2 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
4 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
10 * (7-bit I2C slave address 0x0e)
12 * TODO: irq, user offset, oversampling, continuous mode
15 #include <linux/module.h>
16 #include <linux/i2c.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/trigger_consumer.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/delay.h>
24 #define MAG3110_STATUS 0x00
25 #define MAG3110_OUT_X 0x01 /* MSB first */
26 #define MAG3110_OUT_Y 0x03
27 #define MAG3110_OUT_Z 0x05
28 #define MAG3110_WHO_AM_I 0x07
29 #define MAG3110_OFF_X 0x09 /* MSB first */
30 #define MAG3110_OFF_Y 0x0b
31 #define MAG3110_OFF_Z 0x0d
32 #define MAG3110_DIE_TEMP 0x0f
33 #define MAG3110_CTRL_REG1 0x10
34 #define MAG3110_CTRL_REG2 0x11
36 #define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
38 #define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
39 #define MAG3110_CTRL_DR_SHIFT 5
40 #define MAG3110_CTRL_DR_DEFAULT 0
42 #define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
43 #define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
45 #define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
46 #define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
48 #define MAG3110_DEVICE_ID 0xc4
50 /* Each client has this additional data */
52 struct i2c_client *client;
57 static int mag3110_request(struct mag3110_data *data)
61 /* trigger measurement */
62 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
63 data->ctrl_reg1 | MAG3110_CTRL_TM);
68 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
71 /* wait for data ready */
72 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
78 dev_err(&data->client->dev, "data not ready\n");
85 static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
89 mutex_lock(&data->lock);
90 ret = mag3110_request(data);
92 mutex_unlock(&data->lock);
95 ret = i2c_smbus_read_i2c_block_data(data->client,
96 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
97 mutex_unlock(&data->lock);
102 static ssize_t mag3110_show_int_plus_micros(char *buf,
103 const int (*vals)[2], int n)
108 len += scnprintf(buf + len, PAGE_SIZE - len,
109 "%d.%d ", vals[n][0], vals[n][1]);
111 /* replace trailing space by newline */
117 static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
121 if (val == vals[n][0] && val2 == vals[n][1])
127 static const int mag3110_samp_freq[8][2] = {
128 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
129 {1, 250000}, {0, 625000}
132 static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
133 struct device_attribute *attr, char *buf)
135 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
138 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
140 static int mag3110_get_samp_freq_index(struct mag3110_data *data,
143 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
147 static int mag3110_read_raw(struct iio_dev *indio_dev,
148 struct iio_chan_spec const *chan,
149 int *val, int *val2, long mask)
151 struct mag3110_data *data = iio_priv(indio_dev);
156 case IIO_CHAN_INFO_RAW:
157 switch (chan->type) {
158 case IIO_MAGN: /* in 0.1 uT / LSB */
159 ret = mag3110_read(data, buffer);
162 *val = sign_extend32(
163 be16_to_cpu(buffer[chan->scan_index]), 15);
165 case IIO_TEMP: /* in 1 C / LSB */
166 mutex_lock(&data->lock);
167 ret = mag3110_request(data);
169 mutex_unlock(&data->lock);
172 ret = i2c_smbus_read_byte_data(data->client,
174 mutex_unlock(&data->lock);
177 *val = sign_extend32(ret, 7);
182 case IIO_CHAN_INFO_SCALE:
185 return IIO_VAL_INT_PLUS_MICRO;
186 case IIO_CHAN_INFO_SAMP_FREQ:
187 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
188 *val = mag3110_samp_freq[i][0];
189 *val2 = mag3110_samp_freq[i][1];
190 return IIO_VAL_INT_PLUS_MICRO;
195 static int mag3110_write_raw(struct iio_dev *indio_dev,
196 struct iio_chan_spec const *chan,
197 int val, int val2, long mask)
199 struct mag3110_data *data = iio_priv(indio_dev);
203 case IIO_CHAN_INFO_SAMP_FREQ:
204 rate = mag3110_get_samp_freq_index(data, val, val2);
208 data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
