driver/mag_lis2mdl: Add LIS2MDL magnetometer module

Add support for LIS2MDL magnetometer module in cascade mode to LSM6DSM
accelerometer module.

BRANCH=none
BUG=b:115587004
TEST=Collect magnetometer readings through ectool motionsense

Change-Id: I06d11777543f14a557ebe6524f7ede15440f1f1e
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1257504
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>

3 files changed, 180 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index a9f266ba16..5d48edb242 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -15,6 +15,7 @@ driver-$(CONFIG_ACCELGYRO_BMI160)+=accelgyro_bmi160.o
 driver-$(CONFIG_MAG_BMI160_BMM150)+=mag_bmm150.o
 driver-$(CONFIG_ACCELGYRO_LSM6DSM)+=accelgyro_lsm6dsm.o stm_mems_common.o
 driver-$(CONFIG_ACCEL_LIS2D_COMMON)+=accel_lis2dh.o stm_mems_common.o
+driver-$(CONFIG_MAG_LIS2MDL)+=mag_lis2mdl.o
 driver-$(CONFIG_SENSORHUB_LSM6DSM)+=sensorhub_lsm6dsm.o
 driver-$(CONFIG_SYNC)+=sync.o
 
diff --git a/driver/mag_lis2mdl.c b/driver/mag_lis2mdl.c
new file mode 100644
index 0000000000..de0650cd38
--- /dev/null
+++ b/driver/mag_lis2mdl.c
@@ -0,0 +1,143 @@
+/* Copyright 2018 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * LIS2MDL magnetometer module for Chrome EC.
+ * This driver supports LIS2MDL magnetometer in cascade with LSM6DSx (x stands
+ * for L or M) accel/gyro module.
+ */
+
+#include "common.h"
+#include "driver/mag_lis2mdl.h"
+#include "driver/sensorhub_lsm6dsm.h"
+#include "driver/stm_mems_common.h"
+#include "task.h"
+
+#ifndef CONFIG_SENSORHUB_LSM6DSM
+#error "Need Sensor Hub LSM6DSM support"
+#endif
+
+static int irq_handler(struct motion_sensor_t *s, uint32_t *event)
+{
+	if (!s->parent) {
+		/* Sensor is not supported in direct connection/slave mode */
+		return EC_ERROR_UNIMPLEMENTED;
+	}
+	/*
+	 * Magnetometer in cascade mode. The main sensor should take
+	 * care of interrupt situation.
+	 */
+	return EC_SUCCESS;
+}
+
+static int set_data_rate(const struct motion_sensor_t *s, int rate, int rnd)
+{
+	int ret = EC_ERROR_UNIMPLEMENTED;
+	/*
+	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
+	 * the address of lsm6dsm_data is the same as a_data's. Using this
+	 * fact, we can do the following conversion. This conversion is equal
+	 * to:
+	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
+	 *     struct stprivate_data *data = &lsm_data->a_data;
+	 */
+	struct stprivate_data *data = s->drv_data;
+
+	if (!s->parent)
+		return ret;
+
+	mutex_lock(s->mutex);
+	ret = sensorhub_set_ext_data_rate(s->parent, rate, rnd,
+						&data->base.odr);
+	mutex_unlock(s->mutex);
+
+	return ret;
+}
+
+static int set_range(const struct motion_sensor_t *s, int range, int rnd)
+{
+	struct stprivate_data *data = s->drv_data;
+
+	if (range != LIS2MDL_RANGE)
+		return EC_ERROR_INVAL;
+
+	/* Range is fixed to LIS2MDL_RANGE by hardware */
