xref: /openbmc/linux/drivers/iio/light/tcs3414.c (revision aeb64ff3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tcs3414.c - Support for TAOS TCS3414 digital color sensor
4  *
5  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * Digital color sensor with 16-bit channels for red, green, blue, clear);
8  * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
9  * TCS3415, TCS3416, resp.)
10  *
11  * TODO: sync, interrupt support, thresholds, prescaler
12  */
13 
14 #include <linux/module.h>
15 #include <linux/i2c.h>
16 #include <linux/delay.h>
17 #include <linux/pm.h>
18 
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/triggered_buffer.h>
24 
25 #define TCS3414_DRV_NAME "tcs3414"
26 
27 #define TCS3414_COMMAND BIT(7)
28 #define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
29 
30 #define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
31 #define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
32 #define TCS3414_ID (TCS3414_COMMAND | 0x04)
33 #define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
34 #define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
35 #define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
36 #define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
37 #define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
38 
39 #define TCS3414_CONTROL_ADC_VALID BIT(4)
40 #define TCS3414_CONTROL_ADC_EN BIT(1)
41 #define TCS3414_CONTROL_POWER BIT(0)
42 
43 #define TCS3414_INTEG_MASK GENMASK(1, 0)
44 #define TCS3414_INTEG_12MS 0x0
45 #define TCS3414_INTEG_100MS 0x1
46 #define TCS3414_INTEG_400MS 0x2
47 
48 #define TCS3414_GAIN_MASK GENMASK(5, 4)
49 #define TCS3414_GAIN_SHIFT 4
50 
51 struct tcs3414_data {
52 	struct i2c_client *client;
53 	u8 control;
54 	u8 gain;
55 	u8 timing;
56 	u16 buffer[8]; /* 4x 16-bit + 8 bytes timestamp */
57 };
58 
59 #define TCS3414_CHANNEL(_color, _si, _addr) { \
60 	.type = IIO_INTENSITY, \
61 	.modified = 1, \
62 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
63 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
64 		BIT(IIO_CHAN_INFO_INT_TIME), \
65 	.channel2 = IIO_MOD_LIGHT_##_color, \
66 	.address = _addr, \
67 	.scan_index = _si, \
68 	.scan_type = { \
69 		.sign = 'u', \
70 		.realbits = 16, \
71 		.storagebits = 16, \
72 		.endianness = IIO_CPU, \
73 	}, \
74 }
75 
76 /* scale factors: 1/gain */
77 static const int tcs3414_scales[][2] = {
78 	{1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
79 };
80 
81 /* integration time in ms */
82 static const int tcs3414_times[] = { 12, 100, 400 };
83 
84 static const struct iio_chan_spec tcs3414_channels[] = {
85 	TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
86 	TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
87 	TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
88 	TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
89 	IIO_CHAN_SOFT_TIMESTAMP(4),
90 };
91 
92 static int tcs3414_req_data(struct tcs3414_data *data)
93 {
94 	int tries = 25;
95 	int ret;
96 
97 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
98 		data->control | TCS3414_CONTROL_ADC_EN);
99 	if (ret < 0)
100 		return ret;
101 
102 	while (tries--) {
103 		ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
104 		if (ret < 0)
105 			return ret;
106 		if (ret & TCS3414_CONTROL_ADC_VALID)
107 			break;
108 		msleep(20);
109 	}
110 
111 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
112 		data->control);
113 	if (ret < 0)
114 		return ret;
115 
116 	if (tries < 0) {
117 		dev_err(&data->client->dev, "data not ready\n");
118 		return -EIO;
119 	}
120 
121 	return 0;
122 }
123 
124 static int tcs3414_read_raw(struct iio_dev *indio_dev,
125 			   struct iio_chan_spec const *chan,
126 			   int *val, int *val2, long mask)
127 {
128 	struct tcs3414_data *data = iio_priv(indio_dev);
129 	int i, ret;
130 
131 	switch (mask) {
