--- /dev/null
+/*
+ * 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
+
+/* 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;
+}
+
+/*
+ * 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));
+ unsigned 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);
+ 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());
+
+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)
+ 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 = dev->driver->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");
Code Review / kvmfornfv.git / blobdiff