linux/drivers/iio/magnetometer/hmc5843_core.c

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/*
* Device driver for the the HMC5843 multi-chip module designed
* for low field magnetic sensing.
*
* Copyright (C) 2010 Texas Instruments
*
* Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
* Acknowledgment: Jonathan Cameron <jic23@kernel.org> for valuable inputs.
* Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>.
* Split to multiple files by Josef Gajdusek <atx@atx.name> - 2014
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/delay.h>
#include "hmc5843.h"
/*
* Range gain settings in (+-)Ga
* Beware: HMC5843 and HMC5883 have different recommended sensor field
* ranges; default corresponds to +-1.0 Ga and +-1.3 Ga, respectively
*/
#define HMC5843_RANGE_GAIN_OFFSET 0x05
#define HMC5843_RANGE_GAIN_DEFAULT 0x01
#define HMC5843_RANGE_GAIN_MASK 0xe0
/* Device status */
#define HMC5843_DATA_READY 0x01
#define HMC5843_DATA_OUTPUT_LOCK 0x02
/* Mode register configuration */
#define HMC5843_MODE_CONVERSION_CONTINUOUS 0x00
#define HMC5843_MODE_CONVERSION_SINGLE 0x01
#define HMC5843_MODE_IDLE 0x02
#define HMC5843_MODE_SLEEP 0x03
#define HMC5843_MODE_MASK 0x03
/*
* HMC5843: Minimum data output rate
* HMC5883: Typical data output rate
*/
#define HMC5843_RATE_OFFSET 0x02
#define HMC5843_RATE_DEFAULT 0x04
#define HMC5843_RATE_MASK 0x1c
/* Device measurement configuration */
#define HMC5843_MEAS_CONF_NORMAL 0x00
#define HMC5843_MEAS_CONF_POSITIVE_BIAS 0x01
#define HMC5843_MEAS_CONF_NEGATIVE_BIAS 0x02
#define HMC5843_MEAS_CONF_MASK 0x03
/*
* API for setting the measurement configuration to
* Normal, Positive bias and Negative bias
*
* From the datasheet:
* 0 - Normal measurement configuration (default): In normal measurement
* configuration the device follows normal measurement flow. Pins BP
* and BN are left floating and high impedance.
*
* 1 - Positive bias configuration: In positive bias configuration, a
* positive current is forced across the resistive load on pins BP
* and BN.
*
* 2 - Negative bias configuration. In negative bias configuration, a
* negative current is forced across the resistive load on pins BP
* and BN.
*
* 3 - Only available on HMC5983. Magnetic sensor is disabled.
* Temperature sensor is enabled.
*/
static const char *const hmc5843_meas_conf_modes[] = {"normal", "positivebias",
"negativebias"};
static const char *const hmc5983_meas_conf_modes[] = {"normal", "positivebias",
"negativebias",
"disabled"};
/* Scaling factors: 10000000/Gain */
static const int hmc5843_regval_to_nanoscale[] = {
6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
};
static const int hmc5883_regval_to_nanoscale[] = {
7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
};
static const int hmc5883l_regval_to_nanoscale[] = {
7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
};
/*
* From the datasheet:
* Value | HMC5843 | HMC5883/HMC5883L
* | Data output rate (Hz) | Data output rate (Hz)
* 0 | 0.5 | 0.75
* 1 | 1 | 1.5
* 2 | 2 | 3
* 3 | 5 | 7.5
* 4 | 10 (default) | 15
* 5 | 20 | 30
* 6 | 50 | 75
* 7 | Not used | Not used
*/
static const int hmc5843_regval_to_samp_freq[][2] = {
{0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0}
};
static const int hmc5883_regval_to_samp_freq[][2] = {
{0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
{75, 0}
};
static const int hmc5983_regval_to_samp_freq[][2] = {
{0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
{75, 0}, {220, 0}
};
/* Describe chip variants */
struct hmc5843_chip_info {
const struct iio_chan_spec *channels;
const int (*regval_to_samp_freq)[2];
const int n_regval_to_samp_freq;
const int *regval_to_nanoscale;
const int n_regval_to_nanoscale;
};
/* The lower two bits contain the current conversion mode */
