diff options
Diffstat (limited to 'drivers/staging/iio/magnetometer/hmc5843_core.c')
| -rw-r--r-- | drivers/staging/iio/magnetometer/hmc5843_core.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/drivers/staging/iio/magnetometer/hmc5843_core.c b/drivers/staging/iio/magnetometer/hmc5843_core.c new file mode 100644 index 000000000000..914ae1acd31d --- /dev/null +++ b/drivers/staging/iio/magnetometer/hmc5843_core.c @@ -0,0 +1,638 @@ +/* Copyright (C) 2010 Texas Instruments + Author: Shubhrajyoti Datta <shubhrajyoti@ti.com> + Acknowledgement: 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. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#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 + +/* 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; + 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; +} + +/* + * 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. + * + */ +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 ssize_t hmc5843_show_measurement_configuration(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); + int val; + int ret; + + ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &val); + if (ret) + return ret; + val &= HMC5843_MEAS_CONF_MASK; + + return sprintf(buf, "%d\n", val); +} + +static ssize_t hmc5843_set_measurement_configuration(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); + unsigned long meas_conf = 0; + int ret; + + ret = kstrtoul(buf, 10, &meas_conf); + if (ret) + return ret; + if (meas_conf >= HMC5843_MEAS_CONF_MASK) + return -EINVAL; + + ret = hmc5843_set_meas_conf(data, meas_conf); + + return (ret < 0) ? ret : count; +} + +static IIO_DEVICE_ATTR(meas_conf, + S_IWUSR | S_IRUGO, + hmc5843_show_measurement_configuration, + hmc5843_set_measurement_configuration, + 0); + +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 != 0) + 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); + 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()); + +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, \ + }, \ + } + +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 struct attribute *hmc5843_attributes[] = { + &iio_dev_attr_meas_conf.dev_attr.attr, + &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 = hmc5883_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_CONVERSION_CONTINUOUS); +} +EXPORT_SYMBOL(hmc5843_common_suspend); + +int hmc5843_common_resume(struct device *dev) +{ + return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)), + HMC5843_MODE_SLEEP); +} +EXPORT_SYMBOL(hmc5843_common_resume); + +int hmc5843_common_probe(struct device *dev, struct regmap *regmap, + enum hmc5843_ids id) +{ + struct hmc5843_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (indio_dev == NULL) + 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->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) + return ret; + + ret = iio_device_register(indio_dev); + if (ret < 0) + goto buffer_cleanup; + + return 0; + +buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); + 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"); |