1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor
4 *
5 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
6 *
7 * (7-bit I2C slave address 0x60)
8 *
9 * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
10 * interrupts, user offset correction, raw mode
11 */
12
13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17#include <linux/iio/trigger_consumer.h>
18#include <linux/iio/buffer.h>
19#include <linux/iio/triggered_buffer.h>
20#include <linux/delay.h>
21
22#define MPL3115_STATUS 0x00
23#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
24#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
25#define MPL3115_WHO_AM_I 0x0c
26#define MPL3115_CTRL_REG1 0x26
27
28#define MPL3115_DEVICE_ID 0xc4
29
30#define MPL3115_STATUS_PRESS_RDY BIT(2)
31#define MPL3115_STATUS_TEMP_RDY BIT(1)
32
33#define MPL3115_CTRL_RESET BIT(2) /* software reset */
34#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
35#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
36#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */
37
38struct mpl3115_data {
39	struct i2c_client *client;
40	struct mutex lock;
41	u8 ctrl_reg1;
42};
43
44static int mpl3115_request(struct mpl3115_data *data)
45{
46	int ret, tries = 15;
47
48	/* trigger measurement */
49	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
50		data->ctrl_reg1 | MPL3115_CTRL_OST);
51	if (ret < 0)
52		return ret;
53
54	while (tries-- > 0) {
55		ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
56		if (ret < 0)
57			return ret;
58		/* wait for data ready, i.e. OST cleared */
59		if (!(ret & MPL3115_CTRL_OST))
60			break;
61		msleep(20);
62	}
63
64	if (tries < 0) {
65		dev_err(&data->client->dev, "data not ready\n");
66		return -EIO;
67	}
68
69	return 0;
70}
71
72static int mpl3115_read_raw(struct iio_dev *indio_dev,
73			    struct iio_chan_spec const *chan,
74			    int *val, int *val2, long mask)
75{
76	struct mpl3115_data *data = iio_priv(indio_dev);
77	__be32 tmp = 0;
78	int ret;
79
80	switch (mask) {
81	case IIO_CHAN_INFO_RAW:
82		ret = iio_device_claim_direct_mode(indio_dev);
83		if (ret)
84			return ret;
85
86		switch (chan->type) {
87		case IIO_PRESSURE: /* in 0.25 pascal / LSB */
88			mutex_lock(&data->lock);
89			ret = mpl3115_request(data);
90			if (ret < 0) {
91				mutex_unlock(&data->lock);
92				break;
93			}
94			ret = i2c_smbus_read_i2c_block_data(data->client,
95				MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
96			mutex_unlock(&data->lock);
97			if (ret < 0)
98				break;
99			*val = be32_to_cpu(tmp) >> 12;
100			ret = IIO_VAL_INT;
101			break;
102		case IIO_TEMP: /* in 0.0625 celsius / LSB */
103			mutex_lock(&data->lock);
104			ret = mpl3115_request(data);
105			if (ret < 0) {
106				mutex_unlock(&data->lock);
107				break;
108			}
109			ret = i2c_smbus_read_i2c_block_data(data->client,
110				MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
111			mutex_unlock(&data->lock);
112			if (ret < 0)
113				break;
114			*val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
115			ret = IIO_VAL_INT;
116			break;
117		default:
118			ret = -EINVAL;
119			break;
120		}
121
122		iio_device_release_direct_mode(indio_dev);
123		return ret;
124
125	case IIO_CHAN_INFO_SCALE:
126		switch (chan->type) {
127		case IIO_PRESSURE:
128			*val = 0;
129			*val2 = 250; /* want kilopascal */
130			return IIO_VAL_INT_PLUS_MICRO;
131		case IIO_TEMP:
132			*val = 0;
133			*val2 = 62500;
134			return IIO_VAL_INT_PLUS_MICRO;
135		default:
136			return -EINVAL;
137		}
138	}
139	return -EINVAL;
140}
141
142static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
143{
144	struct iio_poll_func *pf = p;
145	struct iio_dev *indio_dev = pf->indio_dev;
146	struct mpl3115_data *data = iio_priv(indio_dev);
147	/*
148	 * 32-bit channel + 16-bit channel + padding + ts
149	 * Note that it is possible for only one of the first 2
150	 * channels to be enabled. If that happens, the first element
151	 * of the buffer may be either 16 or 32-bits.  As such we cannot
152	 * use a simple structure definition to express this data layout.
