xref: /openbmc/linux/drivers/iio/light/tcs3414.c (revision 7cf15f42)
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 	/* Ensure timestamp is naturally aligned */
57 	struct {
58 		u16 chans[4];
59 		s64 timestamp __aligned(8);
60 	} scan;
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 
tcs3414_req_data(struct tcs3414_data * data)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 
tcs3414_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)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 		ret = iio_device_claim_direct_mode(indio_dev);
138 		if (ret)
139 			return ret;
140 		ret = tcs3414_req_data(data);
141 		if (ret < 0) {
142 			iio_device_release_direct_mode(indio_dev);
143 			return ret;
144 		}
145 		ret = i2c_smbus_read_word_data(data->client, chan->address);
146 		iio_device_release_direct_mode(indio_dev);
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 
tcs3414_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)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 
tcs3414_trigger_handler(int irq,void * p)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->scan.chans[j++] = ret;
217 	}
218 
219 	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
220 		iio_get_time_ns(indio_dev));
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 };
246 
tcs3414_buffer_postenable(struct iio_dev * indio_dev)247 static int tcs3414_buffer_postenable(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 
tcs3414_buffer_predisable(struct iio_dev * indio_dev)256 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
257 {
258 	struct tcs3414_data *data = iio_priv(indio_dev);
259 
260 	data->control &= ~TCS3414_CONTROL_ADC_EN;
261 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
262 		data->control);
263 }
264 
265 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
266 	.postenable = tcs3414_buffer_postenable,
267 	.predisable = tcs3414_buffer_predisable,
268 };
269 
tcs3414_powerdown(struct tcs3414_data * data)270 static int tcs3414_powerdown(struct tcs3414_data *data)
271 {
272 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
273 		data->control & ~(TCS3414_CONTROL_POWER |
274 		TCS3414_CONTROL_ADC_EN));
275 }
276 
tcs3414_powerdown_cleanup(void * data)277 static void tcs3414_powerdown_cleanup(void *data)
278 {
279 	tcs3414_powerdown(data);
280 }
281 
tcs3414_probe(struct i2c_client * client)282 static int tcs3414_probe(struct i2c_client *client)
283 {
284 	struct tcs3414_data *data;
285 	struct iio_dev *indio_dev;
286 	int ret;
287 
288 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
289 	if (indio_dev == NULL)
290 		return -ENOMEM;
291 
292 	data = iio_priv(indio_dev);
293 	i2c_set_clientdata(client, indio_dev);
294 	data->client = client;
295 
296 	indio_dev->info = &tcs3414_info;
297 	indio_dev->name = TCS3414_DRV_NAME;
298 	indio_dev->channels = tcs3414_channels;
299 	indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
300 	indio_dev->modes = INDIO_DIRECT_MODE;
301 
302 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
303 	if (ret < 0)
304 		return ret;
305 
306 	switch (ret & 0xf0) {
307 	case 0x00:
308 		dev_info(&client->dev, "TCS3404 found\n");
309 		break;
310 	case 0x10:
311 		dev_info(&client->dev, "TCS3413/14/15/16 found\n");
312 		break;
313 	default:
314 		return -ENODEV;
315 	}
316 
317 	data->control = TCS3414_CONTROL_POWER;
318 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
319 		data->control);
320 	if (ret < 0)
321 		return ret;
322 
323 	ret = devm_add_action_or_reset(&client->dev, tcs3414_powerdown_cleanup,
324 				       data);
325 	if (ret < 0)
326 		return ret;
327 
328 	data->timing = TCS3414_INTEG_12MS; /* free running */
329 	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
330 		data->timing);
331 	if (ret < 0)
332 		return ret;
333 
334 	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
335 	if (ret < 0)
336 		return ret;
337 	data->gain = ret;
338 
339 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
340 		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
341 	if (ret < 0)
342 		return ret;
343 
344 	return devm_iio_device_register(&client->dev, indio_dev);
345 }
346 
tcs3414_suspend(struct device * dev)347 static int tcs3414_suspend(struct device *dev)
348 {
349 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
350 		to_i2c_client(dev)));
351 	return tcs3414_powerdown(data);
352 }
353 
tcs3414_resume(struct device * dev)354 static int tcs3414_resume(struct device *dev)
355 {
356 	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
357 		to_i2c_client(dev)));
358 	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
359 		data->control);
360 }
361 
362 static DEFINE_SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend,
363 				tcs3414_resume);
364 
365 static const struct i2c_device_id tcs3414_id[] = {
366 	{ "tcs3414", 0 },
367 	{ }
368 };
369 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
370 
371 static struct i2c_driver tcs3414_driver = {
372 	.driver = {
373 		.name	= TCS3414_DRV_NAME,
374 		.pm	= pm_sleep_ptr(&tcs3414_pm_ops),
375 	},
376 	.probe		= tcs3414_probe,
377 	.id_table	= tcs3414_id,
378 };
379 module_i2c_driver(tcs3414_driver);
380 
381 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
382 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
383 MODULE_LICENSE("GPL");
384