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fa4c9c93 CDL |
1 | /* |
2 | * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor | |
3 | * | |
4 | * Copyright (c) 2016, Intel Corporation. | |
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 0x76) | |
11 | * | |
12 | * Datasheet: | |
13 | * http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf | |
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/delay.h> | |
21 | #include <linux/util_macros.h> | |
22 | #include <linux/acpi.h> | |
23 | ||
24 | /* I2C commands: */ | |
25 | #define HP206C_CMD_SOFT_RST 0x06 | |
26 | ||
27 | #define HP206C_CMD_ADC_CVT 0x40 | |
28 | ||
29 | #define HP206C_CMD_ADC_CVT_OSR_4096 0x00 | |
30 | #define HP206C_CMD_ADC_CVT_OSR_2048 0x04 | |
31 | #define HP206C_CMD_ADC_CVT_OSR_1024 0x08 | |
32 | #define HP206C_CMD_ADC_CVT_OSR_512 0x0c | |
33 | #define HP206C_CMD_ADC_CVT_OSR_256 0x10 | |
34 | #define HP206C_CMD_ADC_CVT_OSR_128 0x14 | |
35 | ||
36 | #define HP206C_CMD_ADC_CVT_CHNL_PT 0x00 | |
37 | #define HP206C_CMD_ADC_CVT_CHNL_T 0x02 | |
38 | ||
39 | #define HP206C_CMD_READ_P 0x30 | |
40 | #define HP206C_CMD_READ_T 0x32 | |
41 | ||
42 | #define HP206C_CMD_READ_REG 0x80 | |
43 | #define HP206C_CMD_WRITE_REG 0xc0 | |
44 | ||
45 | #define HP206C_REG_INT_EN 0x0b | |
46 | #define HP206C_REG_INT_CFG 0x0c | |
47 | ||
48 | #define HP206C_REG_INT_SRC 0x0d | |
49 | #define HP206C_FLAG_DEV_RDY 0x40 | |
50 | ||
51 | #define HP206C_REG_PARA 0x0f | |
52 | #define HP206C_FLAG_CMPS_EN 0x80 | |
53 | ||
54 | /* Maximum spin for DEV_RDY */ | |
55 | #define HP206C_MAX_DEV_RDY_WAIT_COUNT 20 | |
56 | #define HP206C_DEV_RDY_WAIT_US 20000 | |
57 | ||
58 | struct hp206c_data { | |
59 | struct mutex mutex; | |
60 | struct i2c_client *client; | |
61 | int temp_osr_index; | |
62 | int pres_osr_index; | |
63 | }; | |
64 | ||
65 | struct hp206c_osr_setting { | |
66 | u8 osr_mask; | |
67 | unsigned int temp_conv_time_us; | |
68 | unsigned int pres_conv_time_us; | |
69 | }; | |
70 | ||
71 | /* Data from Table 5 in datasheet. */ | |
72 | static const struct hp206c_osr_setting hp206c_osr_settings[] = { | |
73 | { HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 }, | |
74 | { HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 }, | |
75 | { HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 }, | |
76 | { HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 }, | |
77 | { HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 }, | |
78 | { HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 }, | |
79 | }; | |
80 | static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 }; | |
81 | static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128"; | |
82 | ||
83 | static inline int hp206c_read_reg(struct i2c_client *client, u8 reg) | |
84 | { | |
85 | return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg); | |
86 | } | |
87 | ||
88 | static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val) | |
89 | { | |
90 | return i2c_smbus_write_byte_data(client, | |
91 | HP206C_CMD_WRITE_REG | reg, val); | |
92 | } | |
93 | ||
94 | static int hp206c_read_20bit(struct i2c_client *client, u8 cmd) | |
95 | { | |
96 | int ret; | |
97 | u8 values[3]; | |
98 | ||
99 | ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values); | |
100 | if (ret < 0) | |
101 | return ret; | |
102 | if (ret != 3) | |
103 | return -EIO; | |
104 | return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]); | |
