ */
+#define        TOT_EVT_WARN            (1 << 1)
+
+/*!
+ * Next warning is due.
+ */
+#define TOT_EVT_WARN_NEXT      (1 << 2)
+
+/*!
+ * Time-out reached.
+ */
+#define TOT_EVT_TIMEOUT                (1 << 3)
+
+/*!
+ * Timer sequence complete
+ */
+#define TOT_EVT_DONE           (1 << 4)
+
+/*!
+ * Reset the time-out timer.  This zeroes the counter and event flags.
+ */
+void tot_reset(struct tot_t * const tot);
+
+/*!
+ * Start the time-out timer ticking.
+ */
+void tot_start(struct tot_t * const tot, uint32_t tot_ticks,
+               uint16_t warn_ticks);
+
+/*!
+ * Count a time-out timer tick.
+ */
+static inline void tot_tick(struct tot_t * const tot)
+{
+       if (tot->ticks)
+               tot->ticks--;
+}
+
+/*!
+ * Update the time-out timer state.
+ */
+void tot_update(struct tot_t * const tot);
+
+#endif

diff --git a/codec2-dev/stm32/src/tot.c b/codec2-dev/stm32/src/tot.c
new file mode 100644 (file)
index 0000000..1fce495
--- /dev/null
+++ b/codec2-dev/stm32/src/tot.c
@@ -0,0 +1,90 @@
+/*!
+ * Time-out timer.
+ *
+ * This is a simple time-out timer for ensuring a maximum transmission
+ * time is observed.  The time-out timer is configured with a total time
+ * in "ticks", which get counted down in an interrupt.
+ *
+ * When the "warning" level is reached, a flag is repeatedly set permit
+ * triggering of LEDs/sounds to warn the user that time is nearly up.
+ *
+ * Upon timeout, a separate flag is set to indicate timeout has taken
+ * place.
+ *
+ * Author Stuart Longland <me@vk4msl.id.au>
+ * Copyright (C) 2015 FreeDV project.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.  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 Lesser General Public
+ * License along with this program; if not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include "tot.h"
+
+/*!
+ * Reset the time-out timer.  This zeroes the counter and event flags.
+ */
+void tot_reset(struct tot_t * const tot)
+{
+       tot->event              = 0;
+       tot->remaining          = 0;
+       tot->warn_remain        = 0;
+       tot->ticks              = 0;
+}
+
+/*!
+ * Start the time-out timer ticking.
+ */
+void tot_start(struct tot_t * const tot, uint32_t tot_ticks,
+               uint16_t warn_ticks)
+{
+       tot->event              = TOT_EVT_START;
+       tot->warn_remain        = tot_ticks - warn_ticks;
+       tot->remaining          = tot_ticks;
+       tot->ticks              = tot->tick_period;
+}
+
+/*!
+ * Update the time-out timer state.
+ */
+void tot_update(struct tot_t * const tot)
+{
+       if (!tot->event)
+               /* We are not active */
+               return;
+
+       if (tot->event & TOT_EVT_DONE)
+               /* We are done, do not process */
+               return;
+
+       if (tot->ticks)
+               /* Wait for a tick to pass */
+               return;
+
+       /* One "tick" has passed */
+       if (!tot->remaining) {
+               /* Time-out reached, reset all flags except timeout */
+               tot->event      |= TOT_EVT_TIMEOUT | TOT_EVT_DONE;
+               return;
+       } else {
+               tot->remaining--;
+       }
+
+       if (!tot->warn_remain) {
+               /* Warning period has passed */
+               tot->event      |= TOT_EVT_WARN | TOT_EVT_WARN_NEXT;
+               tot->warn_remain = tot->remain_warn_ticks;
+       } else {
+               tot->warn_remain--;
+       }
+
+       tot->ticks = tot->tick_period;
+}