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 u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
47 };
48
49 static const struct iio_chan_spec lidar_channels[] = {
50 {
51 .type = IIO_DISTANCE,
52 .info_mask_separate =
53 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
54 .scan_index = 0,
55 .scan_type = {
56 .sign = 'u',
57 .realbits = 16,
58 .storagebits = 16,
59 },
60 },
61 IIO_CHAN_SOFT_TIMESTAMP(1),
62 };
63
lidar_i2c_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)64 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
65 {
66 struct i2c_client *client = data->client;
67 struct i2c_msg msg[2];
68 int ret;
69
70 msg[0].addr = client->addr;
71 msg[0].flags = client->flags | I2C_M_STOP;
72 msg[0].len = 1;
73 msg[0].buf = (char *) ®
74
75 msg[1].addr = client->addr;
76 msg[1].flags = client->flags | I2C_M_RD;
77 msg[1].len = len;
78 msg[1].buf = (char *) val;
79
80 ret = i2c_transfer(client->adapter, msg, 2);
81
82 return (ret == 2) ? 0 : -EIO;
83 }
84
lidar_smbus_xfer(struct lidar_data * data,u8 reg,u8 * val,int len)85 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
86 {
87 struct i2c_client *client = data->client;
88 int ret;
89
90 /*
91 * Device needs a STOP condition between address write, and data read
92 * so in turn i2c_smbus_read_byte_data cannot be used
93 */
94
95 while (len--) {
96 ret = i2c_smbus_write_byte(client, reg++);
97 if (ret < 0) {
98 dev_err(&client->dev, "cannot write addr value");
99 return ret;
100 }
101
102 ret = i2c_smbus_read_byte(client);
103 if (ret < 0) {
104 dev_err(&client->dev, "cannot read data value");
105 return ret;
106 }
107
108 *(val++) = ret;
109 }
110
111 return 0;
112 }
113
lidar_read_byte(struct lidar_data * data,u8 reg)114 static int lidar_read_byte(struct lidar_data *data, u8 reg)
115 {
116 int ret;
117 u8 val;
118
119 ret = data->xfer(data, reg, &val, 1);
120 if (ret < 0)
121 return ret;
122
123 return val;
124 }
125
lidar_write_control(struct lidar_data * data,int val)126 static inline int lidar_write_control(struct lidar_data *data, int val)
127 {
128 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
129 }
130
lidar_write_power(struct lidar_data * data,int val)131 static inline int lidar_write_power(struct lidar_data *data, int val)
132 {
133 return i2c_smbus_write_byte_data(data->client,
134 LIDAR_REG_PWR_CONTROL, val);
135 }
136
lidar_read_measurement(struct lidar_data * data,u16 * reg)137 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
138 {
139 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
140 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
141 (u8 *) reg, 2);
142
143 if (!ret)
144 *reg = be16_to_cpu(*reg);
145
146 return ret;
147 }
148
lidar_get_measurement(struct lidar_data * data,u16 * reg)149 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
150 {
151 struct i2c_client *client = data->client;
152 int tries = 10;
153 int ret;
154
155 pm_runtime_get_sync(&client->dev);
156
157 /* start sample */
158 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
159 if (ret < 0) {
160 dev_err(&client->dev, "cannot send start measurement command");
161 return ret;
162 }
163
164 while (tries--) {
165 usleep_range(1000, 2000);
166
167 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
168 if (ret < 0)
169 break;
170
171 /* return -EINVAL since laser is likely pointed out of range */
172 if (ret & LIDAR_REG_STATUS_INVALID) {
173 *reg = 0;
174 ret = -EINVAL;
175 break;
176 }
177
178 /* sample ready to read */
179 if (!(ret & LIDAR_REG_STATUS_READY)) {
180 ret = lidar_read_measurement(data, reg);
181 break;
182 }
183 ret = -EIO;
184 }
185 pm_runtime_mark_last_busy(&client->dev);
186 pm_runtime_put_autosuspend(&client->dev);
187
188 return ret;
189 }
190
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)191 static int lidar_read_raw(struct iio_dev *indio_dev,
192 struct iio_chan_spec const *chan,
193 int *val, int *val2, long mask)
194 {
195 struct lidar_data *data = iio_priv(indio_dev);
196 int ret = -EINVAL;
197
198 switch (mask) {
199 case IIO_CHAN_INFO_RAW: {
200 u16 reg;
201
202 if (iio_device_claim_direct_mode(indio_dev))
203 return -EBUSY;
204