static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_MODE_REG,
HMC5843_MODE_MASK, operating_mode);
mutex_unlock(&data->lock);
return ret;
}
static int hmc5843_wait_measurement(struct hmc5843_data *data)
{
int tries = 150;
unsigned int val;
int ret;
while (tries-- > 0) {
ret = regmap_read(data->regmap, HMC5843_STATUS_REG, &val);
if (ret < 0)
return ret;
if (val & HMC5843_DATA_READY)
break;
msleep(20);
}
if (tries < 0) {
dev_err(data->dev, "data not ready\n");
return -EIO;
}
return 0;
}
/* Return the measurement value from the specified channel */
static int hmc5843_read_measurement(struct hmc5843_data *data,
int idx, int *val)
{
__be16 values[3];
int ret;
mutex_lock(&data->lock);
ret = hmc5843_wait_measurement(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
values, sizeof(values));
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = sign_extend32(be16_to_cpu(values[idx]), 15);
return IIO_VAL_INT;
}
static int hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
HMC5843_MEAS_CONF_MASK, meas_conf);
mutex_unlock(&data->lock);
return ret;
}
static
int hmc5843_show_measurement_configuration(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct hmc5843_data *data = iio_priv(indio_dev);
unsigned int val;
int ret;
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &val);
if (ret)
return ret;
return val & HMC5843_MEAS_CONF_MASK;
}
static
int hmc5843_set_measurement_configuration(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int meas_conf)
{
struct hmc5843_data *data = iio_priv(indio_dev);
return hmc5843_set_meas_conf(data, meas_conf);
}
static const struct iio_enum hmc5843_meas_conf_enum = {
.items = hmc5843_meas_conf_modes,
.num_items = ARRAY_SIZE(hmc5843_meas_conf_modes),
.get = hmc5843_show_measurement_configuration,
.set = hmc5843_set_measurement_configuration,
};
static const struct iio_chan_spec_ext_info hmc5843_ext_info[] = {
IIO_ENUM("meas_conf", true, &hmc5843_meas_conf_enum),
IIO_ENUM_AVAILABLE("meas_conf", &hmc5843_meas_conf_enum),
{ },
};
static const struct iio_enum hmc5983_meas_conf_enum = {
.items = hmc5983_meas_conf_modes,
.num_items = ARRAY_SIZE(hmc5983_meas_conf_modes),
.get = hmc5843_show_measurement_configuration,
.set = hmc5843_set_measurement_configuration,
};
static const struct iio_chan_spec_ext_info hmc5983_ext_info[] = {
IIO_ENUM("meas_conf", true, &hmc5983_meas_conf_enum),
IIO_ENUM_AVAILABLE("meas_conf", &hmc5983_meas_conf_enum),
{ },
};
static
ssize_t hmc5843_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
size_t len = 0;
int i;
for (i = 0; i < data->variant->n_regval_to_samp_freq; i++)
len += scnprintf(buf + len, PAGE_SIZE - len,
"%d.%d ", data->variant->regval_to_samp_freq[i][0],
data->variant->regval_to_samp_freq[i][1]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_samp_freq_avail);
static int hmc5843_set_samp_freq(struct hmc5843_data *data, u8 rate)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
HMC5843_RATE_MASK,
rate << HMC5843_RATE_OFFSET);
mutex_unlock(&data->lock);
return ret;
}
static int hmc5843_get_samp_freq_index(struct hmc5843_data *data,
int val, int val2)
{
int i;
for (i = 0; i < data->variant->n_regval_to_samp_freq; i++)
if (val == data->variant->regval_to_samp_freq[i][0] &&
val2 == data->variant->regval_to_samp_freq[i][1])
return i;
return -EINVAL;
}
static int hmc5843_set_range_gain(struct hmc5843_data *data, u8 range)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_B,
HMC5843_RANGE_GAIN_MASK,
range << HMC5843_RANGE_GAIN_OFFSET);
mutex_unlock(&data->lock);
return ret;
}
static ssize_t hmc5843_show_scale_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
size_t len = 0;
int i;
for (i = 0; i < data->variant->n_regval_to_nanoscale; i++)
