efm32: driver: implement direct gpio key driver

Signed-off-by: perigoso <perigoso@riseup.net>

Author: perigoso

config/families/efm32gg12b.toml

@@ -37,6 +37,7 @@ source = [
 	'usb.c',
 	'usb_descriptors.c',
 	'hal/hid.c',
+	'driver/key_direct.c',
 ]
 
 [dependencies]

src/platform/efm32gg/driver/key_direct.c

@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: MIT
+ * SPDX-FileCopyrightText: 2021 Rafael Silva <perigoso@riseup.net>
+ */
+
+#include "platform/efm32gg/driver/key_direct.h"
+#include "platform/efm32gg/systick.h"
+
+struct key_direct_t key_direct_init(struct gpio_pin_t pin, u8 active_low)
+{
+	struct key_direct_t key;
+
+	key.pin = pin;
+	key.active_low = active_low;
+	key.key.key_status = key_released;
+	key.change_timestamp = systick_get_ticks();
+
+	return key;
+}
+
+void key_direct_update(struct key_direct_t *key)
+{
+	enum key_status_t last_status = key->key.key_status;
+
+	key->key.key_status = (gpio_get(key->pin) ^ key->active_low) ? key_pressed : key_released;
+
+	if (key->key.key_status != last_status)
+		key->change_timestamp = systick_get_ticks();
+
+	key->key.key_t_delta = systick_get_ticks() - key->change_timestamp;
+}

src/platform/efm32gg/driver/key_direct.h

@@ -0,0 +1,22 @@
+/*
+ * SPDX-License-Identifier: MIT
+ * SPDX-FileCopyrightText: 2021 Rafael Silva <perigoso@riseup.net>
+ */
+
+#pragma once
+
+#include "util/types.h"
+
+#include "platform/efm32gg/gpio.h"
+
+#include "key_actions/key_actions.h"
+
+struct key_direct_t {
+	struct gpio_pin_t pin;
+	u32 change_timestamp;
+	u8 active_low : 1;
+	struct key_t key;
+};
+
+struct key_direct_t key_direct_init(struct gpio_pin_t pin, u8 active_low);
+void key_direct_update(struct key_direct_t *key);