/* 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 #define HMC5843_CONFIG_REG_A 0x00 #define HMC5843_CONFIG_REG_B 0x01 #define HMC5843_MODE_REG 0x02 #define HMC5843_DATA_OUT_X_MSB_REG 0x03 #define HMC5843_DATA_OUT_X_LSB_REG 0x04 #define HMC5843_DATA_OUT_Y_MSB_REG 0x05 #define HMC5843_DATA_OUT_Y_LSB_REG 0x06 #define HMC5843_DATA_OUT_Z_MSB_REG 0x07 #define HMC5843_DATA_OUT_Z_LSB_REG 0x08 /* Beware: Y and Z are exchanged on HMC5883 */ #define HMC5883_DATA_OUT_Z_MSB_REG 0x05 #define HMC5883_DATA_OUT_Z_LSB_REG 0x06 #define HMC5883_DATA_OUT_Y_MSB_REG 0x07 #define HMC5883_DATA_OUT_Y_LSB_REG 0x08 #define HMC5843_STATUS_REG 0x09 #define HMC5843_ID_REG_A 0x0A #define HMC5843_ID_REG_B 0x0B #define HMC5843_ID_REG_C 0x0C enum hmc5843_ids { HMC5843_ID, HMC5883_ID, HMC5883L_ID, }; /* * Beware: identification of the HMC5883 is still "H43"; * I2C address is also unchanged */ #define HMC5843_ID_REG_LENGTH 0x03 #define HMC5843_ID_STRING "H43" #define HMC5843_I2C_ADDRESS 0x1E /* * 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_MAX 0x07 /* * Device status */ #define HMC5843_DATA_READY 0x01 #define HMC5843_DATA_OUTPUT_LOCK 0x02 /* Does not exist on HMC5883, not used */ #define HMC5843_VOLTAGE_REGULATOR_ENABLED 0x04 /* * 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_BITMASK 0x1C #define HMC5843_RATE_NOT_USED 0x07 /* * 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_NOT_USED 0x03 #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 HMC5843 datasheet: * Value | Sensor input field range (Ga) | Gain (counts/milli-Gauss) * 0 | (+-)0.7 | 1620 * 1 | (+-)1.0 | 1300 * 2 | (+-)1.5 | 970 * 3 | (+-)2.0 | 780 * 4 | (+-)3.2 | 530 * 5 | (+-)3.8 | 460 * 6 | (+-)4.5 | 390 * 7 | (+-)6.5 | 280 * * From the HMC5883 datasheet: * Value | Recommended sensor field range (Ga) | Gain (counts/Gauss) * 0 | (+-)0.9 | 1280 * 1 | (+-)1.2 | 1024 * 2 | (+-)1.9 | 768 * 3 | (+-)2.5 | 614 * 4 | (+-)4.0 | 415 * 5 | (+-)4.6 | 361 * 6 | (+-)5.5 | 307 * 7 | (+-)7.9 | 219 * * From the HMC5883L datasheet: * Value | Recommended sensor field range (Ga) | Gain (LSB/Gauss) * 0 | (+-)0.88 | 1370 * 1 | (+-)1.3 | 1090 * 2 | (+-)1.9 | 820 * 3 | (+-)2.5 | 660 * 4 | (+-)4.0 | 440 * 5 | (+-)4.7 | 390 * 6 | (+-)5.6 | 330 * 7 | (+-)8.1 | 230 */ static const int hmc5843_regval_to_input_field_mga[] = { 700, 1000, 1500, 2000, 3200, 3800, 4500, 6500 }; static const int hmc5883_regval_to_input_field_mga[] = { 900, 1200, 1900, 2500, 4000, 4600, 5500, 7900 }; static const int hmc5883l_regval_to_input_field_mga[] = { 880, 1300, 1900, 2500, 4000, 4700, 5600, 8100 }; /* * 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 char * const hmc5843_regval_to_sample_freq[] = { "0.5", "1", "2", "5", "10", "20", "50", }; static const char * const hmc5883_regval_to_sample_freq[] = { "0.75", "1.5", "3", "7.5", "15", "30", "75", }; /* Addresses to scan: 0x1E */ static const unsigned short normal_i2c[] = { HMC5843_I2C_ADDRESS, I2C_CLIENT_END }; /* Describe chip variants */ struct hmc5843_chip_info { const struct iio_chan_spec *channels; int num_channels; const char * const *regval_to_sample_freq; const int *regval_to_input_field_mga; const int *regval_to_nanoscale; }; /* Each client has this additional data */ struct hmc5843_data { struct mutex lock; u8 rate; u8 meas_conf; u8 operating_mode; u8 range; const struct hmc5843_chip_info *variant; }; /* The lower two bits contain the current conversion mode */ static s32 hmc5843_configure(struct i2c_client *client, u8 operating_mode) { return i2c_smbus_write_byte_data(client, HMC5843_MODE_REG, operating_mode & HMC5843_MODE_MASK); } /* Return the measurement value from the specified channel */ static int hmc5843_read_measurement(struct iio_dev *indio_dev, int address, int *val) { struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct hmc5843_data *data = iio_priv(indio_dev); s32 result; mutex_lock(&data->lock); result = i2c_smbus_read_byte_data(client, HMC5843_STATUS_REG); while (!