/* Copyright (C) 2010 Texas Instruments Author: Shubhrajyoti Datta Acknowledgement: Jonathan Cameron for valuable inputs. Support for HMC5883 and HMC5883L by Peter Meerwald . 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 #include #include #include #include #include #include #include #define HMC5843_CONFIG_REG_A 0x00 #define HMC5843_CONFIG_REG_B 0x01 #define HMC5843_MODE_REG 0x02 #define HMC5843_DATA_OUT_MSB_REGS 0x03 #define HMC5843_STATUS_REG 0x09 #define HMC5843_ID_REG 0x0a enum hmc5843_ids { HMC5843_ID, HMC5883_ID, HMC5883L_ID, }; /* * 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_GAINS 8 /* 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_RATES 7 /* 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[HMC5843_RANGE_GAINS] = { 6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714 }; static const int hmc5883_regval_to_nanoscale[HMC5843_RANGE_GAINS] = { 7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662 }; static const int hmc5883l_regval_to_nanoscale[HMC5843_RANGE_GAINS] = { 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[7][2] = { {0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0} }; static const int hmc5883_regval_to_samp_freq[7][2] = { {0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0}, {75, 0} }; /* Describe chip variants */ struct hmc5843_chip_info { const struct iio_chan_spec *channels; const int (*regval_to_samp_freq)[2]; const int *regval_to_nanoscale; }; /* Each client has this additional data */ struct hmc5843_data { struct i2c_client *client; struct mutex lock; u8 rate; u8 meas_conf; u8 operating_mode; u8 range; const struct hmc5843_chip_info *variant; __be16 buffer[8]; /* 3x 16-bit channels + padding + 64-bit timestamp */ }; /* 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 = i2c_smbus_write_byte_data(data->client, HMC5843_MODE_REG, operating_mode & HMC5843_MODE_MASK); if (ret >= 0) data->operating_mode = operating_mode; mutex_unlock(&data->lock); return ret; } static int hmc5843_wait_measurement(struct hmc5843_data *data) { s32 result; int tries = 150; while (tries-- > 0) { result = i2c_smbus_read_byte_data(data->client, HMC5843_STATUS_REG); if (result < 0) return result; if (result & HMC5843_DATA_READY) break; msleep(20); } if (tries < 0) { dev_err(&data->client->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) { s32 result; __be16 values[3]; mutex_lock(&data->lock); result = hmc5843_wait_measurement(data); if (result < 0) { mutex_unlock(&data->lock); return result; } result = i2c_smbus_read_i2c_block_data(data->client, HMC5843_DATA_OUT_MSB_REGS, sizeof(values), (u8 *) values); mutex_unlock(&data->lock); if (result < 0) return -EINVAL; *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 s32 hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf) { int ret; mutex_lock(&data->lock); ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A, (meas_conf & HMC5843_MEAS_CONF_MASK) | (data->rate << HMC5843_RATE_OFFSET)); if (ret >= 0) data->meas_conf = 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)); return sprintf(buf, "%d\n", data->meas_conf); } 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 < HMC5843_RATES; 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 = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A, data->meas_conf | (rate << HMC5843_RATE_OFFSET)); if (ret >= 0) data->rate = rate; 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 < HMC5843_RATES; 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 = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_B, range << HMC5843_RANGE_GAIN_OFFSET); if (ret >= 0) data->range = range; 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 < HMC5843_RANGE_GAINS; 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 < HMC5843_RANGE_GAINS; 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); switch (mask) { case IIO_CHAN_INFO_RAW: return hmc5843_read_measurement(data, chan->scan_index, val); case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = data->variant->regval_to_nanoscale[data->range]; return IIO_VAL_INT_PLUS_NANO; case IIO_CHAN_INFO_SAMP_FREQ: *val = data->variant->regval_to_samp_freq[data->rate][0]; *val2 = data->variant->regval_to_samp_freq[data->rate][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 = i2c_smbus_read_i2c_block_data(data->client, HMC5843_DATA_OUT_MSB_REGS, 3 * sizeof(__be16), (u8 *) data->buffer); 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 = IIO_ST('s', 16, 16, 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 */ 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, .regval_to_nanoscale = hmc5843_regval_to_nanoscale, }, [HMC5883_ID] = { .channels = hmc5883_channels, .regval_to_samp_freq = hmc5883_regval_to_samp_freq, .regval_to_nanoscale = hmc5883_regval_to_nanoscale, }, [HMC5883L_ID] = { .channels = hmc5883_channels, .regval_to_samp_freq = hmc5883_regval_to_samp_freq, .regval_to_nanoscale = hmc5883l_regval_to_nanoscale, }, }; static int hmc5843_init(struct hmc5843_data *data) { int ret; u8 id[3]; ret = i2c_smbus_read_i2c_block_data(data->client, HMC5843_ID_REG, sizeof(id), id); if (ret < 0) return ret; if (id[0] != 'H' || id[1] != '4' || id[2] != '3') { dev_err(&data->client->dev, "no HMC5843/5883/5883L 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}; static int hmc5843_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct hmc5843_data *data; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); if (indio_dev == NULL) return -ENOMEM; /* default settings at probe */ data = iio_priv(indio_dev); data->client = client; data->variant = &hmc5843_chip_info_tbl[id->driver_data]; mutex_init(&data->lock); i2c_set_clientdata(client, indio_dev); indio_dev->info = &hmc5843_info; indio_dev->name = id->name; indio_dev->dev.parent = &client->dev; 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; } static int hmc5843_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); 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; } #ifdef CONFIG_PM_SLEEP static int hmc5843_suspend(struct device *dev) { struct hmc5843_data *data = iio_priv(i2c_get_clientdata( to_i2c_client(dev))); return hmc5843_set_mode(data, HMC5843_MODE_SLEEP); } static int hmc5843_resume(struct device *dev) { struct hmc5843_data *data = iio_priv(i2c_get_clientdata( to_i2c_client(dev))); return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS); } static SIMPLE_DEV_PM_OPS(hmc5843_pm_ops, hmc5843_suspend, hmc5843_resume); #define HMC5843_PM_OPS (&hmc5843_pm_ops) #else #define HMC5843_PM_OPS NULL #endif static const struct i2c_device_id hmc5843_id[] = { { "hmc5843", HMC5843_ID }, { "hmc5883", HMC5883_ID }, { "hmc5883l", HMC5883L_ID }, { } }; MODULE_DEVICE_TABLE(i2c, hmc5843_id); static const struct of_device_id hmc5843_of_match[] = { { .compatible = "honeywell,hmc5843" }, {} }; MODULE_DEVICE_TABLE(of, hmc5843_of_match); static struct i2c_driver hmc5843_driver = { .driver = { .name = "hmc5843", .pm = HMC5843_PM_OPS, .of_match_table = of_match_ptr(hmc5843_of_match), }, .id_table = hmc5843_id, .probe = hmc5843_probe, .remove = hmc5843_remove, }; module_i2c_driver(hmc5843_driver); MODULE_AUTHOR("Shubhrajyoti Datta "); MODULE_DESCRIPTION("HMC5843/5883/5883L driver"); MODULE_LICENSE("GPL");