1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor
4 *
5 * Copyright (c) 2016, Intel Corporation.
6 *
7 * (7-bit I2C slave address 0x76)
8 *
9 * Datasheet:
10 * http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf
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/delay.h>
18 #include <linux/util_macros.h>
19 #include <linux/acpi.h>
20
21 #include <asm/unaligned.h>
22
23 /* I2C commands: */
24 #define HP206C_CMD_SOFT_RST 0x06
25
26 #define HP206C_CMD_ADC_CVT 0x40
27
28 #define HP206C_CMD_ADC_CVT_OSR_4096 0x00
29 #define HP206C_CMD_ADC_CVT_OSR_2048 0x04
30 #define HP206C_CMD_ADC_CVT_OSR_1024 0x08
31 #define HP206C_CMD_ADC_CVT_OSR_512 0x0c
32 #define HP206C_CMD_ADC_CVT_OSR_256 0x10
33 #define HP206C_CMD_ADC_CVT_OSR_128 0x14
34
35 #define HP206C_CMD_ADC_CVT_CHNL_PT 0x00
36 #define HP206C_CMD_ADC_CVT_CHNL_T 0x02
37
38 #define HP206C_CMD_READ_P 0x30
39 #define HP206C_CMD_READ_T 0x32
40
41 #define HP206C_CMD_READ_REG 0x80
42 #define HP206C_CMD_WRITE_REG 0xc0
43
44 #define HP206C_REG_INT_EN 0x0b
45 #define HP206C_REG_INT_CFG 0x0c
46
47 #define HP206C_REG_INT_SRC 0x0d
48 #define HP206C_FLAG_DEV_RDY 0x40
49
50 #define HP206C_REG_PARA 0x0f
51 #define HP206C_FLAG_CMPS_EN 0x80
52
53 /* Maximum spin for DEV_RDY */
54 #define HP206C_MAX_DEV_RDY_WAIT_COUNT 20
55 #define HP206C_DEV_RDY_WAIT_US 20000
56
57 struct hp206c_data {
58 struct mutex mutex;
59 struct i2c_client *client;
60 int temp_osr_index;
61 int pres_osr_index;
62 };
63
64 struct hp206c_osr_setting {
65 u8 osr_mask;
66 unsigned int temp_conv_time_us;
67 unsigned int pres_conv_time_us;
68 };
69
70 /* Data from Table 5 in datasheet. */
71 static const struct hp206c_osr_setting hp206c_osr_settings[] = {
72 { HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 },
73 { HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 },
74 { HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 },
75 { HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 },
76 { HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 },
77 { HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 },
78 };
79 static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };
80 static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";
81
hp206c_read_reg(struct i2c_client * client,u8 reg)82 static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)
83 {
84 return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);
85 }
86
hp206c_write_reg(struct i2c_client * client,u8 reg,u8 val)87 static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)
88 {
89 return i2c_smbus_write_byte_data(client,
90 HP206C_CMD_WRITE_REG | reg, val);
91 }
92
hp206c_read_20bit(struct i2c_client * client,u8 cmd)93 static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)
94 {
95 int ret;
96 u8 values[3];
97
98 ret = i2c_smbus_read_i2c_block_data(client, cmd, sizeof(values), values);
99 if (ret < 0)
100 return ret;
101 if (ret != sizeof(values))
102 return -EIO;
103 return get_unaligned_be24(&values[0]) & GENMASK(19, 0);
104 }
105
106 /* Spin for max 160ms until DEV_RDY is 1, or return error. */
hp206c_wait_dev_rdy(struct iio_dev * indio_dev)107 static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)
108 {
109 int ret;
110 int count = 0;
111 struct hp206c_data *data = iio_priv(indio_dev);
112 struct i2c_client *client = data->client;
113
114 while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {
115 ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);
116 if (ret < 0) {
117 dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);
