100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
// Commands for counting edges on GPIO input pins
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//
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// Copyright (C) 2021 Adrian Keet <arkeet@gmail.com>
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//
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// This file may be distributed under the terms of the GNU GPLv3 license.
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#include "basecmd.h" // oid_alloc
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#include "board/gpio.h" // struct gpio_in
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#include "board/irq.h" // irq_disable
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#include "board/misc.h" // timer_read_time
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#include "command.h" // DECL_COMMAND
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#include "sched.h" // DECL_TASK
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struct counter {
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struct timer timer;
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uint32_t poll_ticks;
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uint32_t sample_ticks, next_sample_time;
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uint32_t count, last_count_time;
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uint8_t flags;
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struct gpio_in pin;
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};
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enum {
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CF_PENDING = 1,
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};
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static struct task_wake counter_wake;
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static uint_fast8_t
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counter_event(struct timer *timer)
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{
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struct counter *c = container_of(timer, struct counter, timer);
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uint32_t time = c->timer.waketime;
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uint8_t last_value = c->count & 1;
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uint8_t value = gpio_in_read(c->pin);
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if (last_value != value) {
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c->count++;
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c->last_count_time = time;
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}
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// useful invariant: c->count & 1 == value
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if (timer_is_before(c->next_sample_time, time)) {
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c->flags |= CF_PENDING;
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c->next_sample_time = time + c->sample_ticks;
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sched_wake_task(&counter_wake);
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}
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c->timer.waketime += c->poll_ticks;
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return SF_RESCHEDULE;
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}
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void
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command_config_counter(uint32_t *args)
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{
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struct counter *c = oid_alloc(
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args[0], command_config_counter, sizeof(*c));
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c->pin = gpio_in_setup(args[1], args[2]);
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c->timer.func = counter_event;
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}
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DECL_COMMAND(command_config_counter,
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"config_counter oid=%c pin=%u pull_up=%c");
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void
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command_query_counter(uint32_t *args)
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{
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struct counter *c = oid_lookup(args[0], command_config_counter);
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sched_del_timer(&c->timer);
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c->timer.waketime = args[1];
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c->poll_ticks = args[2];
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c->sample_ticks = args[3];
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c->next_sample_time = c->timer.waketime; // sample immediately
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sched_add_timer(&c->timer);
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}
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DECL_COMMAND(command_query_counter,
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"query_counter oid=%c clock=%u poll_ticks=%u sample_ticks=%u");
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void
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counter_task(void)
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{
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if (!sched_check_wake(&counter_wake))
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return;
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uint8_t oid;
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struct counter *c;
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foreach_oid(oid, c, command_config_counter) {
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if (!(c->flags & CF_PENDING))
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continue;
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irq_disable();
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uint32_t time = c->timer.waketime - c->poll_ticks;
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uint32_t count = c->count;
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uint32_t count_time = c->last_count_time;
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c->flags &= ~CF_PENDING;
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irq_enable();
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sendf("counter_state oid=%c time=%u count=%u count_time=%u",
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oid, time, count, count_time);
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}
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}
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DECL_TASK(counter_task);
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