// SPDX-License-Identifier: GPL-2.0-only /* * Core IIO driver for Bosch BMA400 triaxial acceleration sensor. * * Copyright 2019 Dan Robertson * * TODO: * - Support for power management * - Support events and interrupts * - Create channel for step count * - Create channel for sensor time */ #include #include #include #include #include #include #include #include #include "bma400.h" /* * The G-range selection may be one of 2g, 4g, 8, or 16g. The scale may * be selected with the acc_range bits of the ACC_CONFIG1 register. * NB: This buffer is populated in the device init. */ static int bma400_scales[8]; /* * See the ACC_CONFIG1 section of the datasheet. * NB: This buffer is populated in the device init. */ static int bma400_sample_freqs[14]; static const int bma400_osr_range[] = { 0, 1, 3 }; /* See the ACC_CONFIG0 section of the datasheet */ enum bma400_power_mode { POWER_MODE_SLEEP = 0x00, POWER_MODE_LOW = 0x01, POWER_MODE_NORMAL = 0x02, POWER_MODE_INVALID = 0x03, }; struct bma400_sample_freq { int hz; int uhz; }; struct bma400_data { struct device *dev; struct regmap *regmap; struct regulator_bulk_data regulators[BMA400_NUM_REGULATORS]; struct mutex mutex; /* data register lock */ struct iio_mount_matrix orientation; enum bma400_power_mode power_mode; struct bma400_sample_freq sample_freq; int oversampling_ratio; int scale; }; static bool bma400_is_writable_reg(struct device *dev, unsigned int reg) { switch (reg) { case BMA400_CHIP_ID_REG: case BMA400_ERR_REG: case BMA400_STATUS_REG: case BMA400_X_AXIS_LSB_REG: case BMA400_X_AXIS_MSB_REG: case BMA400_Y_AXIS_LSB_REG: case BMA400_Y_AXIS_MSB_REG: case BMA400_Z_AXIS_LSB_REG: case BMA400_Z_AXIS_MSB_REG: case BMA400_SENSOR_TIME0: case BMA400_SENSOR_TIME1: case BMA400_SENSOR_TIME2: case BMA400_EVENT_REG: case BMA400_INT_STAT0_REG: case BMA400_INT_STAT1_REG: case BMA400_INT_STAT2_REG: case BMA400_TEMP_DATA_REG: case BMA400_FIFO_LENGTH0_REG: case BMA400_FIFO_LENGTH1_REG: case BMA400_FIFO_DATA_REG: case BMA400_STEP_CNT0_REG: case BMA400_STEP_CNT1_REG: case BMA400_STEP_CNT3_REG: case BMA400_STEP_STAT_REG: return false; default: return true; } } static bool bma400_is_volatile_reg(struct device *dev, unsigned int reg) { switch (reg) { case BMA400_ERR_REG: case BMA400_STATUS_REG: case BMA400_X_AXIS_LSB_REG: case BMA400_X_AXIS_MSB_REG: case BMA400_Y_AXIS_LSB_REG: case BMA400_Y_AXIS_MSB_REG: case BMA400_Z_AXIS_LSB_REG: case BMA400_Z_AXIS_MSB_REG: case BMA400_SENSOR_TIME0: case BMA400_SENSOR_TIME1: case BMA400_SENSOR_TIME2: case BMA400_EVENT_REG: case BMA400_INT_STAT0_REG: case BMA400_INT_STAT1_REG: case BMA400_INT_STAT2_REG: case BMA400_TEMP_DATA_REG: case BMA400_FIFO_LENGTH0_REG: case BMA400_FIFO_LENGTH1_REG: case BMA400_FIFO_DATA_REG: case BMA400_STEP_CNT0_REG: case BMA400_STEP_CNT1_REG: case BMA400_STEP_CNT3_REG: case BMA400_STEP_STAT_REG: return true; default: return false; } } const struct regmap_config bma400_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = BMA400_CMD_REG, .cache_type = REGCACHE_RBTREE, .writeable_reg = bma400_is_writable_reg, .volatile_reg = bma400_is_volatile_reg, }; EXPORT_SYMBOL(bma400_regmap_config); static const struct iio_mount_matrix * bma400_accel_get_mount_matrix(const struct iio_dev *indio_dev, const struct iio_chan_spec *chan) { struct bma400_data *data = iio_priv(indio_dev); return &data->orientation; } static const struct iio_chan_spec_ext_info bma400_ext_info[] = { IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bma400_accel_get_mount_matrix), { } }; #define