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 aligned_s64 timestamp;
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 if (!iio_device_claim_direct(indio_dev))
138 return -EBUSY;
139 ret = tcs3414_req_data(data);
140 if (ret < 0) {
141 iio_device_release_direct(indio_dev);
142 return ret;
143 }
144 ret = i2c_smbus_read_word_data(data->client, chan->address);
145 iio_device_release_direct(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
tcs3414_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)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
tcs3414_trigger_handler(int irq,void * p)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 iio_for_each_active_channel(indio_dev, i) {
209 int ret = i2c_smbus_read_word_data(data->client,
210 TCS3414_DATA_GREEN + 2*i);
211 if (ret < 0)
212 goto done;
213
214 data->scan.chans[j++] = ret;
215 }
216
217 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
218 iio_get_time_ns(indio_dev));
219
220 done:
221 iio_trigger_notify_done(indio_dev->trig);
222
223 return IRQ_HANDLED;
224 }
225
226 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
227 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
228
229 static struct attribute *tcs3414_attributes[] = {
230 &iio_const_attr_scale_available.dev_attr.attr,
231 &iio_const_attr_integration_time_available.dev_attr.attr,
232 NULL
233 };
234
235 static const struct attribute_group tcs3414_attribute_group = {
236 .attrs = tcs3414_attributes,
237 };
238
239 static const struct iio_info tcs3414_info = {
240 .read_raw = tcs3414_read_raw,
241 .write_raw = tcs3414_write_raw,
242 .attrs = &tcs3414_attribute_group,
243 };
244
tcs3414_buffer_postenable(struct iio_dev * indio_dev)245 static int tcs3414_buffer_postenable(struct iio_dev *indio_dev)
246 {
247 struct tcs3414_data *data = iio_priv(indio_dev);
248
249 data->control |= TCS3414_CONTROL_ADC_EN;
250 return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
251 data->control);
252 }
253
tcs3414_buffer_predisable(struct iio_dev * indio_dev)254 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
255 {
256 struct tcs3414_data *data = iio_priv(indio_dev);
257
258 data->control &= ~TCS3414_CONTROL_ADC_EN;
259 return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
260 data->control);
261 }
262
263 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
264 .postenable = tcs3414_buffer_postenable,
265 .predisable = tcs3414_buffer_predisable,
266 };
267
tcs3414_powerdown(struct tcs3414_data * data)268 static int tcs3414_powerdown(struct tcs3414_data *data)
269 {
270 return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
271 data->control & ~(TCS3414_CONTROL_POWER |
272 TCS3414_CONTROL_ADC_EN));
273 }
274
tcs3414_powerdown_cleanup(void * data)275 static void tcs3414_powerdown_cleanup(void *data)
276 {
277 tcs3414_powerdown(data);
278 }
279
tcs3414_probe(struct i2c_client * client)280 static int tcs3414_probe(struct i2c_client *client)
281 {
282 struct tcs3414_data *data;
283 struct iio_dev *indio_dev;
284 int ret;
285
286 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
287 if (indio_dev == NULL)
288 return -ENOMEM;
289
290 data = iio_priv(indio_dev);
291 i2c_set_clientdata(client, indio_dev);
292 data->client = client;
293
294 indio_dev->info = &tcs3414_info;
295 indio_dev->name = TCS3414_DRV_NAME;
296 indio_dev->channels = tcs3414_channels;
297 indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
298 indio_dev->modes = INDIO_DIRECT_MODE;
299
300 ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
301 if (ret < 0)
302 return ret;
303
304 switch (ret & 0xf0) {
305 case 0x00:
306 dev_info(&client->dev, "TCS3404 found\n");
307 break;
308 case 0x10:
309 dev_info(&client->dev, "TCS3413/14/15/16 found\n");
310 break;
311 default:
312 return -ENODEV;
313 }
314
315 data->control = TCS3414_CONTROL_POWER;
316 ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
317 data->control);
318 if (ret < 0)
319 return ret;
320
321 ret = devm_add_action_or_reset(&client->dev, tcs3414_powerdown_cleanup,
322 data);
323 if (ret < 0)
324 return ret;
325
326 data->timing = TCS3414_INTEG_12MS; /* free running */
327 ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
328 data->timing);
329 if (ret < 0)
330 return ret;
331
332 ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
333 if (ret < 0)
334 return ret;
335 data->gain = ret;
336
337 ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
338 tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
339 if (ret < 0)
340 return ret;
341
342 return devm_iio_device_register(&client->dev, indio_dev);
343 }
344
tcs3414_suspend(struct device * dev)345 static int tcs3414_suspend(struct device *dev)
346 {
347 struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
348 to_i2c_client(dev)));
349 return tcs3414_powerdown(data);
350 }
351
tcs3414_resume(struct device * dev)352 static int tcs3414_resume(struct device *dev)
353 {
354 struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
355 to_i2c_client(dev)));
356 return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
357 data->control);
358 }
359
360 static DEFINE_SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend,
361 tcs3414_resume);
362
363 static const struct i2c_device_id tcs3414_id[] = {
364 { "tcs3414" },
365 { }
366 };
367 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
368
369 static struct i2c_driver tcs3414_driver = {
370 .driver = {
371 .name = TCS3414_DRV_NAME,
372 .pm = pm_sleep_ptr(&tcs3414_pm_ops),
373 },
374 .probe = tcs3414_probe,
375 .id_table = tcs3414_id,
376 };
377 module_i2c_driver(tcs3414_driver);
378
379 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
380 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
381 MODULE_LICENSE("GPL");
382