Commit | Line | Data |
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39ea6ea3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
251eb40f JC |
2 | /* |
3 | * sht15.c - support for the SHT15 Temperature and Humidity Sensor | |
4 | * | |
edec5af7 | 5 | * Portions Copyright (c) 2010-2012 Savoir-faire Linux Inc. |
82c7465b | 6 | * Jerome Oufella <jerome.oufella@savoirfairelinux.com> |
cc15c7eb VD |
7 | * Vivien Didelot <vivien.didelot@savoirfairelinux.com> |
8 | * | |
251eb40f JC |
9 | * Copyright (c) 2009 Jonathan Cameron |
10 | * | |
11 | * Copyright (c) 2007 Wouter Horre | |
12 | * | |
7ebd8b66 | 13 | * For further information, see the Documentation/hwmon/sht15.rst file. |
251eb40f JC |
14 | */ |
15 | ||
16 | #include <linux/interrupt.h> | |
17 | #include <linux/irq.h> | |
251eb40f JC |
18 | #include <linux/module.h> |
19 | #include <linux/init.h> | |
20 | #include <linux/hwmon.h> | |
21 | #include <linux/hwmon-sysfs.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/platform_device.h> | |
d43c36dc | 24 | #include <linux/sched.h> |
251eb40f JC |
25 | #include <linux/delay.h> |
26 | #include <linux/jiffies.h> | |
27 | #include <linux/err.h> | |
251eb40f | 28 | #include <linux/regulator/consumer.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
60063497 | 30 | #include <linux/atomic.h> |
33836ee9 | 31 | #include <linux/bitrev.h> |
18673114 LW |
32 | #include <linux/gpio/consumer.h> |
33 | #include <linux/of.h> | |
251eb40f | 34 | |
99a0378d VD |
35 | /* Commands */ |
36 | #define SHT15_MEASURE_TEMP 0x03 | |
37 | #define SHT15_MEASURE_RH 0x05 | |
cc15c7eb VD |
38 | #define SHT15_WRITE_STATUS 0x06 |
39 | #define SHT15_READ_STATUS 0x07 | |
181148ae | 40 | #define SHT15_SOFT_RESET 0x1E |
251eb40f | 41 | |
99a0378d VD |
42 | /* Min timings */ |
43 | #define SHT15_TSCKL 100 /* (nsecs) clock low */ | |
44 | #define SHT15_TSCKH 100 /* (nsecs) clock high */ | |
45 | #define SHT15_TSU 150 /* (nsecs) data setup time */ | |
181148ae | 46 | #define SHT15_TSRST 11 /* (msecs) soft reset time */ |
251eb40f | 47 | |
cc15c7eb VD |
48 | /* Status Register Bits */ |
49 | #define SHT15_STATUS_LOW_RESOLUTION 0x01 | |
50 | #define SHT15_STATUS_NO_OTP_RELOAD 0x02 | |
51 | #define SHT15_STATUS_HEATER 0x04 | |
52 | #define SHT15_STATUS_LOW_BATTERY 0x40 | |
53 | ||
edec5af7 VD |
54 | /* List of supported chips */ |
55 | enum sht15_chips { sht10, sht11, sht15, sht71, sht75 }; | |
56 | ||
99a0378d VD |
57 | /* Actions the driver may be doing */ |
58 | enum sht15_state { | |
59 | SHT15_READING_NOTHING, | |
60 | SHT15_READING_TEMP, | |
61 | SHT15_READING_HUMID | |
62 | }; | |
251eb40f JC |
63 | |
64 | /** | |
25985edc | 65 | * struct sht15_temppair - elements of voltage dependent temp calc |
251eb40f JC |
66 | * @vdd: supply voltage in microvolts |
67 | * @d1: see data sheet | |
68 | */ | |
69 | struct sht15_temppair { | |
70 | int vdd; /* microvolts */ | |
71 | int d1; | |
72 | }; | |
73 | ||
99a0378d | 74 | /* Table 9 from datasheet - relates temperature calculation to supply voltage */ |
251eb40f JC |
75 | static const struct sht15_temppair temppoints[] = { |
76 | { 2500000, -39400 }, | |
77 | { 3000000, -39600 }, | |
78 | { 3500000, -39700 }, | |
79 | { 4000000, -39800 }, | |
80 | { 5000000, -40100 }, | |
81 | }; | |
82 | ||
82c7465b JO |
83 | /* Table from CRC datasheet, section 2.4 */ |
84 | static const u8 sht15_crc8_table[] = { | |
85 | 0, 49, 98, 83, 196, 245, 166, 151, | |
86 | 185, 136, 219, 234, 125, 76, 31, 46, | |
87 | 67, 114, 33, 16, 135, 182, 229, 212, | |
88 | 250, 203, 152, 169, 62, 15, 92, 109, | |
89 | 134, 183, 228, 213, 66, 115, 32, 17, | |
90 | 63, 14, 93, 108, 251, 202, 153, 168, | |
91 | 197, 244, 167, 150, 1, 48, 99, 82, | |
92 | 124, 77, 30, 47, 184, 137, 218, 235, | |
93 | 61, 12, 95, 110, 249, 200, 155, 170, | |
94 | 132, 181, 230, 215, 64, 113, 34, 19, | |
95 | 126, 79, 28, 45, 186, 139, 216, 233, | |
96 | 199, 246, 165, 148, 3, 50, 97, 80, | |
97 | 187, 138, 217, 232, 127, 78, 29, 44, | |
98 | 2, 51, 96, 81, 198, 247, 164, 149, | |
99 | 248, 201, 154, 171, 60, 13, 94, 111, | |
100 | 65, 112, 35, 18, 133, 180, 231, 214, | |
101 | 122, 75, 24, 41, 190, 143, 220, 237, | |
102 | 195, 242, 161, 144, 7, 54, 101, 84, | |
103 | 57, 8, 91, 106, 253, 204, 159, 174, | |
104 | 128, 177, 226, 211, 68, 117, 38, 23, | |
105 | 252, 205, 158, 175, 56, 9, 90, 107, | |
106 | 69, 116, 39, 22, 129, 176, 227, 210, | |
107 | 191, 142, 221, 236, 123, 74, 25, 40, | |
108 | 6, 55, 100, 85, 194, 243, 160, 145, | |
109 | 71, 118, 37, 20, 131, 178, 225, 208, | |
110 | 254, 207, 156, 173, 58, 11, 88, 105, | |
111 | 4, 53, 102, 87, 192, 241, 162, 147, | |
112 | 189, 140, 223, 238, 121, 72, 27, 42, | |
113 | 193, 240, 163, 146, 5, 52, 103, 86, | |
114 | 120, 73, 26, 43, 188, 141, 222, 239, | |
115 | 130, 179, 224, 209, 70, 119, 36, 21, | |
116 | 59, 10, 89, 104, 255, 206, 157, 172 | |
117 | }; | |
118 | ||
251eb40f JC |
119 | /** |
120 | * struct sht15_data - device instance specific data | |
18673114 LW |
121 | * @sck: clock GPIO line |
122 | * @data: data GPIO line | |
99a0378d VD |
123 | * @read_work: bh of interrupt handler. |
124 | * @wait_queue: wait queue for getting values from device. | |
