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cc26ad45 PM |
1 | /* |
2 | * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor | |
3 | * | |
4 | * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> | |
5 | * | |
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. | |
9 | * | |
10 | * (7-bit I2C slave address 0x60) | |
11 | * | |
12 | * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode, | |
13 | * interrupts, user offset correction, raw mode | |
14 | */ | |
15 | ||
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> | |
24 | ||
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 | |
30 | ||
31 | #define MPL3115_DEVICE_ID 0xc4 | |
32 | ||
33 | #define MPL3115_STATUS_PRESS_RDY BIT(2) | |
34 | #define MPL3115_STATUS_TEMP_RDY BIT(1) | |
35 | ||
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 */ | |
40 | ||
41 | struct mpl3115_data { | |
42 | struct i2c_client *client; | |
43 | struct mutex lock; | |
44 | u8 ctrl_reg1; | |
45 | }; | |
46 | ||
47 | static int mpl3115_request(struct mpl3115_data *data) | |
48 | { | |
49 | int ret, tries = 15; | |
50 | ||
51 | /* trigger measurement */ | |
52 | ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, | |
53 | data->ctrl_reg1 | MPL3115_CTRL_OST); | |
54 | if (ret < 0) | |
55 | return ret; | |
56 | ||
57 | while (tries-- > 0) { | |
58 | ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1); | |
59 | if (ret < 0) | |
60 | return ret; | |
61 | /* wait for data ready, i.e. OST cleared */ | |
62 | if (!(ret & MPL3115_CTRL_OST)) | |
63 | break; | |
64 | msleep(20); | |
65 | } | |
66 | ||
67 | if (tries < 0) { | |
68 | dev_err(&data->client->dev, "data not ready\n"); | |
69 | return -EIO; | |
70 | } | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
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) | |
78 | { | |
79 | struct mpl3115_data *data = iio_priv(indio_dev); | |
4a2bbdb4 | 80 | __be32 tmp = 0; |
cc26ad45 PM |
81 | int ret; |
82 | ||
83 | switch (mask) { | |
84 | case IIO_CHAN_INFO_RAW: | |
85 | if (iio_buffer_enabled(indio_dev)) | |
86 | return -EBUSY; | |
87 | ||
88 | switch (chan->type) { | |
89 | case IIO_PRESSURE: /* in 0.25 pascal / LSB */ | |
90 | mutex_lock(&data->lock); | |
91 | ret = mpl3115_request(data); | |
92 | if (ret < 0) { | |
93 | mutex_unlock(&data->lock); | |
94 | return ret; | |
95 | } | |
96 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
97 | MPL3115_OUT_PRESS, 3, (u8 *) &tmp); | |
98 | mutex_unlock(&data->lock); | |
99 | if (ret < 0) | |
100 | return ret; | |
d29f5929 | 101 | *val = be32_to_cpu(tmp) >> 12; |
cc26ad45 PM |
102 | return IIO_VAL_INT; |
103 | case IIO_TEMP: /* in 0.0625 celsius / LSB */ | |
104 | mutex_lock(&data->lock); | |
105 | ret = mpl3115_request(data); | |
106 | if (ret < 0) { | |
107 | mutex_unlock(&data->lock); | |
108 | return ret; | |
109 | } | |
110 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
111 | MPL3115_OUT_TEMP, 2, (u8 *) &tmp); | |
112 | mutex_unlock(&data->lock); | |
113 | if (ret < 0) | |
114 | return ret; | |
d29f5929 | 115 | *val = sign_extend32(be32_to_cpu(tmp) >> 20, 11); |
cc26ad45 PM |
116 | return IIO_VAL_INT; |
117 | default: | |
118 | return -EINVAL; | |
119 | } | |
120 | case IIO_CHAN_INFO_SCALE: | |
121 | switch (chan->type) { | |