205 ret = lidar_get_measurement(data, ®);
206 if (!ret) {
207 *val = reg;
208 ret = IIO_VAL_INT;
209 }
210 iio_device_release_direct_mode(indio_dev);
211 break;
212 }
213 case IIO_CHAN_INFO_SCALE:
214 *val = 0;
215 *val2 = 10000;
216 ret = IIO_VAL_INT_PLUS_MICRO;
217 break;
218 }
219
220 return ret;
221 }
222
lidar_trigger_handler(int irq,void * private)223 static irqreturn_t lidar_trigger_handler(int irq, void *private)
224 {
225 struct iio_poll_func *pf = private;
226 struct iio_dev *indio_dev = pf->indio_dev;
227 struct lidar_data *data = iio_priv(indio_dev);
228 int ret;
229
230 ret = lidar_get_measurement(data, data->buffer);
231 if (!ret) {
232 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
233 iio_get_time_ns(indio_dev));
234 } else if (ret != -EINVAL) {
235 dev_err(&data->client->dev, "cannot read LIDAR measurement");
236 }
237
238 iio_trigger_notify_done(indio_dev->trig);
239
240 return IRQ_HANDLED;
241 }
242
243 static const struct iio_info lidar_info = {
244 .read_raw = lidar_read_raw,
245 };
246
lidar_probe(struct i2c_client * client,const struct i2c_device_id * id)247 static int lidar_probe(struct i2c_client *client,
248 const struct i2c_device_id *id)
249 {
250 struct lidar_data *data;
251 struct iio_dev *indio_dev;
252 int ret;
253
254 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
255 if (!indio_dev)
256 return -ENOMEM;
257 data = iio_priv(indio_dev);
258
259 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
260 data->xfer = lidar_i2c_xfer;
261 data->i2c_enabled = 1;
262 } else if (i2c_check_functionality(client->adapter,
263 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
264 data->xfer = lidar_smbus_xfer;
265 else
266 return -EOPNOTSUPP;
267
268 indio_dev->info = &lidar_info;
269 indio_dev->name = LIDAR_DRV_NAME;
270 indio_dev->channels = lidar_channels;
271 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
272 indio_dev->dev.parent = &client->dev;
273 indio_dev->modes = INDIO_DIRECT_MODE;
274
275 i2c_set_clientdata(client, indio_dev);
276
277 data->client = client;
278 data->indio_dev = indio_dev;
279
280 ret = iio_triggered_buffer_setup(indio_dev, NULL,
281 lidar_trigger_handler, NULL);
282 if (ret)
283 return ret;
284
285 ret = iio_device_register(indio_dev);
286 if (ret)
287 goto error_unreg_buffer;
288
289 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
290 pm_runtime_use_autosuspend(&client->dev);
291
292 ret = pm_runtime_set_active(&client->dev);
293 if (ret)
294 goto error_unreg_buffer;
295 pm_runtime_enable(&client->dev);
296 pm_runtime_idle(&client->dev);
297
298 return 0;
299
300 error_unreg_buffer:
301 iio_triggered_buffer_cleanup(indio_dev);
302
303 return ret;
304 }
305
lidar_remove(struct i2c_client * client)306 static int lidar_remove(struct i2c_client *client)
307 {
308 struct iio_dev *indio_dev = i2c_get_clientdata(client);
309
310 iio_device_unregister(indio_dev);
311 iio_triggered_buffer_cleanup(indio_dev);
312
313 pm_runtime_disable(&client->dev);
314 pm_runtime_set_suspended(&client->dev);
315
316 return 0;
317 }
318
319 static const struct i2c_device_id lidar_id[] = {
320 {"lidar-lite-v2", 0},
321 {"lidar-lite-v3", 0},
322 { },
323 };
324 MODULE_DEVICE_TABLE(i2c, lidar_id);
325
326 static const struct of_device_id lidar_dt_ids[] = {
327 { .compatible = "pulsedlight,lidar-lite-v2" },
328 { .compatible = "grmn,lidar-lite-v3" },
329 { }
330 };
331 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
332
333 #ifdef CONFIG_PM
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 #endif
354
355 static const struct dev_pm_ops lidar_pm_ops = {
356 SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
357 lidar_pm_runtime_resume, NULL)
358 };
359
360 static struct i2c_driver lidar_driver = {
361 .driver = {
362 .name = LIDAR_DRV_NAME,
363 .of_match_table = of_match_ptr(lidar_dt_ids),
364 .pm = &lidar_pm_ops,
365 },
366 .probe = lidar_probe,
367 .remove = lidar_remove,
368 .id_table = lidar_id,
369 };
370 module_i2c_driver(lidar_driver);
371
372 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
373 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
374 MODULE_LICENSE("GPL");
375
