xref: /openbmc/linux/drivers/iio/light/vcnl4000.c (revision cfbb9be8)
1 /*
2  * vcnl4000.c - Support for Vishay VCNL4000/4010/4020 combined ambient
3  * light and proximity sensor
4  *
5  * Copyright 2012 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * This file is subject to the terms and conditions of version 2 of
8  * the GNU General Public License.  See the file COPYING in the main
9  * directory of this archive for more details.
10  *
11  * IIO driver for VCNL4000 (7-bit I2C slave address 0x13)
12  *
13  * TODO:
14  *   allow to adjust IR current
15  *   proximity threshold and event handling
16  *   periodic ALS/proximity measurement (VCNL4010/20)
17  *   interrupts (VCNL4010/20)
18  */
19 
20 #include <linux/module.h>
21 #include <linux/i2c.h>
22 #include <linux/err.h>
23 #include <linux/delay.h>
24 
25 #include <linux/iio/iio.h>
26 #include <linux/iio/sysfs.h>
27 
28 #define VCNL4000_DRV_NAME "vcnl4000"
29 #define VCNL4000_ID		0x01
30 #define VCNL4010_ID		0x02 /* for VCNL4020, VCNL4010 */
31 
32 #define VCNL4000_COMMAND	0x80 /* Command register */
33 #define VCNL4000_PROD_REV	0x81 /* Product ID and Revision ID */
34 #define VCNL4000_LED_CURRENT	0x83 /* IR LED current for proximity mode */
35 #define VCNL4000_AL_PARAM	0x84 /* Ambient light parameter register */
36 #define VCNL4000_AL_RESULT_HI	0x85 /* Ambient light result register, MSB */
37 #define VCNL4000_AL_RESULT_LO	0x86 /* Ambient light result register, LSB */
38 #define VCNL4000_PS_RESULT_HI	0x87 /* Proximity result register, MSB */
39 #define VCNL4000_PS_RESULT_LO	0x88 /* Proximity result register, LSB */
40 #define VCNL4000_PS_MEAS_FREQ	0x89 /* Proximity test signal frequency */
41 #define VCNL4000_PS_MOD_ADJ	0x8a /* Proximity modulator timing adjustment */
42 
43 /* Bit masks for COMMAND register */
44 #define VCNL4000_AL_RDY		BIT(6) /* ALS data ready? */
45 #define VCNL4000_PS_RDY		BIT(5) /* proximity data ready? */
46 #define VCNL4000_AL_OD		BIT(4) /* start on-demand ALS measurement */
47 #define VCNL4000_PS_OD		BIT(3) /* start on-demand proximity measurement */
48 
49 struct vcnl4000_data {
50 	struct i2c_client *client;
51 	struct mutex lock;
52 };
53 
54 static const struct i2c_device_id vcnl4000_id[] = {
55 	{ "vcnl4000", 0 },
56 	{ }
57 };
58 MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
59 
60 static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
61 				u8 rdy_mask, u8 data_reg, int *val)
62 {
63 	int tries = 20;
64 	__be16 buf;
65 	int ret;
66 
67 	mutex_lock(&data->lock);
68 
69 	ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
70 					req_mask);
71 	if (ret < 0)
72 		goto fail;
73 
74 	/* wait for data to become ready */
75 	while (tries--) {
76 		ret = i2c_smbus_read_byte_data(data->client, VCNL4000_COMMAND);
77 		if (ret < 0)
78 			goto fail;
79 		if (ret & rdy_mask)
80 			break;
81 		msleep(20); /* measurement takes up to 100 ms */
82 	}
83 
84 	if (tries < 0) {
85 		dev_err(&data->client->dev,
86 			"vcnl4000_measure() failed, data not ready\n");
87 		ret = -EIO;
88 		goto fail;
89 	}
90 
91 	ret = i2c_smbus_read_i2c_block_data(data->client,
92 		data_reg, sizeof(buf), (u8 *) &buf);
