1 files changed, 157 insertions, 0 deletions
diff --git a/circuitpython/shared-module/keypad/__init__.c b/circuitpython/shared-module/keypad/__init__.c
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+++ b/circuitpython/shared-module/keypad/__init__.c
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+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Dan Halbert for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+#include "shared-bindings/keypad/__init__.h"
+#include "shared-bindings/keypad/EventQueue.h"
+#include "shared-bindings/keypad/Keys.h"
+#include "shared-bindings/keypad/KeyMatrix.h"
+#include "shared-bindings/keypad/ShiftRegisterKeys.h"
+#include "shared-bindings/supervisor/__init__.h"
+#include "supervisor/port.h"
+#include "supervisor/shared/lock.h"
+#include "supervisor/shared/tick.h"
+
+supervisor_lock_t keypad_scanners_linked_list_lock;
+static void keypad_scan_now(keypad_scanner_obj_t *self, uint64_t now);
+static void keypad_scan_maybe(keypad_scanner_obj_t *self, uint64_t now);
+
+void keypad_tick(void) {
+    // Fast path. Return immediately there are no scanners.
+    if (!MP_STATE_VM(keypad_scanners_linked_list)) {
+        return;
+    }
+
+    // Skip scanning if someone else has the lock. Don't wait for the lock.
+    if (supervisor_try_lock(&keypad_scanners_linked_list_lock)) {
+        uint64_t now = port_get_raw_ticks(NULL);
+        mp_obj_t scanner = MP_STATE_VM(keypad_scanners_linked_list);
+        while (scanner) {
+            keypad_scan_maybe(scanner, now);
+            scanner = ((keypad_scanner_obj_t *)scanner)->next;
+        }
+        supervisor_release_lock(&keypad_scanners_linked_list_lock);
+    }
+}
+
+void keypad_reset(void) {
+    while (MP_STATE_VM(keypad_scanners_linked_list)) {
+        keypad_deregister_scanner(MP_STATE_VM(keypad_scanners_linked_list));
+    }
+}
+
+// Register a Keys, KeyMatrix, etc. that will be scanned in the background
+void keypad_register_scanner(keypad_scanner_obj_t *scanner) {
+    supervisor_acquire_lock(&keypad_scanners_linked_list_lock);
+    scanner->next = MP_STATE_VM(keypad_scanners_linked_list);
+    MP_STATE_VM(keypad_scanners_linked_list) = scanner;
+    supervisor_release_lock(&keypad_scanners_linked_list_lock);
+
+    // One more request for ticks.
+    supervisor_enable_tick();
+}
+
+// Remove scanner from the list of active scanners.
+void keypad_deregister_scanner(keypad_scanner_obj_t *scanner) {
+    // One less request for ticks.
+    supervisor_disable_tick();
+
+    supervisor_acquire_lock(&keypad_scanners_linked_list_lock);
+    if (MP_STATE_VM(keypad_scanners_linked_list) == scanner) {
+        // Scanner is at the front; splice it out.
+        MP_STATE_VM(keypad_scanners_linked_list) = scanner->next;
+        scanner->next = NULL;
+    } else {
+        keypad_scanner_obj_t *current = MP_STATE_VM(keypad_scanners_linked_list);
+        while (current) {
+            if (current->next == scanner) {
+                // Splice myself out.
+                current->next = scanner->next;
+                scanner->next = NULL;
+                break;
+            }
+            current = current->next;
+        }
+    }
+    supervisor_release_lock(&keypad_scanners_linked_list_lock);
+}
+
+void keypad_construct_common(keypad_scanner_obj_t *self, mp_float_t interval, size_t max_events) {
+    size_t key_count = common_hal_keypad_generic_get_key_count(self);
+    self->currently_pressed = (bool *)gc_alloc(sizeof(bool) * key_count, false, false);
+    self->previously_pressed = (bool *)gc_alloc(sizeof(bool) * key_count, false, false);
+
+    self->interval_ticks = (mp_uint_t)(interval * 1024);   // interval * 1000 * (1024/1000)
+
+    keypad_eventqueue_obj_t *events = m_new_obj(keypad_eventqueue_obj_t);
+    events->base.type = &keypad_eventqueue_type;
+    common_hal_keypad_eventqueue_construct(events, max_events);
+    self->events = events;
+
+    // Add self to the list of active keypad scanners.
+    keypad_register_scanner(self);
+    keypad_scan_now(self, port_get_raw_ticks(NULL));
+}
+
+static void keypad_scan_now(keypad_scanner_obj_t *self, uint64_t now) {
+    self->next_scan_ticks = now + self->interval_ticks;
+    self->funcs->scan_now(self, supervisor_ticks_ms());
+}
+
+static void keypad_scan_maybe(keypad_scanner_obj_t *self, uint64_t now) {
+    if (now < self->next_scan_ticks) {
+        return;
+    }
+    keypad_scan_now(self, now);
+}
+
+void common_hal_keypad_generic_reset(void *self_in) {
+    keypad_scanner_obj_t *self = self_in;
+    size_t key_count = common_hal_keypad_generic_get_key_count(self);
+    memset(self->previously_pressed, false, key_count);
+    memset(self->currently_pressed, false, key_count);
+    keypad_scan_now(self, port_get_raw_ticks(NULL));
+}
+
+void common_hal_keypad_deinit_core(void *self_in) {
+    keypad_scanner_obj_t *self = self_in;
+    self->events = NULL;
+}
+
+bool common_hal_keypad_deinited(void *self_in) {
+    keypad_scanner_obj_t *self = self_in;
+    return !self->events;
+}
+
+size_t common_hal_keypad_generic_get_key_count(void *self_in) {
+    keypad_scanner_obj_t *self = self_in;
+    return self->funcs->get_key_count(self);
+}
+
+mp_obj_t common_hal_keypad_generic_get_events(void *self_in) {
+    keypad_scanner_obj_t *self = self_in;
+    return self->events;
+}