xref: /linux/drivers/iio/light/tcs3472.c (revision d91517839e5d95adc0cf4b28caa7af62a71de526)
1 /*
2  * tcs3472.c - Support for TAOS TCS3472 color light-to-digital converter
3  *
4  * Copyright (c) 2013 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  * Color light sensor with 16-bit channels for red, green, blue, clear);
11  * 7-bit I2C slave address 0x39 (TCS34721, TCS34723) or 0x29 (TCS34725,
12  * TCS34727)
13  *
14  * TODO: interrupt support, thresholds, wait time
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 TCS3472_DRV_NAME "tcs3472"
29 
30 #define TCS3472_COMMAND BIT(7)
31 #define TCS3472_AUTO_INCR BIT(5)
32 
33 #define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)
34 #define TCS3472_ATIME (TCS3472_COMMAND | 0x01)
35 #define TCS3472_WTIME (TCS3472_COMMAND | 0x03)
36 #define TCS3472_AILT (TCS3472_COMMAND | 0x04)
37 #define TCS3472_AIHT (TCS3472_COMMAND | 0x06)
38 #define TCS3472_PERS (TCS3472_COMMAND | 0x0c)
39 #define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)
40 #define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
41 #define TCS3472_ID (TCS3472_COMMAND | 0x12)
42 #define TCS3472_STATUS (TCS3472_COMMAND | 0x13)
43 #define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14)
44 #define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16)
45 #define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)
46 #define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)
47 
48 #define TCS3472_STATUS_AVALID BIT(0)
49 #define TCS3472_ENABLE_AEN BIT(1)
50 #define TCS3472_ENABLE_PON BIT(0)
51 #define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))
52 
53 struct tcs3472_data {
54 	struct i2c_client *client;
55 	u8 enable;
56 	u8 control;
57 	u8 atime;
58 	u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
59 };
60 
61 #define TCS3472_CHANNEL(_color, _si, _addr) { \
62 	.type = IIO_INTENSITY, \
63 	.modified = 1, \
64 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
65 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
66 		BIT(IIO_CHAN_INFO_INT_TIME), \
67 	.channel2 = IIO_MOD_LIGHT_##_color, \
68 	.address = _addr, \
69 	.scan_index = _si, \
70 	.scan_type = { \
71 		.sign = 'u', \
72 		.realbits = 16, \
73 		.storagebits = 16, \
74 		.endianness = IIO_CPU, \
75 	}, \
76 }
77 
78 static const int tcs3472_agains[] = { 1, 4, 16, 60 };
79 
80 static const struct iio_chan_spec tcs3472_channels[] = {
81 	TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
82 	TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
83 	TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
84 	TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
85 	IIO_CHAN_SOFT_TIMESTAMP(4),
86 };
87 
88 static int tcs3472_req_data(struct tcs3472_data *data)
89 {
90 	int tries = 50;
91 	int ret;
92 
93 	while (tries--) {
94 		ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
95 		if (ret < 0)
96 			return ret;
97 		if (ret & TCS3472_STATUS_AVALID)
98 			break;
99 		msleep(20);
100 	}
101 
102 	if (tries < 0) {
103 		dev_err(&data->client->dev, "data not ready\n");
104 		return -EIO;
105 	}
106 
107 	return 0;
108 }
109 
110 static int tcs3472_read_raw(struct iio_dev *indio_dev,
111 			   struct iio_chan_spec const *chan,
112 			   int *val, int *val2, long mask)
113 {
114 	struct tcs3472_data *data = iio_priv(indio_dev);
115 	int ret;
116 
117 	switch (mask) {
118 	case IIO_CHAN_INFO_RAW:
119 		ret = tcs3472_req_data(data);
120 		if (ret < 0)
121 			return ret;
122 		ret = i2c_smbus_read_word_data(data->client, chan->address);
123 		if (ret < 0)
124 			return ret;
125 		*val = ret;
126 		return IIO_VAL_INT;
127 	case IIO_CHAN_INFO_CALIBSCALE:
128 		*val = tcs3472_agains[data->control &
129 			TCS3472_CONTROL_AGAIN_MASK];
130 		return IIO_VAL_INT;
131 	case IIO_CHAN_INFO_INT_TIME:
132 		*val = 0;
133 		*val2 = (256 - data->atime) * 2400;
134 		return IIO_VAL_INT_PLUS_MICRO;
135 	}
136 	return -EINVAL;
137 }
138 
139 static int tcs3472_write_raw(struct iio_dev *indio_dev,
140 			       struct iio_chan_spec const *chan,
141 			       int val, int val2, long mask)
142 {
143 	struct tcs3472_data *data = iio_priv(indio_dev);
144 	int i;
145 
146 	switch (mask) {
147 	case IIO_CHAN_INFO_CALIBSCALE:
148 		if (val2 != 0)
149 			return -EINVAL;
150 		for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
151 			if (val == tcs3472_agains[i]) {
152 				data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
153 				data->control |= i;
154 				return i2c_smbus_write_byte_data(
155 					data->client, TCS3472_CONTROL,
156 					data->control);
157 			}
158 		}
159 		return -EINVAL;
160 	case IIO_CHAN_INFO_INT_TIME:
161 		if (val != 0)
162 			return -EINVAL;
163 		for (i = 0; i < 256; i++) {
164 			if (val2 == (256 - i) * 2400) {
165 				data->atime = i;
166 				return i2c_smbus_write_word_data(
167 					data->client, TCS3472_ATIME,
168 					data->atime);
169 			}
170 
171 		}
172 		return -EINVAL;
173 	}
174 	return -EINVAL;
175 }
176 
177 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
178 {
179 	struct iio_poll_func *pf = p;
180 	struct iio_dev *indio_dev = pf->indio_dev;
181 	struct tcs3472_data *data = iio_priv(indio_dev);
