summaryrefslogtreecommitdiff
path: root/drivers/iio/proximity/rfd77402.c
blob: fe29fb1a19a6453aa497376c8db15a874b9a14b3 (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
/*
 * rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor
 *
 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 *
 * 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 0x4c
 *
 * TODO: interrupt
 * https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD77402.pdf
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>

#include <linux/iio/iio.h>

#define RFD77402_DRV_NAME "rfd77402"

#define RFD77402_ICSR		0x00 /* Interrupt Control Status Register */
#define RFD77402_ICSR_INT_MODE	BIT(2)
#define RFD77402_ICSR_INT_POL	BIT(3)
#define RFD77402_ICSR_RESULT	BIT(4)
#define RFD77402_ICSR_M2H_MSG	BIT(5)
#define RFD77402_ICSR_H2M_MSG	BIT(6)
#define RFD77402_ICSR_RESET	BIT(7)

#define RFD77402_CMD_R		0x04
#define RFD77402_CMD_SINGLE	0x01
#define RFD77402_CMD_STANDBY	0x10
#define RFD77402_CMD_MCPU_OFF	0x11
#define RFD77402_CMD_MCPU_ON	0x12
#define RFD77402_CMD_RESET	BIT(6)
#define RFD77402_CMD_VALID	BIT(7)

#define RFD77402_STATUS_R	0x06
#define RFD77402_STATUS_PM_MASK	GENMASK(4, 0)
#define RFD77402_STATUS_STANDBY	0x00
#define RFD77402_STATUS_MCPU_OFF	0x10
#define RFD77402_STATUS_MCPU_ON	0x18

#define RFD77402_RESULT_R	0x08
#define RFD77402_RESULT_DIST_MASK	GENMASK(12, 2)
#define RFD77402_RESULT_ERR_MASK	GENMASK(14, 13)
#define RFD77402_RESULT_VALID	BIT(15)

#define RFD77402_PMU_CFG	0x14
#define RFD77402_PMU_MCPU_INIT	BIT(9)

#define RFD77402_I2C_INIT_CFG	0x1c
#define RFD77402_I2C_ADDR_INCR	BIT(0)
#define RFD77402_I2C_DATA_INCR	BIT(2)
#define RFD77402_I2C_HOST_DEBUG	BIT(5)
#define RFD77402_I2C_MCPU_DEBUG	BIT(6)

#define RFD77402_CMD_CFGR_A	0x0c
#define RFD77402_CMD_CFGR_B	0x0e
#define RFD77402_HFCFG_0	0x20
#define RFD77402_HFCFG_1	0x22
#define RFD77402_HFCFG_2	0x24
#define RFD77402_HFCFG_3	0x26

#define RFD77402_MOD_CHIP_ID	0x28

/* magic configuration values from datasheet */
static const struct {
	u8 reg;
	u16 val;
} rf77402_tof_config[] = {
	{RFD77402_CMD_CFGR_A,	0xe100},
	{RFD77402_CMD_CFGR_B,	0x10ff},
	{RFD77402_HFCFG_0,	0x07d0},
	{RFD77402_HFCFG_1,	0x5008},
	{RFD77402_HFCFG_2,	0xa041},
	{RFD77402_HFCFG_3,	0x45d4},
};

struct rfd77402_data {
	struct i2c_client *client;
	/* Serialize reads from the sensor */
	struct mutex lock;
};

static const struct iio_chan_spec rfd77402_channels[] = {
	{
		.type = IIO_DISTANCE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
	},
};

static int rfd77402_set_state(struct rfd77402_data *data, u8 state, u16 check)
{
	int ret;

	ret = i2c_smbus_write_byte_data(data->client, RFD77402_CMD_R,
					state | RFD77402_CMD_VALID);
	if (ret < 0)
		return ret;

	usleep_range(10000, 20000);

	ret = i2c_smbus_read_word_data(data->client, RFD77402_STATUS_R);
	if (ret < 0)
		return ret;
	if ((ret & RFD77402_STATUS_PM_MASK) != check)
		return -ENODEV;

	return 0;
}

static int rfd77402_measure(struct rfd77402_data *data)
{
	int ret;
	int tries = 10;

	ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
				 RFD77402_STATUS_MCPU_ON);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_write_byte_data(data->client, RFD77402_CMD_R,
					RFD77402_CMD_SINGLE |
					RFD77402_CMD_VALID);
	if (ret < 0)
		goto err;

