xref: /openbmc/linux/drivers/iio/light/tcs3414.c (revision 9cfc5c90)
1 /*
2  * tcs3414.c - Support for TAOS TCS3414 digital color sensor
3  *
4  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
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  * Digital color sensor with 16-bit channels for red, green, blue, clear);
11  * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
12  * TCS3415, TCS3416, resp.)
13  *
14  * TODO: sync, interrupt support, thresholds, prescaler
15  */
16 
17 #include <linux/module.h>
18 #include <linux/i2c.h>
19 #include <linux/delay.h>
20 #include <linux/pm.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/triggered_buffer.h>
27 
28 #define TCS3414_DRV_NAME "tcs3414"
29 
30 #define TCS3414_COMMAND BIT(7)
31 #define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
32 
33 #define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
34 #define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
35 #define TCS3414_ID (TCS3414_COMMAND | 0x04)
36 #define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
37 #define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
38 #define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
39 #define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
40 #define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
41 
42 #define TCS3414_CONTROL_ADC_VALID BIT(4)
43 #define TCS3414_CONTROL_ADC_EN BIT(1)
44 #define TCS3414_CONTROL_POWER BIT(0)
45 
46 #define TCS3414_INTEG_MASK GENMASK(1, 0)
47 #define TCS3414_INTEG_12MS 0x0
48 #define TCS3414_INTEG_100MS 0x1
49 #define TCS3414_INTEG_400MS 0x2
50 
51 #define TCS3414_GAIN_MASK GENMASK(5, 4)
52 #define TCS3414_GAIN_SHIFT 4
53 
54 struct tcs3414_data {
55 	struct i2c_client *client;
56 	struct mutex lock;
57 	u8 control;
58 	u8 gain;
59 	u8 timing;
60 	u16 buffer[8]; /* 4x 16-bit + 8 bytes timestamp */
61 };
62 
63 #define TCS3414_CHANNEL(_color, _si, _addr) { \
64 	.type = IIO_INTENSITY, \
65 	.modified = 1, \
66 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
67 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
68 		BIT(IIO_CHAN_INFO_INT_TIME), \
69 	.channel2 = IIO_MOD_LIGHT_##_color, \
70 	.address = _addr, \
71 	.scan_index = _si, \
72 	.scan_type = { \
73 		.sign = 'u', \
74 		.realbits = 16, \
75 		.storagebits = 16, \
76 		.endianness = IIO_CPU, \
77 	}, \
78 }
79 
80 /* scale factors: 1/gain */
81 static const int tcs3414_scales[][2] = {
82 	{1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
83 };
84 
85 /* integration time in ms */
86 static const int tcs3414_times[] = { 12, 100, 400 };
87 
88 static const struct iio_chan_spec tcs3414_channels[] = {
89 	TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
90 	TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
91 	TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
92 	TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
93 	IIO_CHAN_SOFT_TIMESTAMP(4),
94 };
95 
96 static int tcs3414_req_data(struct tcs3414_data *data)
97 {
98 	int tries = 25;
99 	int ret;
100 
101 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
102 		data->control | TCS3414_CONTROL_ADC_EN);
103 	if (ret < 0)
104 		return ret;
105 
106 	while (tries--) {
107 		ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
108 		if (ret < 0)
109 			return ret;
110 		if (ret & TCS3414_CONTROL_ADC_VALID)
111 			break;
112 		msleep(20);
113 	}
114 
115 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
116 		data->control);
117 	if (ret < 0)
118 		return ret;
119 
120 	if (tries < 0) {
121 		dev_err(&data->client->dev, "data not ready\n");
122 		return -EIO;
123 	}
124 
125 	return 0;
126 }
127 
128 static int tcs3414_read_raw(struct iio_dev *indio_dev,
129 			   struct iio_chan_spec const *chan,
130 			   int *val, int *val2, long mask)
131 {
132 	struct tcs3414_data *data = iio_priv(indio_dev);