93 	if (ret < 0)
94 		goto fail;
95 
96 	mutex_unlock(&data->lock);
97 	*val = be16_to_cpu(buf);
98 
99 	return 0;
100 
101 fail:
102 	mutex_unlock(&data->lock);
103 	return ret;
104 }
105 
106 static const struct iio_chan_spec vcnl4000_channels[] = {
107 	{
108 		.type = IIO_LIGHT,
109 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
110 			BIT(IIO_CHAN_INFO_SCALE),
111 	}, {
112 		.type = IIO_PROXIMITY,
113 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
114 	}
115 };
116 
117 static int vcnl4000_read_raw(struct iio_dev *indio_dev,
118 				struct iio_chan_spec const *chan,
119 				int *val, int *val2, long mask)
120 {
121 	int ret;
122 	struct vcnl4000_data *data = iio_priv(indio_dev);
123 
124 	switch (mask) {
125 	case IIO_CHAN_INFO_RAW:
126 		switch (chan->type) {
127 		case IIO_LIGHT:
128 			ret = vcnl4000_measure(data,
129 				VCNL4000_AL_OD, VCNL4000_AL_RDY,
130 				VCNL4000_AL_RESULT_HI, val);
131 			if (ret < 0)
132 				return ret;
133 			return IIO_VAL_INT;
134 		case IIO_PROXIMITY:
135 			ret = vcnl4000_measure(data,
136 				VCNL4000_PS_OD, VCNL4000_PS_RDY,
137 				VCNL4000_PS_RESULT_HI, val);
138 			if (ret < 0)
139 				return ret;
140 			return IIO_VAL_INT;
141 		default:
142 			return -EINVAL;
143 		}
144 	case IIO_CHAN_INFO_SCALE:
145 		if (chan->type != IIO_LIGHT)
146 			return -EINVAL;
147 
148 		*val = 0;
149 		*val2 = 250000;
150 		return IIO_VAL_INT_PLUS_MICRO;
151 	default:
152 		return -EINVAL;
153 	}
154 }
155 
156 static const struct iio_info vcnl4000_info = {
157 	.read_raw = vcnl4000_read_raw,
158 };
159 
160 static int vcnl4000_probe(struct i2c_client *client,
161 			  const struct i2c_device_id *id)
162 {
163 	struct vcnl4000_data *data;
164 	struct iio_dev *indio_dev;
165 	int ret, prod_id;
166 
167 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
168 	if (!indio_dev)
169 		return -ENOMEM;
170 
171 	data = iio_priv(indio_dev);
172 	i2c_set_clientdata(client, indio_dev);
173 	data->client = client;
174 	mutex_init(&data->lock);
175 
176 	ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
177 	if (ret < 0)
178 		return ret;
179 
180 	prod_id = ret >> 4;
181 	if (prod_id != VCNL4010_ID && prod_id != VCNL4000_ID)
182 		return -ENODEV;
183 
184 	dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
185 		(prod_id == VCNL4010_ID) ? "VCNL4010/4020" : "VCNL4000",
186 		ret & 0xf);
187 
188 	indio_dev->dev.parent = &client->dev;
189 	indio_dev->info = &vcnl4000_info;
190 	indio_dev->channels = vcnl4000_channels;
191 	indio_dev->num_channels = ARRAY_SIZE(vcnl4000_channels);
192 	indio_dev->name = VCNL4000_DRV_NAME;
193 	indio_dev->modes = INDIO_DIRECT_MODE;
194 
195 	return devm_iio_device_register(&client->dev, indio_dev);
196 }
197 
198 static struct i2c_driver vcnl4000_driver = {
199 	.driver = {
200 		.name   = VCNL4000_DRV_NAME,
201 	},
202 	.probe  = vcnl4000_probe,
203 	.id_table = vcnl4000_id,
204 };
205 
206 module_i2c_driver(vcnl4000_driver);
207 
208 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
209 MODULE_DESCRIPTION("Vishay VCNL4000 proximity/ambient light sensor driver");
210 MODULE_LICENSE("GPL");
211