summaryrefslogtreecommitdiff
path: root/drivers/iio/pressure/hp206c.c
blob: 12f769e863555c73b7fe8f200e7f8493b09cdfea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
/*
 * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor
 *
 * Copyright (c) 2016, Intel Corporation.
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * (7-bit I2C slave address 0x76)
 *
 * Datasheet:
 *  http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/delay.h>
#include <linux/util_macros.h>
#include <linux/acpi.h>

/* I2C commands: */
#define HP206C_CMD_SOFT_RST	0x06

#define HP206C_CMD_ADC_CVT	0x40

#define HP206C_CMD_ADC_CVT_OSR_4096	0x00
#define HP206C_CMD_ADC_CVT_OSR_2048	0x04
#define HP206C_CMD_ADC_CVT_OSR_1024	0x08
#define HP206C_CMD_ADC_CVT_OSR_512	0x0c
#define HP206C_CMD_ADC_CVT_OSR_256	0x10
#define HP206C_CMD_ADC_CVT_OSR_128	0x14

#define HP206C_CMD_ADC_CVT_CHNL_PT	0x00
#define HP206C_CMD_ADC_CVT_CHNL_T	0x02

#define HP206C_CMD_READ_P	0x30
#define HP206C_CMD_READ_T	0x32

#define HP206C_CMD_READ_REG	0x80
#define HP206C_CMD_WRITE_REG	0xc0

#define HP206C_REG_INT_EN	0x0b
#define HP206C_REG_INT_CFG	0x0c

#define HP206C_REG_INT_SRC	0x0d
#define HP206C_FLAG_DEV_RDY	0x40

#define HP206C_REG_PARA		0x0f
#define HP206C_FLAG_CMPS_EN	0x80

/* Maximum spin for DEV_RDY */
#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20
#define HP206C_DEV_RDY_WAIT_US    20000

struct hp206c_data {
	struct mutex mutex;
	struct i2c_client *client;
	int temp_osr_index;
	int pres_osr_index;
};

struct hp206c_osr_setting {
	u8 osr_mask;
	unsigned int temp_conv_time_us;
	unsigned int pres_conv_time_us;
};

/* Data from Table 5 in datasheet. */
static const struct hp206c_osr_setting hp206c_osr_settings[] = {
	{ HP206C_CMD_ADC_CVT_OSR_4096,	65600,	131100	},
	{ HP206C_CMD_ADC_CVT_OSR_2048,	32800,	65600	},
	{ HP206C_CMD_ADC_CVT_OSR_1024,	16400,	32800	},
	{ HP206C_CMD_ADC_CVT_OSR_512,	8200,	16400	},
	{ HP206C_CMD_ADC_CVT_OSR_256,	4100,	8200	},
	{ HP206C_CMD_ADC_CVT_OSR_128,	2100,	4100	},
};
static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };
static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";

static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)
{
	return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);
}

static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
	return i2c_smbus_write_byte_data(client,
			HP206C_CMD_WRITE_REG | reg, val);
}

static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)
{
	int ret;
	u8 values[3];

	ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values);
	if (ret < 0)
		return ret;
	if (ret != 3)
		return -EIO;
	return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]);
}

/* Spin for max 160ms until DEV_RDY is 1, or return error. */
static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)
{
	int ret;
	int count = 0;
	struct hp206c_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;

	while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {
		ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);
		if (ret < 0) {
			dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);
			return ret;
		}
		if (ret & HP206C_FLAG_DEV_RDY)
			return 0;
		usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);
	}
	return -ETIMEDOUT;
}

static int hp206c_set_compensation(struct i2c_client *client, bool enabled)
{
	int val;

	val = hp206c_read_reg(client, HP206C_REG_PARA);
	if (val < 0)
		return val;
	if (enabled)
		val |= HP206C_FLAG_CMPS_EN;
	else
		val &= ~HP206C_FLAG_CMPS_EN;

	return hp206c_write_reg(client, HP206C_REG_PARA, val);
}

/* Do a soft reset */
static int hp206c_soft_reset(struct iio_dev *indio_dev)
{
	int ret;
	struct hp206c_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;

	ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);
	if (ret) {
		dev_err(&client->dev, "Failed to reset device: %d\n", ret);
		return ret;
	}

	usleep_range(400, 600);

	ret = hp206c_wait_dev_rdy(indio_dev);
	if (ret) {
		dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);
		return ret;
	}

	ret = hp206c_set_compensation(client, true);
	if (ret)
		dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);
	return ret;
}

static int hp206c_conv_and_read(struct iio_dev *indio_dev,
				u8 conv_cmd, u8 read_cmd,
				unsigned int sleep_us)
{
	int ret;
	struct hp206c_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;

	ret = hp206c_wait_dev_rdy(indio_dev);
	if (ret < 0) {
		dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
		return ret;
	}

	ret = i2c_smbus_write_byte(client, conv_cmd);
	if (ret < 0) {
		dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);
		return ret;
	}

	usleep_range(sleep_us, sleep_us * 3 / 2);

	ret = hp206c_wait_dev_rdy(indio_dev);
	if (ret < 0) {
		dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
		return ret;
	}