125 | * @val_temp: last temperature value read from device. | |
126 | * @val_humid: last humidity value read from device. | |
cc15c7eb | 127 | * @val_status: last status register value read from device. |
82c7465b JO |
128 | * @checksum_ok: last value read from the device passed CRC validation. |
129 | * @checksumming: flag used to enable the data validation with CRC. | |
99a0378d VD |
130 | * @state: state identifying the action the driver is doing. |
131 | * @measurements_valid: are the current stored measures valid (start condition). | |
cc15c7eb | 132 | * @status_valid: is the current stored status valid (start condition). |
99a0378d | 133 | * @last_measurement: time of last measure. |
cc15c7eb | 134 | * @last_status: time of last status reading. |
99a0378d VD |
135 | * @read_lock: mutex to ensure only one read in progress at a time. |
136 | * @dev: associate device structure. | |
137 | * @hwmon_dev: device associated with hwmon subsystem. | |
138 | * @reg: associated regulator (if specified). | |
139 | * @nb: notifier block to handle notifications of voltage | |
140 | * changes. | |
142c0901 | 141 | * @supply_uv: local copy of supply voltage used to allow use of |
99a0378d | 142 | * regulator consumer if available. |
142c0901 | 143 | * @supply_uv_valid: indicates that an updated value has not yet been |
99a0378d VD |
144 | * obtained from the regulator and so any calculations |
145 | * based upon it will be invalid. | |
142c0901 | 146 | * @update_supply_work: work struct that is used to update the supply_uv. |
99a0378d | 147 | * @interrupt_handled: flag used to indicate a handler has been scheduled. |
251eb40f JC |
148 | */ |
149 | struct sht15_data { | |
18673114 LW |
150 | struct gpio_desc *sck; |
151 | struct gpio_desc *data; | |
251eb40f JC |
152 | struct work_struct read_work; |
153 | wait_queue_head_t wait_queue; | |
154 | uint16_t val_temp; | |
155 | uint16_t val_humid; | |
cc15c7eb | 156 | u8 val_status; |
82c7465b JO |
157 | bool checksum_ok; |
158 | bool checksumming; | |
99a0378d VD |
159 | enum sht15_state state; |
160 | bool measurements_valid; | |
cc15c7eb | 161 | bool status_valid; |
99a0378d | 162 | unsigned long last_measurement; |
cc15c7eb | 163 | unsigned long last_status; |
251eb40f JC |
164 | struct mutex read_lock; |
165 | struct device *dev; | |
166 | struct device *hwmon_dev; | |
167 | struct regulator *reg; | |
168 | struct notifier_block nb; | |
142c0901 VD |
169 | int supply_uv; |
170 | bool supply_uv_valid; | |
251eb40f JC |
171 | struct work_struct update_supply_work; |
172 | atomic_t interrupt_handled; | |
173 | }; | |
174 | ||
82c7465b JO |
175 | /** |
176 | * sht15_crc8() - compute crc8 | |
177 | * @data: sht15 specific data. | |
178 | * @value: sht15 retrieved data. | |
d5324e90 | 179 | * @len: Length of retrieved data |
82c7465b JO |
180 | * |
181 | * This implements section 2 of the CRC datasheet. | |
182 | */ | |
183 | static u8 sht15_crc8(struct sht15_data *data, | |
184 | const u8 *value, | |
185 | int len) | |
186 | { | |
33836ee9 | 187 | u8 crc = bitrev8(data->val_status & 0x0F); |
82c7465b JO |
188 | |
189 | while (len--) { | |
190 | crc = sht15_crc8_table[*value ^ crc]; | |
191 | value++; | |
192 | } | |
193 | ||
194 | return crc; | |
195 | } | |
196 | ||
251eb40f JC |
197 | /** |
198 | * sht15_connection_reset() - reset the comms interface | |
199 | * @data: sht15 specific data | |
200 | * | |
201 | * This implements section 3.4 of the data sheet | |
202 | */ | |
412e29c1 | 203 | static int sht15_connection_reset(struct sht15_data *data) |
251eb40f | 204 | { |
412e29c1 | 205 | int i, err; |
99a0378d | 206 | |
18673114 | 207 | err = gpiod_direction_output(data->data, 1); |
412e29c1 VD |
208 | if (err) |
209 | return err; | |
251eb40f | 210 | ndelay(SHT15_TSCKL); |
18673114 | 211 | gpiod_set_value(data->sck, 0); |
251eb40f JC |
212 | ndelay(SHT15_TSCKL); |
213 | for (i = 0; i < 9; ++i) { | |
18673114 | 214 | gpiod_set_value(data->sck, 1); |
251eb40f | 215 | ndelay(SHT15_TSCKH); |
18673114 | 216 | gpiod_set_value(data->sck, 0); |
251eb40f JC |
217 | ndelay(SHT15_TSCKL); |
218 | } | |
412e29c1 | 219 | return 0; |
251eb40f | 220 | } |
99a0378d | 221 | |
251eb40f JC |
222 | /** |
223 | * sht15_send_bit() - send an individual bit to the device | |
224 | * @data: device state data | |
225 | * @val: value of bit to be sent | |
99a0378d | 226 | */ |
251eb40f JC |
227 | static inline void sht15_send_bit(struct sht15_data *data, int val) |
228 | { | |
18673114 | 229 | gpiod_set_value(data->data, val); |
251eb40f | 230 | ndelay(SHT15_TSU); |
18673114 | 231 | gpiod_set_value(data->sck, 1); |
251eb40f | 232 | ndelay(SHT15_TSCKH); |
18673114 | 233 | gpiod_set_value(data->sck, 0); |
251eb40f JC |
234 | ndelay(SHT15_TSCKL); /* clock low time */ |
235 | } | |
236 | ||
237 | /** | |
238 | * sht15_transmission_start() - specific sequence for new transmission | |
251eb40f | 239 | * @data: device state data |
99a0378d | 240 | * |
251eb40f JC |
241 | * Timings for this are not documented on the data sheet, so very |
242 | * conservative ones used in implementation. This implements | |
243 | * figure 12 on the data sheet. | |
99a0378d | 244 | */ |
