- 根目录:
- drivers
- iio
- magnetometer
- mag3110.c
/*
* mag3110.c - Support for Freescale MAG3110 magnetometer sensor
*
* Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* (7-bit I2C slave address 0x0e)
*
* TODO: irq, user offset, oversampling, continuous mode
*/
#include <linux/module.h>
#include <linux/i2c.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>
#define MAG3110_STATUS 0x00
#define MAG3110_OUT_X 0x01 /* MSB first */
#define MAG3110_OUT_Y 0x03
#define MAG3110_OUT_Z 0x05
#define MAG3110_WHO_AM_I 0x07
#define MAG3110_OFF_X 0x09 /* MSB first */
#define MAG3110_OFF_Y 0x0b
#define MAG3110_OFF_Z 0x0d
#define MAG3110_DIE_TEMP 0x0f
#define MAG3110_CTRL_REG1 0x10
#define MAG3110_CTRL_REG2 0x11
#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
#define MAG3110_CTRL_DR_SHIFT 5
#define MAG3110_CTRL_DR_DEFAULT 0
#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
#define MAG3110_DEVICE_ID 0xc4
/* Each client has this additional data */
struct mag3110_data {
struct i2c_client *client;
struct mutex lock;
u8 ctrl_reg1;
};
static int mag3110_request(struct mag3110_data *data)
{
int ret, tries = 150;
/* trigger measurement */
ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1 | MAG3110_CTRL_TM);
if (ret < 0)
return ret;
while (tries-- > 0) {
ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
if (ret < 0)
return ret;
/* wait for data ready */
if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
break;
msleep(20);
}
if (tries < 0) {
dev_err(&data->client->dev, "data not ready\n");
return -EIO;
}
return 0;
}
static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
{
int ret;
mutex_lock(&data->lock);
ret = mag3110_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = i2c_smbus_read_i2c_block_data(data->client,
MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
mutex_unlock(&data->lock);
return ret;
}
static ssize_t mag3110_show_int_plus_micros(char *buf,
const int (*vals)[2], int n)
{
size_t len = 0;
while (n-- > 0)
len += scnprintf(buf + len, PAGE_SIZE - len,
"%d.%06d ", vals[n][0], vals[n][1]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
int val, int val2)
{
while (n-- > 0)
if (val == vals[n][0] && val2 == vals[n][1])
return n;
return -EINVAL;
}
static const int mag3110_samp_freq[8][2] = {
{80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
{1, 250000}, {0, 625000}
};
static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
static int mag3110_get_samp_freq_index(struct mag3110_data *data,
int val, int val2)
{
return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
val2);
}
static int mag3110_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mag3110_data *data = iio_priv(indio_dev);
__be16 buffer[3];
int i, ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
switch (chan->type) {
case IIO_MAGN: /* in 0.1 uT / LSB */
ret = mag3110_read(data, buffer);
if (ret < 0)
return ret;
*val = sign_extend32(
be16_to_cpu(buffer[chan->scan_index]), 15);
return IIO_VAL_INT;
case IIO_TEMP: /* in 1 C / LSB */
mutex_lock(&data->lock);
ret = mag3110_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = i2c_smbus_read_byte_data(data->client,
MAG3110_DIE_TEMP);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 7);
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_MAGN:
*val = 0;
*val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_TEMP:
*val = 1000;
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SAMP_FREQ:
i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
*val = mag3110_samp_freq[i][0];
*val2 = mag3110_samp_freq[i][1];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_CALIBBIAS:
ret = i2c_smbus_read_word_swapped(data->client,
MAG3110_OFF_X + 2 * chan->scan_index);
if (ret < 0)
return ret;
*val = sign_extend32(ret >> 1, 14);
return IIO_VAL_INT;
}
return -EINVAL;
}
static int mag3110_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct mag3110_data *data = iio_priv(indio_dev);
int rate;
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
rate = mag3110_get_samp_freq_index(data, val, val2);
if (rate < 0)
return -EINVAL;
data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
return i2c_smbus_write_byte_data(data->client,
MAG3110_CTRL_REG1, data->ctrl_reg1);
case IIO_CHAN_INFO_CALIBBIAS:
if (val < -10000 || val > 10000)
return -EINVAL;
return i2c_smbus_write_word_swapped(data->client,
MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
default:
return -EINVAL;
}
}
static irqreturn_t mag3110_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct mag3110_data *data = iio_priv(indio_dev);
u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */
int ret;
ret = mag3110_read(data, (__be16 *) buffer);
if (ret < 0)
goto done;
if (test_bit(3, indio_dev->active_scan_mask)) {
ret = i2c_smbus_read_byte_data(data->client,
MAG3110_DIE_TEMP);
if (ret < 0)
goto done;
buffer[6] = ret;
}
iio_push_to_buffers_with_timestamp(indio_dev, buffer,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
#define MAG3110_CHANNEL(axis, idx) { \
.type = IIO_MAGN, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
BIT(IIO_CHAN_INFO_SCALE), \
.scan_index = idx, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_BE, \
}, \
}
static const struct iio_chan_spec mag3110_channels[] = {
MAG3110_CHANNEL(X, 0),
MAG3110_CHANNEL(Y, 1),
MAG3110_CHANNEL(Z, 2),
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 3,
.scan_type = {
.sign = 's',
.realbits = 8,
.storagebits = 8,
},
},
IIO_CHAN_SOFT_TIMESTAMP(4),
};
static struct attribute *mag3110_attributes[] = {
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group mag3110_group = {
.attrs = mag3110_attributes,
};
static const struct iio_info mag3110_info = {
.attrs = &mag3110_group,
.read_raw = &mag3110_read_raw,
.write_raw = &mag3110_write_raw,
.driver_module = THIS_MODULE,
};
static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
static int mag3110_standby(struct mag3110_data *data)
{
return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1 & ~MAG3110_CTRL_AC);
}
static int mag3110_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mag3110_data *data;
struct iio_dev *indio_dev;
int ret;
ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
if (ret < 0)
return ret;
if (ret != MAG3110_DEVICE_ID)
return -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
i2c_set_clientdata(client, indio_dev);
indio_dev->info = &mag3110_info;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mag3110_channels;
indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
indio_dev->available_scan_masks = mag3110_scan_masks;
data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1,
data->ctrl_reg1);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
MAG3110_CTRL_AUTO_MRST_EN);
if (ret < 0)
goto standby_on_error;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
mag3110_trigger_handler, NULL);
if (ret < 0)
goto standby_on_error;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
standby_on_error:
mag3110_standby(iio_priv(indio_dev));
return ret;
}
static int mag3110_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);
mag3110_standby(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mag3110_suspend(struct device *dev)
{
return mag3110_standby(iio_priv(i2c_get_clientdata(
to_i2c_client(dev))));
}
static int mag3110_resume(struct device *dev)
{
struct mag3110_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1);
}
static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
#define MAG3110_PM_OPS (&mag3110_pm_ops)
#else
#define MAG3110_PM_OPS NULL
#endif
static const struct i2c_device_id mag3110_id[] = {
{ "mag3110", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, mag3110_id);
static struct i2c_driver mag3110_driver = {
.driver = {
.name = "mag3110",
.pm = MAG3110_PM_OPS,
},
.probe = mag3110_probe,
.remove = mag3110_remove,
.id_table = mag3110_id,
};
module_i2c_driver(mag3110_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
MODULE_LICENSE("GPL");