--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+#include <linux/bitfield.h>
+#include <linux/firmware.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+
+#include "bmi270.h"
+
+#define BMI270_CHIP_ID_REG 0x00
+#define BMI270_CHIP_ID_VAL 0x24
+#define BMI270_CHIP_ID_MSK GENMASK(7, 0)
+
+#define BMI270_ACCEL_X_REG 0x0c
+#define BMI270_ANG_VEL_X_REG 0x12
+
+#define BMI270_INTERNAL_STATUS_REG 0x21
+#define BMI270_INTERNAL_STATUS_MSG_MSK GENMASK(3, 0)
+#define BMI270_INTERNAL_STATUS_MSG_INIT_OK 0x01
+
+#define BMI270_INTERNAL_STATUS_AXES_REMAP_ERR_MSK BIT(5)
+#define BMI270_INTERNAL_STATUS_ODR_50HZ_ERR_MSK BIT(6)
+
+#define BMI270_ACC_CONF_REG 0x40
+#define BMI270_ACC_CONF_ODR_MSK GENMASK(3, 0)
+#define BMI270_ACC_CONF_ODR_100HZ 0x08
+#define BMI270_ACC_CONF_BWP_MSK GENMASK(6, 4)
+#define BMI270_ACC_CONF_BWP_NORMAL_MODE 0x02
+#define BMI270_ACC_CONF_FILTER_PERF_MSK BIT(7)
+
+#define BMI270_GYR_CONF_REG 0x42
+#define BMI270_GYR_CONF_ODR_MSK GENMASK(3, 0)
+#define BMI270_GYR_CONF_ODR_200HZ 0x09
+#define BMI270_GYR_CONF_BWP_MSK GENMASK(5, 4)
+#define BMI270_GYR_CONF_BWP_NORMAL_MODE 0x02
+#define BMI270_GYR_CONF_NOISE_PERF_MSK BIT(6)
+#define BMI270_GYR_CONF_FILTER_PERF_MSK BIT(7)
+
+#define BMI270_INIT_CTRL_REG 0x59
+#define BMI270_INIT_CTRL_LOAD_DONE_MSK BIT(0)
+
+#define BMI270_INIT_DATA_REG 0x5e
+
+#define BMI270_PWR_CONF_REG 0x7c
+#define BMI270_PWR_CONF_ADV_PWR_SAVE_MSK BIT(0)
+#define BMI270_PWR_CONF_FIFO_WKUP_MSK BIT(1)
+#define BMI270_PWR_CONF_FUP_EN_MSK BIT(2)
+
+#define BMI270_PWR_CTRL_REG 0x7d
+#define BMI270_PWR_CTRL_AUX_EN_MSK BIT(0)
+#define BMI270_PWR_CTRL_GYR_EN_MSK BIT(1)
+#define BMI270_PWR_CTRL_ACCEL_EN_MSK BIT(2)
+#define BMI270_PWR_CTRL_TEMP_EN_MSK BIT(3)
+
+#define BMI270_INIT_DATA_FILE "bmi270-init-data.fw"
+
+enum bmi270_scan {
+ BMI270_SCAN_ACCEL_X,
+ BMI270_SCAN_ACCEL_Y,
+ BMI270_SCAN_ACCEL_Z,
+ BMI270_SCAN_GYRO_X,
+ BMI270_SCAN_GYRO_Y,
+ BMI270_SCAN_GYRO_Z,
+};
+
+const struct regmap_config bmi270_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+EXPORT_SYMBOL_NS_GPL(bmi270_regmap_config, IIO_BMI270);
+
+static int bmi270_get_data(struct bmi270_data *bmi270_device,
+ int chan_type, int axis, int *val)
+{
+ __le16 sample;
+ int reg;
+ int ret;
+
+ switch (chan_type) {
+ case IIO_ACCEL:
+ reg = BMI270_ACCEL_X_REG + (axis - IIO_MOD_X) * 2;
+ break;
+ case IIO_ANGL_VEL:
+ reg = BMI270_ANG_VEL_X_REG + (axis - IIO_MOD_X) * 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_bulk_read(bmi270_device->regmap, reg, &sample, sizeof(sample));
+ if (ret)
+ return ret;
+
+ *val = sign_extend32(le16_to_cpu(sample), 15);
+
+ return 0;
+}
+
+static int bmi270_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret;
+ struct bmi270_data *bmi270_device = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = bmi270_get_data(bmi270_device, chan->type, chan->channel2, val);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info bmi270_info = {
+ .read_raw = bmi270_read_raw,
+};
+
+#define BMI270_ACCEL_CHANNEL(_axis) { \
+ .type = IIO_ACCEL, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##_axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_FREQUENCY), \
+}
+
+#define BMI270_ANG_VEL_CHANNEL(_axis) { \
+ .type = IIO_ANGL_VEL, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##_axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_FREQUENCY), \
+}
+
+static const struct iio_chan_spec bmi270_channels[] = {
+ BMI270_ACCEL_CHANNEL(X),
+ BMI270_ACCEL_CHANNEL(Y),
+ BMI270_ACCEL_CHANNEL(Z),
+ BMI270_ANG_VEL_CHANNEL(X),
+ BMI270_ANG_VEL_CHANNEL(Y),
+ BMI270_ANG_VEL_CHANNEL(Z),
+};
+
+static int bmi270_validate_chip_id(struct bmi270_data *bmi270_device)
+{
+ int chip_id;
+ int ret;
+ struct device *dev = bmi270_device->dev;
+ struct regmap *regmap = bmi270_device->regmap;
+
+ ret = regmap_read(regmap, BMI270_CHIP_ID_REG, &chip_id);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read chip id");
+
+ if (chip_id != BMI270_CHIP_ID_VAL)
+ dev_info(dev, "Unknown chip id 0x%x", chip_id);
+
+ return 0;
+}
+
+static int bmi270_write_calibration_data(struct bmi270_data *bmi270_device)
+{
+ int ret;
+ int status = 0;
+ const struct firmware *init_data;
+ struct device *dev = bmi270_device->dev;
+ struct regmap *regmap = bmi270_device->regmap;
+
+ ret = regmap_clear_bits(regmap, BMI270_PWR_CONF_REG,
+ BMI270_PWR_CONF_ADV_PWR_SAVE_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to write power configuration");
+
+ /*
+ * After disabling advanced power save, all registers are accessible
+ * after a 450us delay. This delay is specified in table A of the
+ * datasheet.
