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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
53struct tcs3472_data {
54 struct i2c_client *client;
55 struct mutex lock;
56 u8 enable;
57 u8 control;
58 u8 atime;
59 u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
60};
61
62#define TCS3472_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_CALIBSCALE) | \
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
79static const int tcs3472_agains[] = { 1, 4, 16, 60 };
80
81static const struct iio_chan_spec tcs3472_channels[] = {
82 TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
83 TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
84 TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
85 TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
86 IIO_CHAN_SOFT_TIMESTAMP(4),
87};
88
89static int tcs3472_req_data(struct tcs3472_data *data)
90{
91 int tries = 50;
92 int ret;
93
94 while (tries--) {
95 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
96 if (ret < 0)
97 return ret;
98 if (ret & TCS3472_STATUS_AVALID)
99 break;
100 msleep(20);
101 }
102
103 if (tries < 0) {
104 dev_err(&data->client->dev, "data not ready\n");
105 return -EIO;
106 }
107
108 return 0;
109}
110
111static int tcs3472_read_raw(struct iio_dev *indio_dev,
112 struct iio_chan_spec const *chan,
113 int *val, int *val2, long mask)
114{
115 struct tcs3472_data *data = iio_priv(indio_dev);
116 int ret;
117
118 switch (mask) {
119 case IIO_CHAN_INFO_RAW:
120 if (iio_buffer_enabled(indio_dev))
121 return -EBUSY;
122
123 mutex_lock(&data->lock);
124 ret = tcs3472_req_data(data);
125 if (ret < 0) {
126 mutex_unlock(&data->lock);
127 return ret;
128 }
129 ret = i2c_smbus_read_word_data(data->client, chan->address);
130 mutex_unlock(&data->lock);
131 if (ret < 0)
132 return ret;
133 *val = ret;
134 return IIO_VAL_INT;
135 case IIO_CHAN_INFO_CALIBSCALE:
136 *val = tcs3472_agains[data->control &
137 TCS3472_CONTROL_AGAIN_MASK];
138 return IIO_VAL_INT;
139 case IIO_CHAN_INFO_INT_TIME:
140 *val = 0;
141 *val2 = (256 - data->atime) * 2400;
142 return IIO_VAL_INT_PLUS_MICRO;
143 }
144 return -EINVAL;
145}
146
147static int tcs3472_write_raw(struct iio_dev *indio_dev,
148 struct iio_chan_spec const *chan,
149 int val, int val2, long mask)
150{
151 struct tcs3472_data *data = iio_priv(indio_dev);
152 int i;
153
154 switch (mask) {
155 case IIO_CHAN_INFO_CALIBSCALE:
156 if (val2 != 0)
157 return -EINVAL;
158 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
159 if (val == tcs3472_agains[i]) {
160 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
161 data->control |= i;
162 return i2c_smbus_write_byte_data(
163 data->client, TCS3472_CONTROL,
164 data->control);
165 }
166 }
167 return -EINVAL;
168 case IIO_CHAN_INFO_INT_TIME:
169 if (val != 0)
170 return -EINVAL;
171 for (i = 0; i < 256; i++) {
172 if (val2 == (256 - i) * 2400) {
173 data->atime = i;
174 return i2c_smbus_write_word_data(
175 data->client, TCS3472_ATIME,
176 data->atime);
177 }
178
179 }
180 return -EINVAL;
181 }
182 return -EINVAL;
183}
184
185static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
186{
187 struct iio_poll_func *pf = p;
188 struct iio_dev *indio_dev = pf->indio_dev;
189 struct tcs3472_data *data = iio_priv(indio_dev);
190 int i, j = 0;
191
192 int ret = tcs3472_req_data(data);
193 if (ret < 0)
194 goto done;
195
196 for_each_set_bit(i, indio_dev->active_scan_mask,
197 indio_dev->masklength) {
198 ret = i2c_smbus_read_word_data(data->client,
199 TCS3472_CDATA + 2*i);
200 if (ret < 0)
201 goto done;
202
203 data->buffer[j++] = ret;
204 }
205
206 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
207 iio_get_time_ns());
208
209done:
210 iio_trigger_notify_done(indio_dev->trig);
211
212 return IRQ_HANDLED;
213}
214
215static ssize_t tcs3472_show_int_time_available(struct device *dev,
216 struct device_attribute *attr,
217 char *buf)
218{
219 size_t len = 0;
220 int i;
221
222 for (i = 1; i <= 256; i++)
223 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
224 2400 * i);
225
226 /* replace trailing space by newline */