182 	int len = 0;
183 	int i, j = 0;
184 
185 	int ret = tcs3472_req_data(data);
186 	if (ret < 0)
187 		goto done;
188 
189 	for_each_set_bit(i, indio_dev->active_scan_mask,
190 		indio_dev->masklength) {
191 		ret = i2c_smbus_read_word_data(data->client,
192 			TCS3472_CDATA + 2*i);
193 		if (ret < 0)
194 			goto done;
195 
196 		data->buffer[j++] = ret;
197 		len += 2;
198 	}
199 
200 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
201 		iio_get_time_ns());
202 
203 done:
204 	iio_trigger_notify_done(indio_dev->trig);
205 
206 	return IRQ_HANDLED;
207 }
208 
209 static ssize_t tcs3472_show_int_time_available(struct device *dev,
210 					struct device_attribute *attr,
211 					char *buf)
212 {
213 	size_t len = 0;
214 	int i;
215 
216 	for (i = 1; i <= 256; i++)
217 		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
218 			2400 * i);
219 
220 	/* replace trailing space by newline */
221 	buf[len - 1] = '\n';
222 
223 	return len;
224 }
225 
226 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
227 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
228 
229 static struct attribute *tcs3472_attributes[] = {
230 	&iio_const_attr_calibscale_available.dev_attr.attr,
231 	&iio_dev_attr_integration_time_available.dev_attr.attr,
232 	NULL
233 };
234 
235 static const struct attribute_group tcs3472_attribute_group = {
236 	.attrs = tcs3472_attributes,
237 };
238 
239 static const struct iio_info tcs3472_info = {
240 	.read_raw = tcs3472_read_raw,
241 	.write_raw = tcs3472_write_raw,
242 	.attrs = &tcs3472_attribute_group,
243 	.driver_module = THIS_MODULE,
244 };
245 
246 static int tcs3472_probe(struct i2c_client *client,
247 			   const struct i2c_device_id *id)
248 {
249 	struct tcs3472_data *data;
250 	struct iio_dev *indio_dev;
251 	int ret;
252 
253 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
254 	if (indio_dev == NULL)
255 		return -ENOMEM;
256 
257 	data = iio_priv(indio_dev);
258 	i2c_set_clientdata(client, indio_dev);
259 	data->client = client;
260 
261 	indio_dev->dev.parent = &client->dev;
262 	indio_dev->info = &tcs3472_info;
263 	indio_dev->name = TCS3472_DRV_NAME;
264 	indio_dev->channels = tcs3472_channels;
265 	indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
266 	indio_dev->modes = INDIO_DIRECT_MODE;
267 
268 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
269 	if (ret < 0)
270 		return ret;
271 
272 	if (ret == 0x44)
273 		dev_info(&client->dev, "TCS34721/34725 found\n");
274 	else if (ret == 0x4d)
275 		dev_info(&client->dev, "TCS34723/34727 found\n");
276 	else
277 		return -ENODEV;
278 
279 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
280 	if (ret < 0)
281 		return ret;
282 	data->control = ret;
283 
284 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
285 	if (ret < 0)
286 		return ret;
287 	data->atime = ret;
288 
289 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
290 	if (ret < 0)
291 		return ret;
292 
293 	/* enable device */
294 	data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
295 	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
296 		data->enable);
297 	if (ret < 0)
298 		return ret;
299 
300 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
301 		tcs3472_trigger_handler, NULL);
302 	if (ret < 0)
303 		return ret;
304 
305 	ret = iio_device_register(indio_dev);
306 	if (ret < 0)
307 		goto buffer_cleanup;
308 
309 	return 0;
310 
311 buffer_cleanup:
312 	iio_triggered_buffer_cleanup(indio_dev);
313 	return ret;
314 }
315 
316 static int tcs3472_powerdown(struct tcs3472_data *data)
317 {
318 	return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
319 		data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
320 }
321 
322 static int tcs3472_remove(struct i2c_client *client)
323 {
324 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
325 
326 	iio_device_unregister(indio_dev);
327 	iio_triggered_buffer_cleanup(indio_dev);
328 	tcs3472_powerdown(iio_priv(indio_dev));
329 
330 	return 0;
331 }
332 
333 #ifdef CONFIG_PM_SLEEP
334 static int tcs3472_suspend(struct device *dev)
335 {
336 	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
337 		to_i2c_client(dev)));
338 	return tcs3472_powerdown(data);
339 }
340 
341 static int tcs3472_resume(struct device *dev)
342 {
343 	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
344 		to_i2c_client(dev)));
345 	return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
346 		data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
347 }
348 #endif
349 
350 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
351 
352 static const struct i2c_device_id tcs3472_id[] = {
353 	{ "tcs3472", 0 },
354 	{ }
355 };
356 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
357 
358 static struct i2c_driver tcs3472_driver = {
359 	.driver = {
360 		.name	= TCS3472_DRV_NAME,
361 		.pm	= &tcs3472_pm_ops,
362 		.owner	= THIS_MODULE,
363 	},
364 	.probe		= tcs3472_probe,
365 	.remove		= tcs3472_remove,
366 	.id_table	= tcs3472_id,
367 };
368 module_i2c_driver(tcs3472_driver);
369 
370 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
371 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
372 MODULE_LICENSE("GPL");
373