xref: /openbmc/linux/drivers/iio/light/vcnl4000.c (revision 293d5b43)
1 /*
2  * vcnl4000.c - Support for Vishay VCNL4000 combined ambient light and
3  * 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  */
17 
18 #include <linux/module.h>
19 #include <linux/i2c.h>
20 #include <linux/err.h>
21 #include <linux/delay.h>
22 
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25 
26 #define VCNL4000_DRV_NAME "vcnl4000"
27 
28 #define VCNL4000_COMMAND	0x80 /* Command register */
29 #define VCNL4000_PROD_REV	0x81 /* Product ID and Revision ID */
30 #define VCNL4000_LED_CURRENT	0x83 /* IR LED current for proximity mode */
31 #define VCNL4000_AL_PARAM	0x84 /* Ambient light parameter register */
32 #define VCNL4000_AL_RESULT_HI	0x85 /* Ambient light result register, MSB */
33 #define VCNL4000_AL_RESULT_LO	0x86 /* Ambient light result register, LSB */
34 #define VCNL4000_PS_RESULT_HI	0x87 /* Proximity result register, MSB */
35 #define VCNL4000_PS_RESULT_LO	0x88 /* Proximity result register, LSB */
36 #define VCNL4000_PS_MEAS_FREQ	0x89 /* Proximity test signal frequency */
37 #define VCNL4000_PS_MOD_ADJ	0x8a /* Proximity modulator timing adjustment */
38 
39 /* Bit masks for COMMAND register */
40 #define VCNL4000_AL_RDY		0x40 /* ALS data ready? */
41 #define VCNL4000_PS_RDY		0x20 /* proximity data ready? */
42 #define VCNL4000_AL_OD		0x10 /* start on-demand ALS measurement */
43 #define VCNL4000_PS_OD		0x08 /* start on-demand proximity measurement */
44 
45 struct vcnl4000_data {
46 	struct i2c_client *client;
47 };
48 
49 static const struct i2c_device_id vcnl4000_id[] = {
50 	{ "vcnl4000", 0 },
51 	{ }
52 };
53 MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
54 
55 static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
56 				u8 rdy_mask, u8 data_reg, int *val)
57 {
58 	int tries = 20;
59 	__be16 buf;
60 	int ret;
61 
62 	ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
63 					req_mask);
64 	if (ret < 0)
65 		return ret;
66 
67 	/* wait for data to become ready */
68 	while (tries--) {
69 		ret = i2c_smbus_read_byte_data(data->client, VCNL4000_COMMAND);
70 		if (ret < 0)
71 			return ret;
72 		if (ret & rdy_mask)
73 			break;
74 		msleep(20); /* measurement takes up to 100 ms */
75 	}
76 
77 	if (tries < 0) {
78 		dev_err(&data->client->dev,
79 			"vcnl4000_measure() failed, data not ready\n");
80 		return -EIO;
81 	}
82 
83 	ret = i2c_smbus_read_i2c_block_data(data->client,
84 		data_reg, sizeof(buf), (u8 *) &buf);
85 	if (ret < 0)
86 		return ret;
87 
88 	*val = be16_to_cpu(buf);
89 
90 	return 0;
91 }
92 
93 static const struct iio_chan_spec vcnl4000_channels[] = {
94 	{
95 		.type = IIO_LIGHT,
96 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
97 			BIT(IIO_CHAN_INFO_SCALE),
98 	}, {
99 		.type = IIO_PROXIMITY,
100 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
101 	}
102 };
103 
104 static int vcnl4000_read_raw(struct iio_dev *indio_dev,
105 				struct iio_chan_spec const *chan,
106 				int *val, int *val2, long mask)
107 {
108 	int ret = -EINVAL;
109 	struct vcnl4000_data *data = iio_priv(indio_dev);
110 
111 	switch (mask) {
112 	case IIO_CHAN_INFO_RAW:
113 		switch (chan->type) {
114 		case IIO_LIGHT:
115 			ret = vcnl4000_measure(data,
116 				VCNL4000_AL_OD, VCNL4000_AL_RDY,
117 				VCNL4000_AL_RESULT_HI, val);
118 			if (ret < 0)
119 				return ret;
120 			ret = IIO_VAL_INT;
121 			break;
122 		case IIO_PROXIMITY:
123 			ret = vcnl4000_measure(data,
124 				VCNL4000_PS_OD, VCNL4000_PS_RDY,
125 				VCNL4000_PS_RESULT_HI, val);
126 			if (ret < 0)
127 				return ret;
128 			ret = IIO_VAL_INT;
129 			break;
130 		default:
131 			break;
132 		}
133 		break;
134 	case IIO_CHAN_INFO_SCALE:
135 		if (chan->type == IIO_LIGHT) {
136 			*val = 0;
137 			*val2 = 250000;
138 			ret = IIO_VAL_INT_PLUS_MICRO;
139 		}
140 		break;
141 	default:
142 		break;
143 	}
144 
145 	return ret;
146 }
147 
148 static const struct iio_info vcnl4000_info = {
149 	.read_raw = vcnl4000_read_raw,
150 	.driver_module = THIS_MODULE,
151 };
152 
153 static int vcnl4000_probe(struct i2c_client *client,
154 			  const struct i2c_device_id *id)
155 {
156 	struct vcnl4000_data *data;
157 	struct iio_dev *indio_dev;
158 	int ret;
159 
160 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
161 	if (!indio_dev)
162 		return -ENOMEM;
163 
164 	data = iio_priv(indio_dev);
165 	i2c_set_clientdata(client, indio_dev);
166 	data->client = client;
167 
168 	ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
169 	if (ret < 0)
170 		return ret;
171 
172 	dev_info(&client->dev, "VCNL4000 Ambient light/proximity sensor, Prod %02x, Rev: %02x\n",
173 		ret >> 4, ret & 0xf);
174 
175 	indio_dev->dev.parent = &client->dev;
176 	indio_dev->info = &vcnl4000_info;
177 	indio_dev->channels = vcnl4000_channels;
178 	indio_dev->num_channels = ARRAY_SIZE(vcnl4000_channels);
179 	indio_dev->name = VCNL4000_DRV_NAME;
180 	indio_dev->modes = INDIO_DIRECT_MODE;
181 
182 	return devm_iio_device_register(&client->dev, indio_dev);
183 }
184 
185 static struct i2c_driver vcnl4000_driver = {
186 	.driver = {
187 		.name   = VCNL4000_DRV_NAME,
188 	},
189 	.probe  = vcnl4000_probe,
190 	.id_table = vcnl4000_id,
191 };
192 
193 module_i2c_driver(vcnl4000_driver);
194 
195 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
196 MODULE_DESCRIPTION("Vishay VCNL4000 proximity/ambient light sensor driver");
197 MODULE_LICENSE("GPL");
198