227 buf[len - 1] = '\n';
228
229 return len;
230}
231
232static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
233static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
234
235static struct attribute *tcs3472_attributes[] = {
236 &iio_const_attr_calibscale_available.dev_attr.attr,
237 &iio_dev_attr_integration_time_available.dev_attr.attr,
238 NULL
239};
240
241static const struct attribute_group tcs3472_attribute_group = {
242 .attrs = tcs3472_attributes,
243};
244
245static const struct iio_info tcs3472_info = {
246 .read_raw = tcs3472_read_raw,
247 .write_raw = tcs3472_write_raw,
248 .attrs = &tcs3472_attribute_group,
249 .driver_module = THIS_MODULE,
250};
251
252static int tcs3472_probe(struct i2c_client *client,
253 const struct i2c_device_id *id)
254{
255 struct tcs3472_data *data;
256 struct iio_dev *indio_dev;
257 int ret;
258
259 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
260 if (indio_dev == NULL)
261 return -ENOMEM;
262
263 data = iio_priv(indio_dev);
264 i2c_set_clientdata(client, indio_dev);
265 data->client = client;
266 mutex_init(&data->lock);
267
268 indio_dev->dev.parent = &client->dev;
269 indio_dev->info = &tcs3472_info;
270 indio_dev->name = TCS3472_DRV_NAME;
271 indio_dev->channels = tcs3472_channels;
272 indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
273 indio_dev->modes = INDIO_DIRECT_MODE;
274
275 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
276 if (ret < 0)
277 return ret;
278
279 if (ret == 0x44)
280 dev_info(&client->dev, "TCS34721/34725 found\n");
281 else if (ret == 0x4d)
282 dev_info(&client->dev, "TCS34723/34727 found\n");
283 else
284 return -ENODEV;
285
286 ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
287 if (ret < 0)
288 return ret;
289 data->control = ret;
290
291 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
292 if (ret < 0)
293 return ret;
294 data->atime = ret;
295
296 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
297 if (ret < 0)
298 return ret;
299
300 /* enable device */
301 data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
302 ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
303 data->enable);
304 if (ret < 0)
305 return ret;
306
307 ret = iio_triggered_buffer_setup(indio_dev, NULL,
308 tcs3472_trigger_handler, NULL);
309 if (ret < 0)
310 return ret;
311
312 ret = iio_device_register(indio_dev);
313 if (ret < 0)
314 goto buffer_cleanup;
315
316 return 0;
317
318buffer_cleanup:
319 iio_triggered_buffer_cleanup(indio_dev);
320 return ret;
321}
322
323static int tcs3472_powerdown(struct tcs3472_data *data)
324{
325 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
326 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
327}
328
329static int tcs3472_remove(struct i2c_client *client)
330{
331 struct iio_dev *indio_dev = i2c_get_clientdata(client);
332
333 iio_device_unregister(indio_dev);
334 iio_triggered_buffer_cleanup(indio_dev);
335 tcs3472_powerdown(iio_priv(indio_dev));
336
337 return 0;
338}
339
340#ifdef CONFIG_PM_SLEEP
341static int tcs3472_suspend(struct device *dev)
342{
343 struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
344 to_i2c_client(dev)));
345 return tcs3472_powerdown(data);
346}
347
348static int tcs3472_resume(struct device *dev)
349{
350 struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
351 to_i2c_client(dev)));
352 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
353 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
354}
355#endif
356
357static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
358
359static const struct i2c_device_id tcs3472_id[] = {
360 { "tcs3472", 0 },
361 { }
362};
363MODULE_DEVICE_TABLE(i2c, tcs3472_id);
364
365static struct i2c_driver tcs3472_driver = {
366 .driver = {
367 .name = TCS3472_DRV_NAME,
368 .pm = &tcs3472_pm_ops,
369 },
370 .probe = tcs3472_probe,
371 .remove = tcs3472_remove,
372 .id_table = tcs3472_id,
373};
374module_i2c_driver(tcs3472_driver);
375
376MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
377MODULE_DESCRIPTION("TCS3472 color light sensors driver");
378MODULE_LICENSE("GPL");