root/drivers/iio/proximity/vl53l0x-i2c.c

DEFINITIONS

1. vl53l0x_read_proximity
2. vl53l0x_read_raw
3. vl53l0x_probe

   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->dev.parent = &client->dev;
 138         indio_dev->name = "vl53l0x";
 139         indio_dev->info = &vl53l0x_info;
 140         indio_dev->channels = vl53l0x_channels;
 141         indio_dev->num_channels = ARRAY_SIZE(vl53l0x_channels);
 142         indio_dev->modes = INDIO_DIRECT_MODE;
 143 
 144         return devm_iio_device_register(&client->dev, indio_dev);
 145 }
 146 
 147 static const struct of_device_id st_vl53l0x_dt_match[] = {
 148         { .compatible = "st,vl53l0x", },
 149         { }
 150 };
 151 MODULE_DEVICE_TABLE(of, st_vl53l0x_dt_match);
 152 
 153 static struct i2c_driver vl53l0x_driver = {
 154         .driver = {
 155                 .name = "vl53l0x-i2c",
 156                 .of_match_table = st_vl53l0x_dt_match,
 157         },
 158         .probe_new = vl53l0x_probe,
 159 };
 160 module_i2c_driver(vl53l0x_driver);
 161 
 162 MODULE_AUTHOR("Song Qiang <songqiang1304521@gmail.com>");
 163 MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor driver");
 164 MODULE_LICENSE("GPL v2");