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 ret = pm_runtime_resume_and_get(&client->dev);
162 if (ret < 0)
163 return ret;
164
165 /* start sample */
166 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
167 if (ret < 0) {
168 dev_err(&client->dev, "cannot send start measurement command");
169 pm_runtime_put_noidle(&client->dev);
170 return ret;
171 }
172
173 while (tries--) {
174 usleep_range(1000, 2000);
175
176 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
177 if (ret < 0)
178 break;
179
180 /* return -EINVAL since laser is likely pointed out of range */
181 if (ret & LIDAR_REG_STATUS_INVALID) {
182 *reg = 0;
183 ret = -EINVAL;
184 break;
185 }
186
187 /* sample ready to read */
188 if (!(ret & LIDAR_REG_STATUS_READY)) {
189 ret = lidar_read_measurement(data, reg);
190 break;
191 }
192 ret = -EIO;
193 }
194 pm_runtime_mark_last_busy(&client->dev);
195 pm_runtime_put_autosuspend(&client->dev);
196
197 return ret;
198 }
199
lidar_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)200 static int lidar_read_raw(struct iio_dev *indio_dev,
201 struct iio_chan_spec const *chan,
202 int *val, int *val2, long mask)
203 {
204 struct lidar_data *data = iio_priv(indio_dev);
205 int ret = -EINVAL;
206
207 switch (mask) {
208 case IIO_CHAN_INFO_RAW: {
209 u16 reg;
210
211 if (iio_device_claim_direct_mode(indio_dev))
212 return -EBUSY;
213
214 ret = lidar_get_measurement(data, ®);
215 if (!ret) {
216 *val = reg;
217 ret = IIO_VAL_INT;
218 }
219 iio_device_release_direct_mode(indio_dev);
220 break;
221 }
222 case IIO_CHAN_INFO_SCALE:
223 *val = 0;
224 *val2 = 10000;
225 ret = IIO_VAL_INT_PLUS_MICRO;
226 break;
227 }
228
229 return ret;
230 }
231
lidar_trigger_handler(int irq,void * private)232 static irqreturn_t lidar_trigger_handler(int irq, void *private)
233 {
234 struct iio_poll_func *pf = private;
235 struct iio_dev *indio_dev = pf->indio_dev;
236 struct lidar_data *data = iio_priv(indio_dev);
237 int ret;
238
239 ret = lidar_get_measurement(data, &data->scan.chan);
240 if (!ret) {
241 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
242 iio_get_time_ns(indio_dev));
243 } else if (ret != -EINVAL) {
244 dev_err(&data->client->dev, "cannot read LIDAR measurement");
245 }
246
247 iio_trigger_notify_done(indio_dev->trig);
248
249 return IRQ_HANDLED;
250 }
251
252 static const struct iio_info lidar_info = {
253 .read_raw = lidar_read_raw,
254 };
255
lidar_probe(struct i2c_client * client,const struct i2c_device_id * id)256 static int lidar_probe(struct i2c_client *client,
257 const struct i2c_device_id *id)
258 {
259 struct lidar_data *data;
260 struct iio_dev *indio_dev;
261 int ret;
262
263 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
264 if (!indio_dev)
265 return -ENOMEM;
266 data = iio_priv(indio_dev);
267
268 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
269 data->xfer = lidar_i2c_xfer;
270 data->i2c_enabled = 1;
271 } else if (i2c_check_functionality(client->adapter,
272 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
273 data->xfer = lidar_smbus_xfer;
274 else
275 return -EOPNOTSUPP;
276
277 indio_dev->info = &lidar_info;
278 indio_dev->name = LIDAR_DRV_NAME;
279 indio_dev->channels = lidar_channels;
280 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
281 indio_dev->modes = INDIO_DIRECT_MODE;
282
283 i2c_set_clientdata(client, indio_dev);
284
285 data->client = client;
286 data->indio_dev = indio_dev;
287
288 ret = iio_triggered_buffer_setup(indio_dev, NULL,
289 lidar_trigger_handler, NULL);
290 if (ret)
291 return ret;
292
293 ret = iio_device_register(indio_dev);
294 if (ret)
295 goto error_unreg_buffer;
296
297 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
298 pm_runtime_use_autosuspend(&client->dev);
299
300 ret = pm_runtime_set_active(&client->dev);
301 if (ret)
302 goto error_unreg_buffer;
303 pm_runtime_enable(&client->dev);
304 pm_runtime_idle(&client->dev);
305
306 return 0;
307
308 error_unreg_buffer:
309 iio_triggered_buffer_cleanup(indio_dev);
310
311 return ret;
312 }
313
lidar_remove(struct i2c_client * client)314 static void lidar_remove(struct i2c_client *client)
315 {
316 struct iio_dev *indio_dev = i2c_get_clientdata(client);
317
318 iio_device_unregister(indio_dev);
319 iio_triggered_buffer_cleanup(indio_dev);
320
321 pm_runtime_disable(&client->dev);
322 pm_runtime_set_suspended(&client->dev);
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
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
359 static const struct dev_pm_ops lidar_pm_ops = {
360 RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL)
361 };
362
363 static struct i2c_driver lidar_driver = {
364 .driver = {
365 .name = LIDAR_DRV_NAME,
366 .of_match_table = lidar_dt_ids,
367 .pm = pm_ptr(&lidar_pm_ops),
368 },
369 .probe = lidar_probe,
370 .remove = lidar_remove,
371 .id_table = lidar_id,
372 };
373 module_i2c_driver(lidar_driver);
374
375 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
376 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
377 MODULE_LICENSE("GPL");
378
