linux/drivers/iio/magnetometer/mag3110.c
Cristina Opriceana 66687e6aed iio: magnetometer: mag3110: Place driver on standby on error
Place driver on standby mode on error in order to prevent wasting
power. Move standby function above to be seen by the new call.

Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-01 17:24:09 +02:00

441 lines
10 KiB
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");