105 | } | |
106 | ||
107 | /* Spin for max 160ms until DEV_RDY is 1, or return error. */ | |
108 | static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev) | |
109 | { | |
110 | int ret; | |
111 | int count = 0; | |
112 | struct hp206c_data *data = iio_priv(indio_dev); | |
113 | struct i2c_client *client = data->client; | |
114 | ||
115 | while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) { | |
116 | ret = hp206c_read_reg(client, HP206C_REG_INT_SRC); | |
117 | if (ret < 0) { | |
118 | dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret); | |
119 | return ret; | |
120 | } | |
121 | if (ret & HP206C_FLAG_DEV_RDY) | |
122 | return 0; | |
123 | usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2); | |
124 | } | |
125 | return -ETIMEDOUT; | |
126 | } | |
127 | ||
128 | static int hp206c_set_compensation(struct i2c_client *client, bool enabled) | |
129 | { | |
130 | int val; | |
131 | ||
132 | val = hp206c_read_reg(client, HP206C_REG_PARA); | |
133 | if (val < 0) | |
134 | return val; | |
135 | if (enabled) | |
136 | val |= HP206C_FLAG_CMPS_EN; | |
137 | else | |
138 | val &= ~HP206C_FLAG_CMPS_EN; | |
139 | ||
140 | return hp206c_write_reg(client, HP206C_REG_PARA, val); | |
141 | } | |
142 | ||
143 | /* Do a soft reset */ | |
144 | static int hp206c_soft_reset(struct iio_dev *indio_dev) | |
145 | { | |
146 | int ret; | |
147 | struct hp206c_data *data = iio_priv(indio_dev); | |
148 | struct i2c_client *client = data->client; | |
149 | ||
150 | ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST); | |
151 | if (ret) { | |
152 | dev_err(&client->dev, "Failed to reset device: %d\n", ret); | |
153 | return ret; | |
154 | } | |
155 | ||
156 | usleep_range(400, 600); | |
157 | ||
158 | ret = hp206c_wait_dev_rdy(indio_dev); | |
159 | if (ret) { | |
160 | dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret); | |
161 | return ret; | |
162 | } | |
163 | ||
164 | ret = hp206c_set_compensation(client, true); | |
165 | if (ret) | |
166 | dev_err(&client->dev, "Failed to enable compensation: %d\n", ret); | |
167 | return ret; | |
168 | } | |
169 | ||
170 | static int hp206c_conv_and_read(struct iio_dev *indio_dev, | |
171 | u8 conv_cmd, u8 read_cmd, | |
172 | unsigned int sleep_us) | |
173 | { | |
174 | int ret; | |
175 | struct hp206c_data *data = iio_priv(indio_dev); | |
176 | struct i2c_client *client = data->client; | |
177 | ||
178 | ret = hp206c_wait_dev_rdy(indio_dev); | |
179 | if (ret < 0) { | |
180 | dev_err(&indio_dev->dev, "Device not ready: %d\n", ret); | |
181 | return ret; | |
182 | } | |
183 | ||
184 | ret = i2c_smbus_write_byte(client, conv_cmd); | |
185 | if (ret < 0) { | |
186 | dev_err(&indio_dev->dev, "Failed convert: %d\n", ret); | |
187 | return ret; | |
188 | } | |
189 | ||
190 | usleep_range(sleep_us, sleep_us * 3 / 2); | |
191 | ||
192 | ret = hp206c_wait_dev_rdy(indio_dev); | |
193 | if (ret < 0) { | |
194 | dev_err(&indio_dev->dev, "Device not ready: %d\n", ret); | |
195 | return ret; | |
196 | } | |
197 | ||
198 | ret = hp206c_read_20bit(client, read_cmd); | |
199 | if (ret < 0) | |
200 | dev_err(&indio_dev->dev, "Failed read: %d\n", ret); | |
201 | ||
202 | return ret; | |
203 | } | |
204 | ||
205 | static int hp206c_read_raw(struct iio_dev *indio_dev, | |
206 | struct iio_chan_spec const *chan, int *val, | |
207 | int *val2, long mask) | |
208 | { | |
209 | int ret; | |
