xref: /openbmc/linux/drivers/iio/light/vcnl4000.c (revision 5b394b2d)
1 /*
2  * vcnl4000.c - Support for Vishay VCNL4000/4010/4020/4200 combined ambient
3  * light and proximity sensor
4  *
5  * Copyright 2012 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * This file is subject to the terms and conditions of version 2 of
8  * the GNU General Public License.  See the file COPYING in the main
9  * directory of this archive for more details.
10  *
11  * IIO driver for:
12  *   VCNL4000/10/20 (7-bit I2C slave address 0x13)
13  *   VCNL4200 (7-bit I2C slave address 0x51)
14  *
15  * TODO:
16  *   allow to adjust IR current
17  *   proximity threshold and event handling
18  *   periodic ALS/proximity measurement (VCNL4010/20)
19  *   interrupts (VCNL4010/20, VCNL4200)
20  */
21 
22 #include <linux/module.h>
23 #include <linux/i2c.h>
24 #include <linux/err.h>
25 #include <linux/delay.h>
26 
27 #include <linux/iio/iio.h>
28 #include <linux/iio/sysfs.h>
29 
30 #define VCNL4000_DRV_NAME "vcnl4000"
31 #define VCNL4000_PROD_ID	0x01
32 #define VCNL4010_PROD_ID	0x02 /* for VCNL4020, VCNL4010 */
33 #define VCNL4200_PROD_ID	0x58
34 
35 #define VCNL4000_COMMAND	0x80 /* Command register */
36 #define VCNL4000_PROD_REV	0x81 /* Product ID and Revision ID */
37 #define VCNL4000_LED_CURRENT	0x83 /* IR LED current for proximity mode */
38 #define VCNL4000_AL_PARAM	0x84 /* Ambient light parameter register */
39 #define VCNL4000_AL_RESULT_HI	0x85 /* Ambient light result register, MSB */
40 #define VCNL4000_AL_RESULT_LO	0x86 /* Ambient light result register, LSB */
41 #define VCNL4000_PS_RESULT_HI	0x87 /* Proximity result register, MSB */
42 #define VCNL4000_PS_RESULT_LO	0x88 /* Proximity result register, LSB */
43 #define VCNL4000_PS_MEAS_FREQ	0x89 /* Proximity test signal frequency */
44 #define VCNL4000_PS_MOD_ADJ	0x8a /* Proximity modulator timing adjustment */
45 
46 #define VCNL4200_AL_CONF	0x00 /* Ambient light configuration */
47 #define VCNL4200_PS_CONF1	0x03 /* Proximity configuration */
48 #define VCNL4200_PS_DATA	0x08 /* Proximity data */
49 #define VCNL4200_AL_DATA	0x09 /* Ambient light data */
50 #define VCNL4200_DEV_ID		0x0e /* Device ID, slave address and version */
51 
52 /* Bit masks for COMMAND register */
53 #define VCNL4000_AL_RDY		BIT(6) /* ALS data ready? */
54 #define VCNL4000_PS_RDY		BIT(5) /* proximity data ready? */
55 #define VCNL4000_AL_OD		BIT(4) /* start on-demand ALS measurement */
56 #define VCNL4000_PS_OD		BIT(3) /* start on-demand proximity measurement */
57 
58 enum vcnl4000_device_ids {
59 	VCNL4000,
60 	VCNL4010,
61 	VCNL4200,
62 };
63 
64 struct vcnl4200_channel {
65 	u8 reg;
66 	ktime_t last_measurement;
67 	ktime_t sampling_rate;
68 	struct mutex lock;
69 };
70 
71 struct vcnl4000_data {
72 	struct i2c_client *client;
73 	enum vcnl4000_device_ids id;
74 	int rev;
75 	int al_scale;
76 	const struct vcnl4000_chip_spec *chip_spec;
77 	struct mutex vcnl4000_lock;
78 	struct vcnl4200_channel vcnl4200_al;
79 	struct vcnl4200_channel vcnl4200_ps;
80 };
81 
82 struct vcnl4000_chip_spec {
83 	const char *prod;
84 	int (*init)(struct vcnl4000_data *data);
85 	int (*measure_light)(struct vcnl4000_data *data, int *val);
86 	int (*measure_proximity)(struct vcnl4000_data *data, int *val);
87 };
88 
89 static const struct i2c_device_id vcnl4000_id[] = {
90 	{ "vcnl4000", VCNL4000 },
91 	{ "vcnl4010", VCNL4010 },
92 	{ "vcnl4020", VCNL4010 },
93 	{ "vcnl4200", VCNL4200 },
94 	{ }
95 };
96 MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
97 
98 static int vcnl4000_init(struct vcnl4000_data *data)
99 {
100 	int ret, prod_id;
101 
102 	ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
103 	if (ret < 0)
104 		return ret;
105 
106 	prod_id = ret >> 4;