+	data->base.range = LIS2MDL_RANGE;
+	return EC_SUCCESS;
+}
+
+static int get_range(const struct motion_sensor_t *s)
+{
+	struct stprivate_data *data = s->drv_data;
+
+	return data->base.range;
+}
+
+static int read(const struct motion_sensor_t *s, intv3_t v)
+{
+	int ret = EC_ERROR_UNIMPLEMENTED;
+
+	if (!s->parent)
+		return ret;
+
+	mutex_lock(s->mutex);
+	ret = sensorhub_slv0_data_read(s->parent, v);
+	mutex_unlock(s->mutex);
+
+	return ret;
+}
+
+static int init(const struct motion_sensor_t *s)
+{
+	int ret = EC_ERROR_UNIMPLEMENTED;
+	struct stprivate_data *data = s->drv_data;
+
+	if (!s->parent)
+		return ret;
+
+	mutex_lock(s->mutex);
+	/* Magnetometer in cascade mode */
+	ret = sensorhub_check_and_rst(s->parent, s->addr,
+			LIS2MDL_WHO_AM_I_REG, LIS2MDL_WHO_AM_I,
+			LIS2MDL_CFG_REG_A_ADDR, LIS2MDL_SW_RESET);
+	if (ret != EC_SUCCESS)
+		goto err_unlock;
+
+	ret = sensorhub_config_ext_reg(s->parent, s->addr,
+			LIS2MDL_CFG_REG_A_ADDR,
+			LIS2MDL_ODR_100HZ | LIS2MDL_CONT_MODE);
+	if (ret != EC_SUCCESS)
+		goto err_unlock;
+
+	ret = sensorhub_config_slv0_read(s->parent, s->addr,
+				LIS2MDL_OUT_REG, OUT_XYZ_SIZE);
+	if (ret != EC_SUCCESS)
+		goto err_unlock;
+
+	/* Set default resolution to 16 bit */
+	data->resol = LIS2MDL_RESOLUTION;
+	/* Range is fixed to LIS2MDL_RANGE by hardware */
+	data->base.range = LIS2MDL_RANGE;
+	mutex_unlock(s->mutex);
+
+	return sensor_init_done(s);
+
+err_unlock:
+	mutex_unlock(s->mutex);
+	return ret;
+}
+
+const struct accelgyro_drv lis2mdl_drv = {
+	.init = init,
+	.read = read,
+	.set_range = set_range,
+	.get_range = get_range,
+	.get_resolution = st_get_resolution,
+	.set_data_rate = set_data_rate,
+	.get_data_rate = st_get_data_rate,
+	.set_offset = st_set_offset,
+	.get_offset = st_get_offset,
+	.irq_handler = irq_handler,
+};
diff --git a/driver/mag_lis2mdl.h b/driver/mag_lis2mdl.h
new file mode 100644
index 0000000000..ae7907c225
--- /dev/null
+++ b/driver/mag_lis2mdl.h
@@ -0,0 +1,36 @@
+/* Copyright 2018 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* LIS2MSL magnetometer module for Chrome EC */
+
+#ifndef __CROS_EC_MAG_LIS2MDL_H
+#define __CROS_EC_MAG_LIS2MDL_H
+
+#define LIS2MDL_I2C_ADDR(__x)		(__x << 1)
+
+#define LIS2MDL_ADDR0			LIS2MDL_I2C_ADDR(0x1e)
+#define LIS2MDL_ADDR1			LIS2MDL_I2C_ADDR(0x1f)
+
+#define LIS2MDL_WHO_AM_I_REG		0x4f
+#define LIS2MDL_WHO_AM_I		0x40
+
+#define LIS2MDL_CFG_REG_A_ADDR		0x60
+#define LIS2MDL_SW_RESET		0x20
+#define LIS2MDL_ODR_100HZ		0xc
+#define LIS2MDL_CONT_MODE		0x0
+
+#define LIS2MDL_STATUS_REG		0x67
+#define LIS2MDL_OUT_REG			0x68
+
+#define LIS2MDL_RANGE			4915
+#define LIS2MDL_RESOLUTION		16
+
+#define LIS2MDL_ODR_MIN_VAL	10000
+#define LIS2MDL_ODR_MAX_VAL	100000
+
+extern const struct accelgyro_drv lis2mdl_drv;
+
+#endif /* __CROS_EC_MAG_LIS2MDL_H */
+