1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus.
4  *
5  * Copyright (C) 2016 STMicroelectronics Imaging Division.
6  * Copyright (C) 2018 Song Qiang <songqiang1304521@gmail.com>
7  *
8  * Datasheet available at
9  * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf>
10  *
11  * Default 7-bit i2c slave address 0x29.
12  *
13  * TODO: FIFO buffer, continuous mode, interrupts, range selection,
14  * sensor ID check.
15  */
16 
17 #include <linux/delay.h>
18 #include <linux/i2c.h>
19 #include <linux/module.h>
20 
21 #include <linux/iio/iio.h>
22 
23 #define VL_REG_SYSRANGE_START				0x00
24 
25 #define VL_REG_SYSRANGE_MODE_MASK			GENMASK(3, 0)
26 #define VL_REG_SYSRANGE_MODE_SINGLESHOT			0x00
27 #define VL_REG_SYSRANGE_MODE_START_STOP			BIT(0)
28 #define VL_REG_SYSRANGE_MODE_BACKTOBACK			BIT(1)
29 #define VL_REG_SYSRANGE_MODE_TIMED			BIT(2)
30 #define VL_REG_SYSRANGE_MODE_HISTOGRAM			BIT(3)
31 
32 #define VL_REG_RESULT_INT_STATUS			0x13
33 #define VL_REG_RESULT_RANGE_STATUS			0x14
34 #define VL_REG_RESULT_RANGE_STATUS_COMPLETE		BIT(0)
35 
36 struct vl53l0x_data {
37 	struct i2c_client *client;
38 };
39 
40 static int vl53l0x_read_proximity(struct vl53l0x_data *data,
41 				  const struct iio_chan_spec *chan,
42 				  int *val)
43 {
44 	struct i2c_client *client = data->client;
45 	u16 tries = 20;
46 	u8 buffer[12];
47 	int ret;
48 
49 	ret = i2c_smbus_write_byte_data(client, VL_REG_SYSRANGE_START, 1);
50 	if (ret < 0)
51 		return ret;
52 
53 	do {
54 		ret = i2c_smbus_read_byte_data(client,
55 					       VL_REG_RESULT_RANGE_STATUS);
56 		if (ret < 0)
57 			return ret;
58 
59 		if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE)
60 			break;
61 
62 		usleep_range(1000, 5000);
63 	} while (--tries);
64 	if (!tries)
65 		return -ETIMEDOUT;
66 
67 	ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS,
68 					    12, buffer);
69 	if (ret < 0)
70 		return ret;
71 	else if (ret != 12)
72 		return -EREMOTEIO;
73 
74 	/* Values should be between 30~1200 in millimeters. */
75 	*val = (buffer[10] << 8) + buffer[11];
76 
77 	return 0;
78 }
79 
80 static const struct iio_chan_spec vl53l0x_channels[] = {
81 	{
82 		.type = IIO_DISTANCE,
83 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
84 				      BIT(IIO_CHAN_INFO_SCALE),
85 	},
86 };
87 
88 static int vl53l0x_read_raw(struct iio_dev *indio_dev,
89 			    const struct iio_chan_spec *chan,
90 			    int *val, int *val2, long mask)
91 {
92 	struct vl53l0x_data *data = iio_priv(indio_dev);
93 	int ret;
94 
95 	if (chan->type != IIO_DISTANCE)
96 		return -EINVAL;
97 
98 	switch (mask) {
99 	case IIO_CHAN_INFO_RAW:
100 		ret = vl53l0x_read_proximity(data, chan, val);
101 		if (ret < 0)
102 			return ret;
103 
104 		return IIO_VAL_INT;
105 	case IIO_CHAN_INFO_SCALE:
106 		*val = 0;
107 		*val2 = 1000;
108 
109 		return IIO_VAL_INT_PLUS_MICRO;
110 	default:
111 		return -EINVAL;
112 	}
113 }
114 
115 static const struct iio_info vl53l0x_info = {
116 	.read_raw = vl53l0x_read_raw,
117 };
118 
119 static int vl53l0x_probe(struct i2c_client *client)
120 {
121 	struct vl53l0x_data *data;
122 	struct iio_dev *indio_dev;
123 
124 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
125 	if (!indio_dev)
126 		return -ENOMEM;
127 
128 	data = iio_priv(indio_dev);
129 	data->client = client;
130 	i2c_set_clientdata(client, indio_dev);
131 
132 	if (!i2c_check_functionality(client->adapter,
133 				     I2C_FUNC_SMBUS_READ_I2C_BLOCK |
134 				     I2C_FUNC_SMBUS_BYTE_DATA))
135 		return -EOPNOTSUPP;
136 
137 	indio_dev->name = "vl53l0x";
138 	indio_dev->info = &vl53l0x_info;
139 	indio_dev->channels = vl53l0x_channels;
140 	indio_dev->num_channels = ARRAY_SIZE(vl53l0x_channels);
141 	indio_dev->modes = INDIO_DIRECT_MODE;
142 
143 	return devm_iio_device_register(&client->dev, indio_dev);
144 }
145 
146 static const struct of_device_id st_vl53l0x_dt_match[] = {
147 	{ .compatible = "st,vl53l0x", },
148 	{ }
149 };
150 MODULE_DEVICE_TABLE(of, st_vl53l0x_dt_match);
151 
152 static struct i2c_driver vl53l0x_driver = {
153 	.driver = {
154 		.name = "vl53l0x-i2c",
155 		.of_match_table = st_vl53l0x_dt_match,
156 	},
157 	.probe_new = vl53l0x_probe,
158 };
159 module_i2c_driver(vl53l0x_driver);
160 
161 MODULE_AUTHOR("Song Qiang <songqiang1304521@gmail.com>");
162 MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor driver");
163 MODULE_LICENSE("GPL v2");
164