107 	switch (prod_id) {
108 	case VCNL4000_PROD_ID:
109 		if (data->id != VCNL4000)
110 			dev_warn(&data->client->dev,
111 					"wrong device id, use vcnl4000");
112 		break;
113 	case VCNL4010_PROD_ID:
114 		if (data->id != VCNL4010)
115 			dev_warn(&data->client->dev,
116 					"wrong device id, use vcnl4010/4020");
117 		break;
118 	default:
119 		return -ENODEV;
120 	}
121 
122 	data->rev = ret & 0xf;
123 	data->al_scale = 250000;
124 	mutex_init(&data->vcnl4000_lock);
125 
126 	return 0;
127 };
128 
129 static int vcnl4200_init(struct vcnl4000_data *data)
130 {
131 	int ret;
132 
133 	ret = i2c_smbus_read_word_data(data->client, VCNL4200_DEV_ID);
134 	if (ret < 0)
135 		return ret;
136 
137 	if ((ret & 0xff) != VCNL4200_PROD_ID)
138 		return -ENODEV;
139 
140 	data->rev = (ret >> 8) & 0xf;
141 
142 	/* Set defaults and enable both channels */
143 	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_AL_CONF, 0x00);
144 	if (ret < 0)
145 		return ret;
146 	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_PS_CONF1, 0x00);
147 	if (ret < 0)
148 		return ret;
149 
150 	data->al_scale = 24000;
151 	data->vcnl4200_al.reg = VCNL4200_AL_DATA;
152 	data->vcnl4200_ps.reg = VCNL4200_PS_DATA;
153 	/* Integration time is 50ms, but the experiments show 54ms in total. */
154 	data->vcnl4200_al.sampling_rate = ktime_set(0, 54000 * 1000);
155 	data->vcnl4200_ps.sampling_rate = ktime_set(0, 4200 * 1000);
156 	data->vcnl4200_al.last_measurement = ktime_set(0, 0);
157 	data->vcnl4200_ps.last_measurement = ktime_set(0, 0);
158 	mutex_init(&data->vcnl4200_al.lock);
159 	mutex_init(&data->vcnl4200_ps.lock);
160 
161 	return 0;
162 };
163 
164 static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
165 				u8 rdy_mask, u8 data_reg, int *val)
166 {
167 	int tries = 20;
168 	__be16 buf;
169 	int ret;
170 
171 	mutex_lock(&data->vcnl4000_lock);
172 
173 	ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
174 					req_mask);
175 	if (ret < 0)
176 		goto fail;
177 
178 	/* wait for data to become ready */
179 	while (tries--) {
180 		ret = i2c_smbus_read_byte_data(data->client, VCNL4000_COMMAND);
181 		if (ret < 0)
182 			goto fail;
183 		if (ret & rdy_mask)
184 			break;
185 		msleep(20); /* measurement takes up to 100 ms */
186 	}
187 
188 	if (tries < 0) {
189 		dev_err(&data->client->dev,
190 			"vcnl4000_measure() failed, data not ready\n");
191 		ret = -EIO;
192 		goto fail;
193 	}
194 
195 	ret = i2c_smbus_read_i2c_block_data(data->client,
196 		data_reg, sizeof(buf), (u8 *) &buf);
197 	if (ret < 0)
198 		goto fail;
199 
200 	mutex_unlock(&data->vcnl4000_lock);
201 	*val = be16_to_cpu(buf);
202 
203 	return 0;
204 
205 fail:
206 	mutex_unlock(&data->vcnl4000_lock);
207 	return ret;
208 }
209 
210 static int vcnl4200_measure(struct vcnl4000_data *data,
211 		struct vcnl4200_channel *chan, int *val)
212 {
213 	int ret;
214 	s64 delta;
215 	ktime_t next_measurement;
216 
217 	mutex_lock(&chan->lock);
218 
219 	next_measurement = ktime_add(chan->last_measurement,
220 			chan->sampling_rate);
221 	delta = ktime_us_delta(next_measurement, ktime_get());
222 	if (delta > 0)
223 		usleep_range(delta, delta + 500);
224 	chan->last_measurement = ktime_get();
225 
226 	mutex_unlock(&chan->lock);
227 
228 	ret = i2c_smbus_read_word_data(data->client, chan->reg);
229 	if (ret < 0)
230 		return ret;
231 
232 	*val = ret;
233 
234 	return 0;
235 }
236 
237 static int vcnl4000_measure_light(struct vcnl4000_data *data, int *val)
238 {
239 	return vcnl4000_measure(data,
240 			VCNL4000_AL_OD, VCNL4000_AL_RDY,
241 			VCNL4000_AL_RESULT_HI, val);
242 }
243 
244 static int vcnl4200_measure_light(struct vcnl4000_data *data, int *val)
245 {
246 	return vcnl4200_measure(data, &data->vcnl4200_al, val);
