| /* Copyright (C) 2010 Texas Instruments |
| Author: Shubhrajyoti Datta <shubhrajyoti@ti.com> |
| Acknowledgement: Jonathan Cameron <jic23@cam.ac.uk> for valuable inputs. |
| |
| 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/init.h> |
| #include <linux/i2c.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include "../iio.h" |
| #include "../sysfs.h" |
| |
| #define HMC5843_I2C_ADDRESS 0x1E |
| |
| #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 |
| #define HMC5843_STATUS_REG 0x09 |
| #define HMC5843_ID_REG_A 0x0A |
| #define HMC5843_ID_REG_B 0x0B |
| #define HMC5843_ID_REG_C 0x0C |
| |
| #define HMC5843_ID_REG_LENGTH 0x03 |
| #define HMC5843_ID_STRING "H43" |
| |
| /* |
| * Range settings in (+-)Ga |
| * */ |
| #define RANGE_GAIN_OFFSET 0x05 |
| |
| #define RANGE_0_7 0x00 |
| #define RANGE_1_0 0x01 /* default */ |
| #define RANGE_1_5 0x02 |
| #define RANGE_2_0 0x03 |
| #define RANGE_3_2 0x04 |
| #define RANGE_3_8 0x05 |
| #define RANGE_4_5 0x06 |
| #define RANGE_6_5 0x07 /* Not recommended */ |
| |
| /* |
| * Device status |
| */ |
| #define DATA_READY 0x01 |
| #define DATA_OUTPUT_LOCK 0x02 |
| #define VOLTAGE_REGULATOR_ENABLED 0x04 |
| |
| /* |
| * Mode register configuration |
| */ |
| #define MODE_CONVERSION_CONTINUOUS 0x00 |
| #define MODE_CONVERSION_SINGLE 0x01 |
| #define MODE_IDLE 0x02 |
| #define MODE_SLEEP 0x03 |
| |
| /* Minimum Data Output Rate in 1/10 Hz */ |
| #define RATE_OFFSET 0x02 |
| #define RATE_BITMASK 0x1C |
| #define RATE_5 0x00 |
| #define RATE_10 0x01 |
| #define RATE_20 0x02 |
| #define RATE_50 0x03 |
| #define RATE_100 0x04 |
| #define RATE_200 0x05 |
| #define RATE_500 0x06 |
| #define RATE_NOT_USED 0x07 |
| |
| /* |
| * Device Configutration |
| */ |
| #define CONF_NORMAL 0x00 |
| #define CONF_POSITIVE_BIAS 0x01 |
| #define CONF_NEGATIVE_BIAS 0x02 |
| #define CONF_NOT_USED 0x03 |
| #define MEAS_CONF_MASK 0x03 |
| |
| static int hmc5843_regval_to_nanoscale[] = { |
| 6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714 |
| }; |
| |
| static const int regval_to_input_field_mg[] = { |
| 700, |
| 1000, |
| 1500, |
| 2000, |
| 3200, |
| 3800, |
| 4500, |
| 6500 |
| }; |
| static const char * const regval_to_samp_freq[] = { |
| "0.5", |
| "1", |
| "2", |
| "5", |
| "10", |
| "20", |
| "50", |
| }; |
| |
| /* Addresses to scan: 0x1E */ |
| static const unsigned short normal_i2c[] = { HMC5843_I2C_ADDRESS, |
| I2C_CLIENT_END }; |
| |
| /* Each client has this additional data */ |
| struct hmc5843_data { |
| struct mutex lock; |
| u8 rate; |
| u8 meas_conf; |
| u8 operating_mode; |
| u8 range; |
| }; |
| |
| static void hmc5843_init_client(struct i2c_client *client); |
| |
| static s32 hmc5843_configure(struct i2c_client *client, |
| u8 operating_mode) |
| { |
| /* The lower two bits contain the current conversion mode */ |
| return i2c_smbus_write_byte_data(client, |
| HMC5843_MODE_REG, |
| (operating_mode & 0x03)); |
| } |
| |
| /* 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 & 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 an places the result in the |
| * data register. |
| * |
| * 1 - Single-Conversion Mode : device performs a single measurement, |
| * sets RDY high and returned 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_get_drvdata(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_get_drvdata(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 = strict_strtoul(buf, 10, &operating_mode); |
| if (error) { |
| count = error; |
| goto exit; |
| } |
| dev_dbg(dev, "set Conversion mode to %lu\n", operating_mode); |
| if (operating_mode > 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 |
| * |
| * Normal measurement configuration (default): In normal measurement |
