xref: /openbmc/linux/drivers/iio/light/cm3323.c (revision 1edd0337) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * CM3323 - Capella Color Light Sensor
4  *
5  * Copyright (c) 2015, Intel Corporation.
6  *
7  * IIO driver for CM3323 (7-bit I2C slave address 0x10)
8  *
9  * TODO: calibscale to correct the lens factor
10  */
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/i2c.h>
14 #include <linux/mutex.h>
15 
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 
19 #define CM3323_DRV_NAME "cm3323"
20 
21 #define CM3323_CMD_CONF		0x00
22 #define CM3323_CMD_RED_DATA	0x08
23 #define CM3323_CMD_GREEN_DATA	0x09
24 #define CM3323_CMD_BLUE_DATA	0x0A
25 #define CM3323_CMD_CLEAR_DATA	0x0B
26 
27 #define CM3323_CONF_SD_BIT	BIT(0) /* sensor disable */
28 #define CM3323_CONF_AF_BIT	BIT(1) /* auto/manual force mode */
29 #define CM3323_CONF_IT_MASK	GENMASK(6, 4)
30 #define CM3323_CONF_IT_SHIFT	4
31 
32 #define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
33 
34 static const struct {
35 	int val;
36 	int val2;
37 } cm3323_int_time[] = {
38 	{0, 40000},  /* 40 ms */
39 	{0, 80000},  /* 80 ms */
40 	{0, 160000}, /* 160 ms */
41 	{0, 320000}, /* 320 ms */
42 	{0, 640000}, /* 640 ms */
43 	{1, 280000}, /* 1280 ms */
44 };
45 
46 struct cm3323_data {
47 	struct i2c_client *client;
48 	u16 reg_conf;
49 	struct mutex mutex;
50 };
51 
52 #define CM3323_COLOR_CHANNEL(_color, _addr) { \
53 	.type = IIO_INTENSITY, \
54 	.modified = 1, \
55 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
56 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
57 	.channel2 = IIO_MOD_LIGHT_##_color, \
58 	.address = _addr, \
59 }
60 
61 static const struct iio_chan_spec cm3323_channels[] = {
62 	CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
63 	CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
64 	CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
65 	CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
66 };
67 
68 static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
69 
70 static struct attribute *cm3323_attributes[] = {
71 	&iio_const_attr_integration_time_available.dev_attr.attr,
72 	NULL
73 };
74 
75 static const struct attribute_group cm3323_attribute_group = {
76 	.attrs = cm3323_attributes,
77 };
78 
79 static int cm3323_init(struct iio_dev *indio_dev)
80 {
81 	int ret;
82 	struct cm3323_data *data = iio_priv(indio_dev);
83 
84 	ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
85 	if (ret < 0) {
86 		dev_err(&data->client->dev, "Error reading reg_conf\n");
87 		return ret;
88 	}
89 
90 	/* enable sensor and set auto force mode */
91 	ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
92 
93 	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
94 	if (ret < 0) {
95 		dev_err(&data->client->dev, "Error writing reg_conf\n");
96 		return ret;
97 	}
98 
99 	data->reg_conf = ret;
100 
101 	return 0;
102 }
103 
104 static void cm3323_disable(void *data)
105 {
106 	int ret;
107 	struct iio_dev *indio_dev = data;
108 	struct cm3323_data *cm_data = iio_priv(indio_dev);
109 
110 	ret = i2c_smbus_write_word_data(cm_data->client, CM3323_CMD_CONF,
111 					CM3323_CONF_SD_BIT);
112 	if (ret < 0)
113 		dev_err(&cm_data->client->dev, "Error writing reg_conf\n");
114 }
115 
116 static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
117 {
118 	int i, ret;
119 	u16 reg_conf;
120 
121 	for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
122 		if (val == cm3323_int_time[i].val &&
123 		    val2 == cm3323_int_time[i].val2) {
