| /* |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <device.h> |
| #include <i2c.h> |
| #include <kernel.h> |
| #include <sensor.h> |
| #include <misc/__assert.h> |
| #include <misc/byteorder.h> |
| #include <misc/util.h> |
| |
| #include "ak8975.h" |
| |
| static int ak8975_sample_fetch(struct device *dev, enum sensor_channel chan) |
| { |
| struct ak8975_data *drv_data = dev->driver_data; |
| u8_t buf[6]; |
| |
| __ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL); |
| |
| if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR, |
| AK8975_REG_CNTL, AK8975_MODE_MEASURE) < 0) { |
| SYS_LOG_ERR("Failed to start measurement."); |
| return -EIO; |
| } |
| |
| k_busy_wait(AK8975_MEASURE_TIME_US); |
| |
| if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR, |
| AK8975_REG_DATA_START, buf, 6) < 0) { |
| SYS_LOG_ERR("Failed to read sample data."); |
| return -EIO; |
| } |
| |
| drv_data->x_sample = sys_le16_to_cpu(buf[0] | (buf[1] << 8)); |
| drv_data->y_sample = sys_le16_to_cpu(buf[2] | (buf[3] << 8)); |
| drv_data->z_sample = sys_le16_to_cpu(buf[4] | (buf[5] << 8)); |
| |
| return 0; |
| } |
| |
| static void ak8975_convert(struct sensor_value *val, s16_t sample, |
| u8_t adjustment) |
| { |
| s32_t conv_val; |
| |
| conv_val = sample * AK8975_MICRO_GAUSS_PER_BIT * |
| ((u16_t)adjustment + 128) / 256; |
| val->val1 = conv_val / 1000000; |
| val->val2 = conv_val % 1000000; |
| } |
| |
| static int ak8975_channel_get(struct device *dev, |
| enum sensor_channel chan, |
| struct sensor_value *val) |
| { |
| struct ak8975_data *drv_data = dev->driver_data; |
| |
| __ASSERT_NO_MSG(chan == SENSOR_CHAN_MAGN_XYZ || |
| chan == SENSOR_CHAN_MAGN_X || |
| chan == SENSOR_CHAN_MAGN_Y || |
| chan == SENSOR_CHAN_MAGN_Z); |
| |
| if (chan == SENSOR_CHAN_MAGN_XYZ) { |
| ak8975_convert(val, drv_data->x_sample, drv_data->x_adj); |
| ak8975_convert(val + 1, drv_data->y_sample, drv_data->y_adj); |
| ak8975_convert(val + 2, drv_data->z_sample, drv_data->z_adj); |
| } else if (chan == SENSOR_CHAN_MAGN_X) { |
| ak8975_convert(val, drv_data->x_sample, drv_data->x_adj); |
| } else if (chan == SENSOR_CHAN_MAGN_Y) { |
| ak8975_convert(val, drv_data->y_sample, drv_data->y_adj); |
| } else { /* chan == SENSOR_CHAN_MAGN_Z */ |
| ak8975_convert(val, drv_data->z_sample, drv_data->z_adj); |
| } |
| |
| return 0; |
| } |
| |
| static const struct sensor_driver_api ak8975_driver_api = { |
| .sample_fetch = ak8975_sample_fetch, |
| .channel_get = ak8975_channel_get, |
| }; |
| |
| static int ak8975_read_adjustment_data(struct ak8975_data *drv_data) |
| { |
| u8_t buf[3]; |
| |
| if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR, |
| AK8975_REG_CNTL, AK8975_MODE_FUSE_ACCESS) < 0) { |
| SYS_LOG_ERR("Failed to set chip in fuse access mode."); |
| return -EIO; |
| } |
| |
| if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR, |
| AK8975_REG_ADJ_DATA_START, buf, 3) < 0) { |
| SYS_LOG_ERR("Failed to read adjustment data."); |
| return -EIO; |
| } |
| |
| drv_data->x_adj = buf[0]; |
| drv_data->y_adj = buf[1]; |
| drv_data->z_adj = buf[2]; |
| |
| return 0; |
| } |
| |
| int ak8975_init(struct device *dev) |
| { |
| struct ak8975_data *drv_data = dev->driver_data; |
| u8_t id; |
| |
| drv_data->i2c = device_get_binding(CONFIG_AK8975_I2C_MASTER_DEV_NAME); |
| if (drv_data->i2c == NULL) { |
| SYS_LOG_ERR("Failed to get pointer to %s device!", |
| CONFIG_AK8975_I2C_MASTER_DEV_NAME); |
| return -EINVAL; |
| } |
| |
| #ifdef CONFIG_MPU9150 |
| /* wake up MPU9150 chip */ |
| if (i2c_reg_update_byte(drv_data->i2c, MPU9150_I2C_ADDR, |
| MPU9150_REG_PWR_MGMT1, MPU9150_SLEEP_EN, |
| 0) < 0) { |
| SYS_LOG_ERR("Failed to wake up MPU9150 chip."); |
| return -EIO; |
| } |
| |
| /* enable MPU9150 pass-though to have access to AK8975 */ |
| if (i2c_reg_update_byte(drv_data->i2c, MPU9150_I2C_ADDR, |
| MPU9150_REG_BYPASS_CFG, MPU9150_I2C_BYPASS_EN, |
| MPU9150_I2C_BYPASS_EN) < 0) { |
| SYS_LOG_ERR("Failed to enable pass-through mode for MPU9150."); |
| return -EIO; |
| } |
| #endif |
| |
| /* check chip ID */ |
| if (i2c_reg_read_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR, |
| AK8975_REG_CHIP_ID, &id) < 0) { |
| SYS_LOG_ERR("Failed to read chip ID."); |
| return -EIO; |
| } |
| |
| if (id != AK8975_CHIP_ID) { |
| SYS_LOG_ERR("Invalid chip ID."); |
| return -EINVAL; |
| } |
| |
| if (ak8975_read_adjustment_data(drv_data) < 0) { |
| return -EIO; |
| } |
| |
| dev->driver_api = &ak8975_driver_api; |
| |
| return 0; |
| } |
| |
| struct ak8975_data ak8975_data; |
| |
| DEVICE_INIT(ak8975, CONFIG_AK8975_NAME, ak8975_init, &ak8975_data, |
| NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY); |