drivers: sensor: Add support for MMA8451Q (3-axis accelerometer)

Only basic features supported initially but more could be added from:
https://www.nxp.com/docs/en/data-sheet/MMA8451Q.pdf

fixes #9006

A sample app will be provided in a separate PR.

Signed-off-by: Lars Knudsen <larsgk@gmail.com>

drivers/sensor/CMakeLists.txt

@@ -29,6 +29,7 @@ add_subdirectory_ifdef(CONFIG_LSM9DS0_MFD	lsm9ds0_mfd)
 add_subdirectory_ifdef(CONFIG_MAX30101		max30101)
 add_subdirectory_ifdef(CONFIG_MAX44009		max44009)
 add_subdirectory_ifdef(CONFIG_MCP9808		mcp9808)
+add_subdirectory_ifdef(CONFIG_MMA8451Q		mma8451q)
 add_subdirectory_ifdef(CONFIG_MPU6050		mpu6050)
 add_subdirectory_ifdef(CONFIG_PMS7003		pms7003)
 add_subdirectory_ifdef(CONFIG_TEMP_NRF5		nrf5)

drivers/sensor/Kconfig

@@ -101,6 +101,8 @@ source "drivers/sensor/max44009/Kconfig"
 
 source "drivers/sensor/mcp9808/Kconfig"
 
+source "drivers/sensor/mma8451q/Kconfig"
+
 source "drivers/sensor/mpu6050/Kconfig"
 
 source "drivers/sensor/nrf5/Kconfig"

drivers/sensor/mma8451q/CMakeLists.txt

@@ -0,0 +1,9 @@
+#
+# Copyright (c) 2018 Lars Knudsen
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_MMA8451Q mma8451q.c)

drivers/sensor/mma8451q/Kconfig

@@ -0,0 +1,58 @@
+# Kconfig - MMA8451Q Accelerometer sensor configuration options
+#
+# Copyright (c) 2018 Lars Knudsen
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig MMA8451Q
+	bool "MMA8451Q Accelerometer driver"
+	depends on I2C
+	help
+	  Enable driver for MMA8451Q Accelerometer.
+
+if !HAS_DTS_I2C_DEVICE
+
+config MMA8451Q_NAME
+	string "Device name"
+	depends on MMA8451Q
+	default "MMA8451Q"
+
+config MMA8451Q_I2C_NAME
+	string "I2C device name"
+	depends on MMA8451Q
+	default I2C_0_NAME
+
+config MMA8451Q_I2C_ADDRESS
+	hex
+	prompt "I2C address for MMA8451Q Sensor"
+	depends on MMA8451Q
+	default 0x1D
+	help
+	  I2C address of the MMA8451Q sensor.
+	  0x1D: I2C_ADDR
+
+endif # !HAS_DTS_I2C_DEVICE
+
+config MMA8451Q_WHOAMI
+	hex "WHOAMI value"
+	depends on MMA8451Q
+	default 0x1A
+	help
+	  The whoami value for MMA8451Q (0x1A).
+
+choice
+	prompt "Range"
+	depends on MMA8451Q
+	default MMA8451Q_RANGE_2G
+
+config MMA8451Q_RANGE_8G
+	bool "8g (0.976 mg/LSB)"
+
+config MMA8451Q_RANGE_4G
+	bool "4g (0.488 mg/LSB)"
+
+config MMA8451Q_RANGE_2G
+	bool "2g (0.244 mg/LSB)"
+
+endchoice

