1/*
2 * tcs3414.c - Support for TAOS TCS3414 digital color sensor
3 *
4 * Copyright (c) 2014 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 * Digital color sensor with 16-bit channels for red, green, blue, clear);
11 * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
12 * TCS3415, TCS3416, resp.)
13 *
14 * TODO: sync, interrupt support, thresholds, prescaler
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 TCS3414_DRV_NAME "tcs3414"
29
30#define TCS3414_COMMAND BIT(7)
31#define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
32
33#define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
34#define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
35#define TCS3414_ID (TCS3414_COMMAND | 0x04)
36#define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
37#define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
38#define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
39#define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
40#define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
41
42#define TCS3414_CONTROL_ADC_VALID BIT(4)
43#define TCS3414_CONTROL_ADC_EN BIT(1)
44#define TCS3414_CONTROL_POWER BIT(0)
45
46#define TCS3414_INTEG_MASK GENMASK(1, 0)
47#define TCS3414_INTEG_12MS 0x0
48#define TCS3414_INTEG_100MS 0x1
49#define TCS3414_INTEG_400MS 0x2
50
51#define TCS3414_GAIN_MASK GENMASK(5, 4)
52#define TCS3414_GAIN_SHIFT 4
53
54struct tcs3414_data {
55	struct i2c_client *client;
56	struct mutex lock;
57	u8 control;
58	u8 gain;
59	u8 timing;
60	u16 buffer[8]; /* 4x 16-bit + 8 bytes timestamp */
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 */
81static const int tcs3414_scales[][2] = {
82	{1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
83};
84
85/* integration time in ms */
86static const int tcs3414_times[] = { 12, 100, 400 };
87
88static 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
96static 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
128static 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_buffer_enabled(indio_dev))
138			return -EBUSY;
139		mutex_lock(&data->lock);
140		ret = tcs3414_req_data(data);
141		if (ret < 0) {
142			mutex_unlock(&data->lock);
143			return ret;
144		}
145		ret = i2c_smbus_read_word_data(data->client, chan->address);
146		mutex_unlock(&data->lock);
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
164static 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 (val == 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
202static 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->buffer[j++] = ret;
217	}
218
219	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
220		iio_get_time_ns());
221
222done:
223	iio_trigger_notify_done(indio_dev->trig);
224
225	return IRQ_HANDLED;
226}
227
228static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
229static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
230
231static 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
237static const struct attribute_group tcs3414_attribute_group = {
238	.attrs = tcs3414_attributes,
239};
240
241static const struct iio_info tcs3414_info = {
242	.read_raw = tcs3414_read_raw,
243	.write_raw = tcs3414_write_raw,
244	.attrs = &tcs3414_attribute_group,
245	.driver_module = THIS_MODULE,
246};
247
248static int tcs3414_buffer_preenable(struct iio_dev *indio_dev)
249{
250	struct tcs3414_data *data = iio_priv(indio_dev);
251
252	data->control |= TCS3414_CONTROL_ADC_EN;
253	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
254		data->control);
255}
256
257static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
258{
259	struct tcs3414_data *data = iio_priv(indio_dev);
260	int ret;
261
262	ret = iio_triggered_buffer_predisable(indio_dev);
263	if (ret < 0)
264		return ret;
265
266	data->control &= ~TCS3414_CONTROL_ADC_EN;
267	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
268		data->control);
269}
270
271static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
272	.preenable = tcs3414_buffer_preenable,
273	.postenable = &iio_triggered_buffer_postenable,
274	.predisable = tcs3414_buffer_predisable,
275};
276
277static int tcs3414_probe(struct i2c_client *client,
278			   const struct i2c_device_id *id)
279{
280	struct tcs3414_data *data;
281	struct iio_dev *indio_dev;
282	int ret;
283
284	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
285	if (indio_dev == NULL)
286		return -ENOMEM;
287
288	data = iio_priv(indio_dev);
289	i2c_set_clientdata(client, indio_dev);
290	data->client = client;
291	mutex_init(&data->lock);
292
293	indio_dev->dev.parent = &client->dev;
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	data->timing = TCS3414_INTEG_12MS; /* free running */
322	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
323		data->timing);
324	if (ret < 0)
325		return ret;
326
327	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
328	if (ret < 0)
329		return ret;
330	data->gain = ret;
331
332	ret = iio_triggered_buffer_setup(indio_dev, NULL,
333		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
334	if (ret < 0)
335		return ret;
336
337	ret = iio_device_register(indio_dev);
338	if (ret < 0)
339		goto buffer_cleanup;
340
341	return 0;
342
343buffer_cleanup:
344	iio_triggered_buffer_cleanup(indio_dev);
345	return ret;
346}
347
348static int tcs3414_powerdown(struct tcs3414_data *data)
349{
350	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
351		data->control & ~(TCS3414_CONTROL_POWER |
352		TCS3414_CONTROL_ADC_EN));
353}
354
355static int tcs3414_remove(struct i2c_client *client)
356{
357	struct iio_dev *indio_dev = i2c_get_clientdata(client);
358
359	iio_device_unregister(indio_dev);
360	iio_triggered_buffer_cleanup(indio_dev);
361	tcs3414_powerdown(iio_priv(indio_dev));
362
363	return 0;
364}
365
366#ifdef CONFIG_PM_SLEEP
367static int tcs3414_suspend(struct device *dev)
368{
369	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
370		to_i2c_client(dev)));
371	return tcs3414_powerdown(data);
372}
373
374static int tcs3414_resume(struct device *dev)
375{
376	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
377		to_i2c_client(dev)));
378	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
379		data->control);
380}
381#endif
382
383static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
384
385static const struct i2c_device_id tcs3414_id[] = {
386	{ "tcs3414", 0 },
387	{ }
388};
389MODULE_DEVICE_TABLE(i2c, tcs3414_id);
390
391static struct i2c_driver tcs3414_driver = {
392	.driver = {
393		.name	= TCS3414_DRV_NAME,
394		.pm	= &tcs3414_pm_ops,
395		.owner	= THIS_MODULE,
396	},
397	.probe		= tcs3414_probe,
398	.remove		= tcs3414_remove,
399	.id_table	= tcs3414_id,
400};
401module_i2c_driver(tcs3414_driver);
402
403MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
404MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
405MODULE_LICENSE("GPL");
406