2 * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature 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 0x60)
12 * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
13 * interrupts, user offset correction, raw mode
16 #include <linux/module.h>
17 #include <linux/i2c.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/trigger_consumer.h>
21 #include <linux/iio/buffer.h>
22 #include <linux/iio/triggered_buffer.h>
23 #include <linux/delay.h>
25 #define MPL3115_STATUS 0x00
26 #define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
27 #define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
28 #define MPL3115_WHO_AM_I 0x0c
29 #define MPL3115_CTRL_REG1 0x26
31 #define MPL3115_DEVICE_ID 0xc4
33 #define MPL3115_STATUS_PRESS_RDY BIT(2)
34 #define MPL3115_STATUS_TEMP_RDY BIT(1)
36 #define MPL3115_CTRL_RESET BIT(2) /* software reset */
37 #define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
38 #define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
39 #define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */
42 struct i2c_client *client;
47 static int mpl3115_request(struct mpl3115_data *data)
51 /* trigger measurement */
52 ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
53 data->ctrl_reg1 | MPL3115_CTRL_OST);
58 ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
61 /* wait for data ready, i.e. OST cleared */
62 if (!(ret & MPL3115_CTRL_OST))
68 dev_err(&data->client->dev, "data not ready\n");
75 static int mpl3115_read_raw(struct iio_dev *indio_dev,
76 struct iio_chan_spec const *chan,
77 int *val, int *val2, long mask)
79 struct mpl3115_data *data = iio_priv(indio_dev);
84 case IIO_CHAN_INFO_RAW:
85 ret = iio_device_claim_direct_mode(indio_dev);
90 case IIO_PRESSURE: /* in 0.25 pascal / LSB */
91 mutex_lock(&data->lock);
92 ret = mpl3115_request(data);
94 mutex_unlock(&data->lock);
97 ret = i2c_smbus_read_i2c_block_data(data->client,
98 MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
99 mutex_unlock(&data->lock);
102 *val = be32_to_cpu(tmp) >> 12;
105 case IIO_TEMP: /* in 0.0625 celsius / LSB */
106 mutex_lock(&data->lock);
107 ret = mpl3115_request(data);
109 mutex_unlock(&data->lock);
112 ret = i2c_smbus_read_i2c_block_data(data->client,
113 MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
114 mutex_unlock(&data->lock);
117 *val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
125 iio_device_release_direct_mode(indio_dev);
128 case IIO_CHAN_INFO_SCALE:
129 switch (chan->type) {
132 *val2 = 250; /* want kilopascal */
133 return IIO_VAL_INT_PLUS_MICRO;
137 return IIO_VAL_INT_PLUS_MICRO;
145 static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
147 struct iio_poll_func *pf = p;
148 struct iio_dev *indio_dev = pf->indio_dev;
149 struct mpl3115_data *data = iio_priv(indio_dev);
151 * 32-bit channel + 16-bit channel + padding + ts
152 * Note that it is possible for only one of the first 2
153 * channels to be enabled. If that happens, the first element
154 * of the buffer may be either 16 or 32-bits. As such we cannot
155 * use a simple structure definition to express this data layout.
157 u8 buffer[16] __aligned(8);
160 mutex_lock(&data->lock);
161 ret = mpl3115_request(data);
163 mutex_unlock(&data->lock);
167 memset(buffer, 0, sizeof(buffer));
168 if (test_bit(0, indio_dev->active_scan_mask)) {
169 ret = i2c_smbus_read_i2c_block_data(data->client,
170 MPL3115_OUT_PRESS, 3, &buffer[pos]);
172 mutex_unlock(&data->lock);
178 if (test_bit(1, indio_dev->active_scan_mask)) {
179 ret = i2c_smbus_read_i2c_block_data(data->client,
180 MPL3115_OUT_TEMP, 2, &buffer[pos]);
182 mutex_unlock(&data->lock);
186 mutex_unlock(&data->lock);
188 iio_push_to_buffers_with_timestamp(indio_dev, buffer,
189 iio_get_time_ns(indio_dev));
192 iio_trigger_notify_done(indio_dev->trig);
196 static const struct iio_chan_spec mpl3115_channels[] = {
198 .type = IIO_PRESSURE,
199 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
200 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
207 .endianness = IIO_BE,
212 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
213 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
220 .endianness = IIO_BE,
223 IIO_CHAN_SOFT_TIMESTAMP(2),
226 static const struct iio_info mpl3115_info = {
227 .read_raw = &mpl3115_read_raw,
230 static int mpl3115_probe(struct i2c_client *client,
231 const struct i2c_device_id *id)
233 struct mpl3115_data *data;
234 struct iio_dev *indio_dev;
237 ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
240 if (ret != MPL3115_DEVICE_ID)
243 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
247 data = iio_priv(indio_dev);
248 data->client = client;
249 mutex_init(&data->lock);
251 i2c_set_clientdata(client, indio_dev);
252 indio_dev->info = &mpl3115_info;
253 indio_dev->name = id->name;
254 indio_dev->dev.parent = &client->dev;
255 indio_dev->modes = INDIO_DIRECT_MODE;
256 indio_dev->channels = mpl3115_channels;
257 indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);
259 /* software reset, I2C transfer is aborted (fails) */
260 i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
264 data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
265 ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
270 ret = iio_triggered_buffer_setup(indio_dev, NULL,
271 mpl3115_trigger_handler, NULL);
275 ret = iio_device_register(indio_dev);
281 iio_triggered_buffer_cleanup(indio_dev);
285 static int mpl3115_standby(struct mpl3115_data *data)
287 return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
288 data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
291 static int mpl3115_remove(struct i2c_client *client)
293 struct iio_dev *indio_dev = i2c_get_clientdata(client);
295 iio_device_unregister(indio_dev);
296 iio_triggered_buffer_cleanup(indio_dev);
297 mpl3115_standby(iio_priv(indio_dev));
302 #ifdef CONFIG_PM_SLEEP
303 static int mpl3115_suspend(struct device *dev)
305 return mpl3115_standby(iio_priv(i2c_get_clientdata(
306 to_i2c_client(dev))));
309 static int mpl3115_resume(struct device *dev)
311 struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
312 to_i2c_client(dev)));
314 return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
318 static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume);
319 #define MPL3115_PM_OPS (&mpl3115_pm_ops)
321 #define MPL3115_PM_OPS NULL
324 static const struct i2c_device_id mpl3115_id[] = {
328 MODULE_DEVICE_TABLE(i2c, mpl3115_id);
330 static const struct of_device_id mpl3115_of_match[] = {
331 { .compatible = "fsl,mpl3115" },
334 MODULE_DEVICE_TABLE(of, mpl3115_of_match);
336 static struct i2c_driver mpl3115_driver = {
339 .of_match_table = mpl3115_of_match,
340 .pm = MPL3115_PM_OPS,
342 .probe = mpl3115_probe,
343 .remove = mpl3115_remove,
344 .id_table = mpl3115_id,
346 module_i2c_driver(mpl3115_driver);
348 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
349 MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
350 MODULE_LICENSE("GPL");