1 /*
2  * CM3323 - Capella Color Light Sensor
3  *
4  * Copyright (c) 2015, Intel Corporation.
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  * IIO driver for CM3323 (7-bit I2C slave address 0x10)
11  *
12  * TODO: calibscale to correct the lens factor
13  */
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/i2c.h>
17 #include <linux/mutex.h>
18 
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 
22 #define CM3323_DRV_NAME "cm3323"
23 
24 #define CM3323_CMD_CONF		0x00
25 #define CM3323_CMD_RED_DATA	0x08
26 #define CM3323_CMD_GREEN_DATA	0x09
27 #define CM3323_CMD_BLUE_DATA	0x0A
28 #define CM3323_CMD_CLEAR_DATA	0x0B
29 
30 #define CM3323_CONF_SD_BIT	BIT(0) /* sensor disable */
31 #define CM3323_CONF_AF_BIT	BIT(1) /* auto/manual force mode */
32 #define CM3323_CONF_IT_MASK	GENMASK(6, 4)
33 #define CM3323_CONF_IT_SHIFT	4
34 
35 #define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
36 
37 static const struct {
38 	int val;
39 	int val2;
40 } cm3323_int_time[] = {
41 	{0, 40000},  /* 40 ms */
42 	{0, 80000},  /* 80 ms */
43 	{0, 160000}, /* 160 ms */
44 	{0, 320000}, /* 320 ms */
45 	{0, 640000}, /* 640 ms */
46 	{1, 280000}, /* 1280 ms */
47 };
48 
49 struct cm3323_data {
50 	struct i2c_client *client;
51 	u16 reg_conf;
52 	struct mutex mutex;
53 };
54 
55 #define CM3323_COLOR_CHANNEL(_color, _addr) { \
56 	.type = IIO_INTENSITY, \
57 	.modified = 1, \
58 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
59 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
60 	.channel2 = IIO_MOD_LIGHT_##_color, \
61 	.address = _addr, \
62 }
63 
64 static const struct iio_chan_spec cm3323_channels[] = {
65 	CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
66 	CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
67 	CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
68 	CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
69 };
70 
71 static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
72 
73 static struct attribute *cm3323_attributes[] = {
74 	&iio_const_attr_integration_time_available.dev_attr.attr,
75 	NULL
76 };
77 
78 static const struct attribute_group cm3323_attribute_group = {
79 	.attrs = cm3323_attributes,
80 };
81 
cm3323_init(struct iio_dev * indio_dev)82 static int cm3323_init(struct iio_dev *indio_dev)
83 {
84 	int ret;
85 	struct cm3323_data *data = iio_priv(indio_dev);
86 
87 	ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
88 	if (ret < 0) {
89 		dev_err(&data->client->dev, "Error reading reg_conf\n");
90 		return ret;
91 	}
92 
93 	/* enable sensor and set auto force mode */
94 	ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
95 
96 	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
97 	if (ret < 0) {
98 		dev_err(&data->client->dev, "Error writing reg_conf\n");
99 		return ret;
100 	}
101 
102 	data->reg_conf = ret;
103 
104 	return 0;
105 }
106 
cm3323_disable(struct iio_dev * indio_dev)107 static void cm3323_disable(struct iio_dev *indio_dev)
108 {
109 	int ret;
110 	struct cm3323_data *data = iio_priv(indio_dev);
111 
112 	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF,
113 					CM3323_CONF_SD_BIT);
114 	if (ret < 0)
115 		dev_err(&data->client->dev, "Error writing reg_conf\n");
116 }
117 
cm3323_set_it_bits(struct cm3323_data * data,int val,int val2)118 static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
119 {
120 	int i, ret;
121 	u16 reg_conf;
122 
123 	for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
124 		if (val == cm3323_int_time[i].val &&
125 		    val2 == cm3323_int_time[i].val2) {
126 			reg_conf = data->reg_conf & ~CM3323_CONF_IT_MASK;
127 			reg_conf |= i << CM3323_CONF_IT_SHIFT;
128 
129 			ret = i2c_smbus_write_word_data(data->client,
130 							CM3323_CMD_CONF,
131 							reg_conf);
132 			if (ret < 0)
133 				return ret;
134 
135 			data->reg_conf = reg_conf;
136 
137 			return 0;
138 		}
139 	}
140 
141 	return -EINVAL;
142 }
143 