len += scnprintf(buf + len, PAGE_SIZE - len,
"0.%09d ", data->variant->regval_to_nanoscale[i]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEVICE_ATTR(scale_available, S_IRUGO,
hmc5843_show_scale_avail, NULL, 0);
static int hmc5843_get_scale_index(struct hmc5843_data *data, int val, int val2)
{
int i;
if (val)
return -EINVAL;
for (i = 0; i < data->variant->n_regval_to_nanoscale; i++)
if (val2 == data->variant->regval_to_nanoscale[i])
return i;
return -EINVAL;
}
static int hmc5843_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct hmc5843_data *data = iio_priv(indio_dev);
unsigned int rval;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
return hmc5843_read_measurement(data, chan->scan_index, val);
case IIO_CHAN_INFO_SCALE:
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_B, &rval);
if (ret < 0)
return ret;
rval >>= HMC5843_RANGE_GAIN_OFFSET;
*val = 0;
*val2 = data->variant->regval_to_nanoscale[rval];
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_SAMP_FREQ:
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &rval);
if (ret < 0)
return ret;
rval >>= HMC5843_RATE_OFFSET;
*val = data->variant->regval_to_samp_freq[rval][0];
*val2 = data->variant->regval_to_samp_freq[rval][1];
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int hmc5843_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct hmc5843_data *data = iio_priv(indio_dev);
int rate, range;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
rate = hmc5843_get_samp_freq_index(data, val, val2);
if (rate < 0)
return -EINVAL;
return hmc5843_set_samp_freq(data, rate);
case IIO_CHAN_INFO_SCALE:
range = hmc5843_get_scale_index(data, val, val2);
if (range < 0)
return -EINVAL;
return hmc5843_set_range_gain(data, range);
default:
return -EINVAL;
}
}
static int hmc5843_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_NANO;
default:
return -EINVAL;
}
}
static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct hmc5843_data *data = iio_priv(indio_dev);
int ret;
mutex_lock(&data->lock);
ret = hmc5843_wait_measurement(data);
if (ret < 0) {
mutex_unlock(&data->lock);
goto done;
}
ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
data->buffer, 3 * sizeof(__be16));
mutex_unlock(&data->lock);
if (ret < 0)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
iio_get_time_ns(indio_dev));
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
#define HMC5843_CHANNEL(axis, idx) \
{ \
.type = IIO_MAGN, \
.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_SAMP_FREQ), \
.scan_index = idx, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_BE, \
}, \
.ext_info = hmc5843_ext_info, \
}
#define HMC5983_CHANNEL(axis, idx) \
{ \
.type = IIO_MAGN, \
.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_SAMP_FREQ), \
.scan_index = idx, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_BE, \
}, \
.ext_info = hmc5983_ext_info, \
}
static const struct iio_chan_spec hmc5843_channels[] = {
HMC5843_CHANNEL(X, 0),
HMC5843_CHANNEL(Y, 1),
HMC5843_CHANNEL(Z, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
/* Beware: Y and Z are exchanged on HMC5883 and 5983 */
static const struct iio_chan_spec hmc5883_channels[] = {
HMC5843_CHANNEL(X, 0),
HMC5843_CHANNEL(Z, 1),
HMC5843_CHANNEL(Y, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const struct iio_chan_spec hmc5983_channels[] = {
HMC5983_CHANNEL(X, 0),
HMC5983_CHANNEL(Z, 1),
HMC5983_CHANNEL(Y, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static struct attribute *hmc5843_attributes[] = {
&iio_dev_attr_scale_available.dev_attr.attr,
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group hmc5843_group = {
.attrs = hmc5843_attributes,
};
static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = {
[HMC5843_ID] = {
