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 /* Ensure timestamp is naturally aligned */
47 struct {
48 u16 chan;
49 s64 timestamp __aligned(8);
50 } scan;
51 };
52
53 static const struct iio_chan_spec lidar_channels[] = {
54 {
55 .type = IIO_DISTANCE,
56 .info_mask_separate =
57 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
58 .scan_index = 0,
59 .scan_type = {
60 .sign = 'u',
61 .realbits = 16,
62 .storagebits = 16,
63 },
64 },
65 IIO_CHAN_SOFT_TIMESTAMP(1),
66 };
67
lidar_i2c_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)68 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
69 {
70 struct i2c_client *client = data->client;
71 struct i2c_msg msg[2];
72 int ret;
73
74 msg[0].addr = client->addr;
75 msg[0].flags = client->flags | I2C_M_STOP;
76 msg[0].len = 1;
77 msg[0].buf = (char *) ®
78
79 msg[1].addr = client->addr;
80 msg[1].flags = client->flags | I2C_M_RD;
81 msg[1].len = len;
82 msg[1].buf = (char *) val;
83
84 ret = i2c_transfer(client->adapter, msg, 2);
85
86 return (ret == 2) ? 0 : -EIO;
87 }
88
lidar_smbus_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)89 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
90 {
91 struct i2c_client *client = data->client;
92 int ret;
93
94 /*
95 * Device needs a STOP condition between address write, and data read
96 * so in turn i2c_smbus_read_byte_data cannot be used
97 */
98
99 while (len--) {
100 ret = i2c_smbus_write_byte(client, reg++);
101 if (ret < 0) {
102 dev_err(&client->dev, "cannot write addr value");
103 return ret;
104 }
105
106 ret = i2c_smbus_read_byte(client);
107 if (ret < 0) {
108 dev_err(&client->dev, "cannot read data value");
109 return ret;
110 }
111
112 *(val++) = ret;
113 }
114
115 return 0;
116 }
117
lidar_read_byte(struct lidar_data * data,u8 reg)118 static int lidar_read_byte(struct lidar_data *data, u8 reg)
119 {
120 int ret;
121 u8 val;
122
123 ret = data->xfer(data, reg, &val, 1);
124 if (ret < 0)
125 return ret;
126
127 return val;
128 }
129
lidar_write_control(struct lidar_data * data,int val)130 static inline int lidar_write_control(struct lidar_data *data, int val)
131 {
132 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
133 }
134
lidar_write_power(struct lidar_data * data,int val)135 static inline int lidar_write_power(struct lidar_data *data, int val)
136 {
137 return i2c_smbus_write_byte_data(data->client,
138 LIDAR_REG_PWR_CONTROL, val);
139 }
140
lidar_read_measurement(struct lidar_data * data,u16 * reg)141 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
142 {
143 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
144 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
145 (u8 *) reg, 2);
146
147 if (!ret)
148 *reg = be16_to_cpu(*reg);
149
150 return ret;
151 }
152
lidar_get_measurement(struct lidar_data * data,u16 * reg)153 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
154 {
155 struct i2c_client *client = data->client;
156 int tries = 10;
157 int ret;
158
159 pm_runtime_get_sync(&client->dev);
160
161 /* start sample */
162 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
163 if (ret < 0) {
164 dev_err(&client->dev, "cannot send start measurement command");
165 pm_runtime_put_noidle(&client->dev);
166 return ret;
167 }
168
169 while (tries--) {
170 usleep_range(1000, 2000);
171
172 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
173 if (ret < 0)
174 break;
175
176 /* return -EINVAL since laser is likely pointed out of range */
177 if (ret & LIDAR_REG_STATUS_INVALID) {
178 *reg = 0;
179 ret = -EINVAL;
180 break;
181 }
182
183 /* sample ready to read */
184 if (!(ret & LIDAR_REG_STATUS_READY)) {
185 ret = lidar_read_measurement(data, reg);
186 break;
187 }
188 ret = -EIO;
189 }
190 pm_runtime_mark_last_busy(&client->dev);
191 pm_runtime_put_autosuspend(&client->dev);
192
193 return ret;
194 }
195
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)196 static int lidar_read_raw(struct iio_dev *indio_dev,
197 struct iio_chan_spec const *chan,
198 int *val, int *val2, long mask)
199 {
200 struct lidar_data *data = iio_priv(indio_dev);
201 int ret = -EINVAL;
202
203 switch (mask) {
204 case IIO_CHAN_INFO_RAW: {
205 u16 reg;
206
207 if (iio_device_claim_direct_mode(indio_dev))
208 return -EBUSY;
209
210 ret = lidar_get_measurement(data, ®);
211 if (!ret) {
212 *val = reg;
213 ret = IIO_VAL_INT;
