drivers: adc: test driver

Add a dummy driver for the `vnd,adc` compatible to allow compilation of
drivers utilising an ADC when running "build_all" tests.

Signed-off-by: Jordan Yates <[email protected]>

Author: Jordan Yates

drivers/adc/CMakeLists.txt

@@ -22,3 +22,4 @@ zephyr_library_sources_ifdef(CONFIG_USERSPACE		adc_handlers.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_CC32XX		adc_cc32xx.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_EMUL		adc_emul.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_XEC_V2		adc_mchp_xec_v2.c)
+zephyr_library_sources_ifdef(CONFIG_ADC_TEST		adc_test.c)

drivers/adc/Kconfig

@@ -68,4 +68,6 @@ source "drivers/adc/Kconfig.cc32xx"
 
 source "drivers/adc/Kconfig.adc_emul"
 
+source "drivers/adc/Kconfig.test"
+
 endif # ADC

drivers/adc/Kconfig.test

@@ -0,0 +1,10 @@
+# Copyright (c) 2021, Commonwealth Scientific and Industrial Research
+# Organisation (CSIRO) ABN 41 687 119 230.
+# SPDX-License-Identifier: Apache-2.0
+
+DT_COMPAT_VND_ADC := vnd,adc
+
+# Hidden option for turning on the dummy driver for vnd,adc devices
+# used in testing.
+config ADC_TEST
+	def_bool $(dt_compat_enabled,$(DT_COMPAT_VND_ADC))

drivers/adc/adc_test.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2021, Commonwealth Scientific and Industrial Research
+ * Organisation (CSIRO) ABN 41 687 119 230.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This is not a real ADC driver. It is used to instantiate struct
+ * devices for the "vnd,adc" devicetree compatible used in test code.
+ */
+
+#define DT_DRV_COMPAT vnd_adc
+
+#include <drivers/adc.h>
+#include <device.h>
+#include <kernel.h>
+
+static int vnd_adc_channel_setup(const struct device *dev,
+				 const struct adc_channel_cfg *channel_cfg)
+{
+	return -ENOTSUP;
+}
+
+static int vnd_adc_read(const struct device *dev,
+			const struct adc_sequence *sequence)
+{
+	return -ENOTSUP;
+}
+
+#ifdef CONFIG_ADC_ASYNC
+static int vnd_adc_read_async(const struct device *dev,
+			      const struct adc_sequence *sequence,
+			      struct k_poll_signal *async)
+{
+	return -ENOTSUP;
+}
+#endif
+
+static const struct adc_driver_api vnd_adc_api = {
+	.channel_setup = vnd_adc_channel_setup,
+	.read = vnd_adc_read,
+#ifdef CONFIG_ADC_ASYNC
+	.read_async = vnd_adc_read_async,
+#endif
+};
+
+static int vnd_adc_init(const struct device *dev)
+{
+	return 0;
+}
+
+#define VND_ADC_INIT(n)						  \
+	DEVICE_DT_INST_DEFINE(n, &vnd_adc_init, NULL,		  \
+			      NULL, NULL, POST_KERNEL,		  \
+			      CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
+			      &vnd_adc_api);
+
+DT_INST_FOREACH_STATUS_OKAY(VND_ADC_INIT)