(result & HMC5843_DATA_READY)) result = i2c_smbus_read_byte_data(client, HMC5843_STATUS_REG); result = i2c_smbus_read_word_data(client, address); mutex_unlock(&data->lock); if (result < 0) return -EINVAL; *val = (s16)swab16((u16)result); return IIO_VAL_INT; } /* * From the datasheet: * 0 - Continuous-Conversion Mode: In continuous-conversion mode, the * device continuously performs conversions and places the result in * the data register. * * 1 - Single-Conversion Mode : Device performs a single measurement, * sets RDY high and returns to sleep mode. * * 2 - Idle Mode : Device is placed in idle mode. * * 3 - Sleep Mode : Device is placed in sleep mode. * */ static ssize_t hmc5843_show_operating_mode(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct hmc5843_data *data = iio_priv(indio_dev); return sprintf(buf, "%d\n", data->operating_mode); } static ssize_t hmc5843_set_operating_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct hmc5843_data *data = iio_priv(indio_dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); unsigned long operating_mode = 0; s32 status; int error; mutex_lock(&data->lock); error = kstrtoul(buf, 10, &operating_mode); if (error) { count = error; goto exit; } dev_dbg(dev, "set conversion mode to %lu\n", operating_mode); if (operating_mode > HMC5843_MODE_SLEEP) { count = -EINVAL; goto exit; } status = i2c_smbus_write_byte_data(client, this_attr->address, operating_mode); if (status) { count = -EINVAL; goto exit; } data->operating_mode = operating_mode; exit: mutex_unlock(&data->lock); return count; } static IIO_DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, hmc5843_show_operating_mode, hmc5843_set_operating_mode, HMC5843_MODE_REG); /* * 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 i2c_client *client, u8 meas_conf) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct hmc5843_data *data = iio_priv(indio_dev); u8 reg_val; reg_val = (meas_conf & HMC5843_MEAS_CONF_MASK) | (data->rate << HMC5843_RATE_OFFSET); return i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_A, reg_val); } static ssize_t hmc5843_show_measurement_configuration(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct hmc5843_data *data = iio_priv(indio_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 iio_dev *indio_dev = dev_to_iio_dev(dev); struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct hmc5843_data *data = iio_priv(indio_dev); unsigned long meas_conf = 0; int error; error = kstrtoul(buf, 10, &meas_conf); if (error) return error; if (meas_conf >= HMC5843_MEAS_CONF_NOT_USED) return -EINVAL; mutex_lock(&data->lock); dev_dbg(dev, "set measurement configuration to %lu\n", meas_conf); if (hmc5843_set_meas_conf(client, meas_conf)) { count = -EINVAL; goto exit; } data->meas_conf = meas_conf; exit: mutex_unlock(&data->lock); return 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_sampling_frequencies_available(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct hmc5843_data *data = iio_priv(indio_dev); ssize_t total_n = 0; int i; for (i = 0; i < HMC5843_RATE_NOT_USED; i++) { ssize_t n = sprintf(buf, "%s ", data->variant->regval_to_sample_freq[i]); buf += n; total_n += n; } /* replace trailing space by newline */ buf[-1] = '\n'; return total_n; } static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_sampling_frequencies_available); static s32 hmc5843_set_rate(struct i2c_client *client, u8 rate) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct hmc5843_data *data = iio_priv(indio_dev); u8 