drivers/sensor/mma8451q/mma8451q.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2018 Lars Knudsen
+ * Copyright (c) 2016 Freescale Semiconductor, Inc. (sample conversion)
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <device.h>
+#include <i2c.h>
+#include <kernel.h>
+#include <misc/util.h>
+#include <sensor.h>
+
+#include "mma8451q.h"
+
+/* Data-sheet: https://www.nxp.com/docs/en/data-sheet/MMA8451Q.pdf */
+
+static int mma8451q_sample_fetch(struct device *dev, enum sensor_channel chan)
+{
+	const struct mma8451q_config *config = dev->config->config_info;
+	struct mma8451q_data *data = dev->driver_data;
+
+	u8_t buf[6];
+
+	/* Read data from all three axes at the same time. */
+	if (i2c_burst_read(data->i2c, config->i2c_address,
+			   MMA8451Q_OUT_X_MSB, buf, 6) < 0) {
+		SYS_LOG_ERR("Could not read accelerometer data");
+		return -EIO;
+	}
+
+	data->x = (buf[0] << 8) | buf[1];
+	data->y = (buf[2] << 8) | buf[3];
+	data->z = (buf[4] << 8) | buf[5];
+
+	return 0;
+}
+
+static void mma8451q_accel_convert(struct sensor_value *val, s16_t raw,
+				   enum mma8451q_range range)
+{
+	u8_t frac_bits;
+	s64_t micro_ms2;
+
+	/* The range encoding is convenient to compute the number of fractional
+	 * bits:
+	 * - 2g mode (range = 0) has 14 fractional bits
+	 * - 4g mode (range = 1) has 13 fractional bits
+	 * - 8g mode (range = 2) has 12 fractional bits
+	 */
+	frac_bits = 14 - range;
+
+	/* Convert units to micro m/s^2. Intermediate results before the shift
+	 * are 40 bits wide.
+	 */
+	micro_ms2 = (raw * SENSOR_G) >> frac_bits;
+
+	/* The maximum possible value is 8g, which in units of micro m/s^2
+	 * always fits into 32-bits. Cast down to s32_t so we can use a
+	 * faster divide.
+	 */
+	val->val1 = (s32_t) micro_ms2 / 1000000;
+	val->val2 = (s32_t) micro_ms2 % 1000000;
+}
+
+static int mma8451q_channel_get(struct device *dev,
+				   enum sensor_channel chan,
+				   struct sensor_value *val)
+{
+	const struct mma8451q_config *config = dev->config->config_info;
+	struct mma8451q_data *data = dev->driver_data;
+
+	switch (chan) {
+	case SENSOR_CHAN_ACCEL_X:
+		mma8451q_accel_convert(val, data->x, config->range);
+		break;
+
+	case SENSOR_CHAN_ACCEL_Y:
+		mma8451q_accel_convert(val, data->y, config->range);
+		break;
+
+	case SENSOR_CHAN_ACCEL_Z:
+		mma8451q_accel_convert(val, data->z, config->range);
+		break;
+
+	case SENSOR_CHAN_ACCEL_XYZ:
+		mma8451q_accel_convert(val++, data->x, config->range);
+		mma8451q_accel_convert(val++, data->y, config->range);
+		mma8451q_accel_convert(val++, data->z, config->range);
+		break;
+
+	default:
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+static const struct sensor_driver_api mma8451q_driver_api = {
+	.sample_fetch = mma8451q_sample_fetch,
+	.channel_get = mma8451q_channel_get,
+};
+
+int mma8451q_init(struct device *dev)
+{
+	const struct mma8451q_config *config = dev->config->config_info;
+	struct mma8451q_data *data = dev->driver_data;
+
+	data->i2c = device_get_binding(config->i2c_name);
+	if (data->i2c == NULL) {
+		SYS_LOG_ERR("Failed to get pointer to %s device!",
+				config->i2c_name);
+		return -EINVAL;
+	}
+
+	u8_t whoami;
+
+	if (i2c_reg_read_byte(data->i2c, config->i2c_address,
+			      MMA8451Q_REG_WHOAMI, &whoami)) {
+		SYS_LOG_ERR("Could not get WHOAMI value");
+		return -EIO;
+	}
+
+	if (whoami != config->whoami) {
+		SYS_LOG_ERR("WHOAMI value received 0x%x, expected 0x%x",
+			    whoami, MMA8451Q_REG_WHOAMI);
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+				   MMA8451Q_CTRL_REG1, 0) < 0) {
+		SYS_LOG_ERR("Could not set accel in config mode");
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+				   MMA8451Q_XYZ_DATA_CFG, config->range) < 0) {
+		SYS_LOG_ERR("Could not set range");
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+				   MMA8451Q_CTRL_REG2, 0) < 0) {
+		SYS_LOG_ERR("Could not set to normal mode");
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+				   MMA8451Q_CTRL_REG3, 0) < 0) {
+		SYS_LOG_ERR("Could not set to low polarity, push-pull output");
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+				   MMA8451Q_CTRL_REG1, 0x09) < 0) {
+		SYS_LOG_ERR("Could not set data rate to 800Hz");
+		return -EIO;
+	}
+
+	SYS_LOG_DBG("Init complete");
+
+	return 0;
+}
+
+static const struct mma8451q_config mma8451q_config = {
+	.i2c_name = CONFIG_MMA8451Q_I2C_NAME,
+	.i2c_address = CONFIG_MMA8451Q_I2C_ADDRESS,
+	.whoami = CONFIG_MMA8451Q_WHOAMI,
+#if CONFIG_MMA8451Q_RANGE_8G
+	.range = MMA8451Q_RANGE_8G,
+#elif CONFIG_MMA8451Q_RANGE_4G
+	.range = MMA8451Q_RANGE_4G,
+#else
+	.range = MMA8451Q_RANGE_2G,
+#endif
+};
+
+static struct mma8451q_data mma8451q_data;
+
+DEVICE_AND_API_INIT(mma8451q, CONFIG_MMA8451Q_NAME, mma8451q_init,
+	&mma8451q_data, &mma8451q_config, POST_KERNEL,
+	CONFIG_SENSOR_INIT_PRIORITY, &mma8451q_driver_api);

