2 * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
4 * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * TODO: runtime pm, interrupt mode, and signal strength reporting
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/i2c.h>
22 #include <linux/delay.h>
23 #include <linux/module.h>
24 #include <linux/iio/iio.h>
25 #include <linux/iio/sysfs.h>
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/trigger.h>
28 #include <linux/iio/triggered_buffer.h>
29 #include <linux/iio/trigger_consumer.h>
31 #define LIDAR_REG_CONTROL 0x00
32 #define LIDAR_REG_CONTROL_ACQUIRE BIT(2)
34 #define LIDAR_REG_STATUS 0x01
35 #define LIDAR_REG_STATUS_INVALID BIT(3)
36 #define LIDAR_REG_STATUS_READY BIT(0)
38 #define LIDAR_REG_DATA_HBYTE 0x0f
39 #define LIDAR_REG_DATA_LBYTE 0x10
41 #define LIDAR_DRV_NAME "lidar"
44 struct iio_dev *indio_dev;
45 struct i2c_client *client;
47 u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
50 static const struct iio_chan_spec lidar_channels[] = {
54 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
62 IIO_CHAN_SOFT_TIMESTAMP(1),
65 static int lidar_read_byte(struct lidar_data *data, int reg)
67 struct i2c_client *client = data->client;
71 * Device needs a STOP condition between address write, and data read
72 * so in turn i2c_smbus_read_byte_data cannot be used
75 ret = i2c_smbus_write_byte(client, reg);
77 dev_err(&client->dev, "cannot write addr value");
81 ret = i2c_smbus_read_byte(client);
83 dev_err(&client->dev, "cannot read data value");
88 static inline int lidar_write_control(struct lidar_data *data, int val)
90 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
93 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
98 ret = lidar_read_byte(data, LIDAR_REG_DATA_HBYTE);
103 ret = lidar_read_byte(data, LIDAR_REG_DATA_LBYTE);
113 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
115 struct i2c_client *client = data->client;
120 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
122 dev_err(&client->dev, "cannot send start measurement command");
127 usleep_range(1000, 2000);
129 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
133 /* return -EINVAL since laser is likely pointed out of range */
134 if (ret & LIDAR_REG_STATUS_INVALID) {
140 /* sample ready to read */
141 if (!(ret & LIDAR_REG_STATUS_READY)) {
142 ret = lidar_read_measurement(data, reg);
151 static int lidar_read_raw(struct iio_dev *indio_dev,
152 struct iio_chan_spec const *chan,
153 int *val, int *val2, long mask)
155 struct lidar_data *data = iio_priv(indio_dev);
158 mutex_lock(&indio_dev->mlock);
160 if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
166 case IIO_CHAN_INFO_RAW: {
169 ret = lidar_get_measurement(data, ®);
176 case IIO_CHAN_INFO_SCALE:
179 ret = IIO_VAL_INT_PLUS_MICRO;
184 mutex_unlock(&indio_dev->mlock);
189 static irqreturn_t lidar_trigger_handler(int irq, void *private)
191 struct iio_poll_func *pf = private;
192 struct iio_dev *indio_dev = pf->indio_dev;
193 struct lidar_data *data = iio_priv(indio_dev);
196 ret = lidar_get_measurement(data, data->buffer);
198 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
200 } else if (ret != -EINVAL) {
201 dev_err(&data->client->dev, "cannot read LIDAR measurement");
204 iio_trigger_notify_done(indio_dev->trig);
209 static const struct iio_info lidar_info = {
210 .driver_module = THIS_MODULE,
211 .read_raw = lidar_read_raw,
214 static int lidar_probe(struct i2c_client *client,
215 const struct i2c_device_id *id)
217 struct lidar_data *data;
218 struct iio_dev *indio_dev;
221 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
225 indio_dev->info = &lidar_info;
226 indio_dev->name = LIDAR_DRV_NAME;
227 indio_dev->channels = lidar_channels;
228 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
229 indio_dev->modes = INDIO_DIRECT_MODE;
231 data = iio_priv(indio_dev);
232 i2c_set_clientdata(client, indio_dev);
234 data->client = client;
235 data->indio_dev = indio_dev;
237 ret = iio_triggered_buffer_setup(indio_dev, NULL,
238 lidar_trigger_handler, NULL);
242 ret = iio_device_register(indio_dev);
244 goto error_unreg_buffer;
249 iio_triggered_buffer_cleanup(indio_dev);
254 static int lidar_remove(struct i2c_client *client)
256 struct iio_dev *indio_dev = i2c_get_clientdata(client);
258 iio_device_unregister(indio_dev);
259 iio_triggered_buffer_cleanup(indio_dev);
264 static const struct i2c_device_id lidar_id[] = {
265 {"lidar-lite-v2", 0},
268 MODULE_DEVICE_TABLE(i2c, lidar_id);
270 static const struct of_device_id lidar_dt_ids[] = {
271 { .compatible = "pulsedlight,lidar-lite-v2" },
274 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
276 static struct i2c_driver lidar_driver = {
278 .name = LIDAR_DRV_NAME,
279 .of_match_table = of_match_ptr(lidar_dt_ids),
281 .probe = lidar_probe,
282 .remove = lidar_remove,
283 .id_table = lidar_id,
285 module_i2c_driver(lidar_driver);
287 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
288 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
289 MODULE_LICENSE("GPL");