reg_val; if (rate >= HMC5843_RATE_NOT_USED) { dev_err(&client->dev, "data output rate is not supported\n"); return -EINVAL; } reg_val = data->meas_conf | (rate << HMC5843_RATE_OFFSET); return i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_A, reg_val); } static int hmc5843_check_sampling_frequency(struct hmc5843_data *data, const char *buf) { const char * const *samp_freq = data->variant->regval_to_sample_freq; int i; for (i = 0; i < HMC5843_RATE_NOT_USED; i++) { if (sysfs_streq(buf, samp_freq[i])) return i; } return -EINVAL; } static ssize_t hmc5843_set_sampling_frequency(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct hmc5843_data *data = iio_priv(indio_dev); int rate; rate = hmc5843_check_sampling_frequency(data, buf); if (rate < 0) { dev_err(&client->dev, "sampling frequency is not supported\n"); return rate; } mutex_lock(&data->lock); dev_dbg(dev, "set rate to %d\n", rate); if (hmc5843_set_rate(client, rate)) { count = -EINVAL; goto exit; } data->rate = rate; exit: mutex_unlock(&data->lock); return count; } static ssize_t hmc5843_show_sampling_frequency(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); struct hmc5843_data *data = iio_priv(indio_dev); s32 rate; rate = i2c_smbus_read_byte_data(client, this_attr->address); if (rate < 0) return rate; rate = (rate & HMC5843_RATE_BITMASK) >> HMC5843_RATE_OFFSET; return sprintf(buf, "%s\n", data->variant->regval_to_sample_freq[rate]); } static IIO_DEVICE_ATTR(sampling_frequency, S_IWUSR | S_IRUGO, hmc5843_show_sampling_frequency, hmc5843_set_sampling_frequency, HMC5843_CONFIG_REG_A); static ssize_t hmc5843_show_range_gain(struct device *dev, struct device_attribute *attr, char *buf) { u8 range; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct hmc5843_data *data = iio_priv(indio_dev); range = data->range; return sprintf(buf, "%d\n", data->variant->regval_to_input_field_mga[range]); } static ssize_t hmc5843_set_range_gain(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); struct hmc5843_data *data = iio_priv(indio_dev); unsigned long range = 0; int error; mutex_lock(&data->lock); error = kstrtoul(buf, 10, &range); if (error) { count = error; goto exit; } dev_dbg(dev, "set range to %lu\n", range); if (range > HMC5843_RANGE_GAIN_MAX) { count = -EINVAL; goto exit; } data->range = range; range = range << HMC5843_RANGE_GAIN_OFFSET; if (i2c_smbus_write_byte_data(client, this_attr->address, range)) count = -EINVAL; exit: mutex_unlock(&data->lock); return count; } static IIO_DEVICE_ATTR(in_magn_range, S_IWUSR | S_IRUGO, hmc5843_show_range_gain, hmc5843_set_range_gain, HMC5843_CONFIG_REG_B); 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(indio_dev, chan->address, val); case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = data->variant->regval_to_nanoscale[data->range]; return IIO_VAL_INT_PLUS_NANO; }; return -EINVAL; } #define HMC5843_CHANNEL(axis, add) \ { \ .type = IIO_MAGN, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ IIO_CHAN_INFO_SCALE_SHARED_BIT, \ .address = add \ } static const struct iio_chan_spec hmc5843_channels[] = { HMC5843_CHANNEL(X, HMC5843_DATA_OUT_X_MSB_REG), HMC5843_CHANNEL(Y, HMC5843_DATA_OUT_Y_MSB_REG), HMC5843_CHANNEL(Z, HMC5843_DATA_OUT_Z_MSB_REG), }; static const struct iio_chan_spec hmc5883_channels[] = { HMC5843_CHANNEL(X, HMC5843_DATA_OUT_X_MSB_REG), HMC5843_CHANNEL(Y, HMC5883_DATA_OUT_Y_MSB_REG), HMC5843_CHANNEL(Z, HMC5883_DATA_OUT_Z_MSB_REG), }; static struct attribute *hmc5843_attributes[] = { &iio_dev_attr_meas_conf.dev_attr.attr, &iio_dev_attr_operating_mode.dev_attr.attr, &iio_dev_attr_sampling_frequency.dev_attr.attr, &iio_dev_attr_in_magn_range.