1 /*
2  * adjd_s311.c - Support for ADJD-S311-CR999 digital color sensor
3  *
4  * Copyright (C) 2012 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  * driver for ADJD-S311-CR999 digital color sensor (10-bit channels for
11  * red, green, blue, clear); 7-bit I2C slave address 0x74
12  *
13  * limitations: no calibration, no offset mode, no sleep mode
14  */
15 
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/i2c.h>
19 #include <linux/slab.h>
20 #include <linux/delay.h>
21 #include <linux/bitmap.h>
22 #include <linux/err.h>
23 #include <linux/irq.h>
24 
25 #include <linux/iio/iio.h>
26 #include <linux/iio/sysfs.h>
27 #include <linux/iio/trigger_consumer.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/triggered_buffer.h>
30 
31 #define ADJD_S311_DRV_NAME "adjd_s311"
32 
33 #define ADJD_S311_CTRL		0x00
34 #define ADJD_S311_CONFIG	0x01
35 #define ADJD_S311_CAP_RED	0x06
36 #define ADJD_S311_CAP_GREEN	0x07
37 #define ADJD_S311_CAP_BLUE	0x08
38 #define ADJD_S311_CAP_CLEAR	0x09
39 #define ADJD_S311_INT_RED	0x0a
40 #define ADJD_S311_INT_GREEN	0x0c
41 #define ADJD_S311_INT_BLUE	0x0e
42 #define ADJD_S311_INT_CLEAR	0x10
43 #define ADJD_S311_DATA_RED	0x40
44 #define ADJD_S311_DATA_GREEN	0x42
45 #define ADJD_S311_DATA_BLUE	0x44
46 #define ADJD_S311_DATA_CLEAR	0x46
47 #define ADJD_S311_OFFSET_RED	0x48
48 #define ADJD_S311_OFFSET_GREEN	0x49
49 #define ADJD_S311_OFFSET_BLUE	0x4a
50 #define ADJD_S311_OFFSET_CLEAR	0x4b
51 
52 #define ADJD_S311_CTRL_GOFS	0x02
53 #define ADJD_S311_CTRL_GSSR	0x01
54 #define ADJD_S311_CAP_MASK	0x0f
55 #define ADJD_S311_INT_MASK	0x0fff
56 #define ADJD_S311_DATA_MASK	0x03ff
57 
58 struct adjd_s311_data {
59 	struct i2c_client *client;
60 	u16 *buffer;
61 };
62 
63 enum adjd_s311_channel_idx {
64 	IDX_RED, IDX_GREEN, IDX_BLUE, IDX_CLEAR
65 };
66 
67 #define ADJD_S311_DATA_REG(chan) (ADJD_S311_DATA_RED + (chan) * 2)
68 #define ADJD_S311_INT_REG(chan) (ADJD_S311_INT_RED + (chan) * 2)
69 #define ADJD_S311_CAP_REG(chan) (ADJD_S311_CAP_RED + (chan))
70 
adjd_s311_req_data(struct iio_dev * indio_dev)71 static int adjd_s311_req_data(struct iio_dev *indio_dev)
72 {
73 	struct adjd_s311_data *data = iio_priv(indio_dev);
74 	int tries = 10;
75 
76 	int ret = i2c_smbus_write_byte_data(data->client, ADJD_S311_CTRL,
77 		ADJD_S311_CTRL_GSSR);
78 	if (ret < 0)
79 		return ret;
80 
81 	while (tries--) {
82 		ret = i2c_smbus_read_byte_data(data->client, ADJD_S311_CTRL);
83 		if (ret < 0)
84 			return ret;
85 		if (!(ret & ADJD_S311_CTRL_GSSR))
86 			break;
87 		msleep(20);
88 	}
89 
90 	if (tries < 0) {
91 		dev_err(&data->client->dev,
92 			"adjd_s311_req_data() failed, data not ready\n");
93 		return -EIO;
94 	}
95 
96 	return 0;
97 }
98 
adjd_s311_read_data(struct iio_dev * indio_dev,u8 reg,int * val)99 static int adjd_s311_read_data(struct iio_dev *indio_dev, u8 reg, int *val)
100 {
101 	struct adjd_s311_data *data = iio_priv(indio_dev);
102 
103 	int ret = adjd_s311_req_data(indio_dev);
104 	if (ret < 0)
105 		return ret;
106 
107 	ret = i2c_smbus_read_word_data(data->client, reg);
108 	if (ret < 0)
109 		return ret;
110 
111 	*val = ret & ADJD_S311_DATA_MASK;
112 