122 | case IIO_PRESSURE: | |
123 | *val = 0; | |
124 | *val2 = 250; /* want kilopascal */ | |
125 | return IIO_VAL_INT_PLUS_MICRO; | |
126 | case IIO_TEMP: | |
127 | *val = 0; | |
128 | *val2 = 62500; | |
129 | return IIO_VAL_INT_PLUS_MICRO; | |
130 | default: | |
131 | return -EINVAL; | |
132 | } | |
133 | } | |
134 | return -EINVAL; | |
135 | } | |
136 | ||
137 | static irqreturn_t mpl3115_trigger_handler(int irq, void *p) | |
138 | { | |
139 | struct iio_poll_func *pf = p; | |
140 | struct iio_dev *indio_dev = pf->indio_dev; | |
141 | struct mpl3115_data *data = iio_priv(indio_dev); | |
142 | u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */ | |
143 | int ret, pos = 0; | |
144 | ||
145 | mutex_lock(&data->lock); | |
146 | ret = mpl3115_request(data); | |
147 | if (ret < 0) { | |
148 | mutex_unlock(&data->lock); | |
149 | goto done; | |
150 | } | |
151 | ||
152 | memset(buffer, 0, sizeof(buffer)); | |
153 | if (test_bit(0, indio_dev->active_scan_mask)) { | |
154 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
155 | MPL3115_OUT_PRESS, 3, &buffer[pos]); | |
156 | if (ret < 0) { | |
157 | mutex_unlock(&data->lock); | |
158 | goto done; | |
159 | } | |
160 | pos += 4; | |
161 | } | |
162 | ||
163 | if (test_bit(1, indio_dev->active_scan_mask)) { | |
164 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
165 | MPL3115_OUT_TEMP, 2, &buffer[pos]); | |
166 | if (ret < 0) { | |
167 | mutex_unlock(&data->lock); | |
168 | goto done; | |
169 | } | |
170 | } | |
171 | mutex_unlock(&data->lock); | |
172 | ||
173 | iio_push_to_buffers_with_timestamp(indio_dev, buffer, | |
174 | iio_get_time_ns()); | |
175 | ||
176 | done: | |
177 | iio_trigger_notify_done(indio_dev->trig); | |
178 | return IRQ_HANDLED; | |
179 | } | |
180 | ||
181 | static const struct iio_chan_spec mpl3115_channels[] = { | |
182 | { | |
183 | .type = IIO_PRESSURE, | |
184 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
185 | BIT(IIO_CHAN_INFO_SCALE), | |
186 | .scan_index = 0, | |
187 | .scan_type = { | |
d29f5929 | 188 | .sign = 'u', |
cc26ad45 PM |
189 | .realbits = 20, |
190 | .storagebits = 32, | |
191 | .shift = 12, | |
192 | .endianness = IIO_BE, | |
193 | } | |
194 | }, | |
195 | { | |
196 | .type = IIO_TEMP, | |
197 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
198 | BIT(IIO_CHAN_INFO_SCALE), | |
199 | .scan_index = 1, | |
200 | .scan_type = { | |
201 | .sign = 's', | |
202 | .realbits = 12, | |
203 | .storagebits = 16, | |
204 | .shift = 4, | |
205 | .endianness = IIO_BE, | |
206 | } | |
207 | }, | |
208 | IIO_CHAN_SOFT_TIMESTAMP(2), | |
209 | }; | |
210 | ||
211 | static const struct iio_info mpl3115_info = { | |
212 | .read_raw = &mpl3115_read_raw, | |
213 | .driver_module = THIS_MODULE, | |
214 | }; | |
215 | ||
216 | static int mpl3115_probe(struct i2c_client *client, | |
217 | const struct i2c_device_id *id) | |
218 | { | |
219 | struct mpl3115_data *data; | |
220 | struct iio_dev *indio_dev; | |
221 | int ret; | |
222 | ||
223 | ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I); | |
224 | if (ret < 0) | |
225 | return ret; | |
226 | if (ret != MPL3115_DEVICE_ID) | |
227 | return -ENODEV; | |
228 | ||
229 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | |
230 | if (!indio_dev) | |