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, .num_channels = ARRAY_SIZE(hmc5843_channels), .regval_to_sample_freq = hmc5843_regval_to_sample_freq, .regval_to_input_field_mga = hmc5843_regval_to_input_field_mga, .regval_to_nanoscale = hmc5843_regval_to_nanoscale, }, [HMC5883_ID] = { .channels = hmc5883_channels, .num_channels = ARRAY_SIZE(hmc5883_channels), .regval_to_sample_freq = hmc5883_regval_to_sample_freq, .regval_to_input_field_mga = hmc5883_regval_to_input_field_mga, .regval_to_nanoscale = hmc5883_regval_to_nanoscale, }, [HMC5883L_ID] = { .channels = hmc5883_channels, .num_channels = ARRAY_SIZE(hmc5883_channels), .regval_to_sample_freq = hmc5883_regval_to_sample_freq, .regval_to_input_field_mga = hmc5883l_regval_to_input_field_mga, .regval_to_nanoscale = hmc5883l_regval_to_nanoscale, }, }; static int hmc5843_detect(struct i2c_client *client, struct i2c_board_info *info) { unsigned char id_str[HMC5843_ID_REG_LENGTH]; if (client->addr != HMC5843_I2C_ADDRESS) return -ENODEV; if (i2c_smbus_read_i2c_block_data(client, HMC5843_ID_REG_A, HMC5843_ID_REG_LENGTH, id_str) != HMC5843_ID_REG_LENGTH) return -ENODEV; if (0 != strncmp(id_str, HMC5843_ID_STRING, HMC5843_ID_REG_LENGTH)) return -ENODEV; return 0; } /* Called when we have found a new HMC58X3 */ static void hmc5843_init_client(struct i2c_client *client, const struct i2c_device_id *id) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct hmc5843_data *data = iio_priv(indio_dev); data->variant = &hmc5843_chip_info_tbl[id->driver_data]; indio_dev->channels = data->variant->channels; indio_dev->num_channels = data->variant->num_channels; hmc5843_set_meas_conf(client, data->meas_conf); hmc5843_set_rate(client, data->rate); hmc5843_configure(client, data->operating_mode); i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_B, data->range); mutex_init(&data->lock); pr_info("%s initialized\n", id->name); } static const struct iio_info hmc5843_info = { .attrs = &hmc5843_group, .read_raw = &hmc5843_read_raw, .driver_module = THIS_MODULE, }; static int __devinit hmc5843_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct hmc5843_data *data; struct iio_dev *indio_dev; int err = 0; indio_dev = iio_device_alloc(sizeof(*data)); if (indio_dev == NULL) { err = -ENOMEM; goto exit; } /* default settings at probe */ data = iio_priv(indio_dev); data->meas_conf = HMC5843_MEAS_CONF_NORMAL; data->range = HMC5843_RANGE_GAIN_DEFAULT; data->operating_mode = HMC5843_MODE_CONVERSION_CONTINUOUS; i2c_set_clientdata(client, indio_dev); hmc5843_init_client(client, id); indio_dev->info = &hmc5843_info; indio_dev->name = id->name; indio_dev->dev.parent = &client->dev; indio_dev->modes = INDIO_DIRECT_MODE; err = iio_device_register(indio_dev); if (err) goto exit_free2; return 0; exit_free2: iio_device_free(indio_dev); exit: return err; } static int __devexit hmc5843_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); iio_device_unregister(indio_dev); /* sleep mode to save power */ hmc5843_configure(client, HMC5843_MODE_SLEEP); iio_device_free(indio_dev); return 0; } #ifdef CONFIG_PM_SLEEP static int hmc5843_suspend(struct device *dev) { hmc5843_configure(to_i2c_client(dev), HMC5843_MODE_SLEEP); return 0; } static int hmc5843_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct iio_dev *indio_dev = i2c_get_clientdata(client); struct hmc5843_data *data = iio_priv(indio_dev); hmc5843_configure(client, data->operating_mode); return 0; } 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 struct i2c_driver hmc5843_driver = { .driver = { .name = "hmc5843", .pm = HMC5843_PM_OPS, }, .id_table = hmc5843_id, .probe = hmc5843_probe, .remove = __devexit_p(hmc5843_remove), .detect = hmc5843_detect, .address_list = normal_i2c, }; module_i2c_driver(hmc5843_driver); MODULE_AUTHOR("Shubhrajyoti Datta