1// SPDX-License-Identifier: GPL-2.0
2/*
3 * All Sensors DLH series low voltage digital pressure sensors
4 *
5 * Copyright (c) 2019 AVL DiTEST GmbH
6 *   Tomislav Denis <tomislav.denis@avl.com>
7 *
8 * Datasheet: https://www.allsensors.com/cad/DS-0355_Rev_B.PDF
9 */
10
11#include <linux/module.h>
12#include <linux/delay.h>
13#include <linux/i2c.h>
14#include <linux/iio/iio.h>
15#include <linux/iio/buffer.h>
16#include <linux/iio/trigger_consumer.h>
17#include <linux/iio/triggered_buffer.h>
18#include <asm/unaligned.h>
19
20/* Commands */
21#define DLH_START_SINGLE    0xAA
22
23/* Status bits */
24#define DLH_STATUS_OK       0x40
25
26/* DLH  data format */
27#define DLH_NUM_READ_BYTES  7
28#define DLH_NUM_DATA_BYTES  3
29#define DLH_NUM_PR_BITS     24
30#define DLH_NUM_TEMP_BITS   24
31
32/* DLH  timings */
33#define DLH_SINGLE_DUT_MS   5
34
35enum dhl_ids {
36	dlhl60d,
37	dlhl60g,
38};
39
40struct dlh_info {
41	u8 osdig;           /* digital offset factor */
42	unsigned int fss;   /* full scale span (inch H2O) */
43};
44
45struct dlh_state {
46	struct i2c_client *client;
47	struct dlh_info info;
48	bool use_interrupt;
49	struct completion completion;
50	u8 rx_buf[DLH_NUM_READ_BYTES];
51};
52
53static struct dlh_info dlh_info_tbl[] = {
54	[dlhl60d] = {
55		.osdig = 2,
56		.fss = 120,
57	},
58	[dlhl60g] = {
59		.osdig = 10,
60		.fss = 60,
61	},
62};
63
64
65static int dlh_cmd_start_single(struct dlh_state *st)
66{
67	int ret;
68
69	ret = i2c_smbus_write_byte(st->client, DLH_START_SINGLE);
70	if (ret)
71		dev_err(&st->client->dev,
72			"%s: I2C write byte failed\n", __func__);
73
74	return ret;
75}
76
77static int dlh_cmd_read_data(struct dlh_state *st)
78{
79	int ret;
80
81	ret = i2c_master_recv(st->client, st->rx_buf, DLH_NUM_READ_BYTES);
82	if (ret < 0) {
83		dev_err(&st->client->dev,
84			"%s: I2C read block failed\n", __func__);
85		return ret;
86	}
87
88	if (st->rx_buf[0] != DLH_STATUS_OK) {
89		dev_err(&st->client->dev,
90			"%s: invalid status 0x%02x\n", __func__, st->rx_buf[0]);
91		return -EBUSY;
92	}
93
94	return 0;
95}
96
97static int dlh_start_capture_and_read(struct dlh_state *st)
98{
99	int ret;
100
101	if (st->use_interrupt)
102		reinit_completion(&st->completion);
103
104	ret = dlh_cmd_start_single(st);
105	if (ret)
106		return ret;
107
108	if (st->use_interrupt) {
109		ret = wait_for_completion_timeout(&st->completion,
110			msecs_to_jiffies(DLH_SINGLE_DUT_MS));
111		if (!ret) {
112			dev_err(&st->client->dev,
113				"%s: conversion timed out\n", __func__);
114			return -ETIMEDOUT;
115		}
116	} else {
117		mdelay(DLH_SINGLE_DUT_MS);
118	}
119
120	return dlh_cmd_read_data(st);
121}
122
123static int dlh_read_direct(struct dlh_state *st,
124	unsigned int *pressure, unsigned int *temperature)
125{
126	int ret;
127
128	ret = dlh_start_capture_and_read(st);
129	if (ret)
130		return ret;
131
132	*pressure = get_unaligned_be24(&st->rx_buf[1]);
133	*temperature = get_unaligned_be24(&st->rx_buf[4]);
134
135	return 0;
136}
137
138static int dlh_read_raw(struct iio_dev *indio_dev,
139	struct iio_chan_spec const *channel, int *value,
140	int *value2, long mask)
141{
142	struct dlh_state *st = iio_priv(indio_dev);
143	unsigned int pressure, temperature;
144	int ret;
145	s64 tmp;
146	s32 rem;
147
148	switch (mask) {
149	case IIO_CHAN_INFO_RAW:
150		ret = iio_device_claim_direct_mode(indio_dev);
151		if (ret)
152			return ret;
153
154		ret = dlh_read_direct(st, &pressure, &temperature);
155		iio_device_release_direct_mode(indio_dev);
156		if (ret)
157			return ret;
158
159		switch (channel->type) {
160		case IIO_PRESSURE:
161			*value = pressure;
162			return IIO_VAL_INT;
163
164		case IIO_TEMP:
165			*value = temperature;
166			return IIO_VAL_INT;
167
168		default:
169			return -EINVAL;
170		}
171	case IIO_CHAN_INFO_SCALE:
172		switch (channel->type) {
173		case IIO_PRESSURE:
174			tmp = div_s64(125LL * st->info.fss * 24909 * 100,
175				1 << DLH_NUM_PR_BITS);
176			tmp = div_s64_rem(tmp, 1000000000LL, &rem);
177			*value = tmp;
178			*value2 = rem;
179			return IIO_VAL_INT_PLUS_NANO;
180
181		case IIO_TEMP:
182			*value = 125 * 1000;
183			*value2 = DLH_NUM_TEMP_BITS;
184			return IIO_VAL_FRACTIONAL_LOG2;
185
186		default:
187			return -EINVAL;
188		}
189	case IIO_CHAN_INFO_OFFSET:
190		switch (channel->type) {
191		case IIO_PRESSURE:
192			*value = -125 * st->info.fss * 24909;
193			*value2 = 100 * st->info.osdig * 100000;
194			return IIO_VAL_FRACTIONAL;
195
196		case IIO_TEMP:
