1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
4 *
5 * Copyright (C) 2015, 2017-2018
6 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
7 *
8 * TODO: interrupt mode, and signal strength reporting
9 */
10
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/i2c.h>
14 #include <linux/delay.h>
15 #include <linux/module.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/trigger.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/iio/trigger_consumer.h>
23
24 #define LIDAR_REG_CONTROL 0x00
25 #define LIDAR_REG_CONTROL_ACQUIRE BIT(2)
26
27 #define LIDAR_REG_STATUS 0x01
28 #define LIDAR_REG_STATUS_INVALID BIT(3)
29 #define LIDAR_REG_STATUS_READY BIT(0)
30
31 #define LIDAR_REG_DATA_HBYTE 0x0f
32 #define LIDAR_REG_DATA_LBYTE 0x10
33 #define LIDAR_REG_DATA_WORD_READ BIT(7)
34
35 #define LIDAR_REG_PWR_CONTROL 0x65
36
37 #define LIDAR_DRV_NAME "lidar"
38
39 struct lidar_data {
40 struct iio_dev *indio_dev;
41 struct i2c_client *client;
42
43 int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len);
44 int i2c_enabled;
45 };
46
47 static const struct iio_chan_spec lidar_channels[] = {
48 {
49 .type = IIO_DISTANCE,
50 .info_mask_separate =
51 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
52 .scan_index = 0,
53 .scan_type = {
54 .sign = 'u',
55 .realbits = 16,
56 .storagebits = 16,
57 },
58 },
59 IIO_CHAN_SOFT_TIMESTAMP(1),
60 };
61
lidar_i2c_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)62 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
63 {
64 struct i2c_client *client = data->client;
65 struct i2c_msg msg[2];
66 int ret;
67
68 msg[0].addr = client->addr;
69 msg[0].flags = client->flags | I2C_M_STOP;
70 msg[0].len = 1;
71 msg[0].buf = (char *) ®
72
73 msg[1].addr = client->addr;
74 msg[1].flags = client->flags | I2C_M_RD;
75 msg[1].len = len;
76 msg[1].buf = (char *) val;
77
78 ret = i2c_transfer(client->adapter, msg, 2);
79
80 return (ret == 2) ? 0 : -EIO;
81 }
82
lidar_smbus_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)83 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
84 {
85 struct i2c_client *client = data->client;
86 int ret;
87
88 /*
89 * Device needs a STOP condition between address write, and data read
90 * so in turn i2c_smbus_read_byte_data cannot be used
91 */
92
93 while (len--) {
94 ret = i2c_smbus_write_byte(client, reg++);
95 if (ret < 0) {
96 dev_err(&client->dev, "cannot write addr value");
97 return ret;
98 }
99
100 ret = i2c_smbus_read_byte(client);
101 if (ret < 0) {
102 dev_err(&client->dev, "cannot read data value");
103 return ret;
104 }
105
106 *(val++) = ret;
107 }
108
109 return 0;
110 }
111
lidar_read_byte(struct lidar_data * data,u8 reg)112 static int lidar_read_byte(struct lidar_data *data, u8 reg)
113 {
114 int ret;
115 u8 val;
116
117 ret = data->xfer(data, reg, &val, 1);
118 if (ret < 0)
119 return ret;
120
121 return val;
122 }
123
lidar_write_control(struct lidar_data * data,int val)124 static inline int lidar_write_control(struct lidar_data *data, int val)
125 {
126 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
127 }
128
lidar_write_power(struct lidar_data * data,int val)129 static inline int lidar_write_power(struct lidar_data *data, int val)
130 {
131 return i2c_smbus_write_byte_data(data->client,
132 LIDAR_REG_PWR_CONTROL, val);
133 }
134
lidar_read_measurement(struct lidar_data * data,u16 * reg)135 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
136 {
137 __be16 value;
138 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
139 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
140 (u8 *) &value, 2);
141
142 if (!ret)
143 *reg = be16_to_cpu(value);
144
145 return ret;
146 }
147
lidar_get_measurement(struct lidar_data * data,u16 * reg)148 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
149 {
150 struct i2c_client *client = data->client;
151 int tries = 10;
152 int ret;
153
154 ret = pm_runtime_resume_and_get(&client->dev);
155 if (ret < 0)
156 return ret;
157
158 /* start sample */
159 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
160 if (ret < 0) {
161 dev_err(&client->dev, "cannot send start measurement command");
162 pm_runtime_put_noidle(&client->dev);
163 return ret;
164 }
165
166 while (tries--) {
167 usleep_range(1000, 2000);
168
169 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
170 if (ret < 0)
171 break;
172
173 /* return -EINVAL since laser is likely pointed out of range */
174 if (ret & LIDAR_REG_STATUS_INVALID) {
175 *reg = 0;
176 ret = -EINVAL;
177 break;
178 }
179
180 /* sample ready to read */
181 if (!(ret & LIDAR_REG_STATUS_READY)) {
182 ret = lidar_read_measurement(data, reg);
183 break;
184 }
185 ret = -EIO;
186 }
187 pm_runtime_put_autosuspend(&client->dev);
188
189 return ret;
190 }
191
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)192 static int lidar_read_raw(struct iio_dev *indio_dev,
193 struct iio_chan_spec const *chan,
