1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * adjd_s311.c - Support for ADJD-S311-CR999 digital color sensor
4 *
5 * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
6 *
7 * driver for ADJD-S311-CR999 digital color sensor (10-bit channels for
8 * red, green, blue, clear); 7-bit I2C slave address 0x74
9 *
10 * limitations: no calibration, no offset mode, no sleep mode
11 */
12
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include <linux/i2c.h>
16#include <linux/slab.h>
17#include <linux/delay.h>
18#include <linux/bitmap.h>
19#include <linux/err.h>
20#include <linux/irq.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 ADJD_S311_DRV_NAME "adjd_s311"
29
30#define ADJD_S311_CTRL		0x00
31#define ADJD_S311_CONFIG	0x01
32#define ADJD_S311_CAP_RED	0x06
33#define ADJD_S311_CAP_GREEN	0x07
34#define ADJD_S311_CAP_BLUE	0x08
35#define ADJD_S311_CAP_CLEAR	0x09
36#define ADJD_S311_INT_RED	0x0a
37#define ADJD_S311_INT_GREEN	0x0c
38#define ADJD_S311_INT_BLUE	0x0e
39#define ADJD_S311_INT_CLEAR	0x10
40#define ADJD_S311_DATA_RED	0x40
41#define ADJD_S311_DATA_GREEN	0x42
42#define ADJD_S311_DATA_BLUE	0x44
43#define ADJD_S311_DATA_CLEAR	0x46
44#define ADJD_S311_OFFSET_RED	0x48
45#define ADJD_S311_OFFSET_GREEN	0x49
46#define ADJD_S311_OFFSET_BLUE	0x4a
47#define ADJD_S311_OFFSET_CLEAR	0x4b
48
49#define ADJD_S311_CTRL_GOFS	0x02
50#define ADJD_S311_CTRL_GSSR	0x01
51#define ADJD_S311_CAP_MASK	0x0f
52#define ADJD_S311_INT_MASK	0x0fff
53#define ADJD_S311_DATA_MASK	0x03ff
54
55struct adjd_s311_data {
56	struct i2c_client *client;
57	u16 *buffer;
58};
59
60enum adjd_s311_channel_idx {
61	IDX_RED, IDX_GREEN, IDX_BLUE, IDX_CLEAR
62};
63
64#define ADJD_S311_DATA_REG(chan) (ADJD_S311_DATA_RED + (chan) * 2)
65#define ADJD_S311_INT_REG(chan) (ADJD_S311_INT_RED + (chan) * 2)
66#define ADJD_S311_CAP_REG(chan) (ADJD_S311_CAP_RED + (chan))
67
68static int adjd_s311_req_data(struct iio_dev *indio_dev)
69{
70	struct adjd_s311_data *data = iio_priv(indio_dev);
71	int tries = 10;
72
73	int ret = i2c_smbus_write_byte_data(data->client, ADJD_S311_CTRL,
74		ADJD_S311_CTRL_GSSR);
75	if (ret < 0)
76		return ret;
77
78	while (tries--) {
79		ret = i2c_smbus_read_byte_data(data->client, ADJD_S311_CTRL);
80		if (ret < 0)
81			return ret;
82		if (!(ret & ADJD_S311_CTRL_GSSR))
83			break;
84		msleep(20);
85	}
86
87	if (tries < 0) {
88		dev_err(&data->client->dev,
89			"adjd_s311_req_data() failed, data not ready\n");
90		return -EIO;
91	}
92
93	return 0;
94}
95
96static int adjd_s311_read_data(struct iio_dev *indio_dev, u8 reg, int *val)
97{
98	struct adjd_s311_data *data = iio_priv(indio_dev);
99
100	int ret = adjd_s311_req_data(indio_dev);
101	if (ret < 0)
102		return ret;
103
104	ret = i2c_smbus_read_word_data(data->client, reg);
105	if (ret < 0)
106		return ret;
107
108	*val = ret & ADJD_S311_DATA_MASK;
109
110	return 0;
111}
112
113static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
114{
115	struct iio_poll_func *pf = p;
116	struct iio_dev *indio_dev = pf->indio_dev;
117	struct adjd_s311_data *data = iio_priv(indio_dev);
118	s64 time_ns = iio_get_time_ns(indio_dev);
119	int i, j = 0;
120
121	int ret = adjd_s311_req_data(indio_dev);
122	if (ret < 0)
123		goto done;
124
125	for_each_set_bit(i, indio_dev->active_scan_mask,
126		indio_dev->masklength) {
127		ret = i2c_smbus_read_word_data(data->client,
128			ADJD_S311_DATA_REG(i));
129		if (ret < 0)
130			goto done;
131
132		data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
133	}
134
135	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, time_ns);
136
137done:
138	iio_trigger_notify_done(indio_dev->trig);
139
140	return IRQ_HANDLED;
141}
142
143#define ADJD_S311_CHANNEL(_color, _scan_idx) { \
144	.type = IIO_INTENSITY, \
145	.modified = 1, \
146	.address = (IDX_##_color), \
147	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
148		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
149		BIT(IIO_CHAN_INFO_INT_TIME), \
150	.channel2 = (IIO_MOD_LIGHT_##_color), \
151	.scan_index = (_scan_idx), \
152	.scan_type = { \
153		.sign = 'u', \
154		.realbits = 10, \
155		.storagebits = 16, \
156		.endianness = IIO_CPU, \
157	}, \
158}
159
160static const struct iio_chan_spec adjd_s311_channels[] = {
161	ADJD_S311_CHANNEL(RED, 0),