| * configuration the device follows normal measurement flow. Pins BP and BN |
| * are left floating and high impedance. |
| * |
| * Positive bias configuration: In positive bias configuration, a positive |
| * current is forced across the resistive load on pins BP and BN. |
| * |
| * 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 hmc5843_data *data = i2c_get_clientdata(client); |
| u8 reg_val; |
| reg_val = (meas_conf & MEAS_CONF_MASK) | (data->rate << 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_get_drvdata(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_get_drvdata(dev); |
| struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); |
| struct hmc5843_data *data = i2c_get_clientdata(client); |
| unsigned long meas_conf = 0; |
| int error = strict_strtoul(buf, 10, &meas_conf); |
| if (error) |
| return error; |
| mutex_lock(&data->lock); |
| |
| dev_dbg(dev, "set mode 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); |
| |
| /* |
| * From Datasheet |
| * The table shows the minimum data output |
| * Value | Minimum data output rate(Hz) |
| * 0 | 0.5 |
| * 1 | 1 |
| * 2 | 2 |
| * 3 | 5 |
| * 4 | 10 (default) |
| * 5 | 20 |
| * 6 | 50 |
| * 7 | Not used |
| */ |
| static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("0.5 1 2 5 10 20 50"); |
| |
| static s32 hmc5843_set_rate(struct i2c_client *client, |
| u8 rate) |
| { |
| struct hmc5843_data *data = i2c_get_clientdata(client); |
| u8 reg_val; |
| |
| reg_val = (data->meas_conf) | (rate << RATE_OFFSET); |
| if (rate >= RATE_NOT_USED) { |
| dev_err(&client->dev, |
| "This data output rate is not supported\n"); |
| return -EINVAL; |
| } |
| return i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_A, reg_val); |
| } |
| |
| static ssize_t set_sampling_frequency(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| |
| struct iio_dev *indio_dev = dev_get_drvdata(dev); |
| struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| unsigned long rate = 0; |
| |
| if (strncmp(buf, "0.5" , 3) == 0) |
| rate = RATE_5; |
| else if (strncmp(buf, "1" , 1) == 0) |
| rate = RATE_10; |
| else if (strncmp(buf, "2", 1) == 0) |
| rate = RATE_20; |
| else if (strncmp(buf, "5", 1) == 0) |
| rate = RATE_50; |
| else if (strncmp(buf, "10", 2) == 0) |
| rate = RATE_100; |
| else if (strncmp(buf, "20" , 2) == 0) |
| rate = RATE_200; |
| else if (strncmp(buf, "50" , 2) == 0) |
| rate = RATE_500; |
| else |
| return -EINVAL; |
| |
| mutex_lock(&data->lock); |
| dev_dbg(dev, "set rate to %lu\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 show_sampling_frequency(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct iio_dev *indio_dev = dev_get_drvdata(dev); |
| struct i2c_client *client = to_i2c_client(indio_dev->dev.parent); |
| struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
| s32 rate; |
| |
| rate = i2c_smbus_read_byte_data(client, this_attr->address); |
| if (rate < 0) |
| return rate; |
| rate = (rate & RATE_BITMASK) >> RATE_OFFSET; |
| return sprintf(buf, "%s\n", regval_to_samp_freq[rate]); |
| } |
| static IIO_DEVICE_ATTR(sampling_frequency, |
| S_IWUSR | S_IRUGO, |
| show_sampling_frequency, |
| set_sampling_frequency, |
| HMC5843_CONFIG_REG_A); |
| |
| /* |
| * From Datasheet |
| * Nominal gain settings |
| * 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 |
| */ |
| static ssize_t show_range(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| u8 range; |
| struct iio_dev *indio_dev = dev_get_drvdata(dev); |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| |
| range = data->range; |
| return sprintf(buf, "%d\n", regval_to_input_field_mg[range]); |
| } |
| |