194 int *val, int *val2, long mask)
195 {
196 struct lidar_data *data = iio_priv(indio_dev);
197 int ret = -EINVAL;
198
199 switch (mask) {
200 case IIO_CHAN_INFO_RAW: {
201 u16 reg;
202
203 if (!iio_device_claim_direct(indio_dev))
204 return -EBUSY;
205
206 ret = lidar_get_measurement(data, ®);
207 if (!ret) {
208 *val = reg;
209 ret = IIO_VAL_INT;
210 }
211 iio_device_release_direct(indio_dev);
212 break;
213 }
214 case IIO_CHAN_INFO_SCALE:
215 *val = 0;
216 *val2 = 10000;
217 ret = IIO_VAL_INT_PLUS_MICRO;
218 break;
219 }
220
221 return ret;
222 }
223
lidar_trigger_handler(int irq,void * private)224 static irqreturn_t lidar_trigger_handler(int irq, void *private)
225 {
226 struct iio_poll_func *pf = private;
227 struct iio_dev *indio_dev = pf->indio_dev;
228 struct lidar_data *data = iio_priv(indio_dev);
229 int ret;
230 struct {
231 u16 chan;
232 aligned_s64 timestamp;
233 } scan = { };
234
235 ret = lidar_get_measurement(data, &scan.chan);
236 if (!ret) {
237 iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
238 iio_get_time_ns(indio_dev));
239 } else if (ret != -EINVAL) {
240 dev_err(&data->client->dev, "cannot read LIDAR measurement");
241 }
242
243 iio_trigger_notify_done(indio_dev->trig);
244
245 return IRQ_HANDLED;
246 }
247
248 static const struct iio_info lidar_info = {
249 .read_raw = lidar_read_raw,
250 };
251
lidar_probe(struct i2c_client * client)252 static int lidar_probe(struct i2c_client *client)
253 {
254 struct lidar_data *data;
255 struct iio_dev *indio_dev;
256 int ret;
257
258 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
259 if (!indio_dev)
260 return -ENOMEM;
261 data = iio_priv(indio_dev);
262
263 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
264 data->xfer = lidar_i2c_xfer;
265 data->i2c_enabled = 1;
266 } else if (i2c_check_functionality(client->adapter,
267 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
268 data->xfer = lidar_smbus_xfer;
269 else
270 return -EOPNOTSUPP;
271
272 indio_dev->info = &lidar_info;
273 indio_dev->name = LIDAR_DRV_NAME;
274 indio_dev->channels = lidar_channels;
275 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
276 indio_dev->modes = INDIO_DIRECT_MODE;
277
278 i2c_set_clientdata(client, indio_dev);
279
280 data->client = client;
281 data->indio_dev = indio_dev;
282
283 ret = iio_triggered_buffer_setup(indio_dev, NULL,
284 lidar_trigger_handler, NULL);
285 if (ret)
286 return ret;
287
288 ret = iio_device_register(indio_dev);
289 if (ret)
290 goto error_unreg_buffer;
291
292 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
293 pm_runtime_use_autosuspend(&client->dev);
294
295 ret = pm_runtime_set_active(&client->dev);
296 if (ret)
297 goto error_unreg_buffer;
298 pm_runtime_enable(&client->dev);
299 pm_runtime_idle(&client->dev);
300
301 return 0;
302
303 error_unreg_buffer:
304 iio_triggered_buffer_cleanup(indio_dev);
305
306 return ret;
307 }
308
lidar_remove(struct i2c_client * client)309 static void lidar_remove(struct i2c_client *client)
310 {
311 struct iio_dev *indio_dev = i2c_get_clientdata(client);
312
313 iio_device_unregister(indio_dev);
314 iio_triggered_buffer_cleanup(indio_dev);
315
316 pm_runtime_disable(&client->dev);
317 pm_runtime_set_suspended(&client->dev);
318 }
319
320 static const struct i2c_device_id lidar_id[] = {
321 { .name = "lidar-lite-v2" },
322 { .name = "lidar-lite-v3" },
323 { }
324 };
325 MODULE_DEVICE_TABLE(i2c, lidar_id);
326
327 static const struct of_device_id lidar_dt_ids[] = {
328 { .compatible = "pulsedlight,lidar-lite-v2" },
329 { .compatible = "grmn,lidar-lite-v3" },
330 { }
331 };
332 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
333
lidar_pm_runtime_suspend(struct device * dev)334 static int lidar_pm_runtime_suspend(struct device *dev)
335 {
336 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
337 struct lidar_data *data = iio_priv(indio_dev);
338
339 return lidar_write_power(data, 0x0f);
340 }
341
lidar_pm_runtime_resume(struct device * dev)342 static int lidar_pm_runtime_resume(struct device *dev)
343 {
344 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
345 struct lidar_data *data = iio_priv(indio_dev);
346 int ret = lidar_write_power(data, 0);
347
348 /* regulator and FPGA needs settling time */
349 usleep_range(15000, 20000);
350
351 return ret;
352 }
353
354 static const struct dev_pm_ops lidar_pm_ops = {
355 RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL)
356 };
357
358 static struct i2c_driver lidar_driver = {
359 .driver = {
360 .name = LIDAR_DRV_NAME,
361 .of_match_table = lidar_dt_ids,
362 .pm = pm_ptr(&lidar_pm_ops),
363 },
364 .probe = lidar_probe,
365 .remove = lidar_remove,
366 .id_table = lidar_id,
367 };
368 module_i2c_driver(lidar_driver);
369
370 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
371 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
372 MODULE_LICENSE("GPL");
373