From 71947d6beafe118259ca2805dbb21fac5ab3b165 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Wed, 8 Jun 2016 19:32:06 -0400
Subject: gpiocmds: Add Kconfig option to allow boards to disable ADC commands

Some boards may not support the ADC hardware.  Update the build so
that those commands do not need to be compiled if they are not
available.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 src/adccmds.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 src/adccmds.c

(limited to 'src/adccmds.c')

diff --git a/src/adccmds.c b/src/adccmds.c
new file mode 100644
index 00000000..2ae7f43c
--- /dev/null
+++ b/src/adccmds.c
@@ -0,0 +1,117 @@
+// Commands for controlling GPIO analog-to-digital input pins
+//
+// Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "basecmd.h" // alloc_oid
+#include "board/gpio.h" // struct gpio_adc
+#include "board/irq.h" // irq_save
+#include "command.h" // DECL_COMMAND
+#include "sched.h" // DECL_TASK
+
+struct analog_in {
+    struct timer timer;
+    uint32_t rest_time, sample_time, next_begin_time;
+    uint16_t value, min_value, max_value;
+    struct gpio_adc pin;
+    uint8_t state, sample_count;
+};
+
+static uint8_t
+analog_in_event(struct timer *timer)
+{
+    struct analog_in *a = container_of(timer, struct analog_in, timer);
+    if (gpio_adc_sample(a->pin)) {
+        a->timer.waketime += gpio_adc_sample_time();
+        return SF_RESCHEDULE;
+    }
+    uint16_t value = gpio_adc_read(a->pin);
+    uint8_t state = a->state;
+    if (state >= a->sample_count) {
+        state = 0;
+    } else {
+        value += a->value;
+    }
+    a->value = value;
+    a->state = state+1;
+    if (a->state < a->sample_count) {
+        a->timer.waketime += a->sample_time;
+        return SF_RESCHEDULE;
+    }
+    if (a->value < a->min_value || a->value > a->max_value)
+        shutdown("adc out of range");
+    a->next_begin_time += a->rest_time;
+    a->timer.waketime = a->next_begin_time;
+    return SF_RESCHEDULE;
+}
+
+void
+command_config_analog_in(uint32_t *args)
+{
+    struct analog_in *a = alloc_oid(
+        args[0], command_config_analog_in, sizeof(*a));
+    a->timer.func = analog_in_event;
+    a->pin = gpio_adc_setup(args[1]);
+    a->state = 1;
+}
+DECL_COMMAND(command_config_analog_in, "config_analog_in oid=%c pin=%u");
+
+void
+command_query_analog_in(uint32_t *args)
+{
+    struct analog_in *a = lookup_oid(args[0], command_config_analog_in);
+    sched_del_timer(&a->timer);
+    gpio_adc_clear_sample(a->pin);
+    a->next_begin_time = args[1];
+    a->timer.waketime = a->next_begin_time;
+    a->sample_time = args[2];
+    a->sample_count = args[3];
+    a->state = a->sample_count + 1;
+    a->rest_time = args[4];
+    a->min_value = args[5];
+    a->max_value = args[6];
+    if (! a->sample_count)
+        return;
+    sched_timer(&a->timer);
+}
+DECL_COMMAND(command_query_analog_in,
+             "query_analog_in oid=%c clock=%u sample_ticks=%u sample_count=%c"
+             " rest_ticks=%u min_value=%hu max_value=%hu");
+
+static void
+analog_in_task(void)
+{
+    static uint16_t next;
+    if (!sched_check_periodic(3, &next))
+        return;
+    uint8_t oid;
+    struct analog_in *a;
+    foreach_oid(oid, a, command_config_analog_in) {
+        if (a->state != a->sample_count)
+            continue;
+        uint8_t flag = irq_save();
+        if (a->state != a->sample_count) {
+            irq_restore(flag);
+            continue;
+        }
+        uint16_t value = a->value;
+        uint32_t next_begin_time = a->next_begin_time;
+        a->state++;
+        irq_restore(flag);
+        sendf("analog_in_state oid=%c next_clock=%u value=%hu"
+              , oid, next_begin_time, value);
+    }
+}
+DECL_TASK(analog_in_task);
+
+static void
+analog_in_shutdown(void)
+{
+    uint8_t i;
+    struct analog_in *a;
+    foreach_oid(i, a, command_config_analog_in) {
+        gpio_adc_clear_sample(a->pin);
+    }
+}
+DECL_SHUTDOWN(analog_in_shutdown);
-- 
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