133 	int i, ret;
134 
135 	switch (mask) {
136 	case IIO_CHAN_INFO_RAW:
137 		if (iio_buffer_enabled(indio_dev))
138 			return -EBUSY;
139 		mutex_lock(&data->lock);
140 		ret = tcs3414_req_data(data);
141 		if (ret < 0) {
142 			mutex_unlock(&data->lock);
143 			return ret;
144 		}
145 		ret = i2c_smbus_read_word_data(data->client, chan->address);
146 		mutex_unlock(&data->lock);
147 		if (ret < 0)
148 			return ret;
149 		*val = ret;
150 		return IIO_VAL_INT;
151 	case IIO_CHAN_INFO_SCALE:
152 		i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
153 		*val = tcs3414_scales[i][0];
154 		*val2 = tcs3414_scales[i][1];
155 		return IIO_VAL_INT_PLUS_MICRO;
156 	case IIO_CHAN_INFO_INT_TIME:
157 		*val = 0;
158 		*val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
159 		return IIO_VAL_INT_PLUS_MICRO;
160 	}
161 	return -EINVAL;
162 }
163 
164 static int tcs3414_write_raw(struct iio_dev *indio_dev,
165 			       struct iio_chan_spec const *chan,
166 			       int val, int val2, long mask)
167 {
168 	struct tcs3414_data *data = iio_priv(indio_dev);
169 	int i;
170 
171 	switch (mask) {
172 	case IIO_CHAN_INFO_SCALE:
173 		for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
174 			if (val == tcs3414_scales[i][0] &&
175 				val2 == tcs3414_scales[i][1]) {
176 				data->gain &= ~TCS3414_GAIN_MASK;
177 				data->gain |= i << TCS3414_GAIN_SHIFT;
178 				return i2c_smbus_write_byte_data(
179 					data->client, TCS3414_GAIN,
180 					data->gain);
181 			}
182 		}
183 		return -EINVAL;
184 	case IIO_CHAN_INFO_INT_TIME:
185 		if (val != 0)
186 			return -EINVAL;
187 		for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
188 			if (val2 == tcs3414_times[i] * 1000) {
189 				data->timing &= ~TCS3414_INTEG_MASK;
190 				data->timing |= i;
191 				return i2c_smbus_write_byte_data(
192 					data->client, TCS3414_TIMING,
193 					data->timing);
194 			}
195 		}
196 		return -EINVAL;
197 	default:
198 		return -EINVAL;
199 	}
200 }
201 
202 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
203 {
204 	struct iio_poll_func *pf = p;
205 	struct iio_dev *indio_dev = pf->indio_dev;
206 	struct tcs3414_data *data = iio_priv(indio_dev);
207 	int i, j = 0;
208 
209 	for_each_set_bit(i, indio_dev->active_scan_mask,
210 		indio_dev->masklength) {
211 		int ret = i2c_smbus_read_word_data(data->client,
212 			TCS3414_DATA_GREEN + 2*i);
213 		if (ret < 0)
214 			goto done;
215 
216 		data->buffer[j++] = ret;
217 	}
218 
219 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
220 		iio_get_time_ns());
221 
222 done:
223 	iio_trigger_notify_done(indio_dev->trig);
224 
225 	return IRQ_HANDLED;
226 }
227 
228 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
229 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
230 
231 static struct attribute *tcs3414_attributes[] = {
232 	&iio_const_attr_scale_available.dev_attr.attr,
233 	&iio_const_attr_integration_time_available.dev_attr.attr,
234 	NULL
235 };
236 
237 static const struct attribute_group tcs3414_attribute_group = {
238 	.attrs = tcs3414_attributes,
239 };
240 
241 static const struct iio_info tcs3414_info = {
242 	.read_raw = tcs3414_read_raw,
243 	.write_raw = tcs3414_write_raw,
244 	.attrs = &tcs3414_attribute_group,
245 	.driver_module = THIS_MODULE,
246 };
247 
248 static int tcs3414_buffer_preenable(struct iio_dev *indio_dev)
249 {
250 	struct tcs3414_data *data = iio_priv(indio_dev);
251 
252 	data->control |= TCS3414_CONTROL_ADC_EN;
253 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
254 		data->control);
255 }
256 
257 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
258 {
259 	struct tcs3414_data *data = iio_priv(indio_dev);
260 	int ret;
261 
262 	ret = iio_triggered_buffer_predisable(indio_dev);
263 	if (ret < 0)
264 		return ret;
265 
266 	data->control &= ~TCS3414_CONTROL_ADC_EN;