118 return ret;
119 }
120 if (ret & HP206C_FLAG_DEV_RDY)
121 return 0;
122 usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);
123 }
124 return -ETIMEDOUT;
125 }
126
hp206c_set_compensation(struct i2c_client * client,bool enabled)127 static int hp206c_set_compensation(struct i2c_client *client, bool enabled)
128 {
129 int val;
130
131 val = hp206c_read_reg(client, HP206C_REG_PARA);
132 if (val < 0)
133 return val;
134 if (enabled)
135 val |= HP206C_FLAG_CMPS_EN;
136 else
137 val &= ~HP206C_FLAG_CMPS_EN;
138
139 return hp206c_write_reg(client, HP206C_REG_PARA, val);
140 }
141
142 /* Do a soft reset */
hp206c_soft_reset(struct iio_dev * indio_dev)143 static int hp206c_soft_reset(struct iio_dev *indio_dev)
144 {
145 int ret;
146 struct hp206c_data *data = iio_priv(indio_dev);
147 struct i2c_client *client = data->client;
148
149 ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);
150 if (ret) {
151 dev_err(&client->dev, "Failed to reset device: %d\n", ret);
152 return ret;
153 }
154
155 usleep_range(400, 600);
156
157 ret = hp206c_wait_dev_rdy(indio_dev);
158 if (ret) {
159 dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);
160 return ret;
161 }
162
163 ret = hp206c_set_compensation(client, true);
164 if (ret)
165 dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);
166 return ret;
167 }
168
hp206c_conv_and_read(struct iio_dev * indio_dev,u8 conv_cmd,u8 read_cmd,unsigned int sleep_us)169 static int hp206c_conv_and_read(struct iio_dev *indio_dev,
170 u8 conv_cmd, u8 read_cmd,
171 unsigned int sleep_us)
172 {
173 int ret;
174 struct hp206c_data *data = iio_priv(indio_dev);
175 struct i2c_client *client = data->client;
176
177 ret = hp206c_wait_dev_rdy(indio_dev);
178 if (ret < 0) {
179 dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
180 return ret;
181 }
182
183 ret = i2c_smbus_write_byte(client, conv_cmd);
184 if (ret < 0) {
185 dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);
186 return ret;
187 }
188
189 usleep_range(sleep_us, sleep_us * 3 / 2);
190
191 ret = hp206c_wait_dev_rdy(indio_dev);
192 if (ret < 0) {
193 dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
194 return ret;
195 }
196
197 ret = hp206c_read_20bit(client, read_cmd);
198 if (ret < 0)
199 dev_err(&indio_dev->dev, "Failed read: %d\n", ret);
200
201 return ret;
202 }
203
hp206c_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)204 static int hp206c_read_raw(struct iio_dev *indio_dev,
205 struct iio_chan_spec const *chan, int *val,
206 int *val2, long mask)
207 {
208 int ret;
209 struct hp206c_data *data = iio_priv(indio_dev);
210 const struct hp206c_osr_setting *osr_setting;
211 u8 conv_cmd;
212
213 mutex_lock(&data->mutex);
214
215 switch (mask) {
216 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
217 switch (chan->type) {
218 case IIO_TEMP:
219 *val = hp206c_osr_rates[data->temp_osr_index];
220 ret = IIO_VAL_INT;
221 break;
222
223 case IIO_PRESSURE:
224 *val = hp206c_osr_rates[data->pres_osr_index];
225 ret = IIO_VAL_INT;
226 break;
227 default:
228 ret = -EINVAL;
229 }
230 break;
231
232 case IIO_CHAN_INFO_RAW:
233 switch (chan->type) {
234 case IIO_TEMP:
235 osr_setting = &hp206c_osr_settings[data->temp_osr_index];
236 conv_cmd = HP206C_CMD_ADC_CVT |
237 osr_setting->osr_mask |
238 HP206C_CMD_ADC_CVT_CHNL_T;
239 ret = hp206c_conv_and_read(indio_dev,
240 conv_cmd,
241 HP206C_CMD_READ_T,
242 osr_setting->temp_conv_time_us);
243 if (ret >= 0) {
244 /* 20 significant bits are provided.
245 * Extend sign over the rest.