BMA400_ACC_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_SAMP_FREQ) | \ BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ .ext_info = bma400_ext_info, \ } static const struct iio_chan_spec bma400_channels[] = { BMA400_ACC_CHANNEL(X), BMA400_ACC_CHANNEL(Y), BMA400_ACC_CHANNEL(Z), { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), }, }; static int bma400_get_temp_reg(struct bma400_data *data, int *val, int *val2) { unsigned int raw_temp; int host_temp; int ret; if (data->power_mode == POWER_MODE_SLEEP) return -EBUSY; ret = regmap_read(data->regmap, BMA400_TEMP_DATA_REG, &raw_temp); if (ret) return ret; host_temp = sign_extend32(raw_temp, 7); /* * The formula for the TEMP_DATA register in the datasheet * is: x * 0.5 + 23 */ *val = (host_temp >> 1) + 23; *val2 = (host_temp & 0x1) * 500000; return IIO_VAL_INT_PLUS_MICRO; } static int bma400_get_accel_reg(struct bma400_data *data, const struct iio_chan_spec *chan, int *val) { __le16 raw_accel; int lsb_reg; int ret; if (data->power_mode == POWER_MODE_SLEEP) return -EBUSY; switch (chan->channel2) { case IIO_MOD_X: lsb_reg = BMA400_X_AXIS_LSB_REG; break; case IIO_MOD_Y: lsb_reg = BMA400_Y_AXIS_LSB_REG; break; case IIO_MOD_Z: lsb_reg = BMA400_Z_AXIS_LSB_REG; break; default: dev_err(data->dev, "invalid axis channel modifier\n"); return -EINVAL; } /* bulk read two registers, with the base being the LSB register */ ret = regmap_bulk_read(data->regmap, lsb_reg, &raw_accel, sizeof(raw_accel)); if (ret) return ret; *val = sign_extend32(le16_to_cpu(raw_accel), 11); return IIO_VAL_INT; } static void bma400_output_data_rate_from_raw(int raw, unsigned int *val, unsigned int *val2) { *val = BMA400_ACC_ODR_MAX_HZ >> (BMA400_ACC_ODR_MAX_RAW - raw); if (raw > BMA400_ACC_ODR_MIN_RAW) *val2 = 0; else *val2 = 500000; } static int bma400_get_accel_output_data_rate(struct bma400_data *data) { unsigned int val; unsigned int odr; int ret; switch (data->power_mode) { case POWER_MODE_LOW: /* * Runs at a fixed rate in low-power mode. See section 4.3 * in the datasheet. */ bma400_output_data_rate_from_raw(BMA400_ACC_ODR_LP_RAW, &data->sample_freq.hz, &data->sample_freq.uhz); return 0; case POWER_MODE_NORMAL: /* * In normal mode the ODR can be found in the ACC_CONFIG1 * register. */ ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val); if (ret) goto error; odr = val & BMA400_ACC_ODR_MASK; if (odr < BMA400_ACC_ODR_MIN_RAW || odr > BMA400_ACC_ODR_MAX_RAW) { ret = -EINVAL; goto error; } bma400_output_data_rate_from_raw(odr, &data->sample_freq.hz, &data->sample_freq.uhz); return 0; case POWER_MODE_SLEEP: data->sample_freq.hz = 0; data->sample_freq.uhz = 0; return 0; default: ret = 0; goto error; } error: data->sample_freq.hz = -1; data->sample_freq.uhz = -1; return ret; } static int bma400_set_accel_output_data_rate(struct bma400_data *data, int hz, int uhz) { unsigned int idx; unsigned int odr; unsigned int val; int ret; if (hz >= BMA400_ACC_ODR_MIN_WHOLE_HZ) { if (uhz || hz > BMA400_ACC_ODR_MAX_HZ) return -EINVAL; /* Note this works because MIN_WHOLE_HZ is odd */ idx = __ffs(hz); if (hz >> idx != BMA400_ACC_ODR_MIN_WHOLE_HZ) return -EINVAL; idx += BMA400_ACC_ODR_MIN_RAW + 1; } else if (hz == BMA400_ACC_ODR_MIN_HZ && uhz == 500000) { idx = BMA400_ACC_ODR_MIN_RAW; } else { return -EINVAL; } ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val); if (ret) return ret; /* preserve the range and normal mode osr */ odr = (~BMA400_ACC_ODR_MASK & val) | idx; ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, odr); if (ret) return