xref: /openbmc/linux/drivers/iio/light/cm3323.c (revision 4f3db074)
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	(BIT(4) | BIT(5) | BIT(6))
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 
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 
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 
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;
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 			return 0;
137 		}
138 	}
139 	return -EINVAL;
140 }
141 
142 static int cm3323_get_it_bits(struct cm3323_data *data)
143 {
144 	int bits;
145 
146 	bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
147 		CM3323_CONF_IT_SHIFT;
148 
149 	if (bits >= ARRAY_SIZE(cm3323_int_time))
150 		return -EINVAL;
151 	return bits;
152 }
153 
154 static int cm3323_read_raw(struct iio_dev *indio_dev,
155 			   struct iio_chan_spec const *chan, int *val,
156 			   int *val2, long mask)
157 {
158 	int i, ret;
159 	struct cm3323_data *data = iio_priv(indio_dev);
160 
161 	switch (mask) {
162 	case IIO_CHAN_INFO_RAW:
163 		mutex_lock(&data->mutex);
164 		ret = i2c_smbus_read_word_data(data->client, chan->address);
165 		if (ret < 0) {
166 			mutex_unlock(&data->mutex);
167 			return ret;
168 		}
169 		*val = ret;
170 		mutex_unlock(&data->mutex);
171 
172 		return IIO_VAL_INT;
173 	case IIO_CHAN_INFO_INT_TIME:
174 		mutex_lock(&data->mutex);
175 		i = cm3323_get_it_bits(data);
176 		if (i < 0) {
177 			mutex_unlock(&data->mutex);
178 			return -EINVAL;
179 		}
180 
181 		*val = cm3323_int_time[i].val;
182 		*val2 = cm3323_int_time[i].val2;
183 		mutex_unlock(&data->mutex);
184 
185 		return IIO_VAL_INT_PLUS_MICRO;
186 	default:
187 		return -EINVAL;
188 	}
189 }
190 
191 static int cm3323_write_raw(struct iio_dev *indio_dev,
192 			    struct iio_chan_spec const *chan, int val,
193 			    int val2, long mask)
194 {
195 	struct cm3323_data *data = iio_priv(indio_dev);
196 	int ret;
197 
198 	switch (mask) {
199 	case IIO_CHAN_INFO_INT_TIME:
200 		mutex_lock(&data->mutex);
201 		ret = cm3323_set_it_bits(data, val, val2);
202 		mutex_unlock(&data->mutex);
203 
204 		return ret;
205 	default:
206 		return -EINVAL;
207 	}
208 }
209 
210 static const struct iio_info cm3323_info = {
211 	.driver_module	= THIS_MODULE,
212 	.read_raw	= cm3323_read_raw,
213 	.write_raw	= cm3323_write_raw,
214 	.attrs		= &cm3323_attribute_group,
215 };
216 
217 static int cm3323_probe(struct i2c_client *client,
218 			const struct i2c_device_id *id)
219 {
220 	struct cm3323_data *data;
221 	struct iio_dev *indio_dev;
222 	int ret;
223 
224 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
225 	if (!indio_dev)
226 		return -ENOMEM;
227 
228 	data = iio_priv(indio_dev);
229 	i2c_set_clientdata(client, indio_dev);
230 	data->client = client;
231 
232 	mutex_init(&data->mutex);
233 
234 	indio_dev->dev.parent = &client->dev;
235 	indio_dev->info = &cm3323_info;
236 	indio_dev->name = CM3323_DRV_NAME;
237 	indio_dev->channels = cm3323_channels;
238 	indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
239 	indio_dev->modes = INDIO_DIRECT_MODE;
240 
241 	ret = cm3323_init(indio_dev);
242 	if (ret < 0) {
243 		dev_err(&client->dev, "cm3323 chip init failed\n");
244 		return ret;
245 	}
246 	ret = iio_device_register(indio_dev);
247 	if (ret < 0) {
248 		dev_err(&client->dev, "failed to register iio dev\n");
249 		goto err_init;
250 	}
251 	return 0;
252 err_init:
253 	cm3323_disable(indio_dev);
254 	return ret;
255 }
256 
257 static int cm3323_remove(struct i2c_client *client)
258 {
259 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
260 
261 	iio_device_unregister(indio_dev);
262 	cm3323_disable(indio_dev);
263 
264 	return 0;
265 }
266 
267 static const struct i2c_device_id cm3323_id[] = {
268 	{"cm3323", 0},
269 	{}
270 };
271 MODULE_DEVICE_TABLE(i2c, cm3323_id);
272 
273 static struct i2c_driver cm3323_driver = {
274 	.driver = {
275 		.name = CM3323_DRV_NAME,
276 	},
277 	.probe		= cm3323_probe,
278 	.remove		= cm3323_remove,
279 	.id_table	= cm3323_id,
280 };
281 
282 module_i2c_driver(cm3323_driver);
283 
284 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
285 MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
286 MODULE_LICENSE("GPL v2");
287