231 | return -ENOMEM; | |
232 | ||
233 | data = iio_priv(indio_dev); | |
234 | data->client = client; | |
235 | mutex_init(&data->lock); | |
236 | ||
237 | i2c_set_clientdata(client, indio_dev); | |
238 | indio_dev->info = &mpl3115_info; | |
239 | indio_dev->name = id->name; | |
240 | indio_dev->dev.parent = &client->dev; | |
241 | indio_dev->modes = INDIO_DIRECT_MODE; | |
242 | indio_dev->channels = mpl3115_channels; | |
243 | indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels); | |
244 | ||
245 | /* software reset, I2C transfer is aborted (fails) */ | |
246 | i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, | |
247 | MPL3115_CTRL_RESET); | |
248 | msleep(50); | |
249 | ||
250 | data->ctrl_reg1 = MPL3115_CTRL_OS_258MS; | |
251 | ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, | |
252 | data->ctrl_reg1); | |
253 | if (ret < 0) | |
254 | return ret; | |
255 | ||
256 | ret = iio_triggered_buffer_setup(indio_dev, NULL, | |
257 | mpl3115_trigger_handler, NULL); | |
258 | if (ret < 0) | |
259 | return ret; | |
260 | ||
261 | ret = iio_device_register(indio_dev); | |
262 | if (ret < 0) | |
263 | goto buffer_cleanup; | |
264 | return 0; | |
265 | ||
266 | buffer_cleanup: | |
267 | iio_triggered_buffer_cleanup(indio_dev); | |
268 | return ret; | |
269 | } | |
270 | ||
271 | static int mpl3115_standby(struct mpl3115_data *data) | |
272 | { | |
273 | return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, | |
274 | data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE); | |
275 | } | |
276 | ||
277 | static int mpl3115_remove(struct i2c_client *client) | |
278 | { | |
279 | struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
280 | ||
281 | iio_device_unregister(indio_dev); | |
282 | iio_triggered_buffer_cleanup(indio_dev); | |
283 | mpl3115_standby(iio_priv(indio_dev)); | |
284 | ||
285 | return 0; | |
286 | } | |
287 | ||
288 | #ifdef CONFIG_PM_SLEEP | |
289 | static int mpl3115_suspend(struct device *dev) | |
290 | { | |
291 | return mpl3115_standby(iio_priv(i2c_get_clientdata( | |
292 | to_i2c_client(dev)))); | |
293 | } | |
294 | ||
295 | static int mpl3115_resume(struct device *dev) | |
296 | { | |
297 | struct mpl3115_data *data = iio_priv(i2c_get_clientdata( | |
298 | to_i2c_client(dev))); | |
299 | ||
300 | return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, | |
301 | data->ctrl_reg1); | |
302 | } | |
303 | ||
304 | static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume); | |
305 | #define MPL3115_PM_OPS (&mpl3115_pm_ops) | |
306 | #else | |
307 | #define MPL3115_PM_OPS NULL | |
308 | #endif | |
309 | ||
310 | static const struct i2c_device_id mpl3115_id[] = { | |
311 | { "mpl3115", 0 }, | |
312 | { } | |
313 | }; | |
314 | MODULE_DEVICE_TABLE(i2c, mpl3115_id); | |
315 | ||
316 | static struct i2c_driver mpl3115_driver = { | |
317 | .driver = { | |
318 | .name = "mpl3115", | |
319 | .pm = MPL3115_PM_OPS, | |
320 | }, | |
321 | .probe = mpl3115_probe, | |
322 | .remove = mpl3115_remove, | |
323 | .id_table = mpl3115_id, | |
324 | }; | |
325 | module_i2c_driver(mpl3115_driver); | |
326 | ||
327 | MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); | |
328 | MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver"); | |
329 | MODULE_LICENSE("GPL"); |