209 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
210 return i2c_smbus_write_byte_data(data->client,
211 MAG3110_CTRL_REG1, data->ctrl_reg1);
217 static irqreturn_t mag3110_trigger_handler(int irq, void *p)
219 struct iio_poll_func *pf = p;
220 struct iio_dev *indio_dev = pf->indio_dev;
221 struct mag3110_data *data = iio_priv(indio_dev);
222 u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */
225 ret = mag3110_read(data, (__be16 *) buffer);
229 if (test_bit(3, indio_dev->active_scan_mask)) {
230 ret = i2c_smbus_read_byte_data(data->client,
237 iio_push_to_buffers_with_timestamp(indio_dev, buffer,
241 iio_trigger_notify_done(indio_dev->trig);
245 #define MAG3110_CHANNEL(axis, idx) { \
248 .channel2 = IIO_MOD_##axis, \
249 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
250 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
251 BIT(IIO_CHAN_INFO_SCALE), \
257 .endianness = IIO_BE, \
261 static const struct iio_chan_spec mag3110_channels[] = {
262 MAG3110_CHANNEL(X, 0),
263 MAG3110_CHANNEL(Y, 1),
264 MAG3110_CHANNEL(Z, 2),
267 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
275 IIO_CHAN_SOFT_TIMESTAMP(4),
278 static struct attribute *mag3110_attributes[] = {
279 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
283 static const struct attribute_group mag3110_group = {
284 .attrs = mag3110_attributes,
287 static const struct iio_info mag3110_info = {
288 .attrs = &mag3110_group,
289 .read_raw = &mag3110_read_raw,
290 .write_raw = &mag3110_write_raw,
291 .driver_module = THIS_MODULE,
294 static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
296 static int mag3110_probe(struct i2c_client *client,
297 const struct i2c_device_id *id)
299 struct mag3110_data *data;
300 struct iio_dev *indio_dev;
303 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
306 if (ret != MAG3110_DEVICE_ID)
309 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
313 data = iio_priv(indio_dev);
314 data->client = client;
315 mutex_init(&data->lock);
317 i2c_set_clientdata(client, indio_dev);
318 indio_dev->info = &mag3110_info;
319 indio_dev->name = id->name;
320 indio_dev->dev.parent = &client->dev;
321 indio_dev->modes = INDIO_DIRECT_MODE;
322 indio_dev->channels = mag3110_channels;
323 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
324 indio_dev->available_scan_masks = mag3110_scan_masks;
326 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT;
327 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1,
332 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
333 MAG3110_CTRL_AUTO_MRST_EN | MAG3110_CTRL_RAW);
337 ret = iio_triggered_buffer_setup(indio_dev, NULL,
338 mag3110_trigger_handler, NULL);
342 ret = iio_device_register(indio_dev);
348 iio_triggered_buffer_cleanup(indio_dev);
352 static int mag3110_standby(struct mag3110_data *data)
354 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
355 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
358 static int mag3110_remove(struct i2c_client *client)
360 struct iio_dev *indio_dev = i2c_get_clientdata(client);
362 iio_device_unregister(indio_dev);
363 iio_triggered_buffer_cleanup(indio_dev);
364 mag3110_standby(iio_priv(indio_dev));
369 #ifdef CONFIG_PM_SLEEP
370 static int mag3110_suspend(struct device *dev)
372 return mag3110_standby(iio_priv(i2c_get_clientdata(
373 to_i2c_client(dev))));
376 static int mag3110_resume(struct device *dev)
378 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
379 to_i2c_client(dev)));
381 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
385 static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
386 #define MAG3110_PM_OPS (&mag3110_pm_ops)
388 #define MAG3110_PM_OPS NULL
391 static const struct i2c_device_id mag3110_id[] = {
395 MODULE_DEVICE_TABLE(i2c, mag3110_id);
397 static struct i2c_driver mag3110_driver = {
400 .pm = MAG3110_PM_OPS,
402 .probe = mag3110_probe,
403 .remove = mag3110_remove,
404 .id_table = mag3110_id,
406 module_i2c_driver(mag3110_driver);
408 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
409 MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
410 MODULE_LICENSE("GPL");