124 			reg_conf = data->reg_conf & ~CM3323_CONF_IT_MASK;
125 			reg_conf |= i << CM3323_CONF_IT_SHIFT;
126 
127 			ret = i2c_smbus_write_word_data(data->client,
128 							CM3323_CMD_CONF,
129 							reg_conf);
130 			if (ret < 0)
131 				return ret;
132 
133 			data->reg_conf = reg_conf;
134 
135 			return 0;
136 		}
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 
152 	return bits;
153 }
154 
155 static int cm3323_read_raw(struct iio_dev *indio_dev,
156 			   struct iio_chan_spec const *chan, int *val,
157 			   int *val2, long mask)
158 {
159 	int ret;
160 	struct cm3323_data *data = iio_priv(indio_dev);
161 
162 	switch (mask) {
163 	case IIO_CHAN_INFO_RAW:
164 		mutex_lock(&data->mutex);
165 		ret = i2c_smbus_read_word_data(data->client, chan->address);
166 		if (ret < 0) {
167 			mutex_unlock(&data->mutex);
168 			return ret;
169 		}
170 		*val = ret;
171 		mutex_unlock(&data->mutex);
172 
173 		return IIO_VAL_INT;
174 	case IIO_CHAN_INFO_INT_TIME:
175 		mutex_lock(&data->mutex);
176 		ret = cm3323_get_it_bits(data);
177 		if (ret < 0) {
178 			mutex_unlock(&data->mutex);
179 			return ret;
180 		}
181 
182 		*val = cm3323_int_time[ret].val;
183 		*val2 = cm3323_int_time[ret].val2;
184 		mutex_unlock(&data->mutex);
185 
186 		return IIO_VAL_INT_PLUS_MICRO;
187 	default:
188 		return -EINVAL;
189 	}
190 }
191 
192 static int cm3323_write_raw(struct iio_dev *indio_dev,
193 			    struct iio_chan_spec const *chan, int val,
194 			    int val2, long mask)
195 {
196 	struct cm3323_data *data = iio_priv(indio_dev);
197 	int ret;
198 
199 	switch (mask) {
200 	case IIO_CHAN_INFO_INT_TIME:
201 		mutex_lock(&data->mutex);
202 		ret = cm3323_set_it_bits(data, val, val2);
203 		mutex_unlock(&data->mutex);
204 
205 		return ret;
206 	default:
207 		return -EINVAL;
208 	}
209 }
210 
211 static const struct iio_info cm3323_info = {
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 {
219 	struct cm3323_data *data;
220 	struct iio_dev *indio_dev;
221 	int ret;
222 
223 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
224 	if (!indio_dev)
225 		return -ENOMEM;
226 
227 	data = iio_priv(indio_dev);
228 	i2c_set_clientdata(client, indio_dev);
229 	data->client = client;
230 
231 	mutex_init(&data->mutex);
232 
233 	indio_dev->info = &cm3323_info;
234 	indio_dev->name = CM3323_DRV_NAME;
235 	indio_dev->channels = cm3323_channels;
236 	indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
237 	indio_dev->modes = INDIO_DIRECT_MODE;
238 
239 	ret = cm3323_init(indio_dev);
240 	if (ret < 0) {
241 		dev_err(&client->dev, "cm3323 chip init failed\n");
242 		return ret;
243 	}
244 
245 	ret = devm_add_action_or_reset(&client->dev, cm3323_disable, indio_dev);
246 	if (ret < 0)
247 		return ret;
248 
249 	return devm_iio_device_register(&client->dev, indio_dev);
250 }
251 
252 static const struct i2c_device_id cm3323_id[] = {
253 	{"cm3323", 0},
254 	{}
255 };
256 MODULE_DEVICE_TABLE(i2c, cm3323_id);
257 
258 static const struct of_device_id cm3323_of_match[] = {
259 	{ .compatible = "capella,cm3323", },
260 	{ /* sentinel */ }
261 };
262 MODULE_DEVICE_TABLE(of, cm3323_of_match);
263 
264 static struct i2c_driver cm3323_driver = {
265 	.driver = {
266 		.name = CM3323_DRV_NAME,
267 		.of_match_table = cm3323_of_match,
268 	},
269 	.probe_new	= cm3323_probe,
270 	.id_table	= cm3323_id,
271 };
272 
273 module_i2c_driver(cm3323_driver);
274 
275 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
276 MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
277 MODULE_LICENSE("GPL v2");
278