267 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
268 		data->control);
269 }
270 
271 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
272 	.preenable = tcs3414_buffer_preenable,
273 	.postenable = &iio_triggered_buffer_postenable,
274 	.predisable = tcs3414_buffer_predisable,
275 };
276 
277 static int tcs3414_probe(struct i2c_client *client,
278 			   const struct i2c_device_id *id)
279 {
280 	struct tcs3414_data *data;
281 	struct iio_dev *indio_dev;
282 	int ret;
283 
284 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
285 	if (indio_dev == NULL)
286 		return -ENOMEM;
287 
288 	data = iio_priv(indio_dev);
289 	i2c_set_clientdata(client, indio_dev);
290 	data->client = client;
291 	mutex_init(&data->lock);
292 
293 	indio_dev->dev.parent = &client->dev;
294 	indio_dev->info = &tcs3414_info;
295 	indio_dev->name = TCS3414_DRV_NAME;
296 	indio_dev->channels = tcs3414_channels;
297 	indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
298 	indio_dev->modes = INDIO_DIRECT_MODE;
299 
300 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
301 	if (ret < 0)
302 		return ret;
303 
304 	switch (ret & 0xf0) {
305 	case 0x00:
306 		dev_info(&client->dev, "TCS3404 found\n");
307 		break;
308 	case 0x10:
309 		dev_info(&client->dev, "TCS3413/14/15/16 found\n");
310 		break;
311 	default:
312 		return -ENODEV;
313 	}
314 
315 	data->control = TCS3414_CONTROL_POWER;
316 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
317 		data->control);
318 	if (ret < 0)
319 		return ret;
320 
321 	data->timing = TCS3414_INTEG_12MS; /* free running */
322 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
323 		data->timing);
324 	if (ret < 0)
325 		return ret;
326 
327 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
328 	if (ret < 0)
329 		return ret;
330 	data->gain = ret;
331 
332 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
333 		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
334 	if (ret < 0)
335 		return ret;
336 
337 	ret = iio_device_register(indio_dev);
338 	if (ret < 0)
339 		goto buffer_cleanup;
340 
341 	return 0;
342 
343 buffer_cleanup:
344 	iio_triggered_buffer_cleanup(indio_dev);
345 	return ret;
346 }
347 
348 static int tcs3414_powerdown(struct tcs3414_data *data)
349 {
350 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
351 		data->control & ~(TCS3414_CONTROL_POWER |
352 		TCS3414_CONTROL_ADC_EN));
353 }
354 
355 static int tcs3414_remove(struct i2c_client *client)
356 {
357 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
358 
359 	iio_device_unregister(indio_dev);
360 	iio_triggered_buffer_cleanup(indio_dev);
361 	tcs3414_powerdown(iio_priv(indio_dev));
362 
363 	return 0;
364 }
365 
366 #ifdef CONFIG_PM_SLEEP
367 static int tcs3414_suspend(struct device *dev)
368 {
369 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
370 		to_i2c_client(dev)));
371 	return tcs3414_powerdown(data);
372 }
373 
374 static int tcs3414_resume(struct device *dev)
375 {
376 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
377 		to_i2c_client(dev)));
378 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
379 		data->control);
380 }
381 #endif
382 
383 static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
384 
385 static const struct i2c_device_id tcs3414_id[] = {
386 	{ "tcs3414", 0 },
387 	{ }
388 };
389 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
390 
391 static struct i2c_driver tcs3414_driver = {
392 	.driver = {
393 		.name	= TCS3414_DRV_NAME,
394 		.pm	= &tcs3414_pm_ops,
395 	},
396 	.probe		= tcs3414_probe,
397 	.remove		= tcs3414_remove,
398 	.id_table	= tcs3414_id,
399 };
400 module_i2c_driver(tcs3414_driver);
401 
402 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
403 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
404 MODULE_LICENSE("GPL");
405