412e29c1 | 245 | static int sht15_transmission_start(struct sht15_data *data) |
251eb40f | 246 | { |
412e29c1 VD |
247 | int err; |
248 | ||
251eb40f | 249 | /* ensure data is high and output */ |
18673114 | 250 | err = gpiod_direction_output(data->data, 1); |
412e29c1 VD |
251 | if (err) |
252 | return err; | |
251eb40f | 253 | ndelay(SHT15_TSU); |
18673114 | 254 | gpiod_set_value(data->sck, 0); |
251eb40f | 255 | ndelay(SHT15_TSCKL); |
18673114 | 256 | gpiod_set_value(data->sck, 1); |
251eb40f | 257 | ndelay(SHT15_TSCKH); |
18673114 | 258 | gpiod_set_value(data->data, 0); |
251eb40f | 259 | ndelay(SHT15_TSU); |
18673114 | 260 | gpiod_set_value(data->sck, 0); |
251eb40f | 261 | ndelay(SHT15_TSCKL); |
18673114 | 262 | gpiod_set_value(data->sck, 1); |
251eb40f | 263 | ndelay(SHT15_TSCKH); |
18673114 | 264 | gpiod_set_value(data->data, 1); |
251eb40f | 265 | ndelay(SHT15_TSU); |
18673114 | 266 | gpiod_set_value(data->sck, 0); |
251eb40f | 267 | ndelay(SHT15_TSCKL); |
412e29c1 | 268 | return 0; |
251eb40f | 269 | } |
99a0378d | 270 | |
251eb40f JC |
271 | /** |
272 | * sht15_send_byte() - send a single byte to the device | |
273 | * @data: device state | |
274 | * @byte: value to be sent | |
99a0378d | 275 | */ |
251eb40f JC |
276 | static void sht15_send_byte(struct sht15_data *data, u8 byte) |
277 | { | |
278 | int i; | |
99a0378d | 279 | |
251eb40f JC |
280 | for (i = 0; i < 8; i++) { |
281 | sht15_send_bit(data, !!(byte & 0x80)); | |
282 | byte <<= 1; | |
283 | } | |
284 | } | |
99a0378d | 285 | |
251eb40f JC |
286 | /** |
287 | * sht15_wait_for_response() - checks for ack from device | |
288 | * @data: device state | |
99a0378d | 289 | */ |
251eb40f JC |
290 | static int sht15_wait_for_response(struct sht15_data *data) |
291 | { | |
412e29c1 VD |
292 | int err; |
293 | ||
18673114 | 294 | err = gpiod_direction_input(data->data); |
412e29c1 VD |
295 | if (err) |
296 | return err; | |
18673114 | 297 | gpiod_set_value(data->sck, 1); |
251eb40f | 298 | ndelay(SHT15_TSCKH); |
18673114 LW |
299 | if (gpiod_get_value(data->data)) { |
300 | gpiod_set_value(data->sck, 0); | |
251eb40f | 301 | dev_err(data->dev, "Command not acknowledged\n"); |
412e29c1 VD |
302 | err = sht15_connection_reset(data); |
303 | if (err) | |
304 | return err; | |
251eb40f JC |
305 | return -EIO; |
306 | } | |
18673114 | 307 | gpiod_set_value(data->sck, 0); |
251eb40f JC |
308 | ndelay(SHT15_TSCKL); |
309 | return 0; | |
310 | } | |
311 | ||
312 | /** | |
313 | * sht15_send_cmd() - Sends a command to the device. | |
314 | * @data: device state | |
315 | * @cmd: command byte to be sent | |
316 | * | |
317 | * On entry, sck is output low, data is output pull high | |
318 | * and the interrupt disabled. | |
99a0378d | 319 | */ |
251eb40f JC |
320 | static int sht15_send_cmd(struct sht15_data *data, u8 cmd) |
321 | { | |
412e29c1 | 322 | int err; |
99a0378d | 323 | |
412e29c1 VD |
324 | err = sht15_transmission_start(data); |
325 | if (err) | |
326 | return err; | |
251eb40f | 327 | sht15_send_byte(data, cmd); |
412e29c1 | 328 | return sht15_wait_for_response(data); |
251eb40f | 329 | } |
99a0378d | 330 | |
181148ae VD |
331 | /** |
332 | * sht15_soft_reset() - send a soft reset command | |
333 | * @data: sht15 specific data. | |
334 | * | |
335 | * As described in section 3.2 of the datasheet. | |
336 | */ | |
337 | static int sht15_soft_reset(struct sht15_data *data) | |
338 | { | |
339 | int ret; | |
340 | ||
341 | ret = sht15_send_cmd(data, SHT15_SOFT_RESET); | |
342 | if (ret) | |
343 | return ret; | |
344 | msleep(SHT15_TSRST); | |
cc15c7eb VD |
345 | /* device resets default hardware status register value */ |
346 | data->val_status = 0; | |
347 | ||
348 | return ret; | |
349 | } | |
350 | ||
82c7465b JO |
351 | /** |
352 | * sht15_ack() - send a ack | |
353 | * @data: sht15 specific data. | |
354 | * | |
355 | * Each byte of data is acknowledged by pulling the data line | |
356 | * low for one clock pulse. | |
357 | */ | |
412e29c1 | 358 | static int sht15_ack(struct sht15_data *data) |
82c7465b | 359 | { |
412e29c1 VD |
360 | int err; |
361 | ||
18673114 | 362 | err = gpiod_direction_output(data->data, 0); |
412e29c1 VD |
363 | if (err) |
364 | return err; | |
82c7465b | 365 | ndelay(SHT15_TSU); |
18673114 | 366 | gpiod_set_value(data->sck, 1); |
82c7465b | 367 | ndelay(SHT15_TSU); |
18673114 | 368 | gpiod_set_value(data->sck, 0); |
82c7465b | 369 | ndelay(SHT15_TSU); |
18673114 | 370 | gpiod_set_value(data->data, 1); |
82c7465b | 371 | |
18673114 | 372 | return gpiod_direction_input(data->data); |
82c7465b JO |
373 | } |
374 | ||
cc15c7eb VD |
375 | /** |
376 | * sht15_end_transmission() - notify device of end of transmission | |
377 | * @data: device state. | |
378 | * | |
379 | * This is basically a NAK (single clock pulse, data high). | |
380 | */ | |
412e29c1 | 381 | static int sht15_end_transmission(struct sht15_data *data) |
cc15c7eb | 382 | { |
412e29c1 VD |
383 | int err; |
384 | ||
18673114 | 385 | err = gpiod_direction_output(data->data, 1); |
412e29c1 VD |
386 | if (err) |
387 | return err; | |
cc15c7eb | 388 | ndelay(SHT15_TSU); |
18673114 | 389 | gpiod_set_value(data->sck, 1); |
cc15c7eb | 390 | ndelay(SHT15_TSCKH); |