	ret = hp206c_read_20bit(client, read_cmd);
	if (ret < 0)
		dev_err(&indio_dev->dev, "Failed read: %d\n", ret);

	return ret;
}

static int hp206c_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan, int *val,
			   int *val2, long mask)
{
	int ret;
	struct hp206c_data *data = iio_priv(indio_dev);
	const struct hp206c_osr_setting *osr_setting;
	u8 conv_cmd;

	mutex_lock(&data->mutex);

	switch (mask) {
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		switch (chan->type) {
		case IIO_TEMP:
			*val = hp206c_osr_rates[data->temp_osr_index];
			ret = IIO_VAL_INT;
			break;

		case IIO_PRESSURE:
			*val = hp206c_osr_rates[data->pres_osr_index];
			ret = IIO_VAL_INT;
			break;
		default:
			ret = -EINVAL;
		}
		break;

	case IIO_CHAN_INFO_RAW:
		switch (chan->type) {
		case IIO_TEMP:
			osr_setting = &hp206c_osr_settings[data->temp_osr_index];
			conv_cmd = HP206C_CMD_ADC_CVT |
					osr_setting->osr_mask |
					HP206C_CMD_ADC_CVT_CHNL_T;
			ret = hp206c_conv_and_read(indio_dev,
					conv_cmd,
					HP206C_CMD_READ_T,
					osr_setting->temp_conv_time_us);
			if (ret >= 0) {
				/* 20 significant bits are provided.
				 * Extend sign over the rest.
				 */
				*val = sign_extend32(ret, 19);
				ret = IIO_VAL_INT;
			}
			break;

		case IIO_PRESSURE:
			osr_setting = &hp206c_osr_settings[data->pres_osr_index];
			conv_cmd = HP206C_CMD_ADC_CVT |
					osr_setting->osr_mask |
					HP206C_CMD_ADC_CVT_CHNL_PT;
			ret = hp206c_conv_and_read(indio_dev,
					conv_cmd,
					HP206C_CMD_READ_P,
					osr_setting->pres_conv_time_us);
			if (ret >= 0) {
				*val = ret;
				ret = IIO_VAL_INT;
			}
			break;
		default:
			ret = -EINVAL;
		}
		break;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_TEMP:
			*val = 0;
			*val2 = 10000;
			ret = IIO_VAL_INT_PLUS_MICRO;
			break;

		case IIO_PRESSURE:
			*val = 0;
			*val2 = 1000;
			ret = IIO_VAL_INT_PLUS_MICRO;
			break;
		default:
			ret = -EINVAL;
		}
		break;

	default:
		ret = -EINVAL;
	}

	mutex_unlock(&data->mutex);
	return ret;
}

static int hp206c_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val, int val2, long mask)
{
	int ret = 0;
	struct hp206c_data *data = iio_priv(indio_dev);

	if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
		return -EINVAL;
	mutex_lock(&data->mutex);
	switch (chan->type) {
	case IIO_TEMP:
		data->temp_osr_index = find_closest_descending(val,
			hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
		break;
	case IIO_PRESSURE:
		data->pres_osr_index = find_closest_descending(val,
			hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
		break;
	default:
		ret = -EINVAL;
	}
	mutex_unlock(&data->mutex);
	return ret;
}

static const struct iio_chan_spec hp206c_channels[] = {
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE) |
				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
	},
	{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE) |
				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
	}
};

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);

static struct attribute *hp206c_attributes[] = {
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group hp206c_attribute_group = {
	.attrs = hp206c_attributes,
};

static const struct iio_info hp206c_info = {
	.attrs = &hp206c_attribute_group,
	.read_raw = hp206c_read_raw,
	.write_raw = hp206c_write_raw,
	.driver_module = THIS_MODULE,
};

static int hp206c_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct iio_dev *indio_dev;
	struct hp206c_data *data;
	int ret;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_BYTE |
				     I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
		dev_err(&client->dev, "Adapter does not support "
				"all required i2c functionality\n");
		return -ENODEV;
	}

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);
	data->client = client;
	mutex_init(&data->mutex);

	indio_dev->info = &hp206c_info;
	indio_dev->name = id->name;
	indio_dev->dev.parent = &client->dev;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = hp206c_channels;
	indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);

	i2c_set_clientdata(client, indio_dev);

	/* Do a soft reset on probe */
	ret = hp206c_soft_reset(indio_dev);
	if (ret) {
		dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);
		return -ENODEV;
	}

	return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct i2c_device_id hp206c_id[] = {
	{"hp206c"},
	{}
};
MODULE_DEVICE_TABLE(i2c, hp206c_id);

#ifdef CONFIG_ACPI
static const struct acpi_device_id hp206c_acpi_match[] = {
	{"HOP206C", 0},
	{ },
};
MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);
#endif

static struct i2c_driver hp206c_driver = {
	.probe = hp206c_probe,
	.id_table = hp206c_id,
	.driver = {
		.name = "hp206c",
		.acpi_match_table = ACPI_PTR(hp206c_acpi_match),
	},
};

module_i2c_driver(hp206c_driver);

MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");
MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");
MODULE_LICENSE("GPL v2");