113 	return 0;
114 }
115 
adjd_s311_trigger_handler(int irq,void * p)116 static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
117 {
118 	struct iio_poll_func *pf = p;
119 	struct iio_dev *indio_dev = pf->indio_dev;
120 	struct adjd_s311_data *data = iio_priv(indio_dev);
121 	s64 time_ns = iio_get_time_ns(indio_dev);
122 	int i, j = 0;
123 
124 	int ret = adjd_s311_req_data(indio_dev);
125 	if (ret < 0)
126 		goto done;
127 
128 	for_each_set_bit(i, indio_dev->active_scan_mask,
129 		indio_dev->masklength) {
130 		ret = i2c_smbus_read_word_data(data->client,
131 			ADJD_S311_DATA_REG(i));
132 		if (ret < 0)
133 			goto done;
134 
135 		data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
136 	}
137 
138 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, time_ns);
139 
140 done:
141 	iio_trigger_notify_done(indio_dev->trig);
142 
143 	return IRQ_HANDLED;
144 }
145 
146 #define ADJD_S311_CHANNEL(_color, _scan_idx) { \
147 	.type = IIO_INTENSITY, \
148 	.modified = 1, \
149 	.address = (IDX_##_color), \
150 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
151 		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
152 		BIT(IIO_CHAN_INFO_INT_TIME), \
153 	.channel2 = (IIO_MOD_LIGHT_##_color), \
154 	.scan_index = (_scan_idx), \
155 	.scan_type = { \
156 		.sign = 'u', \
157 		.realbits = 10, \
158 		.storagebits = 16, \
159 		.endianness = IIO_CPU, \
160 	}, \
161 }
162 
163 static const struct iio_chan_spec adjd_s311_channels[] = {
164 	ADJD_S311_CHANNEL(RED, 0),
165 	ADJD_S311_CHANNEL(GREEN, 1),
166 	ADJD_S311_CHANNEL(BLUE, 2),
167 	ADJD_S311_CHANNEL(CLEAR, 3),
168 	IIO_CHAN_SOFT_TIMESTAMP(4),
169 };
170 
adjd_s311_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)171 static int adjd_s311_read_raw(struct iio_dev *indio_dev,
172 			   struct iio_chan_spec const *chan,
173 			   int *val, int *val2, long mask)
174 {
175 	struct adjd_s311_data *data = iio_priv(indio_dev);
176 	int ret;
177 
178 	switch (mask) {
179 	case IIO_CHAN_INFO_RAW:
180 		ret = adjd_s311_read_data(indio_dev,
181 			ADJD_S311_DATA_REG(chan->address), val);
182 		if (ret < 0)
183 			return ret;
184 		return IIO_VAL_INT;
185 	case IIO_CHAN_INFO_HARDWAREGAIN:
186 		ret = i2c_smbus_read_byte_data(data->client,
187 			ADJD_S311_CAP_REG(chan->address));
188 		if (ret < 0)
189 			return ret;
190 		*val = ret & ADJD_S311_CAP_MASK;
191 		return IIO_VAL_INT;
192 	case IIO_CHAN_INFO_INT_TIME:
193 		ret = i2c_smbus_read_word_data(data->client,
194 			ADJD_S311_INT_REG(chan->address));
195 		if (ret < 0)
196 			return ret;
197 		*val = 0;
198 		/*
199 		 * not documented, based on measurement:
200 		 * 4095 LSBs correspond to roughly 4 ms
201 		 */
202 		*val2 = ret & ADJD_S311_INT_MASK;
203 		return IIO_VAL_INT_PLUS_MICRO;
204 	}
205 	return -EINVAL;
206 }
207 
adjd_s311_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)208 static int adjd_s311_write_raw(struct iio_dev *indio_dev,
209 			       struct iio_chan_spec const *chan,
210 			       int val, int val2, long mask)
211 {
212 	struct adjd_s311_data *data = iio_priv(indio_dev);
213 
214 	switch (mask) {
215 	case IIO_CHAN_INFO_HARDWAREGAIN:
216 		if (val < 0 || val > ADJD_S311_CAP_MASK)
217 			return -EINVAL;
218 
219 		return i2c_smbus_write_byte_data(data->client,
220 			ADJD_S311_CAP_REG(chan->address), val);
221 	case IIO_CHAN_INFO_INT_TIME:
222 		if (val != 0 || val2 < 0 || val2 > ADJD_S311_INT_MASK)
223 			return -EINVAL;
224 
225 		return i2c_smbus_write_word_data(data->client,
226 			ADJD_S311_INT_REG(chan->address), val2);
227 	}
228 	return -EINVAL;
229 }
230 
adjd_s311_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)231 static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
232 	const unsigned long *scan_mask)
233 {
234 	struct adjd_s311_data *data = iio_priv(indio_dev);
235 
236 	kfree(data->buffer);
237 	data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
238 	if (data->buffer == NULL)
239 		return -ENOMEM;
240 
241 	return 0;
242 }
243 
244 static const struct iio_info adjd_s311_info = {
245 	.read_raw = adjd_s311_read_raw,
246 	.write_raw = adjd_s311_write_raw,
247 	.update_scan_mode = adjd_s311_update_scan_mode,
248 };
249 
adjd_s311_probe(struct i2c_client * client,const struct i2c_device_id * id)250 static int adjd_s311_probe(struct i2c_client *client,
251 			   const struct i2c_device_id *id)
252 {
253 	struct adjd_s311_data *data;
254 	struct iio_dev *indio_dev;
255 	int err;
256 
257 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
258 	if (indio_dev == NULL)
259 		return -ENOMEM;
260 
261 	data = iio_priv(indio_dev);
262 	i2c_set_clientdata(client, indio_dev);
263 	data->client = client;
264 
265 	indio_dev->dev.parent = &client->dev;
266 	indio_dev->info = &adjd_s311_info;
267 	indio_dev->name = ADJD_S311_DRV_NAME;
268 	indio_dev->channels = adjd_s311_channels;
269 	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
270 	indio_dev->modes = INDIO_DIRECT_MODE;
271 
272 	err = iio_triggered_buffer_setup(indio_dev, NULL,
273 		adjd_s311_trigger_handler, NULL);
274 	if (err < 0)
275 		return err;
276 
277 	err = iio_device_register(indio_dev);
278 	if (err)
279 		goto exit_unreg_buffer;
280 
281 	dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
282 
283 	return 0;
284 
285 exit_unreg_buffer:
286 	iio_triggered_buffer_cleanup(indio_dev);
287 	return err;
288 }
289 
adjd_s311_remove(struct i2c_client * client)290 static int adjd_s311_remove(struct i2c_client *client)
291 {
292 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
293 	struct adjd_s311_data *data = iio_priv(indio_dev);
294 
295 	iio_device_unregister(indio_dev);
296 	iio_triggered_buffer_cleanup(indio_dev);
297 	kfree(data->buffer);
298 
299 	return 0;
300 }
301 
302 static const struct i2c_device_id adjd_s311_id[] = {
303 	{ "adjd_s311", 0 },
304 	{ }
305 };
306 MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
307 
308 static struct i2c_driver adjd_s311_driver = {
309 	.driver = {
310 		.name	= ADJD_S311_DRV_NAME,
311 	},
312 	.probe		= adjd_s311_probe,
313 	.remove		= adjd_s311_remove,
314 	.id_table	= adjd_s311_id,
315 };
316 module_i2c_driver(adjd_s311_driver);
317 
318 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
319 MODULE_DESCRIPTION("ADJD-S311 color sensor");
320 MODULE_LICENSE("GPL");
321