153	 */
154	u8 buffer[16] __aligned(8);
155	int ret, pos = 0;
156
157	mutex_lock(&data->lock);
158	ret = mpl3115_request(data);
159	if (ret < 0) {
160		mutex_unlock(&data->lock);
161		goto done;
162	}
163
164	memset(buffer, 0, sizeof(buffer));
165	if (test_bit(0, indio_dev->active_scan_mask)) {
166		ret = i2c_smbus_read_i2c_block_data(data->client,
167			MPL3115_OUT_PRESS, 3, &buffer[pos]);
168		if (ret < 0) {
169			mutex_unlock(&data->lock);
170			goto done;
171		}
172		pos += 4;
173	}
174
175	if (test_bit(1, indio_dev->active_scan_mask)) {
176		ret = i2c_smbus_read_i2c_block_data(data->client,
177			MPL3115_OUT_TEMP, 2, &buffer[pos]);
178		if (ret < 0) {
179			mutex_unlock(&data->lock);
180			goto done;
181		}
182	}
183	mutex_unlock(&data->lock);
184
185	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
186		iio_get_time_ns(indio_dev));
187
188done:
189	iio_trigger_notify_done(indio_dev->trig);
190	return IRQ_HANDLED;
191}
192
193static const struct iio_chan_spec mpl3115_channels[] = {
194	{
195		.type = IIO_PRESSURE,
196		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
197		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
198		.scan_index = 0,
199		.scan_type = {
200			.sign = 'u',
201			.realbits = 20,
202			.storagebits = 32,
203			.shift = 12,
204			.endianness = IIO_BE,
205		}
206	},
207	{
208		.type = IIO_TEMP,
209		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
210		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
211		.scan_index = 1,
212		.scan_type = {
213			.sign = 's',
214			.realbits = 12,
215			.storagebits = 16,
216			.shift = 4,
217			.endianness = IIO_BE,
218		}
219	},
220	IIO_CHAN_SOFT_TIMESTAMP(2),
221};
222
223static const struct iio_info mpl3115_info = {
224	.read_raw = &mpl3115_read_raw,
225};
226
227static int mpl3115_probe(struct i2c_client *client,
228			 const struct i2c_device_id *id)
229{
230	struct mpl3115_data *data;
231	struct iio_dev *indio_dev;
232	int ret;
233
234	ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
235	if (ret < 0)
236		return ret;
237	if (ret != MPL3115_DEVICE_ID)
238		return -ENODEV;
239
240	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
241	if (!indio_dev)
242		return -ENOMEM;
243
244	data = iio_priv(indio_dev);
245	data->client = client;
246	mutex_init(&data->lock);
247
248	i2c_set_clientdata(client, indio_dev);
249	indio_dev->info = &mpl3115_info;
250	indio_dev->name = id->name;
251	indio_dev->modes = INDIO_DIRECT_MODE;
252	indio_dev->channels = mpl3115_channels;
253	indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);
254
255	/* software reset, I2C transfer is aborted (fails) */
256	i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
257		MPL3115_CTRL_RESET);
258	msleep(50);
259
260	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
261	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
262		data->ctrl_reg1);
263	if (ret < 0)
264		return ret;
265
266	ret = iio_triggered_buffer_setup(indio_dev, NULL,
267		mpl3115_trigger_handler, NULL);
268	if (ret < 0)
269		return ret;
270
271	ret = iio_device_register(indio_dev);
272	if (ret < 0)
273		goto buffer_cleanup;
274	return 0;
275
276buffer_cleanup:
277	iio_triggered_buffer_cleanup(indio_dev);
278	return ret;
279}
280
281static int mpl3115_standby(struct mpl3115_data *data)
282{
283	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
284		data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
285}
286
287static int mpl3115_remove(struct i2c_client *client)
288{
289	struct iio_dev *indio_dev = i2c_get_clientdata(client);
290
291	iio_device_unregister(indio_dev);
292	iio_triggered_buffer_cleanup(indio_dev);
293	mpl3115_standby(iio_priv(indio_dev));
294
295	return 0;
296}
297
298#ifdef CONFIG_PM_SLEEP
299static int mpl3115_suspend(struct device *dev)
300{
301	return mpl3115_standby(iio_priv(i2c_get_clientdata(
302		to_i2c_client(dev))));
303}
304
305static int mpl3115_resume(struct device *dev)
306{
307	struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
308		to_i2c_client(dev)));
309
310	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
311		data->ctrl_reg1);
312}
313
314static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume);
315#define MPL3115_PM_OPS (&mpl3115_pm_ops)
316#else
317#define MPL3115_PM_OPS NULL
318#endif
319
320static const struct i2c_device_id mpl3115_id[] = {
321	{ "mpl3115", 0 },
322	{ }
323};
324MODULE_DEVICE_TABLE(i2c, mpl3115_id);
325
326static const struct of_device_id mpl3115_of_match[] = {
327	{ .compatible = "fsl,mpl3115" },
328	{ }
329};
330MODULE_DEVICE_TABLE(of, mpl3115_of_match);
331
332static struct i2c_driver mpl3115_driver = {
333	.driver = {
334		.name	= "mpl3115",
335		.of_match_table = mpl3115_of_match,
336		.pm	= MPL3115_PM_OPS,
337	},
338	.probe = mpl3115_probe,
339	.remove = mpl3115_remove,
340	.id_table = mpl3115_id,
341};
342module_i2c_driver(mpl3115_driver);
343
344MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
345MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
346MODULE_LICENSE("GPL");
347