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	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
200static 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, &reg);
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
232static 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
252static const struct iio_info lidar_info = {
253	.read_raw = lidar_read_raw,
254};
255
256static 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
307error_unreg_buffer:
308	iio_triggered_buffer_cleanup(indio_dev);
309
310	return ret;
311}
312
313static 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
324static const struct i2c_device_id lidar_id[] = {
325	{"lidar-lite-v2", 0},
326	{"lidar-lite-v3", 0},
327	{ },
328};
329MODULE_DEVICE_TABLE(i2c, lidar_id);
330
331static const struct of_device_id lidar_dt_ids[] = {
332	{ .compatible = "pulsedlight,lidar-lite-v2" },
333	{ .compatible = "grmn,lidar-lite-v3" },
334	{ }
335};
336MODULE_DEVICE_TABLE(of, lidar_dt_ids);
337
338static 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
346static 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
358static const struct dev_pm_ops lidar_pm_ops = {
359	RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL)
360};
361
362static 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};
372module_i2c_driver(lidar_driver);
373
374MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
375MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
376MODULE_LICENSE("GPL");
377