246 */
247 *val = sign_extend32(ret, 19);
248 ret = IIO_VAL_INT;
249 }
250 break;
251
252 case IIO_PRESSURE:
253 osr_setting = &hp206c_osr_settings[data->pres_osr_index];
254 conv_cmd = HP206C_CMD_ADC_CVT |
255 osr_setting->osr_mask |
256 HP206C_CMD_ADC_CVT_CHNL_PT;
257 ret = hp206c_conv_and_read(indio_dev,
258 conv_cmd,
259 HP206C_CMD_READ_P,
260 osr_setting->pres_conv_time_us);
261 if (ret >= 0) {
262 *val = ret;
263 ret = IIO_VAL_INT;
264 }
265 break;
266 default:
267 ret = -EINVAL;
268 }
269 break;
270
271 case IIO_CHAN_INFO_SCALE:
272 switch (chan->type) {
273 case IIO_TEMP:
274 *val = 0;
275 *val2 = 10000;
276 ret = IIO_VAL_INT_PLUS_MICRO;
277 break;
278
279 case IIO_PRESSURE:
280 *val = 0;
281 *val2 = 1000;
282 ret = IIO_VAL_INT_PLUS_MICRO;
283 break;
284 default:
285 ret = -EINVAL;
286 }
287 break;
288
289 default:
290 ret = -EINVAL;
291 }
292
293 mutex_unlock(&data->mutex);
294 return ret;
295 }
296
hp206c_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)297 static int hp206c_write_raw(struct iio_dev *indio_dev,
298 struct iio_chan_spec const *chan,
299 int val, int val2, long mask)
300 {
301 int ret = 0;
302 struct hp206c_data *data = iio_priv(indio_dev);
303
304 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
305 return -EINVAL;
306 mutex_lock(&data->mutex);
307 switch (chan->type) {
308 case IIO_TEMP:
309 data->temp_osr_index = find_closest_descending(val,
310 hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
311 break;
312 case IIO_PRESSURE:
313 data->pres_osr_index = find_closest_descending(val,
314 hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
315 break;
316 default:
317 ret = -EINVAL;
318 }
319 mutex_unlock(&data->mutex);
320 return ret;
321 }
322
323 static const struct iio_chan_spec hp206c_channels[] = {
324 {
325 .type = IIO_TEMP,
326 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
327 BIT(IIO_CHAN_INFO_SCALE) |
328 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
329 },
330 {
331 .type = IIO_PRESSURE,
332 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
333 BIT(IIO_CHAN_INFO_SCALE) |
334 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
335 }
336 };
337
338 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);
339
340 static struct attribute *hp206c_attributes[] = {
341 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
342 NULL,
343 };
344
345 static const struct attribute_group hp206c_attribute_group = {
346 .attrs = hp206c_attributes,
347 };
348
349 static const struct iio_info hp206c_info = {
350 .attrs = &hp206c_attribute_group,
351 .read_raw = hp206c_read_raw,
352 .write_raw = hp206c_write_raw,
353 };
354
hp206c_probe(struct i2c_client * client)355 static int hp206c_probe(struct i2c_client *client)
356 {
357 const struct i2c_device_id *id = i2c_client_get_device_id(client);
358 struct iio_dev *indio_dev;
359 struct hp206c_data *data;
360 int ret;
361
362 if (!i2c_check_functionality(client->adapter,
363 I2C_FUNC_SMBUS_BYTE |
364 I2C_FUNC_SMBUS_BYTE_DATA |
365 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
366 dev_err(&client->dev, "Adapter does not support "
367 "all required i2c functionality\n");
368 return -ENODEV;
369 }
370
371 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
372 if (!indio_dev)
373 return -ENOMEM;
374
375 data = iio_priv(indio_dev);
376 data->client = client;
377 mutex_init(&data->mutex);
378
379 indio_dev->info = &hp206c_info;
380 indio_dev->name = id->name;
381 indio_dev->modes = INDIO_DIRECT_MODE;
382 indio_dev->channels = hp206c_channels;
383 indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);
384
385 i2c_set_clientdata(client, indio_dev);
386
387 /* Do a soft reset on probe */
388 ret = hp206c_soft_reset(indio_dev);
389 if (ret) {
390 dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);
391 return -ENODEV;
392 }
393
394 return devm_iio_device_register(&client->dev, indio_dev);
395 }
396
397 static const struct i2c_device_id hp206c_id[] = {
398 {"hp206c"},
399 {}
400 };
401 MODULE_DEVICE_TABLE(i2c, hp206c_id);
402
403 #ifdef CONFIG_ACPI
404 static const struct acpi_device_id hp206c_acpi_match[] = {
405 {"HOP206C", 0},
406 { },
407 };
408 MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);
409 #endif
410
411 static struct i2c_driver hp206c_driver = {
412 .probe = hp206c_probe,
413 .id_table = hp206c_id,
414 .driver = {
415 .name = "hp206c",
416 .acpi_match_table = ACPI_PTR(hp206c_acpi_match),
417 },
418 };
419
420 module_i2c_driver(hp206c_driver);
421
422 MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");
423 MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");
424 MODULE_LICENSE("GPL v2");
425