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 /* Ensure timestamp is naturally aligned */
48 struct {
49 u16 chan;
50 s64 timestamp __aligned(8);
51 } scan;
52 };
53
54 static const struct iio_chan_spec lidar_channels[] = {
55 {
56 .type = IIO_DISTANCE,
57 .info_mask_separate =
58 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
59 .scan_index = 0,
60 .scan_type = {
61 .sign = 'u',
62 .realbits = 16,
63 .storagebits = 16,
64 },
65 },
66 IIO_CHAN_SOFT_TIMESTAMP(1),
67 };
68
lidar_i2c_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)69 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
70 {
71 struct i2c_client *client = data->client;
72 struct i2c_msg msg[2];
73 int ret;
74
75 msg[0].addr = client->addr;
76 msg[0].flags = client->flags | I2C_M_STOP;
77 msg[0].len = 1;
78 msg[0].buf = (char *) ®
79
80 msg[1].addr = client->addr;
81 msg[1].flags = client->flags | I2C_M_RD;
82 msg[1].len = len;
83 msg[1].buf = (char *) val;
84
85 ret = i2c_transfer(client->adapter, msg, 2);
86
87 return (ret == 2) ? 0 : -EIO;
88 }
89
lidar_smbus_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)90 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
91 {
92 struct i2c_client *client = data->client;
93 int ret;
94
95 /*
96 * Device needs a STOP condition between address write, and data read
97 * so in turn i2c_smbus_read_byte_data cannot be used
98 */
99
100 while (len--) {
101 ret = i2c_smbus_write_byte(client, reg++);
102 if (ret < 0) {
103 dev_err(&client->dev, "cannot write addr value");
104 return ret;
105 }
106
107 ret = i2c_smbus_read_byte(client);
108 if (ret < 0) {
109 dev_err(&client->dev, "cannot read data value");
110 return ret;
111 }
112
113 *(val++) = ret;
114 }
115
116 return 0;
117 }
118
lidar_read_byte(struct lidar_data * data,u8 reg)119 static int lidar_read_byte(struct lidar_data *data, u8 reg)
120 {
121 int ret;
122 u8 val;
123
124 ret = data->xfer(data, reg, &val, 1);
125 if (ret < 0)
126 return ret;
127
128 return val;
129 }
130
lidar_write_control(struct lidar_data * data,int val)131 static inline int lidar_write_control(struct lidar_data *data, int val)
132 {
133 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
134 }
135
lidar_write_power(struct lidar_data * data,int val)136 static inline int lidar_write_power(struct lidar_data *data, int val)
137 {
138 return i2c_smbus_write_byte_data(data->client,
139 LIDAR_REG_PWR_CONTROL, val);
140 }
141
lidar_read_measurement(struct lidar_data * data,u16 * reg)142 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
143 {
144 __be16 value;
145 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
146 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
147 (u8 *) &value, 2);
148
149 if (!ret)
150 *reg = be16_to_cpu(value);
151
152 return ret;
153 }
154
lidar_get_measurement(struct lidar_data * data,u16 * reg)155 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
156 {
157 struct i2c_client *client = data->client;
158 int tries = 10;
159 int ret;
160
161 pm_runtime_get_sync(&client->dev);
162
163 /* start sample */
164 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
165 if (ret < 0) {
166 dev_err(&client->dev, "cannot send start measurement command");
167 pm_runtime_put_noidle(&client->dev);
168 return ret;
169 }
170
171 while (tries--) {
172 usleep_range(1000, 2000);
173
174 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
175 if (ret < 0)
176 break;
177
178 /* return -EINVAL since laser is likely pointed out of range */
179 if (ret & LIDAR_REG_STATUS_INVALID) {
180 *reg = 0;
181 ret = -EINVAL;
182 break;
183 }
184
185 /* sample ready to read */
186 if (!(ret & LIDAR_REG_STATUS_READY)) {
187 ret = lidar_read_measurement(data, reg);
188 break;
189 }
190 ret = -EIO;
191 }
192 pm_runtime_mark_last_busy(&client->dev);
193 pm_runtime_put_autosuspend(&client->dev);
194
195 return ret;
196 }
197
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)198 static int lidar_read_raw(struct iio_dev *indio_dev,
199 struct iio_chan_spec const *chan,
200 int *val, int *val2, long mask)
201 {
202 struct lidar_data *data = iio_priv(indio_dev);
203 int ret = -EINVAL;
204
205 switch (mask) {
206 case IIO_CHAN_INFO_RAW: {
207 u16 reg;
208
209 if (iio_device_claim_direct_mode(indio_dev))
210 return -EBUSY;
211
212 ret = lidar_get_measurement(data, ®);
213 if (!ret) {
214 *val = reg;
215 ret = IIO_VAL_INT;
216 }
217 iio_device_release_direct_mode(indio_dev);
218 break;
219 }
220 case IIO_CHAN_INFO_SCALE:
221 *val = 0;