	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, RFD77402_ICSR);
		if (ret < 0)
			goto err;
		if (ret & RFD77402_ICSR_RESULT)
			break;
		msleep(20);
	}

	if (tries < 0) {
		ret = -ETIMEDOUT;
		goto err;
	}

	ret = i2c_smbus_read_word_data(data->client, RFD77402_RESULT_R);
	if (ret < 0)
		goto err;

	if ((ret & RFD77402_RESULT_ERR_MASK) ||
	    !(ret & RFD77402_RESULT_VALID)) {
		ret = -EIO;
		goto err;
	}

	return (ret & RFD77402_RESULT_DIST_MASK) >> 2;

err:
	rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
			   RFD77402_STATUS_MCPU_OFF);
	return ret;
}

static int rfd77402_read_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct rfd77402_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&data->lock);
		ret = rfd77402_measure(data);
		mutex_unlock(&data->lock);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		/* 1 LSB is 1 mm */
		*val = 0;
		*val2 = 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static const struct iio_info rfd77402_info = {
	.read_raw = rfd77402_read_raw,
};

static int rfd77402_init(struct rfd77402_data *data)
{
	int ret, i;

	ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
				 RFD77402_STATUS_STANDBY);
	if (ret < 0)
		return ret;

	/* configure INT pad as push-pull, active low */
	ret = i2c_smbus_write_byte_data(data->client, RFD77402_ICSR,
					RFD77402_ICSR_INT_MODE);
	if (ret < 0)
		return ret;

	/* I2C configuration */
	ret = i2c_smbus_write_word_data(data->client, RFD77402_I2C_INIT_CFG,
					RFD77402_I2C_ADDR_INCR |
					RFD77402_I2C_DATA_INCR |
					RFD77402_I2C_HOST_DEBUG	|
					RFD77402_I2C_MCPU_DEBUG);
	if (ret < 0)
		return ret;

	/* set initialization */
	ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0500);
	if (ret < 0)
		return ret;

	ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
				 RFD77402_STATUS_MCPU_OFF);
	if (ret < 0)
		return ret;

	/* set initialization */
	ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0600);
	if (ret < 0)
		return ret;

	ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
				 RFD77402_STATUS_MCPU_ON);
	if (ret < 0)
		return ret;

	for (i = 0; i < ARRAY_SIZE(rf77402_tof_config); i++) {
		ret = i2c_smbus_write_word_data(data->client,
						rf77402_tof_config[i].reg,
						rf77402_tof_config[i].val);
		if (ret < 0)
			return ret;
	}

	ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
				 RFD77402_STATUS_STANDBY);

	return ret;
}

static int rfd77402_powerdown(struct rfd77402_data *data)
{
	return rfd77402_set_state(data, RFD77402_CMD_STANDBY,
				  RFD77402_STATUS_STANDBY);
}

static int rfd77402_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct rfd77402_data *data;
	struct iio_dev *indio_dev;
	int ret;

	ret = i2c_smbus_read_word_data(client, RFD77402_MOD_CHIP_ID);
	if (ret < 0)
		return ret;
	if (ret != 0xad01 && ret != 0xad02) /* known chip ids */
		return -ENODEV;

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

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;
	mutex_init(&data->lock);

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &rfd77402_info;
	indio_dev->channels = rfd77402_channels;
	indio_dev->num_channels = ARRAY_SIZE(rfd77402_channels);
	indio_dev->name = RFD77402_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = rfd77402_init(data);
	if (ret < 0)
		return ret;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto err_powerdown;

	return 0;

err_powerdown:
	rfd77402_powerdown(data);
	return ret;
}

static int rfd77402_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);
	rfd77402_powerdown(iio_priv(indio_dev));

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int rfd77402_suspend(struct device *dev)
{
	struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
				     to_i2c_client(dev)));

	return rfd77402_powerdown(data);
}

static int rfd77402_resume(struct device *dev)
{
	struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
				     to_i2c_client(dev)));

	return rfd77402_init(data);
}
#endif

static SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, rfd77402_resume);

static const struct i2c_device_id rfd77402_id[] = {
	{ "rfd77402", 0},
	{ }
};
MODULE_DEVICE_TABLE(i2c, rfd77402_id);

static struct i2c_driver rfd77402_driver = {
	.driver = {
		.name   = RFD77402_DRV_NAME,
		.pm     = &rfd77402_pm_ops,
	},
	.probe  = rfd77402_probe,
	.remove = rfd77402_remove,
	.id_table = rfd77402_id,
};

module_i2c_driver(rfd77402_driver);

MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("RFD77402 Time-of-Flight sensor driver");
MODULE_LICENSE("GPL");