18673114 | 391 | gpiod_set_value(data->sck, 0); |
cc15c7eb | 392 | ndelay(SHT15_TSCKL); |
412e29c1 | 393 | return 0; |
cc15c7eb VD |
394 | } |
395 | ||
396 | /** | |
397 | * sht15_read_byte() - Read a byte back from the device | |
398 | * @data: device state. | |
399 | */ | |
400 | static u8 sht15_read_byte(struct sht15_data *data) | |
401 | { | |
402 | int i; | |
403 | u8 byte = 0; | |
404 | ||
405 | for (i = 0; i < 8; ++i) { | |
406 | byte <<= 1; | |
18673114 | 407 | gpiod_set_value(data->sck, 1); |
cc15c7eb | 408 | ndelay(SHT15_TSCKH); |
18673114 LW |
409 | byte |= !!gpiod_get_value(data->data); |
410 | gpiod_set_value(data->sck, 0); | |
cc15c7eb VD |
411 | ndelay(SHT15_TSCKL); |
412 | } | |
413 | return byte; | |
414 | } | |
415 | ||
416 | /** | |
417 | * sht15_send_status() - write the status register byte | |
418 | * @data: sht15 specific data. | |
419 | * @status: the byte to set the status register with. | |
420 | * | |
421 | * As described in figure 14 and table 5 of the datasheet. | |
422 | */ | |
423 | static int sht15_send_status(struct sht15_data *data, u8 status) | |
424 | { | |
412e29c1 VD |
425 | int err; |
426 | ||
427 | err = sht15_send_cmd(data, SHT15_WRITE_STATUS); | |
428 | if (err) | |
429 | return err; | |
18673114 | 430 | err = gpiod_direction_output(data->data, 1); |
412e29c1 VD |
431 | if (err) |
432 | return err; | |
cc15c7eb VD |
433 | ndelay(SHT15_TSU); |
434 | sht15_send_byte(data, status); | |
412e29c1 VD |
435 | err = sht15_wait_for_response(data); |
436 | if (err) | |
437 | return err; | |
181148ae | 438 | |
cc15c7eb | 439 | data->val_status = status; |
181148ae VD |
440 | return 0; |
441 | } | |
442 | ||
cc15c7eb VD |
443 | /** |
444 | * sht15_update_status() - get updated status register from device if too old | |
445 | * @data: device instance specific data. | |
446 | * | |
447 | * As described in figure 15 and table 5 of the datasheet. | |
448 | */ | |
449 | static int sht15_update_status(struct sht15_data *data) | |
450 | { | |
451 | int ret = 0; | |
452 | u8 status; | |
82c7465b JO |
453 | u8 previous_config; |
454 | u8 dev_checksum = 0; | |
455 | u8 checksum_vals[2]; | |
cc15c7eb VD |
456 | int timeout = HZ; |
457 | ||
458 | mutex_lock(&data->read_lock); | |
459 | if (time_after(jiffies, data->last_status + timeout) | |
460 | || !data->status_valid) { | |
461 | ret = sht15_send_cmd(data, SHT15_READ_STATUS); | |
462 | if (ret) | |
412e29c1 | 463 | goto unlock; |
cc15c7eb VD |
464 | status = sht15_read_byte(data); |
465 | ||
82c7465b JO |
466 | if (data->checksumming) { |
467 | sht15_ack(data); | |
33836ee9 | 468 | dev_checksum = bitrev8(sht15_read_byte(data)); |
82c7465b JO |
469 | checksum_vals[0] = SHT15_READ_STATUS; |
470 | checksum_vals[1] = status; | |
471 | data->checksum_ok = (sht15_crc8(data, checksum_vals, 2) | |
472 | == dev_checksum); | |
473 | } | |
474 | ||
412e29c1 VD |
475 | ret = sht15_end_transmission(data); |
476 | if (ret) | |
477 | goto unlock; | |
cc15c7eb | 478 | |
82c7465b JO |
479 | /* |
480 | * Perform checksum validation on the received data. | |
481 | * Specification mentions that in case a checksum verification | |
482 | * fails, a soft reset command must be sent to the device. | |
483 | */ | |
484 | if (data->checksumming && !data->checksum_ok) { | |
485 | previous_config = data->val_status & 0x07; | |
486 | ret = sht15_soft_reset(data); | |
487 | if (ret) | |
412e29c1 | 488 | goto unlock; |
82c7465b JO |
489 | if (previous_config) { |
490 | ret = sht15_send_status(data, previous_config); | |
491 | if (ret) { | |
492 | dev_err(data->dev, | |
493 | "CRC validation failed, unable " | |
494 | "to restore device settings\n"); | |
412e29c1 | 495 | goto unlock; |
82c7465b JO |
496 | } |
497 | } | |
498 | ret = -EAGAIN; | |
412e29c1 | 499 | goto unlock; |
82c7465b JO |
500 | } |
501 | ||
cc15c7eb VD |
502 | data->val_status = status; |
503 | data->status_valid = true; | |
504 | data->last_status = jiffies; | |
505 | } | |
cc15c7eb | 506 | |
412e29c1 VD |
507 | unlock: |
508 | mutex_unlock(&data->read_lock); | |
cc15c7eb VD |
509 | return ret; |
510 | } | |
511 | ||
251eb40f | 512 | /** |
99a0378d | 513 | * sht15_measurement() - get a new value from device |
251eb40f JC |
514 | * @data: device instance specific data |
515 | * @command: command sent to request value | |
516 | * @timeout_msecs: timeout after which comms are assumed | |
517 | * to have failed are reset. | |
99a0378d VD |
518 | */ |
519 | static int sht15_measurement(struct sht15_data *data, | |
520 | int command, | |
521 | int timeout_msecs) | |
251eb40f JC |
522 | { |
523 | int ret; | |
82c7465b | 524 | u8 previous_config; |
99a0378d | 525 | |
251eb40f JC |
526 | ret = sht15_send_cmd(data, command); |
527 | if (ret) | |
528 | return ret; | |
529 | ||
18673114 | 530 | ret = gpiod_direction_input(data->data); |
412e29c1 VD |
531 | if (ret) |
532 | return ret; | |
251eb40f JC |
533 | atomic_set(&data->interrupt_handled, 0); |
534 | ||
18673114 LW |
535 | enable_irq(gpiod_to_irq(data->data)); |
536 | if (gpiod_get_value(data->data) == 0) { | |
537 | disable_irq_nosync(gpiod_to_irq(data->data)); | |
25985edc | 538 | /* Only relevant if the interrupt hasn't occurred. */ |
