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	int ret;
78
79	switch (mask) {
80	case IIO_CHAN_INFO_RAW:
81		ret = iio_device_claim_direct_mode(indio_dev);
82		if (ret)
83			return ret;
84
85		switch (chan->type) {
86		case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
87			__be32 tmp = 0;
88
89			mutex_lock(&data->lock);
90			ret = mpl3115_request(data);
91			if (ret < 0) {
92				mutex_unlock(&data->lock);
93				break;
94			}
95			ret = i2c_smbus_read_i2c_block_data(data->client,
96				MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
97			mutex_unlock(&data->lock);
98			if (ret < 0)
99				break;
100			*val = be32_to_cpu(tmp) >> chan->scan_type.shift;
101			ret = IIO_VAL_INT;
102			break;
103		}
104		case IIO_TEMP: { /* in 0.0625 celsius / LSB */
105			__be16 tmp;
106
107			mutex_lock(&data->lock);
108			ret = mpl3115_request(data);
109			if (ret < 0) {
110				mutex_unlock(&data->lock);
111				break;
112			}
113			ret = i2c_smbus_read_i2c_block_data(data->client,
114				MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
115			mutex_unlock(&data->lock);
116			if (ret < 0)
117				break;
118			*val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
119					     chan->scan_type.realbits - 1);
120			ret = IIO_VAL_INT;
121			break;
122		}
123		default:
124			ret = -EINVAL;
125			break;
126		}
127
128		iio_device_release_direct_mode(indio_dev);
129		return ret;
130
131	case IIO_CHAN_INFO_SCALE:
132		switch (chan->type) {
133		case IIO_PRESSURE:
134			*val = 0;
135			*val2 = 250; /* want kilopascal */
136			return IIO_VAL_INT_PLUS_MICRO;
137		case IIO_TEMP:
138			*val = 0;
139			*val2 = 62500;
140			return IIO_VAL_INT_PLUS_MICRO;
141		default:
142			return -EINVAL;
143		}
144	}
145	return -EINVAL;
146}
147
148static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
149{
150	struct iio_poll_func *pf = p;
151	struct iio_dev *indio_dev = pf->indio_dev;
152	struct mpl3115_data *data = iio_priv(indio_dev);
153	/*
154	 * 32-bit channel + 16-bit channel + padding + ts
155	 * Note that it is possible for only one of the first 2
156	 * channels to be enabled. If that happens, the first element
157	 * of the buffer may be either 16 or 32-bits.  As such we cannot
158	 * use a simple structure definition to express this data layout.
159	 */
160	u8 buffer[16] __aligned(8);
161	int ret, pos = 0;
162
163	mutex_lock(&data->lock);
164	ret = mpl3115_request(data);
165	if (ret < 0) {
166		mutex_unlock(&data->lock);
167		goto done;
168	}
169
170	memset(buffer, 0, sizeof(buffer));
171	if (test_bit(0, indio_dev->active_scan_mask)) {
172		ret = i2c_smbus_read_i2c_block_data(data->client,
173			MPL3115_OUT_PRESS, 3, &buffer[pos]);
174		if (ret < 0) {
175			mutex_unlock(&data->lock);
176			goto done;
177		}
178		pos += 4;
179	}
180
181	if (test_bit(1, indio_dev->active_scan_mask)) {
182		ret = i2c_smbus_read_i2c_block_data(data->client,
183			MPL3115_OUT_TEMP, 2, &buffer[pos]);
184		if (ret < 0) {
185			mutex_unlock(&data->lock);
186			goto done;
187		}
188	}
189	mutex_unlock(&data->lock);
190
191	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
192		iio_get_time_ns(indio_dev));
193
194done:
195	iio_trigger_notify_done(indio_dev->trig);
196	return IRQ_HANDLED;
197}
198
199static const struct iio_chan_spec mpl3115_channels[] = {
200	{
201		.type = IIO_PRESSURE,
202		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
203		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
204		.scan_index = 0,
205		.scan_type = {
206			.sign = 'u',
207			.realbits = 20,
208			.storagebits = 32,
209			.shift = 12,
210			.endianness = IIO_BE,
211		}
212	},
213	{
214		.type = IIO_TEMP,
215		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
216		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
217		.scan_index = 1,
218		.scan_type = {
219			.sign = 's',
220			.realbits = 12,
221			.storagebits = 16,
222			.shift = 4,
223			.endianness = IIO_BE,
224		}
225	},
226	IIO_CHAN_SOFT_TIMESTAMP(2),
227};
228
229static const struct iio_info mpl3115_info = {
230	.read_raw = &mpl3115_read_raw,
231};
232
233static int mpl3115_probe(struct i2c_client *client)
234{
235	const struct i2c_device_id *id = i2c_client_get_device_id(client);
236	struct mpl3115_data *data;
237	struct iio_dev *indio_dev;
238	int ret;
239
240	ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
241	if (ret < 0)
242		return ret;
243	if (ret != MPL3115_DEVICE_ID)
244		return -ENODEV;
245
246	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
247	if (!indio_dev)
248		return -ENOMEM;
249
250	data = iio_priv(indio_dev);
251	data->client = client;
252	mutex_init(&data->lock);
253
254	i2c_set_clientdata(client, indio_dev);
255	indio_dev->info = &mpl3115_info;
256	indio_dev->name = id->name;
257	indio_dev->modes = INDIO_DIRECT_MODE;
258	indio_dev->channels = mpl3115_channels;
259	indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);
260
261	/* software reset, I2C transfer is aborted (fails) */
262	i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
263		MPL3115_CTRL_RESET);
264	msleep(50);
265
266	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
267	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
268		data->ctrl_reg1);
269	if (ret < 0)
270		return ret;
271
272	ret = iio_triggered_buffer_setup(indio_dev, NULL,
273		mpl3115_trigger_handler, NULL);
274	if (ret < 0)
275		return ret;
276
277	ret = iio_device_register(indio_dev);
278	if (ret < 0)
279		goto buffer_cleanup;
280	return 0;
281
282buffer_cleanup:
283	iio_triggered_buffer_cleanup(indio_dev);
284	return ret;
285}
286
287static int mpl3115_standby(struct mpl3115_data *data)
288{
289	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
290		data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
291}
292
293static void mpl3115_remove(struct i2c_client *client)
294{
295	struct iio_dev *indio_dev = i2c_get_clientdata(client);
296
297	iio_device_unregister(indio_dev);
298	iio_triggered_buffer_cleanup(indio_dev);
299	mpl3115_standby(iio_priv(indio_dev));
300}
301
302static int mpl3115_suspend(struct device *dev)
303{
304	return mpl3115_standby(iio_priv(i2c_get_clientdata(
305		to_i2c_client(dev))));
306}
307
308static int mpl3115_resume(struct device *dev)
309{
310	struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
311		to_i2c_client(dev)));
312
313	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
314		data->ctrl_reg1);
315}
316
317static DEFINE_SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend,
318				mpl3115_resume);
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	= pm_sleep_ptr(&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