210 | struct hp206c_data *data = iio_priv(indio_dev); | |
211 | const struct hp206c_osr_setting *osr_setting; | |
212 | u8 conv_cmd; | |
213 | ||
214 | mutex_lock(&data->mutex); | |
215 | ||
216 | switch (mask) { | |
217 | case IIO_CHAN_INFO_OVERSAMPLING_RATIO: | |
218 | switch (chan->type) { | |
219 | case IIO_TEMP: | |
220 | *val = hp206c_osr_rates[data->temp_osr_index]; | |
221 | ret = IIO_VAL_INT; | |
222 | break; | |
223 | ||
224 | case IIO_PRESSURE: | |
225 | *val = hp206c_osr_rates[data->pres_osr_index]; | |
226 | ret = IIO_VAL_INT; | |
227 | break; | |
228 | default: | |
229 | ret = -EINVAL; | |
230 | } | |
231 | break; | |
232 | ||
233 | case IIO_CHAN_INFO_RAW: | |
234 | switch (chan->type) { | |
235 | case IIO_TEMP: | |
236 | osr_setting = &hp206c_osr_settings[data->temp_osr_index]; | |
237 | conv_cmd = HP206C_CMD_ADC_CVT | | |
238 | osr_setting->osr_mask | | |
239 | HP206C_CMD_ADC_CVT_CHNL_T; | |
240 | ret = hp206c_conv_and_read(indio_dev, | |
241 | conv_cmd, | |
242 | HP206C_CMD_READ_T, | |
243 | osr_setting->temp_conv_time_us); | |
244 | if (ret >= 0) { | |
245 | /* 20 significant bits are provided. | |
246 | * Extend sign over the rest. | |
247 | */ | |
248 | *val = sign_extend32(ret, 19); | |
249 | ret = IIO_VAL_INT; | |
250 | } | |
251 | break; | |
252 | ||
253 | case IIO_PRESSURE: | |
254 | osr_setting = &hp206c_osr_settings[data->pres_osr_index]; | |
255 | conv_cmd = HP206C_CMD_ADC_CVT | | |
256 | osr_setting->osr_mask | | |
257 | HP206C_CMD_ADC_CVT_CHNL_PT; | |
258 | ret = hp206c_conv_and_read(indio_dev, | |
259 | conv_cmd, | |
260 | HP206C_CMD_READ_P, | |
261 | osr_setting->pres_conv_time_us); | |
262 | if (ret >= 0) { | |
263 | *val = ret; | |
264 | ret = IIO_VAL_INT; | |
265 | } | |
266 | break; | |
267 | default: | |
268 | ret = -EINVAL; | |
269 | } | |
270 | break; | |
271 | ||
272 | case IIO_CHAN_INFO_SCALE: | |
273 | switch (chan->type) { | |
274 | case IIO_TEMP: | |
275 | *val = 0; | |
276 | *val2 = 10000; | |
277 | ret = IIO_VAL_INT_PLUS_MICRO; | |
278 | break; | |
279 | ||
280 | case IIO_PRESSURE: | |
281 | *val = 0; | |
282 | *val2 = 1000; | |
283 | ret = IIO_VAL_INT_PLUS_MICRO; | |
284 | break; | |
285 | default: | |
286 | ret = -EINVAL; | |
287 | } | |
288 | break; | |
289 | ||
290 | default: | |
291 | ret = -EINVAL; | |
292 | } | |
293 | ||
294 | mutex_unlock(&data->mutex); | |
295 | return ret; | |
296 | } | |
297 | ||
298 | static int hp206c_write_raw(struct iio_dev *indio_dev, | |
299 | struct iio_chan_spec const *chan, | |
300 | int val, int val2, long mask) | |
301 | { | |
302 | int ret = 0; | |
303 | struct hp206c_data *data = iio_priv(indio_dev); | |
304 | ||
305 | if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) | |
306 | return -EINVAL; | |
307 | mutex_lock(&data->mutex); | |
308 | switch (chan->type) { | |
309 | case IIO_TEMP: | |
310 | data->temp_osr_index = find_closest_descending(val, | |
311 | hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates)); | |
312 | break; | |
313 | case IIO_PRESSURE: | |
314 | data->pres_osr_index = find_closest_descending(val, | |
315 | hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates)); | |
316 | break; | |
317 | default: | |
318 | ret = -EINVAL; | |
319 | } | |
320 | mutex_unlock(&data->mutex); | |
321 | return ret; | |
322 | } | |
323 | ||
324 | static const struct iio_chan_spec hp206c_channels[] = { | |
325 | { | |
326 | .type = IIO_TEMP, | |
