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Commit 5990dc97 authored by Irina Tirdea's avatar Irina Tirdea Committed by Jonathan Cameron
Browse files

iio: magn: bmc150_magn: add oversampling ratio 

Export the oversampling ratio so that the user can change the
number of repetions for x/y/z axis.

The sampling frequency is limited by the oversampling ratio.
The available sampling frequencies might change depending
on the values of oversampling_ratio.

The specification can be downloaded from:
http://ae-bst.resource.bosch.com/media/products/dokumente/bmc150/BST-BMC150-DS000-04.pdf

.

Signed-off-by: default avatarIrina Tirdea <irina.tirdea@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent faaa4495

drivers/iio/magnetometer/bmc150_magn.c

+129 −4
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ struct bmc150_magn_data { 
	s32 buffer[6];

	struct iio_trigger *dready_trig;

	bool dready_trigger_on;

	int max_odr;

};



static const struct {
@@ -323,6 +324,43 @@ static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val) 
	return -EINVAL;

}



static int bmc150_magn_set_max_odr(struct bmc150_magn_data *data, int rep_xy,

				   int rep_z, int odr)

{

	int ret, reg_val, max_odr;



	if (rep_xy <= 0) {

		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,

				  &reg_val);

		if (ret < 0)

			return ret;

		rep_xy = BMC150_MAGN_REGVAL_TO_REPXY(reg_val);

	}

	if (rep_z <= 0) {

		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,

				  &reg_val);

		if (ret < 0)

			return ret;

		rep_z = BMC150_MAGN_REGVAL_TO_REPZ(reg_val);

	}

	if (odr <= 0) {

		ret = bmc150_magn_get_odr(data, &odr);

		if (ret < 0)

			return ret;

	}

	/* the maximum selectable read-out frequency from datasheet */

	max_odr = 1000000 / (145 * rep_xy + 500 * rep_z + 980);

	if (odr > max_odr) {

		dev_err(&data->client->dev,

			"Can't set oversampling with sampling freq %d\n",

			odr);

		return -EINVAL;

	}

	data->max_odr = max_odr;



	return 0;

}



static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,

				    u16 rhall)

{
@@ -422,7 +460,7 @@ static int bmc150_magn_read_raw(struct iio_dev *indio_dev, 
				int *val, int *val2, long mask)

{

	struct bmc150_magn_data *data = iio_priv(indio_dev);

	int ret;

	int ret, tmp;

	s32 values[AXIS_XYZ_MAX];



	switch (mask) {
@@ -467,6 +505,26 @@ static int bmc150_magn_read_raw(struct iio_dev *indio_dev, 
		if (ret < 0)

			return ret;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		switch (chan->channel2) {

		case IIO_MOD_X:

		case IIO_MOD_Y:

			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,

					  &tmp);

			if (ret < 0)

				return ret;

			*val = BMC150_MAGN_REGVAL_TO_REPXY(tmp);

			return IIO_VAL_INT;

		case IIO_MOD_Z:

			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,

					  &tmp);

			if (ret < 0)

				return ret;

			*val = BMC150_MAGN_REGVAL_TO_REPZ(tmp);

			return IIO_VAL_INT;

		default:

			return -EINVAL;

		}

	default:

		return -EINVAL;

	}
@@ -481,10 +539,50 @@ static int bmc150_magn_write_raw(struct iio_dev *indio_dev, 


	switch (mask) {

	case IIO_CHAN_INFO_SAMP_FREQ:

		if (val > data->max_odr)

			return -EINVAL;

		mutex_lock(&data->mutex);

		ret = bmc150_magn_set_odr(data, val);

		mutex_unlock(&data->mutex);

		return ret;

	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		switch (chan->channel2) {

		case IIO_MOD_X:

		case IIO_MOD_Y:

			if (val < 1 || val > 511)

				return -EINVAL;

			mutex_lock(&data->mutex);

			ret = bmc150_magn_set_max_odr(data, val, 0, 0);

			if (ret < 0) {

				mutex_unlock(&data->mutex);

				return ret;

			}

			ret = regmap_update_bits(data->regmap,

						 BMC150_MAGN_REG_REP_XY,

						 0xFF,

						 BMC150_MAGN_REPXY_TO_REGVAL

						 (val));

			mutex_unlock(&data->mutex);

			return ret;

		case IIO_MOD_Z:

			if (val < 1 || val > 256)

				return -EINVAL;

			mutex_lock(&data->mutex);

			ret = bmc150_magn_set_max_odr(data, 0, val, 0);

			if (ret < 0) {

				mutex_unlock(&data->mutex);

				return ret;

			}

			ret = regmap_update_bits(data->regmap,

						 BMC150_MAGN_REG_REP_Z,

						 0xFF,

						 BMC150_MAGN_REPZ_TO_REGVAL

						 (val));

			mutex_unlock(&data->mutex);

			return ret;

		default:

			return -EINVAL;

		}

	default:

		return -EINVAL;

	}
@@ -501,10 +599,31 @@ static int bmc150_magn_validate_trigger(struct iio_dev *indio_dev, 
	return 0;

}



static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("2 6 8 10 15 20 25 30");

static ssize_t bmc150_magn_show_samp_freq_avail(struct device *dev,

						struct device_attribute *attr,

						char *buf)

{

	struct iio_dev *indio_dev = dev_to_iio_dev(dev);

	struct bmc150_magn_data *data = iio_priv(indio_dev);

	size_t len = 0;

	u8 i;



	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {

		if (bmc150_magn_samp_freq_table[i].freq > data->max_odr)

			break;

		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",

				 bmc150_magn_samp_freq_table[i].freq);

	}

	/* replace last space with a newline */

	buf[len - 1] = '\n';



	return len;

}



static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(bmc150_magn_show_samp_freq_avail);



static struct attribute *bmc150_magn_attributes[] = {

	&iio_const_attr_sampling_frequency_available.dev_attr.attr,

	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,

	NULL,

};
@@ -516,7 +635,8 @@ static const struct attribute_group bmc150_magn_attrs_group = { 
	.type = IIO_MAGN,						\

	.modified = 1,							\

	.channel2 = IIO_MOD_##_axis,					\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\

			      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\

				    BIT(IIO_CHAN_INFO_SCALE),		\

	.scan_index = AXIS_##_axis,					\
@@ -616,6 +736,11 @@ static int bmc150_magn_init(struct bmc150_magn_data *data) 
		goto err_poweroff;

	}



	ret = bmc150_magn_set_max_odr(data, preset.rep_xy, preset.rep_z,

				      preset.odr);

	if (ret < 0)

		goto err_poweroff;



	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,

					 true);

	if (ret < 0) {