222 *val2 = 10000;
223 ret = IIO_VAL_INT_PLUS_MICRO;
224 break;
225 }
226
227 return ret;
228 }
229
lidar_trigger_handler(int irq,void * private)230 static irqreturn_t lidar_trigger_handler(int irq, void *private)
231 {
232 struct iio_poll_func *pf = private;
233 struct iio_dev *indio_dev = pf->indio_dev;
234 struct lidar_data *data = iio_priv(indio_dev);
235 int ret;
236
237 ret = lidar_get_measurement(data, &data->scan.chan);
238 if (!ret) {
239 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
240 iio_get_time_ns(indio_dev));
241 } else if (ret != -EINVAL) {
242 dev_err(&data->client->dev, "cannot read LIDAR measurement");
243 }
244
245 iio_trigger_notify_done(indio_dev->trig);
246
247 return IRQ_HANDLED;
248 }
249
250 static const struct iio_info lidar_info = {
251 .read_raw = lidar_read_raw,
252 };
253
lidar_probe(struct i2c_client * client,const struct i2c_device_id * id)254 static int lidar_probe(struct i2c_client *client,
255 const struct i2c_device_id *id)
256 {
257 struct lidar_data *data;
258 struct iio_dev *indio_dev;
259 int ret;
260
261 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
262 if (!indio_dev)
263 return -ENOMEM;
264 data = iio_priv(indio_dev);
265
266 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
267 data->xfer = lidar_i2c_xfer;
268 data->i2c_enabled = 1;
269 } else if (i2c_check_functionality(client->adapter,
270 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
271 data->xfer = lidar_smbus_xfer;
272 else
273 return -EOPNOTSUPP;
274
275 indio_dev->info = &lidar_info;
276 indio_dev->name = LIDAR_DRV_NAME;
277 indio_dev->channels = lidar_channels;
278 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
279 indio_dev->modes = INDIO_DIRECT_MODE;
280
281 i2c_set_clientdata(client, indio_dev);
282
283 data->client = client;
284 data->indio_dev = indio_dev;
285
286 ret = iio_triggered_buffer_setup(indio_dev, NULL,
287 lidar_trigger_handler, NULL);
288 if (ret)
289 return ret;
290
291 ret = iio_device_register(indio_dev);
292 if (ret)
293 goto error_unreg_buffer;
294
295 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
296 pm_runtime_use_autosuspend(&client->dev);
297
298 ret = pm_runtime_set_active(&client->dev);
299 if (ret)
300 goto error_unreg_buffer;
301 pm_runtime_enable(&client->dev);
302 pm_runtime_idle(&client->dev);
303
304 return 0;
305
306 error_unreg_buffer:
307 iio_triggered_buffer_cleanup(indio_dev);
308
309 return ret;
310 }
311
lidar_remove(struct i2c_client * client)312 static int lidar_remove(struct i2c_client *client)
313 {
314 struct iio_dev *indio_dev = i2c_get_clientdata(client);
315
316 iio_device_unregister(indio_dev);
317 iio_triggered_buffer_cleanup(indio_dev);
318
319 pm_runtime_disable(&client->dev);
320 pm_runtime_set_suspended(&client->dev);
321
322 return 0;
323 }
324
325 static const struct i2c_device_id lidar_id[] = {
326 {"lidar-lite-v2", 0},
327 {"lidar-lite-v3", 0},
328 { },
329 };
330 MODULE_DEVICE_TABLE(i2c, lidar_id);
331
332 static const struct of_device_id lidar_dt_ids[] = {
333 { .compatible = "pulsedlight,lidar-lite-v2" },
334 { .compatible = "grmn,lidar-lite-v3" },
335 { }
336 };
337 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
338
339 #ifdef CONFIG_PM
lidar_pm_runtime_suspend(struct device * dev)340 static int lidar_pm_runtime_suspend(struct device *dev)
341 {
342 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
343 struct lidar_data *data = iio_priv(indio_dev);
344
345 return lidar_write_power(data, 0x0f);
346 }
347
lidar_pm_runtime_resume(struct device * dev)348 static int lidar_pm_runtime_resume(struct device *dev)
349 {
350 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
351 struct lidar_data *data = iio_priv(indio_dev);
352 int ret = lidar_write_power(data, 0);
353
354 /* regulator and FPGA needs settling time */
355 usleep_range(15000, 20000);
356
357 return ret;
358 }
359 #endif
360
361 static const struct dev_pm_ops lidar_pm_ops = {
362 SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
363 lidar_pm_runtime_resume, NULL)
364 };
365
366 static struct i2c_driver lidar_driver = {
367 .driver = {
368 .name = LIDAR_DRV_NAME,
369 .of_match_table = lidar_dt_ids,
370 .pm = &lidar_pm_ops,
371 },
372 .probe = lidar_probe,
373 .remove = lidar_remove,
374 .id_table = lidar_id,
375 };
376 module_i2c_driver(lidar_driver);
377
378 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
379 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
380 MODULE_LICENSE("GPL");
381