[io_bus] Initial implementation (#8227)

CODEOWNERS

@@ -226,6 +226,7 @@ esphome/components/inkplate6/* @jesserockz
 esphome/components/integration/* @OttoWinter
 esphome/components/internal_temperature/* @Mat931
 esphome/components/interval/* @esphome/core
+esphome/components/io_bus/* @clydebarrow
 esphome/components/jsn_sr04t/* @Mafus1
 esphome/components/json/* @OttoWinter
 esphome/components/kamstrup_kmp/* @cfeenstra1024

esphome/components/io_bus/__init__.py

@@ -0,0 +1,8 @@
+import esphome.codegen as cg
+
+io_bus_ns = cg.esphome_ns.namespace("io_bus")
+IOBus = io_bus_ns.class_("IOBus")
+
+CODEOWNERS = ["@clydebarrow"]
+# Allow configuration in yaml, for testing
+CONFIG_SCHEMA = {}

esphome/components/io_bus/io_bus.h

@@ -0,0 +1,73 @@
+#pragma once
+
+#include "esphome/core/log.h"
+#include "esphome/core/gpio.h"
+
+namespace esphome {
+namespace io_bus {
+
+/**
+ * A pin to replace those that don't exist.
+ */
+class NullPin : public GPIOPin {
+ public:
+  void setup() override {}
+
+  void pin_mode(gpio::Flags _) override {}
+
+  bool digital_read() override { return false; }
+
+  void digital_write(bool _) override {}
+
+  std::string dump_summary() const override { return {"Not used"}; }
+
+  gpio::Flags get_flags() const override { return gpio::Flags{}; }
+};
+
+// https://bugs.llvm.org/show_bug.cgi?id=48040
+static GPIOPin *const NULL_PIN = new NullPin();  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
+/**
+ * A class that can write a byte-oriented bus interface with CS and DC controls, typically used for
+ * LCD display controller interfacing.
+ */
+class IOBus {
+ public:
+  virtual void bus_setup() = 0;
+
+  virtual void bus_teardown() = 0;
+
+  /**
+   * Write a data array. Will not control dc or cs pins.
+   * @param data
+   * @param length
+   */
+  virtual void write_array(const uint8_t *data, size_t length) = 0;
+
+  /**
+   * Write a command followed by data. CS and DC will be controlled automatically.
+   * On return, the DC pin will be in DATA mode.
+   * @param cmd An 8 bit command. Passing -1 will suppress the command phase
+   * @param data The data to write. May be null if length==0
+   * @param length The number of data bytes to write (excludes the command byte)
+   */
+  virtual void write_cmd_data(int cmd, const uint8_t *data, size_t length) = 0;
+
+  /**
+   * Convenience function for parameterless commands.
+   * @param cmd The 8 bit command.
+   */
+  void write_cmd(uint8_t cmd) { this->write_cmd_data(cmd, nullptr, 0); }
+
+  virtual void dump_config(){};
+
+  virtual void begin_transaction() = 0;
+  virtual void end_transaction() = 0;
+
+  void set_dc_pin(GPIOPin *dc_pin) { this->dc_pin_ = dc_pin; }
+
+ protected:
+  GPIOPin *dc_pin_{io_bus::NULL_PIN};
+};
+}  // namespace io_bus
+}  // namespace esphome

tests/components/io_bus/common.yaml

@@ -0,0 +1,7 @@
+io_bus:
+
+esphome:
+  on_boot:
+    lambda: |-
+      #include "esphome/components/io_bus/io_bus.h"
+

tests/components/io_bus/test.esp32-ard.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.esp32-c3-ard.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.esp32-c3-idf.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.esp32-idf.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.esp8266-ard.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.host.yaml

@@ -0,0 +1 @@
+!include common.yaml

tests/components/io_bus/test.rp2040-ard.yaml

@@ -0,0 +1 @@
+!include common.yaml