--- /dev/null
+/* 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"
+#include "magnet.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 const int regval_to_counts_per_mg[] = {
+ 1620,
+ 1300,
+ 970,
+ 780,
+ 530,
+ 460,
+ 390,
+ 280
+};
+static const int regval_to_input_field_mg[] = {
+ 700,
+ 1000,
+ 1500,
+ 2000,
+ 3200,
+ 3800,
+ 4500,
+ 6500
+};
+static const char *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 iio_dev *indio_dev;
+ 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 ssize_t hmc5843_read_measurement(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);
+ s16 coordinate_val;
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ struct hmc5843_data *data = indio_dev->dev_data;
+ 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, this_attr->address);
+ mutex_unlock(&data->lock);
+ if (result < 0)
+ return -EINVAL;
+
+ coordinate_val = (s16)swab16((u16)result);
+ return sprintf(buf, "%d\n", coordinate_val);
+}
+static IIO_DEV_ATTR_MAGN_X(hmc5843_read_measurement,
+ HMC5843_DATA_OUT_X_MSB_REG);
+static IIO_DEV_ATTR_MAGN_Y(hmc5843_read_measurement,
+ HMC5843_DATA_OUT_Y_MSB_REG);
+static IIO_DEV_ATTR_MAGN_Z(hmc5843_read_measurement,
+ HMC5843_DATA_OUT_Z_MSB_REG);
+
+/*
+ * 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 = indio_dev->dev_data;
+ 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 = indio_dev->dev_data;
+ 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)
+ return error;
+ dev_dbg(dev, "set Conversion mode to %lu\n", operating_mode);
+ if (operating_mode > MODE_SLEEP)
+ return -EINVAL;
+
+ 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 = indio_dev->dev_data;
+ 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_AVAIL_SAMP_FREQ("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 = indio_dev->dev_data;
+ 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);
+ u32 rate;
+
+ rate = i2c_smbus_read_byte_data(client, this_attr->address);
+ if (rate < 0)
+ return -EINVAL;
+ 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 = indio_dev->dev_data;
+
+ 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 = indio_dev->dev_data;
+ unsigned long range = 0;
+ int error;
+ mutex_lock(&data->lock);
+ error = strict_strtoul(buf, 10, &range);
+ if (error)
+ return error;
+ dev_dbg(dev, "set range to %lu\n", range);
+
+ if (range > RANGE_6_5)
+ return -EINVAL;
+
+ data->range = range;
+ range = range << RANGE_GAIN_OFFSET;
+ if (i2c_smbus_write_byte_data(client, this_attr->address, range))
+ count = -EINVAL;
+
+ mutex_unlock(&data->lock);
+ return count;
+
+}
+static IIO_DEVICE_ATTR(magn_range,
+ S_IWUSR | S_IRUGO,
+ show_range,
+ set_range,
+ HMC5843_CONFIG_REG_B);
+
+static ssize_t show_gain(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct hmc5843_data *data = indio_dev->dev_data;
+ return sprintf(buf, "%d\n", regval_to_counts_per_mg[data->range]);
+}
+static IIO_DEVICE_ATTR(magn_gain,
+ S_IRUGO,
+ show_gain,
+ NULL , 0);
+
+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_magn_range.dev_attr.attr,
+ &iio_dev_attr_magn_gain.dev_attr.attr,
+ &iio_dev_attr_magn_x_raw.dev_attr.attr,
+ &iio_dev_attr_magn_y_raw.dev_attr.attr,
+ &iio_dev_attr_magn_z_raw.dev_attr.attr,
+ &iio_const_attr_available_sampling_frequency.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 hmc5843_data *data = i2c_get_clientdata(client);
+ 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 int hmc5843_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct hmc5843_data *data;
+ int err = 0;
+
+ data = kzalloc(sizeof(struct hmc5843_data), GFP_KERNEL);
+ if (!data) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ /* default settings at probe */
+
+ data->meas_conf = CONF_NORMAL;
+ data->range = RANGE_1_0;
+ data->operating_mode = MODE_CONVERSION_CONTINUOUS;
+
+ i2c_set_clientdata(client, data);
+
+ /* Initialize the HMC5843 chip */
+ hmc5843_init_client(client);
+
+ data->indio_dev = iio_allocate_device();
+ if (!data->indio_dev) {
+ err = -ENOMEM;
+ goto exit_free1;
+ }
+ data->indio_dev->attrs = &hmc5843_group;
+ data->indio_dev->dev.parent = &client->dev;
+ data->indio_dev->dev_data = (void *)(data);
+ data->indio_dev->driver_module = THIS_MODULE;
+ data->indio_dev->modes = INDIO_DIRECT_MODE;
+ err = iio_device_register(data->indio_dev);
+ if (err)
+ goto exit_free2;
+ return 0;
+exit_free2:
+ iio_free_device(data->indio_dev);
+exit_free1:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int hmc5843_remove(struct i2c_client *client)
+{
+ struct hmc5843_data *data = i2c_get_clientdata(client);
+ /* sleep mode to save power */
+ hmc5843_configure(client, MODE_SLEEP);
+ iio_device_unregister(data->indio_dev);
+ kfree(i2c_get_clientdata(client));
+ 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);
projects / mv-sheeva.git / commitdiff