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
40struct 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
54static 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
69static 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 *) &reg;
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
90static 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
119static 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
131static 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
136static 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
142static 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
155static 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
198static 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, &reg);
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
230static 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
250static const struct iio_info lidar_info = {
251	.read_raw = lidar_read_raw,
252};
253
254static 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
306error_unreg_buffer:
307	iio_triggered_buffer_cleanup(indio_dev);
308
309	return ret;
310}
311
312static 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
325static const struct i2c_device_id lidar_id[] = {
326	{"lidar-lite-v2", 0},
327	{"lidar-lite-v3", 0},
328	{ },
329};
330MODULE_DEVICE_TABLE(i2c, lidar_id);
331
332static const struct of_device_id lidar_dt_ids[] = {
333	{ .compatible = "pulsedlight,lidar-lite-v2" },
334	{ .compatible = "grmn,lidar-lite-v3" },
335	{ }
336};
337MODULE_DEVICE_TABLE(of, lidar_dt_ids);
338
339#ifdef CONFIG_PM
340static 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
348static 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
361static 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
366static 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};
376module_i2c_driver(lidar_driver);
377
378MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
379MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
380MODULE_LICENSE("GPL");
381