132 	case IIO_CHAN_INFO_RAW:
133 		ret = iio_device_claim_direct_mode(indio_dev);
134 		if (ret)
135 			return ret;
136 		ret = tcs3414_req_data(data);
137 		if (ret < 0) {
138 			iio_device_release_direct_mode(indio_dev);
139 			return ret;
140 		}
141 		ret = i2c_smbus_read_word_data(data->client, chan->address);
142 		iio_device_release_direct_mode(indio_dev);
143 		if (ret < 0)
144 			return ret;
145 		*val = ret;
146 		return IIO_VAL_INT;
147 	case IIO_CHAN_INFO_SCALE:
148 		i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
149 		*val = tcs3414_scales[i][0];
150 		*val2 = tcs3414_scales[i][1];
151 		return IIO_VAL_INT_PLUS_MICRO;
152 	case IIO_CHAN_INFO_INT_TIME:
153 		*val = 0;
154 		*val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
155 		return IIO_VAL_INT_PLUS_MICRO;
156 	}
157 	return -EINVAL;
158 }
159 
160 static int tcs3414_write_raw(struct iio_dev *indio_dev,
161 			       struct iio_chan_spec const *chan,
162 			       int val, int val2, long mask)
163 {
164 	struct tcs3414_data *data = iio_priv(indio_dev);
165 	int i;
166 
167 	switch (mask) {
168 	case IIO_CHAN_INFO_SCALE:
169 		for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
170 			if (val == tcs3414_scales[i][0] &&
171 				val2 == tcs3414_scales[i][1]) {
172 				data->gain &= ~TCS3414_GAIN_MASK;
173 				data->gain |= i << TCS3414_GAIN_SHIFT;
174 				return i2c_smbus_write_byte_data(
175 					data->client, TCS3414_GAIN,
176 					data->gain);
177 			}
178 		}
179 		return -EINVAL;
180 	case IIO_CHAN_INFO_INT_TIME:
181 		if (val != 0)
182 			return -EINVAL;
183 		for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
184 			if (val2 == tcs3414_times[i] * 1000) {
185 				data->timing &= ~TCS3414_INTEG_MASK;
186 				data->timing |= i;
187 				return i2c_smbus_write_byte_data(
188 					data->client, TCS3414_TIMING,
189 					data->timing);
190 			}
191 		}
192 		return -EINVAL;
193 	default:
194 		return -EINVAL;
195 	}
196 }
197 
198 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
199 {
200 	struct iio_poll_func *pf = p;
201 	struct iio_dev *indio_dev = pf->indio_dev;
202 	struct tcs3414_data *data = iio_priv(indio_dev);
203 	int i, j = 0;
204 
205 	for_each_set_bit(i, indio_dev->active_scan_mask,
206 		indio_dev->masklength) {
207 		int ret = i2c_smbus_read_word_data(data->client,
208 			TCS3414_DATA_GREEN + 2*i);
209 		if (ret < 0)
210 			goto done;
211 
212 		data->buffer[j++] = ret;
213 	}
214 
215 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
216 		iio_get_time_ns(indio_dev));
217 
218 done:
219 	iio_trigger_notify_done(indio_dev->trig);
220 
221 	return IRQ_HANDLED;
222 }
223 
224 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
225 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
226 
227 static struct attribute *tcs3414_attributes[] = {
228 	&iio_const_attr_scale_available.dev_attr.attr,
229 	&iio_const_attr_integration_time_available.dev_attr.attr,
230 	NULL
231 };
232 
233 static const struct attribute_group tcs3414_attribute_group = {
234 	.attrs = tcs3414_attributes,
235 };
236 
237 static const struct iio_info tcs3414_info = {
238 	.read_raw = tcs3414_read_raw,
239 	.write_raw = tcs3414_write_raw,
240 	.attrs = &tcs3414_attribute_group,
241 };
242 
243 static int tcs3414_buffer_postenable(struct iio_dev *indio_dev)
244 {
245 	struct tcs3414_data *data = iio_priv(indio_dev);
246 	int ret;
247 
248 	ret = iio_triggered_buffer_postenable(indio_dev);
249 	if (ret)
250 		return ret;
251 
252 	data->control |= TCS3414_CONTROL_ADC_EN;
253 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
254 		data->control);
255 	if (ret)
256 		iio_triggered_buffer_predisable(indio_dev);
257 
258 	return ret;
259 }
260 
261 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
262 {
263 	struct tcs3414_data *data = iio_priv(indio_dev);
264 	int ret, ret2;
265 
266 	data->control &= ~TCS3414_CONTROL_ADC_EN;
