xref: /openbmc/linux/drivers/iio/light/adjd_s311.c (revision 8e20ba2e)
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 
55 struct adjd_s311_data {
56 	struct i2c_client *client;
57 	u16 *buffer;
58 };
59 
60 enum 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 
68 static 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 
96 static 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 
113 static 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 
137 done:
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 
160 static 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 
168 static 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 
205 static 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 
228 static 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 
241 static 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 
247 static 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->dev.parent = &client->dev;
263 	indio_dev->info = &adjd_s311_info;
264 	indio_dev->name = ADJD_S311_DRV_NAME;
265 	indio_dev->channels = adjd_s311_channels;
266 	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
267 	indio_dev->modes = INDIO_DIRECT_MODE;
268 
269 	err = iio_triggered_buffer_setup(indio_dev, NULL,
270 		adjd_s311_trigger_handler, NULL);
271 	if (err < 0)
272 		return err;
273 
274 	err = iio_device_register(indio_dev);
275 	if (err)
276 		goto exit_unreg_buffer;
277 
278 	dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
279 
280 	return 0;
281 
282 exit_unreg_buffer:
283 	iio_triggered_buffer_cleanup(indio_dev);
284 	return err;
285 }
286 
287 static int adjd_s311_remove(struct i2c_client *client)
288 {
289 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
290 	struct adjd_s311_data *data = iio_priv(indio_dev);
291 
292 	iio_device_unregister(indio_dev);
293 	iio_triggered_buffer_cleanup(indio_dev);
294 	kfree(data->buffer);
295 
296 	return 0;
297 }
298 
299 static const struct i2c_device_id adjd_s311_id[] = {
300 	{ "adjd_s311", 0 },
301 	{ }
302 };
303 MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
304 
305 static struct i2c_driver adjd_s311_driver = {
306 	.driver = {
307 		.name	= ADJD_S311_DRV_NAME,
308 	},
309 	.probe		= adjd_s311_probe,
310 	.remove		= adjd_s311_remove,
311 	.id_table	= adjd_s311_id,
312 };
313 module_i2c_driver(adjd_s311_driver);
314 
315 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
316 MODULE_DESCRIPTION("ADJD-S311 color sensor");
317 MODULE_LICENSE("GPL");
318