+ */
+ usleep_range(450, 1000);
+
+ ret = regmap_clear_bits(regmap, BMI270_INIT_CTRL_REG,
+ BMI270_INIT_CTRL_LOAD_DONE_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to prepare device to load init data");
+
+ ret = request_firmware(&init_data, BMI270_INIT_DATA_FILE, dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to load init data file");
+
+ ret = regmap_bulk_write(regmap, BMI270_INIT_DATA_REG,
+ init_data->data, init_data->size);
+ release_firmware(init_data);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to write init data");
+
+ ret = regmap_set_bits(regmap, BMI270_INIT_CTRL_REG,
+ BMI270_INIT_CTRL_LOAD_DONE_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to stop device initialization");
+
+ /*
+ * Wait at least 140ms for the device to complete configuration.
+ * This delay is specified in table C of the datasheet.
+ */
+ usleep_range(140000, 160000);
+
+ ret = regmap_read(regmap, BMI270_INTERNAL_STATUS_REG, &status);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read internal status");
+
+ if (status != BMI270_INTERNAL_STATUS_MSG_INIT_OK)
+ return dev_err_probe(dev, -ENODEV, "Device failed to initialize");
+
+ return 0;
+}
+
+static int bmi270_configure_imu(struct bmi270_data *bmi270_device)
+{
+ int ret;
+ struct device *dev = bmi270_device->dev;
+ struct regmap *regmap = bmi270_device->regmap;
+
+ ret = regmap_set_bits(regmap, BMI270_PWR_CTRL_REG,
+ BMI270_PWR_CTRL_AUX_EN_MSK |
+ BMI270_PWR_CTRL_GYR_EN_MSK |
+ BMI270_PWR_CTRL_ACCEL_EN_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable accelerometer and gyroscope");
+
+ ret = regmap_set_bits(regmap, BMI270_ACC_CONF_REG,
+ FIELD_PREP(BMI270_ACC_CONF_ODR_MSK,
+ BMI270_ACC_CONF_ODR_100HZ) |
+ FIELD_PREP(BMI270_ACC_CONF_BWP_MSK,
+ BMI270_ACC_CONF_BWP_NORMAL_MODE) |
+ BMI270_PWR_CONF_ADV_PWR_SAVE_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to configure accelerometer");
+
+ ret = regmap_set_bits(regmap, BMI270_GYR_CONF_REG,
+ FIELD_PREP(BMI270_GYR_CONF_ODR_MSK,
+ BMI270_GYR_CONF_ODR_200HZ) |
+ FIELD_PREP(BMI270_GYR_CONF_BWP_MSK,
+ BMI270_GYR_CONF_BWP_NORMAL_MODE) |
+ BMI270_PWR_CONF_ADV_PWR_SAVE_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to configure gyroscope");
+
+ /* Enable FIFO_WKUP, Disable ADV_PWR_SAVE and FUP_EN */
+ ret = regmap_write(regmap, BMI270_PWR_CONF_REG,
+ BMI270_PWR_CONF_FIFO_WKUP_MSK);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to set power configuration");
+
+ return 0;
+}
+
+static int bmi270_chip_init(struct bmi270_data *bmi270_device)
+{
+ int ret;
+
+ ret = bmi270_validate_chip_id(bmi270_device);
+ if (ret)
+ return ret;
+
+ ret = bmi270_write_calibration_data(bmi270_device);
+ if (ret)
+ return ret;
+
+ return bmi270_configure_imu(bmi270_device);
+}
+
+int bmi270_core_probe(struct device *dev, struct regmap *regmap)
+{
+ int ret;
+ struct bmi270_data *bmi270_device;
+ struct iio_dev *indio_dev;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*bmi270_device));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ bmi270_device = iio_priv(indio_dev);
+ bmi270_device->dev = dev;
+ bmi270_device->regmap = regmap;
+
+ ret = bmi270_chip_init(bmi270_device);
+ if (ret)
+ return ret;
+
+ indio_dev->channels = bmi270_channels;
+ indio_dev->num_channels = ARRAY_SIZE(bmi270_channels);
+ indio_dev->name = "bmi270";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &bmi270_info;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(bmi270_core_probe, IIO_BMI270);
+
+MODULE_AUTHOR("Alex Lanzano");
+MODULE_DESCRIPTION("BMI270 driver");
+MODULE_LICENSE("GPL");