267 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
268 		data->control);
269 
270 	ret2 = iio_triggered_buffer_predisable(indio_dev);
271 	if (!ret)
272 		ret = ret2;
273 
274 	return ret;
275 }
276 
277 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
278 	.postenable = tcs3414_buffer_postenable,
279 	.predisable = tcs3414_buffer_predisable,
280 };
281 
282 static int tcs3414_probe(struct i2c_client *client,
283 			   const struct i2c_device_id *id)
284 {
285 	struct tcs3414_data *data;
286 	struct iio_dev *indio_dev;
287 	int ret;
288 
289 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
290 	if (indio_dev == NULL)
291 		return -ENOMEM;
292 
293 	data = iio_priv(indio_dev);
294 	i2c_set_clientdata(client, indio_dev);
295 	data->client = client;
296 
297 	indio_dev->dev.parent = &client->dev;
298 	indio_dev->info = &tcs3414_info;
299 	indio_dev->name = TCS3414_DRV_NAME;
300 	indio_dev->channels = tcs3414_channels;
301 	indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
302 	indio_dev->modes = INDIO_DIRECT_MODE;
303 
304 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
305 	if (ret < 0)
306 		return ret;
307 
308 	switch (ret & 0xf0) {
309 	case 0x00:
310 		dev_info(&client->dev, "TCS3404 found\n");
311 		break;
312 	case 0x10:
313 		dev_info(&client->dev, "TCS3413/14/15/16 found\n");
314 		break;
315 	default:
316 		return -ENODEV;
317 	}
318 
319 	data->control = TCS3414_CONTROL_POWER;
320 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
321 		data->control);
322 	if (ret < 0)
323 		return ret;
324 
325 	data->timing = TCS3414_INTEG_12MS; /* free running */
326 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
327 		data->timing);
328 	if (ret < 0)
329 		return ret;
330 
331 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
332 	if (ret < 0)
333 		return ret;
334 	data->gain = ret;
335 
336 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
337 		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
338 	if (ret < 0)
339 		return ret;
340 
341 	ret = iio_device_register(indio_dev);
342 	if (ret < 0)
343 		goto buffer_cleanup;
344 
345 	return 0;
346 
347 buffer_cleanup:
348 	iio_triggered_buffer_cleanup(indio_dev);
349 	return ret;
350 }
351 
352 static int tcs3414_powerdown(struct tcs3414_data *data)
353 {
354 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
355 		data->control & ~(TCS3414_CONTROL_POWER |
356 		TCS3414_CONTROL_ADC_EN));
357 }
358 
359 static int tcs3414_remove(struct i2c_client *client)
360 {
361 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
362 
363 	iio_device_unregister(indio_dev);
364 	iio_triggered_buffer_cleanup(indio_dev);
365 	tcs3414_powerdown(iio_priv(indio_dev));
366 
367 	return 0;
368 }
369 
370 #ifdef CONFIG_PM_SLEEP
371 static int tcs3414_suspend(struct device *dev)
372 {
373 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
374 		to_i2c_client(dev)));
375 	return tcs3414_powerdown(data);
376 }
377 
378 static int tcs3414_resume(struct device *dev)
379 {
380 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
381 		to_i2c_client(dev)));
382 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
383 		data->control);
384 }
385 #endif
386 
387 static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
388 
389 static const struct i2c_device_id tcs3414_id[] = {
390 	{ "tcs3414", 0 },
391 	{ }
392 };
393 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
394 
395 static struct i2c_driver tcs3414_driver = {
396 	.driver = {
397 		.name	= TCS3414_DRV_NAME,
398 		.pm	= &tcs3414_pm_ops,
399 	},
400 	.probe		= tcs3414_probe,
401 	.remove		= tcs3414_remove,
402 	.id_table	= tcs3414_id,
403 };
404 module_i2c_driver(tcs3414_driver);
405 
406 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
407 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
408 MODULE_LICENSE("GPL");
409