ret; bma400_output_data_rate_from_raw(idx, &data->sample_freq.hz, &data->sample_freq.uhz); return 0; } static int bma400_get_accel_oversampling_ratio(struct bma400_data *data) { unsigned int val; unsigned int osr; int ret; /* * The oversampling ratio is stored in a different register * based on the power-mode. In normal mode the OSR is stored * in ACC_CONFIG1. In low-power mode it is stored in * ACC_CONFIG0. */ switch (data->power_mode) { case POWER_MODE_LOW: ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val); if (ret) { data->oversampling_ratio = -1; return ret; } osr = (val & BMA400_LP_OSR_MASK) >> BMA400_LP_OSR_SHIFT; data->oversampling_ratio = osr; return 0; case POWER_MODE_NORMAL: ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val); if (ret) { data->oversampling_ratio = -1; return ret; } osr = (val & BMA400_NP_OSR_MASK) >> BMA400_NP_OSR_SHIFT; data->oversampling_ratio = osr; return 0; case POWER_MODE_SLEEP: data->oversampling_ratio = 0; return 0; default: data->oversampling_ratio = -1; return -EINVAL; } } static int bma400_set_accel_oversampling_ratio(struct bma400_data *data, int val) { unsigned int acc_config; int ret; if (val & ~BMA400_TWO_BITS_MASK) return -EINVAL; /* * The oversampling ratio is stored in a different register * based on the power-mode. */ switch (data->power_mode) { case POWER_MODE_LOW: ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &acc_config); if (ret) return ret; ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG, (acc_config & ~BMA400_LP_OSR_MASK) | (val << BMA400_LP_OSR_SHIFT)); if (ret) { dev_err(data->dev, "Failed to write out OSR\n"); return ret; } data->oversampling_ratio = val; return 0; case POWER_MODE_NORMAL: ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &acc_config); if (ret) return ret; ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, (acc_config & ~BMA400_NP_OSR_MASK) | (val << BMA400_NP_OSR_SHIFT)); if (ret) { dev_err(data->dev, "Failed to write out OSR\n"); return ret; } data->oversampling_ratio = val; return 0; default: return -EINVAL; } return ret; } static int bma400_accel_scale_to_raw(struct bma400_data *data, unsigned int val) { int raw; if (val == 0) return -EINVAL; /* Note this works because BMA400_SCALE_MIN is odd */ raw = __ffs(val); if (val >> raw != BMA400_SCALE_MIN) return -EINVAL; return raw; } static int bma400_get_accel_scale(struct bma400_data *data) { unsigned int raw_scale; unsigned int val; int ret; ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val); if (ret) return ret; raw_scale = (val & BMA400_ACC_SCALE_MASK) >> BMA400_SCALE_SHIFT; if (raw_scale > BMA400_TWO_BITS_MASK) return -EINVAL; data->scale = BMA400_SCALE_MIN << raw_scale; return 0; } static int bma400_set_accel_scale(struct bma400_data *data, unsigned int val) { unsigned int acc_config; int raw; int ret; ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &acc_config); if (ret) return ret; raw = bma400_accel_scale_to_raw(data, val); if (raw < 0) return raw; ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, (acc_config & ~BMA400_ACC_SCALE_MASK) | (raw << BMA400_SCALE_SHIFT)); if (ret) return ret; data->scale = val; return 0; } static int bma400_get_power_mode(struct bma400_data *data) { unsigned int val; int ret; ret = regmap_read(data->regmap, BMA400_STATUS_REG, &val); if (ret) { dev_err(data->dev, "Failed to read status register\n"); return ret; } data->power_mode = (val >> 1) & BMA400_TWO_BITS_MASK; return 0; } static int bma400_set_power_mode(struct bma400_data *data, enum bma400_power_mode mode) { unsigned int val; int ret; ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val); if (ret) return ret; if (data->power_mode == mode) return 0; if (mode == POWER_MODE_INVALID) return -EINVAL; /* Preserve the low-power oversample ratio etc */ ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG, mode | (val & ~BMA400_TWO_BITS_MASK)); if (ret) { dev_err(data->dev, "Failed to write to power-mode\n"); return ret; } data->power_mode = mode; /* * Update our cached osr and odr based on the new * power-mode. */ bma400_get_accel_output_data_rate(data); bma400_get_accel_oversampling_ratio(data); return 0; } static void bma400_init_tables(void) { int raw; int i; for (i = 0; i + 1 < ARRAY_SIZE(bma400_sample_freqs); i += 2) { raw = (i / 2) + 5; bma400_output_data_rate_from_raw(raw, &bma400_sample_freqs[i], &bma400_sample_freqs[i + 1]); } for (i = 0; i + 1 < ARRAY_SIZE(bma400_scales); i += 2) { raw = i / 2; bma400_scales[i] = 0; bma400_scales[i + 1] = BMA400_SCALE_MIN << raw; } } static int bma400_init(struct bma400_data *data) { unsigned int val; int ret; /* Try to read chip_id register. It must return 0x90. */ ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val); if (ret) { dev_err(data->dev, "Failed to read chip id register\n"); goto out; } if (val != BMA400_ID_REG_VAL) { dev_err(data->dev, "Chip ID mismatch\n"); ret = -ENODEV; goto out; } data->regulators[BMA400_VDD_REGULATOR].supply = "vdd"; data->regulators[BMA400_VDDIO_REGULATOR].supply = "vddio"; ret = devm_regulator_bulk_get(data->dev, ARRAY_SIZE(data->regulators), data->regulators); if (ret) { if (ret != -EPROBE_DEFER) dev_err(data->dev, "Failed to get regulators: %d\n", ret); goto out; } ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators), data->regulators); if (ret) { dev_err(data->dev, "Failed to enable regulators: %d\n", ret); goto out; } ret = bma400_get_power_mode(data); if (ret) { dev_err(data->dev, "Failed to get the initial power-mode\n"); goto err_reg_disable; } if (data->power_mode != POWER_MODE_NORMAL) { ret = bma400_set_power_mode(data, POWER_MODE_NORMAL); if (ret) { dev_err(data->dev, "Failed to wake up the device\n"); goto err_reg_disable; } /* * TODO: The datasheet waits 1500us here in the example, but * lists 2/ODR as the wakeup time. */ usleep_range(1500, 2000); } bma400_init_tables(); ret = bma400_get_accel_output_data_rate(data); if (ret) goto err_reg_disable; ret = bma400_get_accel_oversampling_ratio(data); if (ret) goto err_reg_disable; ret = bma400_get_accel_scale(data); if (ret) goto err_reg_disable; /* * Once the interrupt engine is supported we might use the * data_src_reg, but for now ensure this is set to the * variable ODR filter selectable by the sample frequency * channel. */ return regmap_write(data->regmap, BMA400_ACC_CONFIG2_REG, 0x00); err_reg_disable: regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators); out: return ret; } static int bma400_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct bma400_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_PROCESSED: mutex_lock(&data->mutex); ret = bma400_get_temp_reg(data, val, val2); mutex_unlock(&data->mutex); return ret; case IIO_CHAN_INFO_RAW: mutex_lock(&data->mutex); ret = bma400_get_accel_reg(data, chan, val); mutex_unlock(&data->mutex); return ret; case IIO_CHAN_INFO_SAMP_FREQ: switch (chan->type) { case IIO_ACCEL: if (data->sample_freq.hz < 0) return -EINVAL; *val = data->sample_freq.hz; *val2 = data->sample_freq.uhz; return IIO_VAL_INT_PLUS_MICRO; case IIO_TEMP: /* * Runs at a fixed sampling frequency. See Section 4.4 * of the datasheet. */ *val = 6; *val2 = 250000; return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = data->scale; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: /* * TODO: We could avoid this logic and returning -EINVAL here if * we set both the low-power and normal mode OSR registers when * we configure the device. */ if (data->oversampling_ratio < 0) return -EINVAL; *val = data->oversampling_ratio; return IIO_VAL_INT; default: return -EINVAL; } } static int bma400_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, const int **vals, int *type, int *length, long mask) { switch (mask) { case IIO_CHAN_INFO_SCALE: *type = IIO_VAL_INT_PLUS_MICRO; *vals = bma400_scales; *length = ARRAY_SIZE(bma400_scales); return IIO_AVAIL_LIST; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: *type = IIO_VAL_INT; *vals = bma400_osr_range; *length = ARRAY_SIZE(bma400_osr_range); return IIO_AVAIL_RANGE; case IIO_CHAN_INFO_SAMP_FREQ: *type = IIO_VAL_INT_PLUS_MICRO; *vals = bma400_sample_freqs; *length = ARRAY_SIZE(bma400_sample_freqs); return IIO_AVAIL_LIST; default: return -EINVAL; } } static int bma400_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct bma400_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: /* * The sample frequency is readonly for the temperature * register and a fixed value in low-power mode. */ if (chan->type != IIO_ACCEL) return -EINVAL; mutex_lock(&data->mutex); ret = bma400_set_accel_output_data_rate(data, val, val2); mutex_unlock(&data->mutex); return ret; case IIO_CHAN_INFO_SCALE: if (val != 0 || val2 < BMA400_SCALE_MIN || val2 > BMA400_SCALE_MAX) return -EINVAL; mutex_lock(&data->mutex); ret = bma400_set_accel_scale(data, val2); mutex_unlock(&data->mutex); return ret; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: mutex_lock(&data->mutex); ret = bma400_set_accel_oversampling_ratio(data, val); mutex_unlock(&data->mutex); return ret; default: return -EINVAL; } } static int bma400_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, long mask) { switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SCALE: return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: return IIO_VAL_INT; default: return -EINVAL; } } static const struct iio_info bma400_info = { .read_raw = bma400_read_raw, .read_avail = bma400_read_avail, .write_raw = bma400_write_raw, .write_raw_get_fmt = bma400_write_raw_get_fmt, }; int bma400_probe(struct device *dev, struct regmap *regmap, const char *name) { struct iio_dev *indio_dev; struct bma400_data *data; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); data->regmap = regmap; data->dev = dev; ret = bma400_init(data); if (ret) return ret; ret = iio_read_mount_matrix(dev, &data->orientation); if (ret) return ret; mutex_init(&data->mutex); indio_dev->name = name; indio_dev->info = &bma400_info; indio_dev->channels = bma400_channels; indio_dev->num_channels = ARRAY_SIZE(bma400_channels); indio_dev->modes = INDIO_DIRECT_MODE; dev_set_drvdata(dev, indio_dev); return iio_device_register(indio_dev); } EXPORT_SYMBOL(bma400_probe); int bma400_remove(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct bma400_data *data = iio_priv(indio_dev); int ret; mutex_lock(&data->mutex); ret = bma400_set_power_mode(data, POWER_MODE_SLEEP); mutex_unlock(&data->mutex); regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators); iio_device_unregister(indio_dev); return ret; } EXPORT_SYMBOL(bma400_remove); MODULE_AUTHOR("Dan Robertson "); MODULE_DESCRIPTION("Bosch BMA400 triaxial acceleration sensor core"); MODULE_LICENSE("GPL");