| static ssize_t set_range(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, |
| size_t count) |
| { |
| struct iio_dev *indio_dev = dev_get_drvdata(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 = strict_strtoul(buf, 10, &range); |
| if (error) { |
| count = error; |
| goto exit; |
| } |
| dev_dbg(dev, "set range to %lu\n", range); |
| |
| if (range > RANGE_6_5) { |
| count = -EINVAL; |
| goto exit; |
| } |
| |
| data->range = range; |
| range = range << 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, |
| show_range, |
| set_range, |
| 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 0: |
| return hmc5843_read_measurement(indio_dev, |
| chan->address, |
| val); |
| case (1 << IIO_CHAN_INFO_SCALE_SHARED): |
| *val = 0; |
| *val2 = hmc5843_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 = (1 << IIO_CHAN_INFO_SCALE_SHARED), \ |
| .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 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_const_attr_sampling_frequency_available.dev_attr.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group hmc5843_group = { |
| .attrs = hmc5843_attributes, |
| }; |
| |
| 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 HMC5843. */ |
| static void hmc5843_init_client(struct i2c_client *client) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| |
| 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("HMC5843 initialized\n"); |
| } |
| |
| static const struct iio_info hmc5843_info = { |
| .attrs = &hmc5843_group, |
| .read_raw = &hmc5843_read_raw, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static int 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_allocate_device(sizeof(*data)); |
| if (indio_dev == NULL) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| data = iio_priv(indio_dev); |
| /* default settings at probe */ |
| |
| data->meas_conf = CONF_NORMAL; |
| data->range = RANGE_1_0; |
| data->operating_mode = MODE_CONVERSION_CONTINUOUS; |
| |
| i2c_set_clientdata(client, indio_dev); |
| |
| /* Initialize the HMC5843 chip */ |
| hmc5843_init_client(client); |
| |
| indio_dev->info = &hmc5843_info; |
| indio_dev->name = id->name; |
| indio_dev->channels = hmc5843_channels; |
| indio_dev->num_channels = ARRAY_SIZE(hmc5843_channels); |
| 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_free_device(indio_dev); |
| exit: |
| return err; |
| } |
| |
| static int 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, MODE_SLEEP); |
| iio_free_device(indio_dev); |
| |
| return 0; |
| } |
| |
| static int hmc5843_suspend(struct i2c_client *client, pm_message_t mesg) |
| { |
| hmc5843_configure(client, MODE_SLEEP); |
| return 0; |
| } |
| |
| static int hmc5843_resume(struct i2c_client *client) |
| { |
| struct hmc5843_data *data = i2c_get_clientdata(client); |
| hmc5843_configure(client, data->operating_mode); |
| return 0; |
| } |
| |
| static const struct i2c_device_id hmc5843_id[] = { |
| { "hmc5843", 0 }, |
| { } |
| }; |
| |
| static struct i2c_driver hmc5843_driver = { |
| .driver = { |
| .name = "hmc5843", |
| }, |
| .id_table = hmc5843_id, |
| .probe = hmc5843_probe, |
| .remove = hmc5843_remove, |
| .detect = hmc5843_detect, |
| .address_list = normal_i2c, |
| .suspend = hmc5843_suspend, |
| .resume = hmc5843_resume, |
| }; |
| |
| static int __init hmc5843_init(void) |
| { |
| return i2c_add_driver(&hmc5843_driver); |
| } |
| |
| static void __exit hmc5843_exit(void) |
| { |
| i2c_del_driver(&hmc5843_driver); |
| } |
| |
| MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com"); |
| MODULE_DESCRIPTION("HMC5843 driver"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(hmc5843_init); |
| module_exit(hmc5843_exit); |