cm3323_get_it_bits(struct cm3323_data * data)144 static int cm3323_get_it_bits(struct cm3323_data *data)
145 {
146 	int bits;
147 
148 	bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
149 		CM3323_CONF_IT_SHIFT;
150 
151 	if (bits >= ARRAY_SIZE(cm3323_int_time))
152 		return -EINVAL;
153 
154 	return bits;
155 }
156 
cm3323_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)157 static int cm3323_read_raw(struct iio_dev *indio_dev,
158 			   struct iio_chan_spec const *chan, int *val,
159 			   int *val2, long mask)
160 {
161 	int ret;
162 	struct cm3323_data *data = iio_priv(indio_dev);
163 
164 	switch (mask) {
165 	case IIO_CHAN_INFO_RAW:
166 		mutex_lock(&data->mutex);
167 		ret = i2c_smbus_read_word_data(data->client, chan->address);
168 		if (ret < 0) {
169 			mutex_unlock(&data->mutex);
170 			return ret;
171 		}
172 		*val = ret;
173 		mutex_unlock(&data->mutex);
174 
175 		return IIO_VAL_INT;
176 	case IIO_CHAN_INFO_INT_TIME:
177 		mutex_lock(&data->mutex);
178 		ret = cm3323_get_it_bits(data);
179 		if (ret < 0) {
180 			mutex_unlock(&data->mutex);
181 			return ret;
182 		}
183 
184 		*val = cm3323_int_time[ret].val;
185 		*val2 = cm3323_int_time[ret].val2;
186 		mutex_unlock(&data->mutex);
187 
188 		return IIO_VAL_INT_PLUS_MICRO;
189 	default:
190 		return -EINVAL;
191 	}
192 }
193 
cm3323_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)194 static int cm3323_write_raw(struct iio_dev *indio_dev,
195 			    struct iio_chan_spec const *chan, int val,
196 			    int val2, long mask)
197 {
198 	struct cm3323_data *data = iio_priv(indio_dev);
199 	int ret;
200 
201 	switch (mask) {
202 	case IIO_CHAN_INFO_INT_TIME:
203 		mutex_lock(&data->mutex);
204 		ret = cm3323_set_it_bits(data, val, val2);
205 		mutex_unlock(&data->mutex);
206 
207 		return ret;
208 	default:
209 		return -EINVAL;
210 	}
211 }
212 
213 static const struct iio_info cm3323_info = {
214 	.read_raw	= cm3323_read_raw,
215 	.write_raw	= cm3323_write_raw,
216 	.attrs		= &cm3323_attribute_group,
217 };
218 
cm3323_probe(struct i2c_client * client,const struct i2c_device_id * id)219 static int cm3323_probe(struct i2c_client *client,
220 			const struct i2c_device_id *id)
221 {
222 	struct cm3323_data *data;
223 	struct iio_dev *indio_dev;
224 	int ret;
225 
226 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
227 	if (!indio_dev)
228 		return -ENOMEM;
229 
230 	data = iio_priv(indio_dev);
231 	i2c_set_clientdata(client, indio_dev);
232 	data->client = client;
233 
234 	mutex_init(&data->mutex);
235 
236 	indio_dev->dev.parent = &client->dev;
237 	indio_dev->info = &cm3323_info;
238 	indio_dev->name = CM3323_DRV_NAME;
239 	indio_dev->channels = cm3323_channels;
240 	indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
241 	indio_dev->modes = INDIO_DIRECT_MODE;
242 
243 	ret = cm3323_init(indio_dev);
244 	if (ret < 0) {
245 		dev_err(&client->dev, "cm3323 chip init failed\n");
246 		return ret;
247 	}
248 
249 	ret = iio_device_register(indio_dev);
250 	if (ret < 0) {
251 		dev_err(&client->dev, "failed to register iio dev\n");
252 		goto err_init;
253 	}
254 
255 	return 0;
256 err_init:
257 	cm3323_disable(indio_dev);
258 	return ret;
259 }
260 
cm3323_remove(struct i2c_client * client)261 static int cm3323_remove(struct i2c_client *client)
262 {
263 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
264 
265 	iio_device_unregister(indio_dev);
266 	cm3323_disable(indio_dev);
267 
268 	return 0;
269 }
270 
271 static const struct i2c_device_id cm3323_id[] = {
272 	{"cm3323", 0},
273 	{}
274 };
275 MODULE_DEVICE_TABLE(i2c, cm3323_id);
276 
277 static struct i2c_driver cm3323_driver = {
278 	.driver = {
279 		.name = CM3323_DRV_NAME,
280 	},
281 	.probe		= cm3323_probe,
282 	.remove		= cm3323_remove,
283 	.id_table	= cm3323_id,
284 };
285 
286 module_i2c_driver(cm3323_driver);
287 
288 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
289 MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
290 MODULE_LICENSE("GPL v2");
291