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] ____cacheline_aligned;
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_be32(&st->rx_buf[1]) >> 8;
133	*temperature = get_unaligned_be32(&st->rx_buf[3]) &
134		GENMASK(DLH_NUM_TEMP_BITS - 1, 0);
135
136	return 0;
137}
138
139static int dlh_read_raw(struct iio_dev *indio_dev,
140	struct iio_chan_spec const *channel, int *value,
141	int *value2, long mask)
142{
143	struct dlh_state *st = iio_priv(indio_dev);
144	unsigned int pressure, temperature;
145	int ret;
146	s64 tmp;
147	s32 rem;
148
149	switch (mask) {
150	case IIO_CHAN_INFO_RAW:
151		ret = iio_device_claim_direct_mode(indio_dev);
152		if (ret)
153			return ret;
154
155		ret = dlh_read_direct(st, &pressure, &temperature);
156		iio_device_release_direct_mode(indio_dev);
157		if (ret)
158			return ret;
159
160		switch (channel->type) {
161		case IIO_PRESSURE:
162			*value = pressure;
163			return IIO_VAL_INT;
164
165		case IIO_TEMP:
166			*value = temperature;
167			return IIO_VAL_INT;
168
169		default:
170			return -EINVAL;
171		}
172	case IIO_CHAN_INFO_SCALE:
173		switch (channel->type) {
174		case IIO_PRESSURE:
175			tmp = div_s64(125LL * st->info.fss * 24909 * 100,
176				1 << DLH_NUM_PR_BITS);
177			tmp = div_s64_rem(tmp, 1000000000LL, &rem);
178			*value = tmp;
179			*value2 = rem;
180			return IIO_VAL_INT_PLUS_NANO;
181
182		case IIO_TEMP:
183			*value = 125 * 1000;
184			*value2 = DLH_NUM_TEMP_BITS;
185			return IIO_VAL_FRACTIONAL_LOG2;
186
187		default:
188			return -EINVAL;
189		}
190	case IIO_CHAN_INFO_OFFSET:
191		switch (channel->type) {
192		case IIO_PRESSURE:
193			*value = -125 * st->info.fss * 24909;
194			*value2 = 100 * st->info.osdig * 100000;
195			return IIO_VAL_FRACTIONAL;
196
197		case IIO_TEMP:
198			*value = -40 * 1000;
199			return IIO_VAL_INT;
200
201		default:
202			return -EINVAL;
203		}
204	}
205
206	return -EINVAL;
207}
208
209static const struct iio_info dlh_info = {
210	.read_raw = dlh_read_raw,
211};
212
213static const struct iio_chan_spec dlh_channels[] = {
214	{
215		.type = IIO_PRESSURE,
216		.indexed = 1,
217		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
218		.info_mask_shared_by_type =
219			BIT(IIO_CHAN_INFO_SCALE) |
220			BIT(IIO_CHAN_INFO_OFFSET),
221		.scan_index = 0,
222		.scan_type = {
223			.sign = 'u',
224			.realbits = DLH_NUM_PR_BITS,
225			.storagebits = 32,
226			.shift = 8,
227			.endianness = IIO_BE,
228		},
229	}, {
230		.type = IIO_TEMP,
231		.indexed = 1,
232		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
233		.info_mask_shared_by_type =
234			BIT(IIO_CHAN_INFO_SCALE) |
235			BIT(IIO_CHAN_INFO_OFFSET),
236		.scan_index = 1,
237		.scan_type = {
238			.sign = 'u',
239			.realbits = DLH_NUM_TEMP_BITS,
240			.storagebits = 32,
241			.shift = 8,
242			.endianness = IIO_BE,
243		},
244	}
245};
246
247static irqreturn_t dlh_trigger_handler(int irq, void *private)
248{
249	struct iio_poll_func *pf = private;
250	struct iio_dev *indio_dev = pf->indio_dev;
251	struct dlh_state *st = iio_priv(indio_dev);
252	int ret;
253	unsigned int chn, i = 0;
254	__be32 tmp_buf[2];
255
256	ret = dlh_start_capture_and_read(st);
257	if (ret)
258		goto out;
259
260	for_each_set_bit(chn, indio_dev->active_scan_mask,
261		indio_dev->masklength) {
262		memcpy(tmp_buf + i,
263			&st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
264			DLH_NUM_DATA_BYTES);
265		i++;
266	}
267
268	iio_push_to_buffers(indio_dev, tmp_buf);
269
270out:
271	iio_trigger_notify_done(indio_dev->trig);
272
273	return IRQ_HANDLED;
274}
275
276static irqreturn_t dlh_interrupt(int irq, void *private)
277{
278	struct iio_dev *indio_dev = private;
279	struct dlh_state *st = iio_priv(indio_dev);
280
281	complete(&st->completion);
282
283	return IRQ_HANDLED;
284};
285
286static int dlh_probe(struct i2c_client *client,
287	const struct i2c_device_id *id)
288{
289	struct dlh_state *st;
290	struct iio_dev *indio_dev;
291	int ret;
292
293	if (!i2c_check_functionality(client->adapter,
294		I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
295		dev_err(&client->dev,
296			"adapter doesn't support required i2c functionality\n");
297		return -EOPNOTSUPP;
298	}
299
300	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
301	if (!indio_dev) {
302		dev_err(&client->dev, "failed to allocate iio device\n");
303		return -ENOMEM;
304	}
305
306	i2c_set_clientdata(client, indio_dev);
307
308	st = iio_priv(indio_dev);
309	st->info = dlh_info_tbl[id->driver_data];
310	st->client = client;
311	st->use_interrupt = false;
312
313	indio_dev->name = id->name;
314	indio_dev->info = &dlh_info;
315	indio_dev->modes = INDIO_DIRECT_MODE;
316	indio_dev->channels =  dlh_channels;
317	indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
318
319	if (client->irq > 0) {
320		ret = devm_request_threaded_irq(&client->dev, client->irq,
321			dlh_interrupt, NULL,
322			IRQF_TRIGGER_RISING | IRQF_ONESHOT,
323			id->name, indio_dev);
324		if (ret) {
325			dev_err(&client->dev, "failed to allocate threaded irq");
326			return ret;
327		}
328
329		st->use_interrupt = true;
330		init_completion(&st->completion);
331	}
332
333	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
334		NULL, &dlh_trigger_handler, NULL);
335	if (ret) {
336		dev_err(&client->dev, "failed to setup iio buffer\n");
337		return ret;
338	}
339
340	ret = devm_iio_device_register(&client->dev, indio_dev);
341	if (ret)
342		dev_err(&client->dev, "failed to register iio device\n");
343
344	return ret;
345}
346
347static const struct of_device_id dlh_of_match[] = {
348	{ .compatible = "asc,dlhl60d" },
349	{ .compatible = "asc,dlhl60g" },
350	{}
351};
352MODULE_DEVICE_TABLE(of, dlh_of_match);
353
354static const struct i2c_device_id dlh_id[] = {
355	{ "dlhl60d",    dlhl60d },
356	{ "dlhl60g",    dlhl60g },
357	{}
358};
359MODULE_DEVICE_TABLE(i2c, dlh_id);
360
361static struct i2c_driver dlh_driver = {
362	.driver = {
363		.name = "dlhl60d",
364		.of_match_table = dlh_of_match,
365	},
366	.probe = dlh_probe,
367	.id_table = dlh_id,
368};
369module_i2c_driver(dlh_driver);
370
371MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
372MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
373MODULE_LICENSE("GPL v2");
374