Add SN74x138 demultiplexer driver (#16217)

1 files changed, 48 insertions, 0 deletions

diff --git a/drivers/gpio/sn74x138.h b/drivers/gpio/sn74x138.h
new file mode 100644
index 0000000000..d4d0b6574d
--- /dev/null
+++ b/drivers/gpio/sn74x138.h
@@ -0,0 +1,48 @@
+/* Copyright 2022
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * Driver for 74x138 3-to-8 decoder/demultiplexer with inverting outputs
+ * https://assets.nexperia.com/documents/data-sheet/74HC_HCT138.pdf
+ */
+
+/**
+ * Initialize the address and output enable pins.
+ */
+void sn74x138_init(void);
+
+/**
+ * Set the enabled state.
+ *
+ * When enabled is true, pulls the E1 and E2 pins low, and the E3 pin high.
+ *
+ * \param enabled The enable state to set.
+ */
+void sn74x138_set_enabled(bool enabled);
+
+/**
+ * Set the output pin address.
+ * 
+ * The selected output pin will be pulled low, while the remaining output pins will be high.
+ *
+ * \param address The address to set, from 0 to 7.
+ */
+void sn74x138_set_addr(uint8_t address);