162	ADJD_S311_CHANNEL(GREEN, 1),
163	ADJD_S311_CHANNEL(BLUE, 2),
164	ADJD_S311_CHANNEL(CLEAR, 3),
165	IIO_CHAN_SOFT_TIMESTAMP(4),
166};
167
168static int adjd_s311_read_raw(struct iio_dev *indio_dev,
169			   struct iio_chan_spec const *chan,
170			   int *val, int *val2, long mask)
171{
172	struct adjd_s311_data *data = iio_priv(indio_dev);
173	int ret;
174
175	switch (mask) {
176	case IIO_CHAN_INFO_RAW:
177		ret = adjd_s311_read_data(indio_dev,
178			ADJD_S311_DATA_REG(chan->address), val);
179		if (ret < 0)
180			return ret;
181		return IIO_VAL_INT;
182	case IIO_CHAN_INFO_HARDWAREGAIN:
183		ret = i2c_smbus_read_byte_data(data->client,
184			ADJD_S311_CAP_REG(chan->address));
185		if (ret < 0)
186			return ret;
187		*val = ret & ADJD_S311_CAP_MASK;
188		return IIO_VAL_INT;
189	case IIO_CHAN_INFO_INT_TIME:
190		ret = i2c_smbus_read_word_data(data->client,
191			ADJD_S311_INT_REG(chan->address));
192		if (ret < 0)
193			return ret;
194		*val = 0;
195		/*
196		 * not documented, based on measurement:
197		 * 4095 LSBs correspond to roughly 4 ms
198		 */
199		*val2 = ret & ADJD_S311_INT_MASK;
200		return IIO_VAL_INT_PLUS_MICRO;
201	}
202	return -EINVAL;
203}
204
205static int adjd_s311_write_raw(struct iio_dev *indio_dev,
206			       struct iio_chan_spec const *chan,
207			       int val, int val2, long mask)
208{
209	struct adjd_s311_data *data = iio_priv(indio_dev);
210
211	switch (mask) {
212	case IIO_CHAN_INFO_HARDWAREGAIN:
213		if (val < 0 || val > ADJD_S311_CAP_MASK)
214			return -EINVAL;
215
216		return i2c_smbus_write_byte_data(data->client,
217			ADJD_S311_CAP_REG(chan->address), val);
218	case IIO_CHAN_INFO_INT_TIME:
219		if (val != 0 || val2 < 0 || val2 > ADJD_S311_INT_MASK)
220			return -EINVAL;
221
222		return i2c_smbus_write_word_data(data->client,
223			ADJD_S311_INT_REG(chan->address), val2);
224	}
225	return -EINVAL;
226}
227
228static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
229	const unsigned long *scan_mask)
230{
231	struct adjd_s311_data *data = iio_priv(indio_dev);
232
233	kfree(data->buffer);
234	data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
235	if (data->buffer == NULL)
236		return -ENOMEM;
237
238	return 0;
239}
240
241static const struct iio_info adjd_s311_info = {
242	.read_raw = adjd_s311_read_raw,
243	.write_raw = adjd_s311_write_raw,
244	.update_scan_mode = adjd_s311_update_scan_mode,
245};
246
247static int adjd_s311_probe(struct i2c_client *client,
248			   const struct i2c_device_id *id)
249{
250	struct adjd_s311_data *data;
251	struct iio_dev *indio_dev;
252	int err;
253
254	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
255	if (indio_dev == NULL)
256		return -ENOMEM;
257
258	data = iio_priv(indio_dev);
259	i2c_set_clientdata(client, indio_dev);
260	data->client = client;
261
262	indio_dev->info = &adjd_s311_info;
263	indio_dev->name = ADJD_S311_DRV_NAME;
264	indio_dev->channels = adjd_s311_channels;
265	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
266	indio_dev->modes = INDIO_DIRECT_MODE;
267
268	err = iio_triggered_buffer_setup(indio_dev, NULL,
269		adjd_s311_trigger_handler, NULL);
270	if (err < 0)
271		return err;
272
273	err = iio_device_register(indio_dev);
274	if (err)
275		goto exit_unreg_buffer;
276
277	dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
278
279	return 0;
280
281exit_unreg_buffer:
282	iio_triggered_buffer_cleanup(indio_dev);
283	return err;
284}
285
286static int adjd_s311_remove(struct i2c_client *client)
287{
288	struct iio_dev *indio_dev = i2c_get_clientdata(client);
289	struct adjd_s311_data *data = iio_priv(indio_dev);
290
291	iio_device_unregister(indio_dev);
292	iio_triggered_buffer_cleanup(indio_dev);
293	kfree(data->buffer);
294
295	return 0;
296}
297
298static const struct i2c_device_id adjd_s311_id[] = {
299	{ "adjd_s311", 0 },
300	{ }
301};
302MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
303
304static struct i2c_driver adjd_s311_driver = {
305	.driver = {
306		.name	= ADJD_S311_DRV_NAME,
307	},
308	.probe		= adjd_s311_probe,
309	.remove		= adjd_s311_remove,
310	.id_table	= adjd_s311_id,
311};
312module_i2c_driver(adjd_s311_driver);
313
314MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
315MODULE_DESCRIPTION("ADJD-S311 color sensor");
316MODULE_LICENSE("GPL");
317