251eb40f JC |
539 | if (!atomic_read(&data->interrupt_handled)) |
540 | schedule_work(&data->read_work); | |
541 | } | |
542 | ret = wait_event_timeout(data->wait_queue, | |
99a0378d | 543 | (data->state == SHT15_READING_NOTHING), |
251eb40f | 544 | msecs_to_jiffies(timeout_msecs)); |
412e29c1 VD |
545 | if (data->state != SHT15_READING_NOTHING) { /* I/O error occurred */ |
546 | data->state = SHT15_READING_NOTHING; | |
547 | return -EIO; | |
548 | } else if (ret == 0) { /* timeout occurred */ | |
18673114 | 549 | disable_irq_nosync(gpiod_to_irq(data->data)); |
412e29c1 VD |
550 | ret = sht15_connection_reset(data); |
551 | if (ret) | |
552 | return ret; | |
251eb40f JC |
553 | return -ETIME; |
554 | } | |
82c7465b JO |
555 | |
556 | /* | |
557 | * Perform checksum validation on the received data. | |
558 | * Specification mentions that in case a checksum verification fails, | |
559 | * a soft reset command must be sent to the device. | |
560 | */ | |
561 | if (data->checksumming && !data->checksum_ok) { | |
562 | previous_config = data->val_status & 0x07; | |
563 | ret = sht15_soft_reset(data); | |
564 | if (ret) | |
565 | return ret; | |
566 | if (previous_config) { | |
567 | ret = sht15_send_status(data, previous_config); | |
568 | if (ret) { | |
569 | dev_err(data->dev, | |
570 | "CRC validation failed, unable " | |
571 | "to restore device settings\n"); | |
572 | return ret; | |
573 | } | |
574 | } | |
575 | return -EAGAIN; | |
576 | } | |
577 | ||
251eb40f JC |
578 | return 0; |
579 | } | |
580 | ||
581 | /** | |
99a0378d | 582 | * sht15_update_measurements() - get updated measures from device if too old |
251eb40f | 583 | * @data: device state |
99a0378d VD |
584 | */ |
585 | static int sht15_update_measurements(struct sht15_data *data) | |
251eb40f JC |
586 | { |
587 | int ret = 0; | |
588 | int timeout = HZ; | |
589 | ||
590 | mutex_lock(&data->read_lock); | |
99a0378d VD |
591 | if (time_after(jiffies, data->last_measurement + timeout) |
592 | || !data->measurements_valid) { | |
593 | data->state = SHT15_READING_HUMID; | |
594 | ret = sht15_measurement(data, SHT15_MEASURE_RH, 160); | |
251eb40f | 595 | if (ret) |
412e29c1 | 596 | goto unlock; |
99a0378d VD |
597 | data->state = SHT15_READING_TEMP; |
598 | ret = sht15_measurement(data, SHT15_MEASURE_TEMP, 400); | |
251eb40f | 599 | if (ret) |
412e29c1 | 600 | goto unlock; |
99a0378d VD |
601 | data->measurements_valid = true; |
602 | data->last_measurement = jiffies; | |
251eb40f | 603 | } |
251eb40f | 604 | |
412e29c1 VD |
605 | unlock: |
606 | mutex_unlock(&data->read_lock); | |
251eb40f JC |
607 | return ret; |
608 | } | |
609 | ||
610 | /** | |
611 | * sht15_calc_temp() - convert the raw reading to a temperature | |
612 | * @data: device state | |
613 | * | |
614 | * As per section 4.3 of the data sheet. | |
99a0378d | 615 | */ |
251eb40f JC |
616 | static inline int sht15_calc_temp(struct sht15_data *data) |
617 | { | |
328a2c22 | 618 | int d1 = temppoints[0].d1; |
cc15c7eb | 619 | int d2 = (data->val_status & SHT15_STATUS_LOW_RESOLUTION) ? 40 : 10; |
251eb40f JC |
620 | int i; |
621 | ||
328a2c22 | 622 | for (i = ARRAY_SIZE(temppoints) - 1; i > 0; i--) |
251eb40f | 623 | /* Find pointer to interpolate */ |
142c0901 VD |
624 | if (data->supply_uv > temppoints[i - 1].vdd) { |
625 | d1 = (data->supply_uv - temppoints[i - 1].vdd) | |
251eb40f JC |
626 | * (temppoints[i].d1 - temppoints[i - 1].d1) |
627 | / (temppoints[i].vdd - temppoints[i - 1].vdd) | |
628 | + temppoints[i - 1].d1; | |
629 | break; | |
630 | } | |
631 | ||
cc15c7eb | 632 | return data->val_temp * d2 + d1; |
251eb40f JC |
633 | } |
634 | ||
635 | /** | |
636 | * sht15_calc_humid() - using last temperature convert raw to humid | |
637 | * @data: device state | |
638 | * | |
639 | * This is the temperature compensated version as per section 4.2 of | |
640 | * the data sheet. | |
99a0378d VD |
641 | * |
642 | * The sensor is assumed to be V3, which is compatible with V4. | |
643 | * Humidity conversion coefficients are shown in table 7 of the datasheet. | |
644 | */ | |
251eb40f JC |
645 | static inline int sht15_calc_humid(struct sht15_data *data) |
646 | { | |
99a0378d | 647 | int rh_linear; /* milli percent */ |
251eb40f | 648 | int temp = sht15_calc_temp(data); |
cc15c7eb VD |
649 | int c2, c3; |
650 | int t2; | |
251eb40f | 651 | const int c1 = -4; |
cc15c7eb VD |
652 | |
653 | if (data->val_status & SHT15_STATUS_LOW_RESOLUTION) { | |
654 | c2 = 648000; /* x 10 ^ -6 */ | |
655 | c3 = -7200; /* x 10 ^ -7 */ | |
656 | t2 = 1280; | |
657 | } else { | |
658 | c2 = 40500; /* x 10 ^ -6 */ | |
659 | c3 = -28; /* x 10 ^ -7 */ | |
660 | t2 = 80; | |
661 | } | |
251eb40f | 662 | |
99a0378d VD |
663 | rh_linear = c1 * 1000 |
664 | + c2 * data->val_humid / 1000 | |
ccd32e73 | 665 | + (data->val_humid * data->val_humid * c3) / 10000; |
cc15c7eb | 666 | return (temp - 25000) * (10000 + t2 * data->val_humid) |
99a0378d | 667 | / 1000000 + rh_linear; |
251eb40f JC |
668 | } |
669 | ||
cc15c7eb VD |
670 | /** |
671 | * sht15_show_status() - show status information in sysfs | |
672 | * @dev: device. | |
673 | * @attr: device attribute. | |
