sensor: add driver for AK8975 magnetometer
Add driver for the AK8975 3-axis electonic compass. Datasheet: http://www.akm.com/akm/en/file/datasheet/AK8975.pdf Change-Id: I427f954396c8991a153e4447d746b855d19cb60d Origin: Original Signed-off-by: Bogdan Davidoaia <bogdan.m.davidoaia@intel.com>
This commit is contained in:
Bogdan Davidoaia
parent
01062d97aa
commit
c4c01a92f3
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@ -23,6 +23,8 @@ menuconfig SENSOR
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help
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Include sensor drivers in system config
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source "drivers/sensor/Kconfig.ak8975"
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source "drivers/sensor/Kconfig.bma280"
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source "drivers/sensor/Kconfig.bmc150_magn"
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77
drivers/sensor/Kconfig.ak8975
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77
drivers/sensor/Kconfig.ak8975
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@ -0,0 +1,77 @@
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# Kconfig.ak8975 - AK8975 magnetometer configuration options
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#
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# Copyright (c) 2016 Intel Corporation
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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menuconfig AK8975
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bool
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prompt "AK8975 Magnetometer"
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depends on SENSOR && I2C
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default n
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help
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Enable driver for AK8975 magnetometer.
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config AK8975_SYS_LOG_LEVEL
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int "AK8975 Log level"
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depends on SYS_LOG && AK8975
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default 0
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range 0 4
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help
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Sets log level for AK8975 driver.
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Levels are:
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0 OFF, do not write
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1 ERROR, only write SYS_LOG_ERR
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2 WARNING, write SYS_LOG_WRN in addition to previous level
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3 INFO, write SYS_LOG_INF in addition to previous levels
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4 DEBUG, write SYS_LOG_DBG in addition to previous levels
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config AK8975_NAME
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string
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prompt "Driver name"
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default "AK8975"
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depends on AK8975
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help
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Device name with which the AK8975 sensor is identified.
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config AK8975_INIT_PRIORITY
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int
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prompt "Init priority"
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depends on AK8975
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default 70
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help
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Device driver initialization priority.
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config AK8975_I2C_ADDR
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hex
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prompt "I2C address"
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depends on AK8975
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default 0x0C
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range 0x0C 0x0F
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help
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I2C address of the AK8975 sensor. Choose:
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- 0x0C if CAD1 connected to GND nad CAD0 is connected to GND
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- 0x0D if CAD1 connected to GND nad CAD0 is connected to VDD
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- 0x0E if CAD1 connected to VDD nad CAD0 is connected to GND
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- 0x0F if CAD1 connected to VDD nad CAD0 is connected to VDD
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config AK8975_I2C_MASTER_DEV_NAME
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string
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prompt "I2C master where AK8975 is connected"
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depends on AK8975
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default "I2C_0"
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help
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Specify the device name of the I2C master device to which the
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AK8975 chip is connected.
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@ -1,5 +1,6 @@
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ccflags-y +=-I$(srctree)/drivers
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obj-$(CONFIG_AK8975) += sensor_ak8975.o
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obj-$(CONFIG_BMA280) += sensor_bma280.o
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obj-$(CONFIG_BMA280_TRIGGER) += sensor_bma280_trigger.o
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obj-$(CONFIG_BMC150_MAGN) += sensor_bmc150_magn.o
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155
drivers/sensor/sensor_ak8975.c
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155
drivers/sensor/sensor_ak8975.c
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@ -0,0 +1,155 @@
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/*
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* Copyright (c) 2016 Intel Corporation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <device.h>
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#include <i2c.h>
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#include <nanokernel.h>
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#include <sensor.h>
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#include <misc/__assert.h>
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#include <misc/byteorder.h>
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#include <misc/util.h>
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#include "sensor_ak8975.h"
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static int ak8975_sample_fetch(struct device *dev, enum sensor_channel chan)
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{
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struct ak8975_data *drv_data = dev->driver_data;
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uint8_t buf[6];
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__ASSERT(chan == SENSOR_CHAN_ALL);
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if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
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AK8975_REG_CNTL, AK8975_MODE_MEASURE) < 0) {
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SYS_LOG_ERR("Failed to start measurement.");
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return -EIO;
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}
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sys_thread_busy_wait(AK8975_MEASURE_TIME_US);
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if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
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AK8975_REG_DATA_START, buf, 6) < 0) {
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SYS_LOG_ERR("Failed to read sample data.");
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return -EIO;
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}
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drv_data->x_sample = sys_le16_to_cpu(buf[0] | (buf[1] << 8));
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drv_data->y_sample = sys_le16_to_cpu(buf[2] | (buf[3] << 8));
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drv_data->z_sample = sys_le16_to_cpu(buf[4] | (buf[5] << 8));
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return 0;
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}
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static void ak8975_convert(struct sensor_value *val, int16_t sample,
