wip: Simulated 3-axis accelerometer driver for new sensor API

drivers/sensor/CMakeLists.txt

@@ -41,6 +41,7 @@ add_subdirectory_ifdef(CONFIG_PMS7003		pms7003)
 add_subdirectory_ifdef(CONFIG_QDEC_NRFX		qdec_nrfx)
 add_subdirectory_ifdef(CONFIG_TEMP_NRF5		nrf5)
 add_subdirectory_ifdef(CONFIG_SHT3XD		sht3xd)
+add_subdirectory_ifdef(CONFIG_SIMACCEL		simaccel)
 add_subdirectory_ifdef(CONFIG_SX9500		sx9500)
 add_subdirectory_ifdef(CONFIG_TH02		    th02)
 add_subdirectory_ifdef(CONFIG_TMP007		tmp007)

drivers/sensor/simaccel/CMakeList.txt

@@ -0,0 +1,3 @@
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_SIMACCEL simaccel.c)

drivers/sensor/simaccel/Kconfig

@@ -0,0 +1,36 @@
+# Kconfig - SIMACCEL simulated 3-axis accelerometer sensor driver
+
+#
+# Copyright (c) 2019 Kevin Townsend
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig SIMACCEL
+	bool "SIMACCEL simulated accelerometer sensor driver"
+	help
+	  Enable simulated 3-axis accelerometer sensor driver.
+
+if SIMACCEL
+
+choice
+	prompt "Measurements per second"
+	default SIMACCEL_MPS_1
+	help
+	  Number of measurements per second.
+
+config SIMACCEL_MPS_1
+	bool "1"
+
+config SIMACCEL_MPS_10
+	bool "10"
+
+config SIMACCEL_MPS_100
+	bool "100"
+
+config SIMACCEL_MPS_1000
+	bool "1000"
+
+endchoice
+
+endif # SIMACCEL

drivers/sensor/simaccel/simaccel.c

@@ -0,0 +1,81 @@
+/* simaccel.c - Simulated driver for a 3-axis accelerometer. */
+
+/*
+ * Copyright (c) 2019 Kevin Townsend.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <sensor.h>
+#include <init.h>
+#include <misc/byteorder.h>
+#include <misc/__assert.h>
+
+#include "simaccel.h"
+
+/**
+ * @brief Retrieves a set of data samples from the sensor.
+ *
+ * @param dev   Pointer to the `device` used when executing the read attempt.
+ * @param chan  The `sensor_channel` to request data from. This should
+ *              normally be `SENSOR_CHAN_ALL`.
+ *
+ * @return 0 on success, otherwise an appropriate error code.
+ */
+static int simaccel_sample_fetch(struct device *dev, enum sensor_channel chan)
+{
+	struct simaccel_data *data = dev->driver_data;
+	u8_t buf[6] = { 0 };
+	int ret;
+
+	__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
+
+    /* TODO: Generate sensible random data or use a known lookup table. */
+    data->range = 2;
+    data->xdata = (s16_t)buf[1] << 8 | buf[0];
+    data->ydata = (s16_t)buf[3] << 8 | buf[2];
+    data->zdata = (s16_t)buf[5] << 8 | buf[4];
+
+	return 0;
+}
+
+static int simaccel_channel_get(struct device *dev,
+			      enum sensor_channel chan,
+			      struct sensor_value *val)
+{
+	struct simaccel_data *data = dev->driver_data;
+
+	switch (chan) {
+    	default:
+    		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct sensor_driver_api simaccel_api_funcs = {
+	.sample_fetch = simaccel_sample_fetch,
+	.channel_get = simaccel_channel_get,
+};
+
+/**
+ *  Attempts to initialise a simaccel device.
+ *
+ *  @param dev The 'device' to bind the driver instance to.
+ *
+ *  @return 0 on success, otherwise an appropriate error code.
+ */
+int simaccel_init(struct device *dev)
+{
+	struct simaccel_data *data = dev->driver_data;
+
+    return 0;
+}
+
+static struct simaccel_data simaccel_data;
+
+DEVICE_AND_API_INIT(simaccel, "simaccel",
+            simaccel_init, &simaccel_data,
+		    NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
+		    &simaccel_api_funcs);

drivers/sensor/simaccel/simaccel.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2019 Kevin Townsend
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_DRIVERS_SENSOR_SIMACCEL_SIMACCEL_H_
+#define ZEPHYR_DRIVERS_SENSOR_SIMACCEL_SIMACCEL_H_
+
+#include <zephyr/types.h>
+#include <device.h>
+
+struct simaccel_data {
+    /** Accelerometer measurement (+/-G). Valid values are 2, 4, 8 or 16. */
+    u8_t range;
+	/** Raw x-axis data. */
+	s16_t xdata;
+    /** Raw y-axis data. */
+    s16_t ydata;
+    /** Raw z-axis data. */
+    s16_t zdata;
+};
+
+#endif /* ZEPHYR_DRIVERS_SENSOR_SIMACCEL_SIMACCEL_H_ */