674 | * @buf: sysfs buffer where information is written to. | |
675 | * | |
676 | * Will be called on read access to temp1_fault, humidity1_fault | |
677 | * and heater_enable sysfs attributes. | |
678 | * Returns number of bytes written into buffer, negative errno on error. | |
679 | */ | |
41c9a49a GR |
680 | static ssize_t sht15_status_show(struct device *dev, |
681 | struct device_attribute *attr, char *buf) | |
cc15c7eb VD |
682 | { |
683 | int ret; | |
684 | struct sht15_data *data = dev_get_drvdata(dev); | |
685 | u8 bit = to_sensor_dev_attr(attr)->index; | |
686 | ||
687 | ret = sht15_update_status(data); | |
688 | ||
689 | return ret ? ret : sprintf(buf, "%d\n", !!(data->val_status & bit)); | |
690 | } | |
691 | ||
692 | /** | |
693 | * sht15_store_heater() - change heater state via sysfs | |
694 | * @dev: device. | |
695 | * @attr: device attribute. | |
696 | * @buf: sysfs buffer to read the new heater state from. | |
697 | * @count: length of the data. | |
698 | * | |
e9b6e9f3 | 699 | * Will be called on write access to heater_enable sysfs attribute. |
cc15c7eb VD |
700 | * Returns number of bytes actually decoded, negative errno on error. |
701 | */ | |
41c9a49a | 702 | static ssize_t sht15_status_store(struct device *dev, |
cc15c7eb VD |
703 | struct device_attribute *attr, |
704 | const char *buf, size_t count) | |
705 | { | |
706 | int ret; | |
707 | struct sht15_data *data = dev_get_drvdata(dev); | |
708 | long value; | |
709 | u8 status; | |
710 | ||
179c4fdb | 711 | if (kstrtol(buf, 10, &value)) |
cc15c7eb VD |
712 | return -EINVAL; |
713 | ||
714 | mutex_lock(&data->read_lock); | |
715 | status = data->val_status & 0x07; | |
716 | if (!!value) | |
717 | status |= SHT15_STATUS_HEATER; | |
718 | else | |
719 | status &= ~SHT15_STATUS_HEATER; | |
720 | ||
721 | ret = sht15_send_status(data, status); | |
722 | mutex_unlock(&data->read_lock); | |
723 | ||
724 | return ret ? ret : count; | |
725 | } | |
726 | ||
99a0378d VD |
727 | /** |
728 | * sht15_show_temp() - show temperature measurement value in sysfs | |
729 | * @dev: device. | |
730 | * @attr: device attribute. | |
731 | * @buf: sysfs buffer where measurement values are written to. | |
732 | * | |
733 | * Will be called on read access to temp1_input sysfs attribute. | |
734 | * Returns number of bytes written into buffer, negative errno on error. | |
735 | */ | |
41c9a49a GR |
736 | static ssize_t sht15_temp_show(struct device *dev, |
737 | struct device_attribute *attr, char *buf) | |
251eb40f JC |
738 | { |
739 | int ret; | |
740 | struct sht15_data *data = dev_get_drvdata(dev); | |
741 | ||
742 | /* Technically no need to read humidity as well */ | |
99a0378d | 743 | ret = sht15_update_measurements(data); |
251eb40f JC |
744 | |
745 | return ret ? ret : sprintf(buf, "%d\n", | |
746 | sht15_calc_temp(data)); | |
747 | } | |
748 | ||
99a0378d VD |
749 | /** |
750 | * sht15_show_humidity() - show humidity measurement value in sysfs | |
751 | * @dev: device. | |
752 | * @attr: device attribute. | |
753 | * @buf: sysfs buffer where measurement values are written to. | |
754 | * | |
755 | * Will be called on read access to humidity1_input sysfs attribute. | |
756 | * Returns number of bytes written into buffer, negative errno on error. | |
757 | */ | |
41c9a49a GR |
758 | static ssize_t sht15_humidity_show(struct device *dev, |
759 | struct device_attribute *attr, char *buf) | |
251eb40f JC |
760 | { |
761 | int ret; | |
762 | struct sht15_data *data = dev_get_drvdata(dev); | |
763 | ||
99a0378d | 764 | ret = sht15_update_measurements(data); |
251eb40f JC |
765 | |
766 | return ret ? ret : sprintf(buf, "%d\n", sht15_calc_humid(data)); | |
99a0378d VD |
767 | } |
768 | ||
af3d387f | 769 | static ssize_t name_show(struct device *dev, |
251eb40f JC |
770 | struct device_attribute *attr, |
771 | char *buf) | |
772 | { | |
773 | struct platform_device *pdev = to_platform_device(dev); | |
774 | return sprintf(buf, "%s\n", pdev->name); | |
775 | } | |
776 | ||
41c9a49a GR |
777 | static SENSOR_DEVICE_ATTR_RO(temp1_input, sht15_temp, 0); |
778 | static SENSOR_DEVICE_ATTR_RO(humidity1_input, sht15_humidity, 0); | |
779 | static SENSOR_DEVICE_ATTR_RO(temp1_fault, sht15_status, | |
780 | SHT15_STATUS_LOW_BATTERY); | |
781 | static SENSOR_DEVICE_ATTR_RO(humidity1_fault, sht15_status, | |
782 | SHT15_STATUS_LOW_BATTERY); | |
783 | static SENSOR_DEVICE_ATTR_RW(heater_enable, sht15_status, SHT15_STATUS_HEATER); | |
af3d387f | 784 | static DEVICE_ATTR_RO(name); |
251eb40f JC |
785 | static struct attribute *sht15_attrs[] = { |
786 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
787 | &sensor_dev_attr_humidity1_input.dev_attr.attr, | |
cc15c7eb VD |
788 | &sensor_dev_attr_temp1_fault.dev_attr.attr, |
789 | &sensor_dev_attr_humidity1_fault.dev_attr.attr, | |
790 | &sensor_dev_attr_heater_enable.dev_attr.attr, | |
251eb40f JC |
791 | &dev_attr_name.attr, |
792 | NULL, | |
793 | }; | |
794 | ||
795 | static const struct attribute_group sht15_attr_group = { | |
796 | .attrs = sht15_attrs, | |
797 | }; | |
798 | ||
799 | static irqreturn_t sht15_interrupt_fired(int irq, void *d) | |
800 | { | |
801 | struct sht15_data *data = d; | |
