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/mod_devicetable.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/trigger.h>
22 #include <linux/iio/triggered_buffer.h>
23 #include <linux/iio/trigger_consumer.h>
24
25 #define LIDAR_REG_CONTROL 0x00
26 #define LIDAR_REG_CONTROL_ACQUIRE BIT(2)
27
28 #define LIDAR_REG_STATUS 0x01
29 #define LIDAR_REG_STATUS_INVALID BIT(3)
30 #define LIDAR_REG_STATUS_READY BIT(0)
31
32 #define LIDAR_REG_DATA_HBYTE 0x0f
33 #define LIDAR_REG_DATA_LBYTE 0x10
34 #define LIDAR_REG_DATA_WORD_READ BIT(7)
35
36 #define LIDAR_REG_PWR_CONTROL 0x65
37
38 #define LIDAR_DRV_NAME "lidar"
39
40 struct lidar_data {
41 struct iio_dev *indio_dev;
42 struct i2c_client *client;
43
44 int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len);
45 int i2c_enabled;
46
47 u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
48 };
49
50 static const struct iio_chan_spec lidar_channels[] = {
51 {
52 .type = IIO_DISTANCE,
53 .info_mask_separate =
54 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
55 .scan_index = 0,
56 .scan_type = {
57 .sign = 'u',
58 .realbits = 16,
59 .storagebits = 16,
60 },
61 },
62 IIO_CHAN_SOFT_TIMESTAMP(1),
63 };
64
lidar_i2c_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)65 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
66 {
67 struct i2c_client *client = data->client;
68 struct i2c_msg msg[2];
69 int ret;
70
71 msg[0].addr = client->addr;
72 msg[0].flags = client->flags | I2C_M_STOP;
73 msg[0].len = 1;
74 msg[0].buf = (char *) ®
75
76 msg[1].addr = client->addr;
77 msg[1].flags = client->flags | I2C_M_RD;
78 msg[1].len = len;
79 msg[1].buf = (char *) val;
80
81 ret = i2c_transfer(client->adapter, msg, 2);
82
83 return (ret == 2) ? 0 : -EIO;
84 }
85
lidar_smbus_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)86 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
87 {
88 struct i2c_client *client = data->client;
89 int ret;
90
91 /*
92 * Device needs a STOP condition between address write, and data read
93 * so in turn i2c_smbus_read_byte_data cannot be used
94 */
95
96 while (len--) {
97 ret = i2c_smbus_write_byte(client, reg++);
98 if (ret < 0) {
99 dev_err(&client->dev, "cannot write addr value");
100 return ret;
101 }
102
103 ret = i2c_smbus_read_byte(client);
104 if (ret < 0) {
105 dev_err(&client->dev, "cannot read data value");
106 return ret;
107 }
108
109 *(val++) = ret;
110 }
111
112 return 0;
113 }
114
lidar_read_byte(struct lidar_data * data,u8 reg)115 static int lidar_read_byte(struct lidar_data *data, u8 reg)
116 {
117 int ret;
118 u8 val;
119
120 ret = data->xfer(data, reg, &val, 1);
121 if (ret < 0)
122 return ret;
123
124 return val;
125 }
126
lidar_write_control(struct lidar_data * data,int val)127 static inline int lidar_write_control(struct lidar_data *data, int val)
128 {
129 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
130 }
131
lidar_write_power(struct lidar_data * data,int val)132 static inline int lidar_write_power(struct lidar_data *data, int val)
133 {
134 return i2c_smbus_write_byte_data(data->client,
135 LIDAR_REG_PWR_CONTROL, val);
136 }
137
lidar_read_measurement(struct lidar_data * data,u16 * reg)138 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
139 {
140 __be16 value;
141 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
142 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
143 (u8 *) &value, 2);
144
145 if (!ret)
146 *reg = be16_to_cpu(value);
147
148 return ret;
149 }
150
lidar_get_measurement(struct lidar_data * data,u16 * reg)151 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
152 {
153 struct i2c_client *client = data->client;
154 int tries = 10;
155 int ret;
156
157 pm_runtime_get_sync(&client->dev);
158
159 /* start sample */
160 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
161 if (ret < 0) {
162 dev_err(&client->dev, "cannot send start measurement command");
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_mark_last_busy(&client->dev);
188 pm_runtime_put_autosuspend(&client->dev);
189
190 return ret;
191 }
192
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)193 static int lidar_read_raw(struct iio_dev *indio_dev,
194 struct iio_chan_spec const *chan,
195 int *val, int *val2, long mask)
196 {
197 struct lidar_data *data = iio_priv(indio_dev);
198 int ret = -EINVAL;
199
200 switch (mask) {
201 case IIO_CHAN_INFO_RAW: {
202 u16 reg;
203
204 if (iio_device_claim_direct_mode(indio_dev))
205 return -EBUSY;