327 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | | |
328 | BIT(IIO_CHAN_INFO_SCALE) | | |
329 | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), | |
330 | }, | |
331 | { | |
332 | .type = IIO_PRESSURE, | |
333 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | | |
334 | BIT(IIO_CHAN_INFO_SCALE) | | |
335 | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), | |
336 | } | |
337 | }; | |
338 | ||
339 | static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str); | |
340 | ||
341 | static struct attribute *hp206c_attributes[] = { | |
342 | &iio_const_attr_sampling_frequency_available.dev_attr.attr, | |
343 | NULL, | |
344 | }; | |
345 | ||
346 | static const struct attribute_group hp206c_attribute_group = { | |
347 | .attrs = hp206c_attributes, | |
348 | }; | |
349 | ||
350 | static const struct iio_info hp206c_info = { | |
351 | .attrs = &hp206c_attribute_group, | |
352 | .read_raw = hp206c_read_raw, | |
353 | .write_raw = hp206c_write_raw, | |
354 | .driver_module = THIS_MODULE, | |
355 | }; | |
356 | ||
357 | static int hp206c_probe(struct i2c_client *client, | |
358 | const struct i2c_device_id *id) | |
359 | { | |
360 | struct iio_dev *indio_dev; | |
361 | struct hp206c_data *data; | |
362 | int ret; | |
363 | ||
364 | if (!i2c_check_functionality(client->adapter, | |
365 | I2C_FUNC_SMBUS_BYTE | | |
366 | I2C_FUNC_SMBUS_BYTE_DATA | | |
367 | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | |
368 | dev_err(&client->dev, "Adapter does not support " | |
369 | "all required i2c functionality\n"); | |
370 | return -ENODEV; | |
371 | } | |
372 | ||
373 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | |
374 | if (!indio_dev) | |
375 | return -ENOMEM; | |
376 | ||
377 | data = iio_priv(indio_dev); | |
378 | data->client = client; | |
379 | mutex_init(&data->mutex); | |
380 | ||
381 | indio_dev->info = &hp206c_info; | |
382 | indio_dev->name = id->name; | |
383 | indio_dev->dev.parent = &client->dev; | |
384 | indio_dev->modes = INDIO_DIRECT_MODE; | |
385 | indio_dev->channels = hp206c_channels; | |
386 | indio_dev->num_channels = ARRAY_SIZE(hp206c_channels); | |
387 | ||
388 | i2c_set_clientdata(client, indio_dev); | |
389 | ||
390 | /* Do a soft reset on probe */ | |
391 | ret = hp206c_soft_reset(indio_dev); | |
392 | if (ret) { | |
393 | dev_err(&client->dev, "Failed to reset on startup: %d\n", ret); | |
394 | return -ENODEV; | |
395 | } | |
396 | ||
397 | return devm_iio_device_register(&client->dev, indio_dev); | |
398 | } | |
399 | ||
400 | static const struct i2c_device_id hp206c_id[] = { | |
401 | {"hp206c"}, | |
402 | {} | |
403 | }; | |
cdd469ad | 404 | MODULE_DEVICE_TABLE(i2c, hp206c_id); |
fa4c9c93 CDL |
405 | |
406 | #ifdef CONFIG_ACPI | |
407 | static const struct acpi_device_id hp206c_acpi_match[] = { | |
408 | {"HOP206C", 0}, | |
409 | { }, | |
410 | }; | |
411 | MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match); | |
412 | #endif | |
413 | ||
414 | static struct i2c_driver hp206c_driver = { | |
415 | .probe = hp206c_probe, | |
416 | .id_table = hp206c_id, | |
417 | .driver = { | |
418 | .name = "hp206c", | |
419 | .acpi_match_table = ACPI_PTR(hp206c_acpi_match), | |
420 | }, | |
421 | }; | |
422 | ||
423 | module_i2c_driver(hp206c_driver); | |
424 | ||
425 | MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor"); | |
426 | MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>"); | |
427 | MODULE_LICENSE("GPL v2"); |