From 94f7ed356f0cb97b6cb54899e39822cba99ce964 Mon Sep 17 00:00:00 2001
From: Thomas Stranger <thomas.stranger@outlook.com>
Date: Thu, 8 Jul 2021 17:15:52 +0200
Subject: [PATCH] drivers: serial: add a dummy driver for vnd,serial

This commit adds a serial dummy driver compatible to vnd,serial.
This is needed that devices can access the uart device in tests
like tests/drivers/build_all/... .

Add myself as codeowner to avoid complicance check failure.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>
---
 CODEOWNERS                    |  2 ++
 drivers/serial/CMakeLists.txt |  2 ++
 drivers/serial/Kconfig        |  2 ++
 drivers/serial/Kconfig.test   |  8 +++++
 drivers/serial/serial_test.c  | 67 +++++++++++++++++++++++++++++++++++
 5 files changed, 81 insertions(+)
 create mode 100644 drivers/serial/Kconfig.test
 create mode 100644 drivers/serial/serial_test.c

diff --git a/CODEOWNERS b/CODEOWNERS
index 30daa8ce994..e219714cb4a 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -301,6 +301,8 @@
 /drivers/serial/*nuvoton*                 @ssekar15
 /drivers/serial/*apbuart*                 @martin-aberg
 /drivers/serial/*rcar*                    @aaillet
+/drivers/serial/Kconfig.test              @str4t0m
+/drivers/serial/serial_test.c             @str4t0m
 /drivers/disk/                            @jfischer-no
 /drivers/disk/sdmmc_sdhc.h                @JunYangNXP
 /drivers/disk/sdmmc_spi.c                 @JunYangNXP
diff --git a/drivers/serial/CMakeLists.txt b/drivers/serial/CMakeLists.txt
index 51f792d61ae..03cd54d84ff 100644
--- a/drivers/serial/CMakeLists.txt
+++ b/drivers/serial/CMakeLists.txt
@@ -46,3 +46,5 @@ if(CONFIG_UART_NATIVE_POSIX)
   zephyr_library_compile_definitions(NO_POSIX_CHEATS)
   zephyr_library_sources(uart_native_posix.c)
 endif()
+
+zephyr_library_sources_ifdef(CONFIG_SERIAL_TEST		serial_test.c)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index dc6b1640e2f..637c55f02b3 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -151,4 +151,6 @@ source "drivers/serial/Kconfig.apbuart"
 
 source "drivers/serial/Kconfig.rcar"
 
+source "drivers/serial/Kconfig.test"
+
 endif # SERIAL
diff --git a/drivers/serial/Kconfig.test b/drivers/serial/Kconfig.test
new file mode 100644
index 00000000000..9560b209639
--- /dev/null
+++ b/drivers/serial/Kconfig.test
@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Thomas Stranger
+# SPDX-License-Identifier: Apache-2.0
+
+DT_COMPAT_VND_SERIAL := vnd,serial
+
+# Hidden option to enable the vnd,serial dummy driver used in testing.
+config SERIAL_TEST
+	def_bool $(dt_compat_enabled,$(DT_COMPAT_VND_SERIAL))
diff --git a/drivers/serial/serial_test.c b/drivers/serial/serial_test.c
new file mode 100644
index 00000000000..d70e110e4b6
--- /dev/null
+++ b/drivers/serial/serial_test.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2021, Thomas Stranger
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This is not a real serial driver. It is used to instantiate struct
+ * devices for the "vnd,serial" devicetree compatible used in test code.
+ */
+
+#include <zephyr.h>
+#include <drivers/uart.h>
+
+#define DT_DRV_COMPAT vnd_serial
+
+static int serial_vnd_poll_in(const struct device *dev, unsigned char *c)
+{
+	return -ENOTSUP;
+}
+
+static void serial_vnd_poll_out(const struct device *dev, unsigned char c)
+{
+}
+
+static int serial_vnd_err_check(const struct device *dev)
+{
+	return -ENOTSUP;
+}
+
+#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
+static int serial_vnd_configure(const struct device *dev,
+				const struct uart_config *cfg)
+{
+	return -ENOTSUP;
+}
+
+static int serial_vnd_config_get(const struct device *dev,
+				 struct uart_config *cfg)
+{
+	return -ENOTSUP;
+}
+#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */
+
+
+static const struct uart_driver_api serial_vnd_api = {
+	.poll_in = serial_vnd_poll_in,
+	.poll_out = serial_vnd_poll_out,
+	.err_check = serial_vnd_err_check,
+#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
+	.configure = serial_vnd_configure,
+	.config_get = serial_vnd_config_get,
+#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */
+};
+
+static int serial_vnd_init(const struct device *dev)
+{
+	return 0;
+}
+
+#define VND_SERIAL_INIT(n)						\
+	DEVICE_DT_INST_DEFINE(n, &serial_vnd_init, NULL,		\
+			      NULL, NULL, POST_KERNEL,			\
+			      CONFIG_KERNEL_INIT_PRIORITY_DEVICE,	\
+			      &serial_vnd_api);
+
+DT_INST_FOREACH_STATUS_OKAY(VND_SERIAL_INIT)