99a0378d | 802 | |
251eb40f JC |
803 | /* First disable the interrupt */ |
804 | disable_irq_nosync(irq); | |
805 | atomic_inc(&data->interrupt_handled); | |
806 | /* Then schedule a reading work struct */ | |
99a0378d | 807 | if (data->state != SHT15_READING_NOTHING) |
251eb40f JC |
808 | schedule_work(&data->read_work); |
809 | return IRQ_HANDLED; | |
810 | } | |
811 | ||
251eb40f JC |
812 | static void sht15_bh_read_data(struct work_struct *work_s) |
813 | { | |
251eb40f | 814 | uint16_t val = 0; |
82c7465b JO |
815 | u8 dev_checksum = 0; |
816 | u8 checksum_vals[3]; | |
251eb40f JC |
817 | struct sht15_data *data |
818 | = container_of(work_s, struct sht15_data, | |
819 | read_work); | |
99a0378d | 820 | |
251eb40f | 821 | /* Firstly, verify the line is low */ |
18673114 | 822 | if (gpiod_get_value(data->data)) { |
99a0378d VD |
823 | /* |
824 | * If not, then start the interrupt again - care here as could | |
825 | * have gone low in meantime so verify it hasn't! | |
826 | */ | |
251eb40f | 827 | atomic_set(&data->interrupt_handled, 0); |
18673114 | 828 | enable_irq(gpiod_to_irq(data->data)); |
c9e1498a | 829 | /* If still not occurred or another handler was scheduled */ |
18673114 | 830 | if (gpiod_get_value(data->data) |
251eb40f JC |
831 | || atomic_read(&data->interrupt_handled)) |
832 | return; | |
833 | } | |
99a0378d | 834 | |
251eb40f | 835 | /* Read the data back from the device */ |
cc15c7eb VD |
836 | val = sht15_read_byte(data); |
837 | val <<= 8; | |
412e29c1 VD |
838 | if (sht15_ack(data)) |
839 | goto wakeup; | |
cc15c7eb | 840 | val |= sht15_read_byte(data); |
99a0378d | 841 | |
82c7465b JO |
842 | if (data->checksumming) { |
843 | /* | |
844 | * Ask the device for a checksum and read it back. | |
845 | * Note: the device sends the checksum byte reversed. | |
846 | */ | |
412e29c1 VD |
847 | if (sht15_ack(data)) |
848 | goto wakeup; | |
33836ee9 | 849 | dev_checksum = bitrev8(sht15_read_byte(data)); |
82c7465b JO |
850 | checksum_vals[0] = (data->state == SHT15_READING_TEMP) ? |
851 | SHT15_MEASURE_TEMP : SHT15_MEASURE_RH; | |
852 | checksum_vals[1] = (u8) (val >> 8); | |
853 | checksum_vals[2] = (u8) val; | |
854 | data->checksum_ok | |
855 | = (sht15_crc8(data, checksum_vals, 3) == dev_checksum); | |
856 | } | |
857 | ||
251eb40f | 858 | /* Tell the device we are done */ |
412e29c1 VD |
859 | if (sht15_end_transmission(data)) |
860 | goto wakeup; | |
251eb40f | 861 | |
99a0378d | 862 | switch (data->state) { |
251eb40f JC |
863 | case SHT15_READING_TEMP: |
864 | data->val_temp = val; | |
865 | break; | |
866 | case SHT15_READING_HUMID: | |
867 | data->val_humid = val; | |
868 | break; | |
99a0378d VD |
869 | default: |
870 | break; | |
251eb40f JC |
871 | } |
872 | ||
99a0378d | 873 | data->state = SHT15_READING_NOTHING; |
412e29c1 | 874 | wakeup: |
251eb40f JC |
875 | wake_up(&data->wait_queue); |
876 | } | |
877 | ||
878 | static void sht15_update_voltage(struct work_struct *work_s) | |
879 | { | |
880 | struct sht15_data *data | |
881 | = container_of(work_s, struct sht15_data, | |
882 | update_supply_work); | |
142c0901 | 883 | data->supply_uv = regulator_get_voltage(data->reg); |
251eb40f JC |
884 | } |
885 | ||
886 | /** | |
887 | * sht15_invalidate_voltage() - mark supply voltage invalid when notified by reg | |
888 | * @nb: associated notification structure | |
889 | * @event: voltage regulator state change event code | |
890 | * @ignored: function parameter - ignored here | |
891 | * | |
892 | * Note that as the notification code holds the regulator lock, we have | |
893 | * to schedule an update of the supply voltage rather than getting it directly. | |
99a0378d | 894 | */ |
251eb40f | 895 | static int sht15_invalidate_voltage(struct notifier_block *nb, |
99a0378d VD |
896 | unsigned long event, |
897 | void *ignored) | |
251eb40f JC |
898 | { |
899 | struct sht15_data *data = container_of(nb, struct sht15_data, nb); | |
900 | ||
901 | if (event == REGULATOR_EVENT_VOLTAGE_CHANGE) | |
142c0901 | 902 | data->supply_uv_valid = false; |
251eb40f JC |
903 | schedule_work(&data->update_supply_work); |
904 | ||
905 | return NOTIFY_OK; | |
906 | } | |
907 | ||
2f1736ff MF |
908 | #ifdef CONFIG_OF |
909 | static const struct of_device_id sht15_dt_match[] = { | |
910 | { .compatible = "sensirion,sht15" }, | |
911 | { }, | |
912 | }; | |
913 | MODULE_DEVICE_TABLE(of, sht15_dt_match); | |
2f1736ff MF |
914 | #endif |
915 | ||
6c931ae1 | 916 | static int sht15_probe(struct platform_device *pdev) |
251eb40f | 917 | { |
6edf3c30 | 918 | int ret; |
38fe7560 | 919 | struct sht15_data *data; |
251eb40f | 920 | |
38fe7560 GR |
921 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
922 | if (!data) | |
923 | return -ENOMEM; | |
251eb40f JC |
924 | |
925 | INIT_WORK(&data->read_work, sht15_bh_read_data); | |
926 | INIT_WORK(&data->update_supply_work, sht15_update_voltage); | |
927 | platform_set_drvdata(pdev, data); | |
928 | mutex_init(&data->read_lock); | |
929 | data->dev = &pdev->dev; | |
930 | init_waitqueue_head(&data->wait_queue); | |
931 | ||
99a0378d VD |
932 | /* |
933 | * If a regulator is available, | |
934 | * query what the supply voltage actually is! | |
