summaryrefslogtreecommitdiffstats
path: root/drivers/iio/pressure/mpl3115.c
blob: 6392d7b62841024e237cc5a4d19bdb5b0fbb18b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
/*
 * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature 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 0x60)
 *
 * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
 * interrupts, user offset correction, raw 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 MPL3115_STATUS 0x00
#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
#define MPL3115_WHO_AM_I 0x0c
#define MPL3115_CTRL_REG1 0x26

#define MPL3115_DEVICE_ID 0xc4

#define MPL3115_STATUS_PRESS_RDY BIT(2)
#define MPL3115_STATUS_TEMP_RDY BIT(1)

#define MPL3115_CTRL_RESET BIT(2) /* software reset */
#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */

struct mpl3115_data {
	struct i2c_client *client;
	struct mutex lock;
	u8 ctrl_reg1;
};

static int mpl3115_request(struct mpl3115_data *data)
{
	int ret, tries = 15;

	/* trigger measurement */
	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1 | MPL3115_CTRL_OST);
	if (ret < 0)
		return ret;

	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
		if (ret < 0)
			return ret;
		/* wait for data ready, i.e. OST cleared */
		if (!(ret & MPL3115_CTRL_OST))
			break;
		msleep(20);
	}

	if (tries < 0) {
		dev_err(&data->client->dev, "data not ready\n");
		return -EIO;
	}

	return 0;
}

static int mpl3115_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	__be32 tmp = 0;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (iio_buffer_enabled(indio_dev))
			return -EBUSY;

		switch (chan->type) {
		case IIO_PRESSURE: /* in 0.25 pascal / LSB */
			mutex_lock(&data->lock);
			ret = mpl3115_request(data);
			if (ret < 0) {
				mutex_unlock(&data->lock);
				return ret;
			}
			ret = i2c_smbus_read_i2c_block_data(data->client,
				MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
			mutex_unlock(&data->lock);
			if (ret < 0)
				return ret;
			*val = be32_to_cpu(tmp) >> 12;
			return IIO_VAL_INT;
		case IIO_TEMP: /* in 0.0625 celsius / LSB */
			mutex_lock(&data->lock);
			ret = mpl3115_request(data);
			if (ret < 0) {
				mutex_unlock(&data->lock);
				return ret;
			}
			ret = i2c_smbus_read_i2c_block_data(data->client,
				MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
			mutex_unlock(&data->lock);
			if (ret < 0)
				return ret;
			*val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_PRESSURE:
			*val = 0;
			*val2 = 250; /* want kilopascal */
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_TEMP:
			*val = 0;
			*val2 = 62500;
			return IIO_VAL_INT_PLUS_MICRO;
		default:
			return -EINVAL;
		}
	}
	return -EINVAL;
}

static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct mpl3115_data *data = iio_priv(indio_dev);
	u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */
	int ret, pos = 0;

	mutex_lock(&data->lock);
	ret = mpl3115_request(data);
	if (ret < 0) {
		mutex_unlock(&data->lock);
		goto done;
	}

	memset(buffer, 0, sizeof(buffer));
	if (test_bit(0, indio_dev->active_scan_mask)) {
		ret = i2c_smbus_read_i2c_block_data(data->client,
			MPL3115_OUT_PRESS, 3, &buffer[pos]);
		if (ret < 0) {
			mutex_unlock(&data->lock);
			goto done;
		}
		pos += 4;
	}

	if (test_bit(1, indio_dev->active_scan_mask)) {
		ret = i2c_smbus_read_i2c_block_data(data->client,
			MPL3115_OUT_TEMP, 2, &buffer[pos]);
		if (ret < 0) {
			mutex_unlock(&data->lock);
			goto done;
		}
	}
	mutex_unlock(&data->lock);

	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
		iio_get_time_ns(indio_dev));

done:
	iio_trigger_notify_done(indio_dev->trig);
	return IRQ_HANDLED;
}

static const struct iio_chan_spec mpl3115_channels[] = {
	{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
			BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 0,
		.scan_type = {
			.sign = 'u',
			.realbits = 20,
			.storagebits = 32,
			.shift = 12,
			.endianness = IIO_BE,
		}
	},
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
			BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 1,
		.scan_type = {
			.sign = 's',
			.realbits = 12,
			.storagebits = 16,
			.shift = 4,
			.endianness = IIO_BE,
		}
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
};

static const struct iio_info mpl3115_info = {
	.read_raw = &mpl3115_read_raw,
	.driver_module = THIS_MODULE,
};

static int mpl3115_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct mpl3115_data *data;
	struct iio_dev *indio_dev;
	int ret;

	ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
	if (ret < 0)
		return ret;
	if (ret != MPL3115_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 = &mpl3115_info;
	indio_dev->name = id->name;
	indio_dev->dev.parent = &client->dev;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mpl3115_channels;
	indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);

	/* software reset, I2C transfer is aborted (fails) */
	i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
		MPL3115_CTRL_RESET);
	msleep(50);

	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
		data->ctrl_reg1);
	if (ret < 0)
		return ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
		mpl3115_trigger_handler, NULL);
	if (ret < 0)
		return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto buffer_cleanup;
	return 0;

buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
	return ret;
}

static int mpl3115_standby(struct mpl3115_data *data)
{
	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
}

static int mpl3115_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);
	mpl3115_standby(iio_priv(indio_dev));

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mpl3115_suspend(struct device *dev)
{
	return mpl3115_standby(iio_priv(i2c_get_clientdata(
		to_i2c_client(dev))));
}

static int mpl3115_resume(struct device *dev)
{
	struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
		to_i2c_client(dev)));

	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1);
}

static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume);
#define MPL3115_PM_OPS (&mpl3115_pm_ops)
#else
#define MPL3115_PM_OPS NULL
#endif

static const struct i2c_device_id mpl3115_id[] = {
	{ "mpl3115", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mpl3115_id);

static struct i2c_driver mpl3115_driver = {
	.driver = {
		.name	= "mpl3115",
		.pm	= MPL3115_PM_OPS,
	},
	.probe = mpl3115_probe,
	.remove = mpl3115_remove,
	.id_table = mpl3115_id,
};
module_i2c_driver(mpl3115_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud