xref: /linux/drivers/iio/light/tcs3414.c (revision cc9263874b42bf98209dce0afe698b550648e770)
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 	u8 control;
57 	u8 gain;
58 	u8 timing;
59 	u16 buffer[8]; /* 4x 16-bit + 8 bytes timestamp */
60 };
61 
62 #define TCS3414_CHANNEL(_color, _si, _addr) { \
63 	.type = IIO_INTENSITY, \
64 	.modified = 1, \
65 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
66 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
67 		BIT(IIO_CHAN_INFO_INT_TIME), \
68 	.channel2 = IIO_MOD_LIGHT_##_color, \
69 	.address = _addr, \
70 	.scan_index = _si, \
71 	.scan_type = { \
72 		.sign = 'u', \
73 		.realbits = 16, \
74 		.storagebits = 16, \
75 		.endianness = IIO_CPU, \
76 	}, \
77 }
78 
79 /* scale factors: 1/gain */
80 static const int tcs3414_scales[][2] = {
81 	{1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
82 };
83 
84 /* integration time in ms */
85 static const int tcs3414_times[] = { 12, 100, 400 };
86 
87 static const struct iio_chan_spec tcs3414_channels[] = {
88 	TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
89 	TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
90 	TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
91 	TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
92 	IIO_CHAN_SOFT_TIMESTAMP(4),
93 };
94 
95 static int tcs3414_req_data(struct tcs3414_data *data)
96 {
97 	int tries = 25;
98 	int ret;
99 
100 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
101 		data->control | TCS3414_CONTROL_ADC_EN);
102 	if (ret < 0)
103 		return ret;
104 
105 	while (tries--) {
106 		ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
107 		if (ret < 0)
108 			return ret;
109 		if (ret & TCS3414_CONTROL_ADC_VALID)
110 			break;
111 		msleep(20);
112 	}
113 
114 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
115 		data->control);
116 	if (ret < 0)
117 		return ret;
118 
119 	if (tries < 0) {
120 		dev_err(&data->client->dev, "data not ready\n");
121 		return -EIO;
122 	}
123 
124 	return 0;
125 }
126 
127 static int tcs3414_read_raw(struct iio_dev *indio_dev,
128 			   struct iio_chan_spec const *chan,
129 			   int *val, int *val2, long mask)
130 {
131 	struct tcs3414_data *data = iio_priv(indio_dev);
132 	int i, ret;
133 
134 	switch (mask) {
135 	case IIO_CHAN_INFO_RAW:
136 		ret = iio_device_claim_direct_mode(indio_dev);
137 		if (ret)
138 			return ret;
139 		ret = tcs3414_req_data(data);
140 		if (ret < 0) {
141 			iio_device_release_direct_mode(indio_dev);
142 			return ret;
143 		}
144 		ret = i2c_smbus_read_word_data(data->client, chan->address);
145 		iio_device_release_direct_mode(indio_dev);
146 		if (ret < 0)
147 			return ret;
148 		*val = ret;
149 		return IIO_VAL_INT;
150 	case IIO_CHAN_INFO_SCALE:
151 		i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
152 		*val = tcs3414_scales[i][0];
153 		*val2 = tcs3414_scales[i][1];
154 		return IIO_VAL_INT_PLUS_MICRO;
155 	case IIO_CHAN_INFO_INT_TIME:
156 		*val = 0;
157 		*val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
158 		return IIO_VAL_INT_PLUS_MICRO;
159 	}
160 	return -EINVAL;
161 }
162 
163 static int tcs3414_write_raw(struct iio_dev *indio_dev,
164 			       struct iio_chan_spec const *chan,
165 			       int val, int val2, long mask)
166 {
167 	struct tcs3414_data *data = iio_priv(indio_dev);
168 	int i;
169 
170 	switch (mask) {
171 	case IIO_CHAN_INFO_SCALE:
172 		for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
173 			if (val == tcs3414_scales[i][0] &&
174 				val2 == tcs3414_scales[i][1]) {
175 				data->gain &= ~TCS3414_GAIN_MASK;
176 				data->gain |= i << TCS3414_GAIN_SHIFT;
177 				return i2c_smbus_write_byte_data(
178 					data->client, TCS3414_GAIN,
179 					data->gain);
180 			}
181 		}
182 		return -EINVAL;
183 	case IIO_CHAN_INFO_INT_TIME:
184 		if (val != 0)
185 			return -EINVAL;
186 		for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
187 			if (val2 == tcs3414_times[i] * 1000) {
188 				data->timing &= ~TCS3414_INTEG_MASK;
189 				data->timing |= i;
190 				return i2c_smbus_write_byte_data(
191 					data->client, TCS3414_TIMING,
192 					data->timing);
193 			}
194 		}
195 		return -EINVAL;
196 	default:
197 		return -EINVAL;
198 	}
199 }
200 
201 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
202 {
203 	struct iio_poll_func *pf = p;
204 	struct iio_dev *indio_dev = pf->indio_dev;
205 	struct tcs3414_data *data = iio_priv(indio_dev);
206 	int i, j = 0;
207 
208 	for_each_set_bit(i, indio_dev->active_scan_mask,
209 		indio_dev->masklength) {
210 		int ret = i2c_smbus_read_word_data(data->client,
211 			TCS3414_DATA_GREEN + 2*i);
212 		if (ret < 0)
213 			goto done;
214 
215 		data->buffer[j++] = ret;
216 	}
217 
218 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
219 		iio_get_time_ns(indio_dev));
220 
221 done:
222 	iio_trigger_notify_done(indio_dev->trig);
223 
224 	return IRQ_HANDLED;
225 }
226 
227 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
228 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
229 
230 static struct attribute *tcs3414_attributes[] = {
231 	&iio_const_attr_scale_available.dev_attr.attr,
232 	&iio_const_attr_integration_time_available.dev_attr.attr,
233 	NULL
234 };
235 
236 static const struct attribute_group tcs3414_attribute_group = {
237 	.attrs = tcs3414_attributes,
238 };
239 
240 static const struct iio_info tcs3414_info = {
241 	.read_raw = tcs3414_read_raw,
242 	.write_raw = tcs3414_write_raw,
243 	.attrs = &tcs3414_attribute_group,
244 	.driver_module = THIS_MODULE,
245 };
246 
247 static int tcs3414_buffer_preenable(struct iio_dev *indio_dev)
248 {
249 	struct tcs3414_data *data = iio_priv(indio_dev);
250 
251 	data->control |= TCS3414_CONTROL_ADC_EN;
252 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
253 		data->control);
254 }
255 
256 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
257 {
258 	struct tcs3414_data *data = iio_priv(indio_dev);
259 	int ret;
260 
261 	ret = iio_triggered_buffer_predisable(indio_dev);
262 	if (ret < 0)
263 		return ret;
264 
265 	data->control &= ~TCS3414_CONTROL_ADC_EN;
266 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
267 		data->control);
268 }
269 
270 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
271 	.preenable = tcs3414_buffer_preenable,
272 	.postenable = &iio_triggered_buffer_postenable,
273 	.predisable = tcs3414_buffer_predisable,
274 };
275 
276 static int tcs3414_probe(struct i2c_client *client,
277 			   const struct i2c_device_id *id)
278 {
279 	struct tcs3414_data *data;
280 	struct iio_dev *indio_dev;
281 	int ret;
282 
283 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
284 	if (indio_dev == NULL)
285 		return -ENOMEM;
286 
287 	data = iio_priv(indio_dev);
288 	i2c_set_clientdata(client, indio_dev);
289 	data->client = client;
290 
291 	indio_dev->dev.parent = &client->dev;
292 	indio_dev->info = &tcs3414_info;
293 	indio_dev->name = TCS3414_DRV_NAME;
294 	indio_dev->channels = tcs3414_channels;
295 	indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
296 	indio_dev->modes = INDIO_DIRECT_MODE;
297 
298 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
299 	if (ret < 0)
300 		return ret;
301 
302 	switch (ret & 0xf0) {
303 	case 0x00:
304 		dev_info(&client->dev, "TCS3404 found\n");
305 		break;
306 	case 0x10:
307 		dev_info(&client->dev, "TCS3413/14/15/16 found\n");
308 		break;
309 	default:
310 		return -ENODEV;
311 	}
312 
313 	data->control = TCS3414_CONTROL_POWER;
314 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
315 		data->control);
316 	if (ret < 0)
317 		return ret;
318 
319 	data->timing = TCS3414_INTEG_12MS; /* free running */
320 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
321 		data->timing);
322 	if (ret < 0)
323 		return ret;
324 
325 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
326 	if (ret < 0)
327 		return ret;
328 	data->gain = ret;
329 
330 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
331 		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
332 	if (ret < 0)
333 		return ret;
334 
335 	ret = iio_device_register(indio_dev);
336 	if (ret < 0)
337 		goto buffer_cleanup;
338 
339 	return 0;
340 
341 buffer_cleanup:
342 	iio_triggered_buffer_cleanup(indio_dev);
343 	return ret;
344 }
345 
346 static int tcs3414_powerdown(struct tcs3414_data *data)
347 {
348 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
349 		data->control & ~(TCS3414_CONTROL_POWER |
350 		TCS3414_CONTROL_ADC_EN));
351 }
352 
353 static int tcs3414_remove(struct i2c_client *client)
354 {
355 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
356 
357 	iio_device_unregister(indio_dev);
358 	iio_triggered_buffer_cleanup(indio_dev);
359 	tcs3414_powerdown(iio_priv(indio_dev));
360 
361 	return 0;
362 }
363 
364 #ifdef CONFIG_PM_SLEEP
365 static int tcs3414_suspend(struct device *dev)
366 {
367 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
368 		to_i2c_client(dev)));
369 	return tcs3414_powerdown(data);
370 }
371 
372 static int tcs3414_resume(struct device *dev)
373 {
374 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
375 		to_i2c_client(dev)));
376 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
377 		data->control);
378 }
379 #endif
380 
381 static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
382 
383 static const struct i2c_device_id tcs3414_id[] = {
384 	{ "tcs3414", 0 },
385 	{ }
386 };
387 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
388 
389 static struct i2c_driver tcs3414_driver = {
390 	.driver = {
391 		.name	= TCS3414_DRV_NAME,
392 		.pm	= &tcs3414_pm_ops,
393 	},
394 	.probe		= tcs3414_probe,
395 	.remove		= tcs3414_remove,
396 	.id_table	= tcs3414_id,
397 };
398 module_i2c_driver(tcs3414_driver);
399 
400 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
401 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
402 MODULE_LICENSE("GPL");
403