xref: /openbmc/linux/drivers/iio/light/adjd_s311.c (revision 7cf15f42)
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 	struct {
58 		s16 chans[4];
59 		s64 ts __aligned(8);
60 	} scan;
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->scan.chans[j++] = ret & ADJD_S311_DATA_MASK;
136 	}
137 
138 	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 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 
231 static const struct iio_info adjd_s311_info = {
232 	.read_raw = adjd_s311_read_raw,
233 	.write_raw = adjd_s311_write_raw,
234 };
235 
adjd_s311_probe(struct i2c_client * client)236 static int adjd_s311_probe(struct i2c_client *client)
237 {
238 	struct adjd_s311_data *data;
239 	struct iio_dev *indio_dev;
240 	int err;
241 
242 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
243 	if (indio_dev == NULL)
244 		return -ENOMEM;
245 
246 	data = iio_priv(indio_dev);
247 	data->client = client;
248 
249 	indio_dev->info = &adjd_s311_info;
250 	indio_dev->name = ADJD_S311_DRV_NAME;
251 	indio_dev->channels = adjd_s311_channels;
252 	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
253 	indio_dev->modes = INDIO_DIRECT_MODE;
254 
255 	err = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
256 					      adjd_s311_trigger_handler, NULL);
257 	if (err < 0)
258 		return err;
259 
260 	return devm_iio_device_register(&client->dev, indio_dev);
261 }
262 
263 static const struct i2c_device_id adjd_s311_id[] = {
264 	{ "adjd_s311", 0 },
265 	{ }
266 };
267 MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
268 
269 static struct i2c_driver adjd_s311_driver = {
270 	.driver = {
271 		.name	= ADJD_S311_DRV_NAME,
272 	},
273 	.probe		= adjd_s311_probe,
274 	.id_table	= adjd_s311_id,
275 };
276 module_i2c_driver(adjd_s311_driver);
277 
278 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
279 MODULE_DESCRIPTION("ADJD-S311 color sensor");
280 MODULE_LICENSE("GPL");
281