.channels = hmc5843_channels,
.regval_to_samp_freq = hmc5843_regval_to_samp_freq,
.n_regval_to_samp_freq =
ARRAY_SIZE(hmc5843_regval_to_samp_freq),
.regval_to_nanoscale = hmc5843_regval_to_nanoscale,
.n_regval_to_nanoscale =
ARRAY_SIZE(hmc5843_regval_to_nanoscale),
},
[HMC5883_ID] = {
.channels = hmc5883_channels,
.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
.n_regval_to_samp_freq =
ARRAY_SIZE(hmc5883_regval_to_samp_freq),
.regval_to_nanoscale = hmc5883_regval_to_nanoscale,
.n_regval_to_nanoscale =
ARRAY_SIZE(hmc5883_regval_to_nanoscale),
},
[HMC5883L_ID] = {
.channels = hmc5883_channels,
.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
.n_regval_to_samp_freq =
ARRAY_SIZE(hmc5883_regval_to_samp_freq),
.regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
.n_regval_to_nanoscale =
ARRAY_SIZE(hmc5883l_regval_to_nanoscale),
},
[HMC5983_ID] = {
.channels = hmc5983_channels,
.regval_to_samp_freq = hmc5983_regval_to_samp_freq,
.n_regval_to_samp_freq =
ARRAY_SIZE(hmc5983_regval_to_samp_freq),
.regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
.n_regval_to_nanoscale =
ARRAY_SIZE(hmc5883l_regval_to_nanoscale),
}
};
static int hmc5843_init(struct hmc5843_data *data)
{
int ret;
u8 id[3];
ret = regmap_bulk_read(data->regmap, HMC5843_ID_REG,
id, ARRAY_SIZE(id));
if (ret < 0)
return ret;
if (id[0] != 'H' || id[1] != '4' || id[2] != '3') {
dev_err(data->dev, "no HMC5843/5883/5883L/5983 sensor\n");
return -ENODEV;
}
ret = hmc5843_set_meas_conf(data, HMC5843_MEAS_CONF_NORMAL);
if (ret < 0)
return ret;
ret = hmc5843_set_samp_freq(data, HMC5843_RATE_DEFAULT);
if (ret < 0)
return ret;
ret = hmc5843_set_range_gain(data, HMC5843_RANGE_GAIN_DEFAULT);
if (ret < 0)
return ret;
return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS);
}
static const struct iio_info hmc5843_info = {
.attrs = &hmc5843_group,
.read_raw = &hmc5843_read_raw,
.write_raw = &hmc5843_write_raw,
.write_raw_get_fmt = &hmc5843_write_raw_get_fmt,
.driver_module = THIS_MODULE,
};
static const unsigned long hmc5843_scan_masks[] = {0x7, 0};
int hmc5843_common_suspend(struct device *dev)
{
return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
HMC5843_MODE_SLEEP);
}
EXPORT_SYMBOL(hmc5843_common_suspend);
int hmc5843_common_resume(struct device *dev)
{
return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
HMC5843_MODE_CONVERSION_CONTINUOUS);
}
EXPORT_SYMBOL(hmc5843_common_resume);
int hmc5843_common_probe(struct device *dev, struct regmap *regmap,
enum hmc5843_ids id, const char *name)
{
struct hmc5843_data *data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
dev_set_drvdata(dev, indio_dev);
/* default settings at probe */
data = iio_priv(indio_dev);
data->dev = dev;
data->regmap = regmap;
data->variant = &hmc5843_chip_info_tbl[id];
mutex_init(&data->lock);
indio_dev->dev.parent = dev;
indio_dev->name = name;
indio_dev->info = &hmc5843_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = data->variant->channels;
indio_dev->num_channels = 4;
indio_dev->available_scan_masks = hmc5843_scan_masks;
ret = hmc5843_init(data);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
hmc5843_trigger_handler, NULL);
if (ret < 0)
goto buffer_setup_err;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
buffer_setup_err:
hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
return ret;
}
EXPORT_SYMBOL(hmc5843_common_probe);
int hmc5843_common_remove(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
/* sleep mode to save power */
hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
return 0;
}
EXPORT_SYMBOL(hmc5843_common_remove);
MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com>");
MODULE_DESCRIPTION("HMC5843/5883/5883L/5983 core driver");
MODULE_LICENSE("GPL");