drivers/sensor/mma8451q/mma8451q.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2018 Lars Knudsen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _SENSOR_MMA8451Q
+#define _SENSOR_MMA8451Q
+
+#include <device.h>
+#include <misc/util.h>
+
+#define MMA8451Q_OUT_X_MSB		0x01
+#define MMA8451Q_OUT_Y_MSB		0x03
+#define MMA8451Q_OUT_Z_MSB		0x05
+
+#define MMA8451Q_REG_WHOAMI		0x0d
+
+#define MMA8451Q_XYZ_DATA_CFG		0x0E
+
+#define MMA8451Q_CTRL_REG1		0x2A
+#define MMA8451Q_CTRL_REG2		0x2B
+#define MMA8451Q_CTRL_REG3		0x2C
+#define MMA8451Q_CTRL_REG4		0x2D
+#define MMA8451Q_CTRL_REG5		0x2E
+
+#define MMA8451Q_NUM_ACCEL_CHANNELS	3
+
+enum mma8451q_channel {
+	MMA8451Q_CHANNEL_ACCEL_X	= 0,
+	MMA8451Q_CHANNEL_ACCEL_Y,
+	MMA8451Q_CHANNEL_ACCEL_Z,
+};
+
+enum mma8451q_range {
+	MMA8451Q_RANGE_2G	= 0,
+	MMA8451Q_RANGE_4G,
+	MMA8451Q_RANGE_8G,
+};
+
+struct mma8451q_config {
+	char *i2c_name;
+	u8_t i2c_address;
+	u8_t whoami;
+	enum mma8451q_range range;
+};
+
+struct mma8451q_data {
+	struct device *i2c;
+	s16_t x;
+	s16_t y;
+	s16_t z;
+};
+
+#define SYS_LOG_DOMAIN "MMA8451Q"
+#define SYS_LOG_LEVEL CONFIG_SYS_LOG_SENSOR_LEVEL
+#include <logging/sys_log.h>
+
+#endif /* _SENSOR_MMA8451Q_ */

dts/bindings/sensor/nxp,mma8451q.yaml

@@ -0,0 +1,22 @@
+#
+# Copyright (c) 2018, Lars Knudsen
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+title: MMA8451Q 3-axis Accelerometer
+id: nxp,mma8451q
+version: 0.1
+
+description: >
+    This is a representation of the MMA8451Q 3-axis Accelerometer
+    sensor
+
+inherits:
+    !include i2c-device.yaml
+
+properties:
+    compatible:
+      constraint: "nxp,mma8451q"
+
+...