214 }
215 iio_device_release_direct_mode(indio_dev);
216 break;
217 }
218 case IIO_CHAN_INFO_SCALE:
219 *val = 0;
220 *val2 = 10000;
221 ret = IIO_VAL_INT_PLUS_MICRO;
222 break;
223 }
224
225 return ret;
226 }
227
lidar_trigger_handler(int irq,void * private)228 static irqreturn_t lidar_trigger_handler(int irq, void *private)
229 {
230 struct iio_poll_func *pf = private;
231 struct iio_dev *indio_dev = pf->indio_dev;
232 struct lidar_data *data = iio_priv(indio_dev);
233 int ret;
234
235 ret = lidar_get_measurement(data, &data->scan.chan);
236 if (!ret) {
237 iio_push_to_buffers_with_timestamp(indio_dev, &data->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,const struct i2c_device_id * id)252 static int lidar_probe(struct i2c_client *client,
253 const struct i2c_device_id *id)
254 {
255 struct lidar_data *data;
256 struct iio_dev *indio_dev;
257 int ret;
258
259 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
260 if (!indio_dev)
261 return -ENOMEM;
262 data = iio_priv(indio_dev);
263
264 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
265 data->xfer = lidar_i2c_xfer;
266 data->i2c_enabled = 1;
267 } else if (i2c_check_functionality(client->adapter,
268 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
269 data->xfer = lidar_smbus_xfer;
270 else
271 return -EOPNOTSUPP;
272
273 indio_dev->info = &lidar_info;
274 indio_dev->name = LIDAR_DRV_NAME;
275 indio_dev->channels = lidar_channels;
276 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
277 indio_dev->dev.parent = &client->dev;
278 indio_dev->modes = INDIO_DIRECT_MODE;
279
280 i2c_set_clientdata(client, indio_dev);
281
282 data->client = client;
283 data->indio_dev = indio_dev;
284
285 ret = iio_triggered_buffer_setup(indio_dev, NULL,
286 lidar_trigger_handler, NULL);
287 if (ret)
288 return ret;
289
290 ret = iio_device_register(indio_dev);
291 if (ret)
292 goto error_unreg_buffer;
293
294 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
295 pm_runtime_use_autosuspend(&client->dev);
296
297 ret = pm_runtime_set_active(&client->dev);
298 if (ret)
299 goto error_unreg_buffer;
300 pm_runtime_enable(&client->dev);
301 pm_runtime_idle(&client->dev);
302
303 return 0;
304
305 error_unreg_buffer:
306 iio_triggered_buffer_cleanup(indio_dev);
307
308 return ret;
309 }
310
lidar_remove(struct i2c_client * client)311 static int lidar_remove(struct i2c_client *client)
312 {
313 struct iio_dev *indio_dev = i2c_get_clientdata(client);
314
315 iio_device_unregister(indio_dev);
316 iio_triggered_buffer_cleanup(indio_dev);
317
318 pm_runtime_disable(&client->dev);
319 pm_runtime_set_suspended(&client->dev);
320
321 return 0;
322 }
323
324 static const struct i2c_device_id lidar_id[] = {
325 {"lidar-lite-v2", 0},
326 {"lidar-lite-v3", 0},
327 { },
328 };
329 MODULE_DEVICE_TABLE(i2c, lidar_id);
330
331 static const struct of_device_id lidar_dt_ids[] = {
332 { .compatible = "pulsedlight,lidar-lite-v2" },
333 { .compatible = "grmn,lidar-lite-v3" },
334 { }
335 };
336 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
337
338 #ifdef CONFIG_PM
lidar_pm_runtime_suspend(struct device * dev)339 static int lidar_pm_runtime_suspend(struct device *dev)
340 {
341 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
342 struct lidar_data *data = iio_priv(indio_dev);
343
344 return lidar_write_power(data, 0x0f);
345 }
346
lidar_pm_runtime_resume(struct device * dev)347 static int lidar_pm_runtime_resume(struct device *dev)
348 {
349 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
350 struct lidar_data *data = iio_priv(indio_dev);
351 int ret = lidar_write_power(data, 0);
352
353 /* regulator and FPGA needs settling time */
354 usleep_range(15000, 20000);
355
356 return ret;
357 }
358 #endif
359
360 static const struct dev_pm_ops lidar_pm_ops = {
361 SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
362 lidar_pm_runtime_resume, NULL)
363 };
364
365 static struct i2c_driver lidar_driver = {
366 .driver = {
367 .name = LIDAR_DRV_NAME,
368 .of_match_table = of_match_ptr(lidar_dt_ids),
369 .pm = &lidar_pm_ops,
370 },
371 .probe = lidar_probe,
372 .remove = lidar_remove,
373 .id_table = lidar_id,
374 };
375 module_i2c_driver(lidar_driver);
376
377 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
378 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
379 MODULE_LICENSE("GPL");
380