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uint8_t adjustment)
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{
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int32_t conv_val;
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conv_val = sample * AK8975_MICRO_GAUSS_PER_BIT *
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((uint16_t)adjustment + 128) / 256;
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val->type = SENSOR_VALUE_TYPE_INT_PLUS_MICRO;
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val->val1 = conv_val / 1000000;
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val->val2 = conv_val % 1000000;
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}
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static int ak8975_channel_get(struct device *dev,
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enum sensor_channel chan,
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struct sensor_value *val)
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{
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struct ak8975_data *drv_data = dev->driver_data;
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__ASSERT(chan == SENSOR_CHAN_MAGN_ANY || chan == SENSOR_CHAN_MAGN_X ||
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chan == SENSOR_CHAN_MAGN_Y || chan == SENSOR_CHAN_MAGN_Z);
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if (chan == SENSOR_CHAN_MAGN_ANY) {
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ak8975_convert(val, drv_data->x_sample, drv_data->x_adj);
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ak8975_convert(val + 1, drv_data->y_sample, drv_data->y_adj);
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ak8975_convert(val + 2, drv_data->z_sample, drv_data->z_adj);
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} else if (chan == SENSOR_CHAN_MAGN_X) {
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ak8975_convert(val, drv_data->x_sample, drv_data->x_adj);
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} else if (chan == SENSOR_CHAN_MAGN_Y) {
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ak8975_convert(val, drv_data->y_sample, drv_data->y_adj);
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} else { /* chan == SENSOR_CHAN_MAGN_Z */
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ak8975_convert(val, drv_data->z_sample, drv_data->z_adj);
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}
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return 0;
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}
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static struct sensor_driver_api ak8975_driver_api = {
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.sample_fetch = ak8975_sample_fetch,
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.channel_get = ak8975_channel_get,
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};
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static int ak8975_read_adjustment_data(struct ak8975_data *drv_data)
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{
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uint8_t buf[3];
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if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
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AK8975_REG_CNTL, AK8975_MODE_FUSE_ACCESS) < 0) {
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SYS_LOG_ERR("Failed to set chip in fuse access mode.");
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return -EIO;
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}
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if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
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AK8975_REG_ADJ_DATA_START, buf, 3) < 0) {
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SYS_LOG_ERR("Failed to read adjustment data.");
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return -EIO;
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}
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drv_data->x_adj = buf[0];
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drv_data->y_adj = buf[1];
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drv_data->z_adj = buf[2];
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return 0;
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}
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int ak8975_init(struct device *dev)
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{
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struct ak8975_data *drv_data = dev->driver_data;
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uint8_t id;
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drv_data->i2c = device_get_binding(CONFIG_AK8975_I2C_MASTER_DEV_NAME);
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if (drv_data->i2c == NULL) {
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SYS_LOG_ERR("Failed to get pointer to %s device!",
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CONFIG_AK8975_I2C_MASTER_DEV_NAME);
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return -EINVAL;
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}
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/* check chip ID */
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if (i2c_reg_read_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
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AK8975_REG_CHIP_ID, &id) < 0) {
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SYS_LOG_ERR("Failed to read chip ID.");
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return -EIO;
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}
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if (id != AK8975_CHIP_ID) {
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SYS_LOG_ERR("Invalid chip ID.");
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return -EINVAL;
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}
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if (ak8975_read_adjustment_data(drv_data) < 0) {
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return -EIO;
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}
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dev->driver_api = &ak8975_driver_api;
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return 0;
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}
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struct ak8975_data ak8975_data;
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DEVICE_INIT(ak8975, CONFIG_AK8975_NAME, ak8975_init, &ak8975_data,
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NULL, SECONDARY, CONFIG_AK8975_INIT_PRIORITY);
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52
drivers/sensor/sensor_ak8975.h
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52
drivers/sensor/sensor_ak8975.h
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@ -0,0 +1,52 @@
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/*
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* Copyright (c) 2016 Intel Corporation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __SENSOR_AK8975__
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#define __SENSOR_AK8975__
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#include <device.h>
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#define SYS_LOG_DOMAIN "AK8975"
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#define SYS_LOG_LEVEL CONFIG_AK8975_SYS_LOG_LEVEL
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#include <misc/sys_log.h>
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#define AK8975_REG_CHIP_ID 0x00
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#define AK8975_CHIP_ID 0x48
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#define AK8975_REG_DATA_START 0x03
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#define AK8975_REG_CNTL 0x0A
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#define AK8975_MODE_MEASURE 0x01
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#define AK8975_MODE_FUSE_ACCESS 0x0F
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#define AK8975_REG_ADJ_DATA_START 0x10
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#define AK8975_MEASURE_TIME_US 9000
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#define AK8975_MICRO_GAUSS_PER_BIT 3000
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struct ak8975_data {
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struct device *i2c;
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int16_t x_sample;
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int16_t y_sample;
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int16_t z_sample;
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uint8_t x_adj;
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uint8_t y_adj;
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uint8_t z_adj;
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};
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#endif /* __SENSOR_AK8975__ */
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