247 }
248 
249 static int vcnl4000_measure_proximity(struct vcnl4000_data *data, int *val)
250 {
251 	return vcnl4000_measure(data,
252 			VCNL4000_PS_OD, VCNL4000_PS_RDY,
253 			VCNL4000_PS_RESULT_HI, val);
254 }
255 
256 static int vcnl4200_measure_proximity(struct vcnl4000_data *data, int *val)
257 {
258 	return vcnl4200_measure(data, &data->vcnl4200_ps, val);
259 }
260 
261 static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
262 	[VCNL4000] = {
263 		.prod = "VCNL4000",
264 		.init = vcnl4000_init,
265 		.measure_light = vcnl4000_measure_light,
266 		.measure_proximity = vcnl4000_measure_proximity,
267 	},
268 	[VCNL4010] = {
269 		.prod = "VCNL4010/4020",
270 		.init = vcnl4000_init,
271 		.measure_light = vcnl4000_measure_light,
272 		.measure_proximity = vcnl4000_measure_proximity,
273 	},
274 	[VCNL4200] = {
275 		.prod = "VCNL4200",
276 		.init = vcnl4200_init,
277 		.measure_light = vcnl4200_measure_light,
278 		.measure_proximity = vcnl4200_measure_proximity,
279 	},
280 };
281 
282 static const struct iio_chan_spec vcnl4000_channels[] = {
283 	{
284 		.type = IIO_LIGHT,
285 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
286 			BIT(IIO_CHAN_INFO_SCALE),
287 	}, {
288 		.type = IIO_PROXIMITY,
289 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
290 	}
291 };
292 
293 static int vcnl4000_read_raw(struct iio_dev *indio_dev,
294 				struct iio_chan_spec const *chan,
295 				int *val, int *val2, long mask)
296 {
297 	int ret;
298 	struct vcnl4000_data *data = iio_priv(indio_dev);
299 
300 	switch (mask) {
301 	case IIO_CHAN_INFO_RAW:
302 		switch (chan->type) {
303 		case IIO_LIGHT:
304 			ret = data->chip_spec->measure_light(data, val);
305 			if (ret < 0)
306 				return ret;
307 			return IIO_VAL_INT;
308 		case IIO_PROXIMITY:
309 			ret = data->chip_spec->measure_proximity(data, val);
310 			if (ret < 0)
311 				return ret;
312 			return IIO_VAL_INT;
313 		default:
314 			return -EINVAL;
315 		}
316 	case IIO_CHAN_INFO_SCALE:
317 		if (chan->type != IIO_LIGHT)
318 			return -EINVAL;
319 
320 		*val = 0;
321 		*val2 = data->al_scale;
322 		return IIO_VAL_INT_PLUS_MICRO;
323 	default:
324 		return -EINVAL;
325 	}
326 }
327 
328 static const struct iio_info vcnl4000_info = {
329 	.read_raw = vcnl4000_read_raw,
330 };
331 
332 static int vcnl4000_probe(struct i2c_client *client,
333 			  const struct i2c_device_id *id)
334 {
335 	struct vcnl4000_data *data;
336 	struct iio_dev *indio_dev;
337 	int ret;
338 
339 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
340 	if (!indio_dev)
341 		return -ENOMEM;
342 
343 	data = iio_priv(indio_dev);
344 	i2c_set_clientdata(client, indio_dev);
345 	data->client = client;
346 	data->id = id->driver_data;
347 	data->chip_spec = &vcnl4000_chip_spec_cfg[data->id];
348 
349 	ret = data->chip_spec->init(data);
350 	if (ret < 0)
351 		return ret;
352 
353 	dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
354 		data->chip_spec->prod, data->rev);
355 
356 	indio_dev->dev.parent = &client->dev;
357 	indio_dev->info = &vcnl4000_info;
358 	indio_dev->channels = vcnl4000_channels;
359 	indio_dev->num_channels = ARRAY_SIZE(vcnl4000_channels);
360 	indio_dev->name = VCNL4000_DRV_NAME;
361 	indio_dev->modes = INDIO_DIRECT_MODE;
362 
363 	return devm_iio_device_register(&client->dev, indio_dev);
364 }
365 
366 static struct i2c_driver vcnl4000_driver = {
367 	.driver = {
368 		.name   = VCNL4000_DRV_NAME,
369 	},
370 	.probe  = vcnl4000_probe,
371 	.id_table = vcnl4000_id,
372 };
373 
374 module_i2c_driver(vcnl4000_driver);
375 
376 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
377 MODULE_DESCRIPTION("Vishay VCNL4000 proximity/ambient light sensor driver");
378 MODULE_LICENSE("GPL");
379