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)256 static int lidar_probe(struct i2c_client *client)
257 {
258 struct lidar_data *data;
259 struct iio_dev *indio_dev;
260 int ret;
261
262 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
263 if (!indio_dev)
264 return -ENOMEM;
265 data = iio_priv(indio_dev);
266
267 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
268 data->xfer = lidar_i2c_xfer;
269 data->i2c_enabled = 1;
270 } else if (i2c_check_functionality(client->adapter,
271 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
272 data->xfer = lidar_smbus_xfer;
273 else
274 return -EOPNOTSUPP;
275
276 indio_dev->info = &lidar_info;
277 indio_dev->name = LIDAR_DRV_NAME;
278 indio_dev->channels = lidar_channels;
279 indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
280 indio_dev->modes = INDIO_DIRECT_MODE;
281
282 i2c_set_clientdata(client, indio_dev);
283
284 data->client = client;
285 data->indio_dev = indio_dev;
286
287 ret = iio_triggered_buffer_setup(indio_dev, NULL,
288 lidar_trigger_handler, NULL);
289 if (ret)
290 return ret;
291
292 ret = iio_device_register(indio_dev);
293 if (ret)
294 goto error_unreg_buffer;
295
296 pm_runtime_set_autosuspend_delay(&client->dev, 1000);
297 pm_runtime_use_autosuspend(&client->dev);
298
299 ret = pm_runtime_set_active(&client->dev);
300 if (ret)
301 goto error_unreg_buffer;
302 pm_runtime_enable(&client->dev);
303 pm_runtime_idle(&client->dev);
304
305 return 0;
306
307 error_unreg_buffer:
308 iio_triggered_buffer_cleanup(indio_dev);
309
310 return ret;
311 }
312
lidar_remove(struct i2c_client * client)313 static void lidar_remove(struct i2c_client *client)
314 {
315 struct iio_dev *indio_dev = i2c_get_clientdata(client);
316
317 iio_device_unregister(indio_dev);
318 iio_triggered_buffer_cleanup(indio_dev);
319
320 pm_runtime_disable(&client->dev);
321 pm_runtime_set_suspended(&client->dev);
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
lidar_pm_runtime_suspend(struct device * dev)338 static int lidar_pm_runtime_suspend(struct device *dev)
339 {
340 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
341 struct lidar_data *data = iio_priv(indio_dev);
342
343 return lidar_write_power(data, 0x0f);
344 }
345
lidar_pm_runtime_resume(struct device * dev)346 static int lidar_pm_runtime_resume(struct device *dev)
347 {
348 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
349 struct lidar_data *data = iio_priv(indio_dev);
350 int ret = lidar_write_power(data, 0);
351
352 /* regulator and FPGA needs settling time */
353 usleep_range(15000, 20000);
354
355 return ret;
356 }
357
358 static const struct dev_pm_ops lidar_pm_ops = {
359 RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL)
360 };
361
362 static struct i2c_driver lidar_driver = {
363 .driver = {
364 .name = LIDAR_DRV_NAME,
365 .of_match_table = lidar_dt_ids,
366 .pm = pm_ptr(&lidar_pm_ops),
367 },
368 .probe = lidar_probe,
369 .remove = lidar_remove,
370 .id_table = lidar_id,
371 };
372 module_i2c_driver(lidar_driver);
373
374 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
375 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
376 MODULE_LICENSE("GPL");
377