1 files changed, 110 insertions, 0 deletions
diff --git a/src/endstop.c b/src/endstop.c
new file mode 100644
index 000000000..bc1776059
--- /dev/null
+++ b/src/endstop.c
@@ -0,0 +1,110 @@
+// Handling of end stops.
+//
+// Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include <stddef.h> // offsetof
+#include "basecmd.h" // alloc_oid
+#include "board/gpio.h" // struct gpio
+#include "board/irq.h" // irq_save
+#include "command.h" // DECL_COMMAND
+#include "sched.h" // struct timer
+#include "stepper.h" // stepper_stop
+
+struct end_stop {
+    struct timer time;
+    uint32_t rest_time;
+    struct stepper *stepper;
+    struct gpio_in pin;
+    uint8_t pin_value, flags;
+};
+
+enum { ESF_HOMING=1, ESF_REPORT=2 };
+
+// Timer callback for an end stop
+static uint8_t
+end_stop_event(struct timer *t)
+{
+    struct end_stop *e = container_of(t, struct end_stop, time);
+    uint8_t val = gpio_in_read(e->pin);
+    if (val != e->pin_value) {
+        e->time.waketime += e->rest_time;
+        return SF_RESCHEDULE;
+    }
+    // Stop stepper
+    e->flags = ESF_REPORT;
+    stepper_stop(e->stepper);
+    return SF_DONE;
+}
+
+void
+command_config_end_stop(uint32_t *args)
+{
+    struct end_stop *e = alloc_oid(args[0], command_config_end_stop, sizeof(*e));
+    struct stepper *s = lookup_oid(args[3], command_config_stepper);
+    e->time.func = end_stop_event;
+    e->stepper = s;
+    e->pin = gpio_in_setup(args[1], args[2]);
+}
+DECL_COMMAND(command_config_end_stop,
+             "config_end_stop oid=%c pin=%c pull_up=%c stepper_oid=%c");
+
+// Home an axis
+void
+command_end_stop_home(uint32_t *args)
+{
+    struct end_stop *e = lookup_oid(args[0], command_config_end_stop);
+    sched_del_timer(&e->time);
+    e->time.waketime = args[1];
+    e->rest_time = args[2];
+    if (!e->rest_time) {
+        // Disable end stop checking
+        e->flags = 0;
+        return;
+    }
+    e->pin_value = args[3];
+    e->flags = ESF_HOMING;
+    sched_timer(&e->time);
+}
+DECL_COMMAND(command_end_stop_home,
+             "end_stop_home oid=%c clock=%u rest_ticks=%u pin_value=%c");
+
+static void
+end_stop_report(uint8_t oid, struct end_stop *e)
+{
+    uint8_t flag = irq_save();
+    uint32_t position = stepper_get_position(e->stepper);
+    uint8_t eflags = e->flags;
+    e->flags &= ~ESF_REPORT;
+    irq_restore(flag);
+
+    sendf("end_stop_state oid=%c homing=%c pin=%c pos=%i"
+          , oid, !!(eflags & ESF_HOMING), gpio_in_read(e->pin)
+          , position - STEPPER_POSITION_BIAS);
+}
+
+void
+command_end_stop_query(uint32_t *args)
+{
+    uint8_t oid = args[0];
+    struct end_stop *e = lookup_oid(oid, command_config_end_stop);
+    end_stop_report(oid, e);
+}
+DECL_COMMAND(command_end_stop_query, "end_stop_query oid=%c");
+
+static void
+end_stop_task(void)
+{
+    static uint16_t next;
+    if (!sched_check_periodic(50, &next))
+        return;
+    uint8_t oid;
+    struct end_stop *e;
+    foreach_oid(oid, e, command_config_end_stop) {
+        if (!(e->flags & ESF_REPORT))
+            continue;
+        end_stop_report(oid, e);
+    }
+}
+DECL_TASK(end_stop_task);