935 | */ | |
9e059bac | 936 | data->reg = devm_regulator_get_optional(data->dev, "vcc"); |
251eb40f | 937 | if (!IS_ERR(data->reg)) { |
c7a78d2c JD |
938 | int voltage; |
939 | ||
940 | voltage = regulator_get_voltage(data->reg); | |
941 | if (voltage) | |
142c0901 | 942 | data->supply_uv = voltage; |
c7a78d2c | 943 | |
3e78080f MB |
944 | ret = regulator_enable(data->reg); |
945 | if (ret != 0) { | |
946 | dev_err(&pdev->dev, | |
947 | "failed to enable regulator: %d\n", ret); | |
948 | return ret; | |
949 | } | |
950 | ||
99a0378d VD |
951 | /* |
952 | * Setup a notifier block to update this if another device | |
953 | * causes the voltage to change | |
954 | */ | |
251eb40f JC |
955 | data->nb.notifier_call = &sht15_invalidate_voltage; |
956 | ret = regulator_register_notifier(data->reg, &data->nb); | |
181148ae VD |
957 | if (ret) { |
958 | dev_err(&pdev->dev, | |
959 | "regulator notifier request failed\n"); | |
960 | regulator_disable(data->reg); | |
38fe7560 | 961 | return ret; |
181148ae | 962 | } |
251eb40f | 963 | } |
99a0378d VD |
964 | |
965 | /* Try requesting the GPIOs */ | |
18673114 LW |
966 | data->sck = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_LOW); |
967 | if (IS_ERR(data->sck)) { | |
968 | ret = PTR_ERR(data->sck); | |
412e29c1 | 969 | dev_err(&pdev->dev, "clock line GPIO request failed\n"); |
181148ae | 970 | goto err_release_reg; |
251eb40f | 971 | } |
18673114 LW |
972 | data->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN); |
973 | if (IS_ERR(data->data)) { | |
974 | ret = PTR_ERR(data->data); | |
412e29c1 | 975 | dev_err(&pdev->dev, "data line GPIO request failed\n"); |
38fe7560 | 976 | goto err_release_reg; |
251eb40f | 977 | } |
251eb40f | 978 | |
18673114 | 979 | ret = devm_request_irq(&pdev->dev, gpiod_to_irq(data->data), |
38fe7560 GR |
980 | sht15_interrupt_fired, |
981 | IRQF_TRIGGER_FALLING, | |
982 | "sht15 data", | |
983 | data); | |
251eb40f | 984 | if (ret) { |
99a0378d | 985 | dev_err(&pdev->dev, "failed to get irq for data line\n"); |
38fe7560 | 986 | goto err_release_reg; |
251eb40f | 987 | } |
18673114 | 988 | disable_irq_nosync(gpiod_to_irq(data->data)); |
412e29c1 VD |
989 | ret = sht15_connection_reset(data); |
990 | if (ret) | |
991 | goto err_release_reg; | |
181148ae VD |
992 | ret = sht15_soft_reset(data); |
993 | if (ret) | |
38fe7560 | 994 | goto err_release_reg; |
181148ae VD |
995 | |
996 | ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group); | |
997 | if (ret) { | |
998 | dev_err(&pdev->dev, "sysfs create failed\n"); | |
38fe7560 | 999 | goto err_release_reg; |
181148ae | 1000 | } |
251eb40f JC |
1001 | |
1002 | data->hwmon_dev = hwmon_device_register(data->dev); | |
1003 | if (IS_ERR(data->hwmon_dev)) { | |
1004 | ret = PTR_ERR(data->hwmon_dev); | |
181148ae | 1005 | goto err_release_sysfs_group; |
251eb40f | 1006 | } |
99a0378d | 1007 | |
251eb40f JC |
1008 | return 0; |
1009 | ||
181148ae VD |
1010 | err_release_sysfs_group: |
1011 | sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group); | |
181148ae VD |
1012 | err_release_reg: |
1013 | if (!IS_ERR(data->reg)) { | |
1014 | regulator_unregister_notifier(data->reg, &data->nb); | |
1015 | regulator_disable(data->reg); | |
181148ae | 1016 | } |
251eb40f JC |
1017 | return ret; |
1018 | } | |
1019 | ||
281dfd0b | 1020 | static int sht15_remove(struct platform_device *pdev) |
251eb40f JC |
1021 | { |
1022 | struct sht15_data *data = platform_get_drvdata(pdev); | |
1023 | ||
99a0378d VD |
1024 | /* |
1025 | * Make sure any reads from the device are done and | |
1026 | * prevent new ones beginning | |
1027 | */ | |
251eb40f | 1028 | mutex_lock(&data->read_lock); |
cc15c7eb VD |
1029 | if (sht15_soft_reset(data)) { |
1030 | mutex_unlock(&data->read_lock); | |
1031 | return -EFAULT; | |
1032 | } | |
251eb40f JC |
1033 | hwmon_device_unregister(data->hwmon_dev); |
1034 | sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group); | |
1035 | if (!IS_ERR(data->reg)) { | |
1036 | regulator_unregister_notifier(data->reg, &data->nb); | |
1037 | regulator_disable(data->reg); | |
251eb40f JC |
1038 | } |
1039 | ||
251eb40f | 1040 | mutex_unlock(&data->read_lock); |
99a0378d | 1041 | |
251eb40f JC |
1042 | return 0; |
1043 | } | |
1044 | ||
9c40723e | 1045 | static const struct platform_device_id sht15_device_ids[] = { |
edec5af7 VD |
1046 | { "sht10", sht10 }, |
1047 | { "sht11", sht11 }, | |
1048 | { "sht15", sht15 }, | |
1049 | { "sht71", sht71 }, | |
1050 | { "sht75", sht75 }, | |
1051 | { } | |
251eb40f | 1052 | }; |
edec5af7 | 1053 | MODULE_DEVICE_TABLE(platform, sht15_device_ids); |
251eb40f | 1054 | |
edec5af7 VD |
1055 | static struct platform_driver sht15_driver = { |
1056 | .driver = { | |
1057 | .name = "sht15", | |
2f1736ff | 1058 | .of_match_table = of_match_ptr(sht15_dt_match), |
edec5af7 VD |
1059 | }, |
1060 | .probe = sht15_probe, | |
9e5e9b7a | 1061 | .remove = sht15_remove, |
edec5af7 VD |
1062 | .id_table = sht15_device_ids, |
1063 | }; | |
1064 | module_platform_driver(sht15_driver); | |
251eb40f JC |
1065 | |
1066 | MODULE_LICENSE("GPL"); | |
edec5af7 | 1067 | MODULE_DESCRIPTION("Sensirion SHT15 temperature and humidity sensor driver"); |