197			*value = -40 * 1000;
198			return IIO_VAL_INT;
199
200		default:
201			return -EINVAL;
202		}
203	}
204
205	return -EINVAL;
206}
207
208static const struct iio_info dlh_info = {
209	.read_raw = dlh_read_raw,
210};
211
212static const struct iio_chan_spec dlh_channels[] = {
213	{
214		.type = IIO_PRESSURE,
215		.indexed = 1,
216		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
217		.info_mask_shared_by_type =
218			BIT(IIO_CHAN_INFO_SCALE) |
219			BIT(IIO_CHAN_INFO_OFFSET),
220		.scan_index = 0,
221		.scan_type = {
222			.sign = 'u',
223			.realbits = DLH_NUM_PR_BITS,
224			.storagebits = 32,
225			.shift = 8,
226			.endianness = IIO_BE,
227		},
228	}, {
229		.type = IIO_TEMP,
230		.indexed = 1,
231		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
232		.info_mask_shared_by_type =
233			BIT(IIO_CHAN_INFO_SCALE) |
234			BIT(IIO_CHAN_INFO_OFFSET),
235		.scan_index = 1,
236		.scan_type = {
237			.sign = 'u',
238			.realbits = DLH_NUM_TEMP_BITS,
239			.storagebits = 32,
240			.shift = 8,
241			.endianness = IIO_BE,
242		},
243	}
244};
245
246static irqreturn_t dlh_trigger_handler(int irq, void *private)
247{
248	struct iio_poll_func *pf = private;
249	struct iio_dev *indio_dev = pf->indio_dev;
250	struct dlh_state *st = iio_priv(indio_dev);
251	int ret;
252	unsigned int chn, i = 0;
253	__be32 tmp_buf[2];
254
255	ret = dlh_start_capture_and_read(st);
256	if (ret)
257		goto out;
258
259	for_each_set_bit(chn, indio_dev->active_scan_mask,
260		indio_dev->masklength) {
261		memcpy(tmp_buf + i,
262			&st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
263			DLH_NUM_DATA_BYTES);
264		i++;
265	}
266
267	iio_push_to_buffers(indio_dev, tmp_buf);
268
269out:
270	iio_trigger_notify_done(indio_dev->trig);
271
272	return IRQ_HANDLED;
273}
274
275static irqreturn_t dlh_interrupt(int irq, void *private)
276{
277	struct iio_dev *indio_dev = private;
278	struct dlh_state *st = iio_priv(indio_dev);
279
280	complete(&st->completion);
281
282	return IRQ_HANDLED;
283};
284
285static int dlh_probe(struct i2c_client *client)
286{
287	const struct i2c_device_id *id = i2c_client_get_device_id(client);
288	struct dlh_state *st;
289	struct iio_dev *indio_dev;
290	int ret;
291
292	if (!i2c_check_functionality(client->adapter,
293		I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
294		dev_err(&client->dev,
295			"adapter doesn't support required i2c functionality\n");
296		return -EOPNOTSUPP;
297	}
298
299	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
300	if (!indio_dev) {
301		dev_err(&client->dev, "failed to allocate iio device\n");
302		return -ENOMEM;
303	}
304
305	i2c_set_clientdata(client, indio_dev);
306
307	st = iio_priv(indio_dev);
308	st->info = dlh_info_tbl[id->driver_data];
309	st->client = client;
310	st->use_interrupt = false;
311
312	indio_dev->name = id->name;
313	indio_dev->info = &dlh_info;
314	indio_dev->modes = INDIO_DIRECT_MODE;
315	indio_dev->channels =  dlh_channels;
316	indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
317
318	if (client->irq > 0) {
319		ret = devm_request_threaded_irq(&client->dev, client->irq,
320			dlh_interrupt, NULL,
321			IRQF_TRIGGER_RISING | IRQF_ONESHOT,
322			id->name, indio_dev);
323		if (ret) {
324			dev_err(&client->dev, "failed to allocate threaded irq");
325			return ret;
326		}
327
328		st->use_interrupt = true;
329		init_completion(&st->completion);
330	}
331
332	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
333		NULL, &dlh_trigger_handler, NULL);
334	if (ret) {
335		dev_err(&client->dev, "failed to setup iio buffer\n");
336		return ret;
337	}
338
339	ret = devm_iio_device_register(&client->dev, indio_dev);
340	if (ret)
341		dev_err(&client->dev, "failed to register iio device\n");
342
343	return ret;
344}
345
346static const struct of_device_id dlh_of_match[] = {
347	{ .compatible = "asc,dlhl60d" },
348	{ .compatible = "asc,dlhl60g" },
349	{}
350};
351MODULE_DEVICE_TABLE(of, dlh_of_match);
352
353static const struct i2c_device_id dlh_id[] = {
354	{ "dlhl60d",    dlhl60d },
355	{ "dlhl60g",    dlhl60g },
356	{}
357};
358MODULE_DEVICE_TABLE(i2c, dlh_id);
359
360static struct i2c_driver dlh_driver = {
361	.driver = {
362		.name = "dlhl60d",
363		.of_match_table = dlh_of_match,
364	},
365	.probe = dlh_probe,
366	.id_table = dlh_id,
367};
368module_i2c_driver(dlh_driver);
369
370MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
371MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
372MODULE_LICENSE("GPL v2");
373