206
207 ret = lidar_get_measurement(data, ®);
208 if (!ret) {
209 *val = reg;
210 ret = IIO_VAL_INT;
211 }
212 iio_device_release_direct_mode(indio_dev);
213 break;
214 }
215 case IIO_CHAN_INFO_SCALE:
216 *val = 0;
217 *val2 = 10000;
218 ret = IIO_VAL_INT_PLUS_MICRO;
219 break;
220 }
221
222 return ret;
223 }
224
lidar_trigger_handler(int irq,void * private)225 static irqreturn_t lidar_trigger_handler(int irq, void *private)
226 {
227 struct iio_poll_func *pf = private;
228 struct iio_dev *indio_dev = pf->indio_dev;
229 struct lidar_data *data = iio_priv(indio_dev);
230 int ret;
231
232 ret = lidar_get_measurement(data, data->buffer);
233 if (!ret) {
234 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
235 iio_get_time_ns(indio_dev));
236 } else if (ret != -EINVAL) {
237 dev_err(&data->client->dev, "cannot read LIDAR measurement");
238 }
239
240 iio_trigger_notify_done(indio_dev->trig);
241
242 return IRQ_HANDLED;
243 }
244
245 static const struct iio_info lidar_info = {
246 .read_raw = lidar_read_raw,
247 };
248
lidar_probe(struct i2c_client * client,const struct i2c_device_id * id)249 static int lidar_probe(struct i2c_client *client,
250 const struct i2c_device_id *id)
251 {
252 struct lidar_data *data;
253 struct iio_dev *indio_dev;
254 int ret;
255
256 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
257 if (!indio_dev)
258 return -ENOMEM;
259 data = iio_priv(indio_dev);
260
261 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
262 data->xfer = lidar_i2c_xfer;
263 data->i2c_enabled = 1;
264 } else if (i2c_check_functionality(client->adapter,
265 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
266 data->xfer = lidar_smbus_xfer;
267 else
268 return -EOPNOTSUPP;
269
270 indio_dev->info = &lidar_info;
271 indio_dev->name = LIDAR_DRV_NAME;
272 indio_dev->channels = lidar_channels;
273 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
274 indio_dev->modes = INDIO_DIRECT_MODE;
275
276 i2c_set_clientdata(client, indio_dev);
277
278 data->client = client;
279 data->indio_dev = indio_dev;
280
281 ret = iio_triggered_buffer_setup(indio_dev, NULL,
282 lidar_trigger_handler, NULL);
283 if (ret)
284 return ret;
285
286 ret = iio_device_register(indio_dev);
287 if (ret)
288 goto error_unreg_buffer;
289
290 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
291 pm_runtime_use_autosuspend(&client->dev);
292
293 ret = pm_runtime_set_active(&client->dev);
294 if (ret)
295 goto error_unreg_buffer;
296 pm_runtime_enable(&client->dev);
297 pm_runtime_idle(&client->dev);
298
299 return 0;
300
301 error_unreg_buffer:
302 iio_triggered_buffer_cleanup(indio_dev);
303
304 return ret;
305 }
306
lidar_remove(struct i2c_client * client)307 static int lidar_remove(struct i2c_client *client)
308 {
309 struct iio_dev *indio_dev = i2c_get_clientdata(client);
310
311 iio_device_unregister(indio_dev);
312 iio_triggered_buffer_cleanup(indio_dev);
313
314 pm_runtime_disable(&client->dev);
315 pm_runtime_set_suspended(&client->dev);
316
317 return 0;
318 }
319
320 static const struct i2c_device_id lidar_id[] = {
321 {"lidar-lite-v2", 0},
322 {"lidar-lite-v3", 0},
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
334 #ifdef CONFIG_PM
lidar_pm_runtime_suspend(struct device * dev)335 static int lidar_pm_runtime_suspend(struct device *dev)
336 {
337 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
338 struct lidar_data *data = iio_priv(indio_dev);
339
340 return lidar_write_power(data, 0x0f);
341 }
342
lidar_pm_runtime_resume(struct device * dev)343 static int lidar_pm_runtime_resume(struct device *dev)
344 {
345 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
346 struct lidar_data *data = iio_priv(indio_dev);
347 int ret = lidar_write_power(data, 0);
348
349 /* regulator and FPGA needs settling time */
350 usleep_range(15000, 20000);
351
352 return ret;
353 }
354 #endif
355
356 static const struct dev_pm_ops lidar_pm_ops = {
357 SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
358 lidar_pm_runtime_resume, NULL)
359 };
360
361 static struct i2c_driver lidar_driver = {
362 .driver = {
363 .name = LIDAR_DRV_NAME,
364 .of_match_table = lidar_dt_ids,
365 .pm = &lidar_pm_ops,
366 },
367 .probe = lidar_probe,
368 .remove = lidar_remove,
369 .id_table = lidar_id,
370 };
371 module_i2c_driver(lidar_driver);
372
373 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
374 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
375 MODULE_LICENSE("GPL");
376
