dlhl60d.c

  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 <linux/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
 35struct dlh_info {
 36	const char *name;   /* chip name */
 37	u8 osdig;           /* digital offset factor */
 38	unsigned int fss;   /* full scale span (inch H2O) */
 39};
 40
 41struct dlh_state {
 42	struct i2c_client *client;
 43	const struct dlh_info *info;
 44	bool use_interrupt;
 45	struct completion completion;
 46	u8 rx_buf[DLH_NUM_READ_BYTES];
 47};
 48
 49static const struct dlh_info dlhl60d_info = {
 50	.name = "dlhl60d",
 51	.osdig = 2,
 52	.fss = 120,
 53};
 54
 55static const struct dlh_info dlhl60g_info = {
 56	.name = "dlhl60g",
 57	.osdig = 10,
 58	.fss = 60,
 59};
 60
 61static int dlh_cmd_start_single(struct dlh_state *st)
 62{
 63	int ret;
 64
 65	ret = i2c_smbus_write_byte(st->client, DLH_START_SINGLE);
 66	if (ret)
 67		dev_err(&st->client->dev,
 68			"%s: I2C write byte failed\n", __func__);
 69
 70	return ret;
 71}
 72
 73static int dlh_cmd_read_data(struct dlh_state *st)
 74{
 75	int ret;
 76
 77	ret = i2c_master_recv(st->client, st->rx_buf, DLH_NUM_READ_BYTES);
 78	if (ret < 0) {
 79		dev_err(&st->client->dev,
 80			"%s: I2C read block failed\n", __func__);
 81		return ret;
 82	}
 83
 84	if (st->rx_buf[0] != DLH_STATUS_OK) {
 85		dev_err(&st->client->dev,
 86			"%s: invalid status 0x%02x\n", __func__, st->rx_buf[0]);
 87		return -EBUSY;
 88	}
 89
 90	return 0;
 91}
 92
 93static int dlh_start_capture_and_read(struct dlh_state *st)
 94{
 95	int ret;
 96
 97	if (st->use_interrupt)
 98		reinit_completion(&st->completion);
 99
100	ret = dlh_cmd_start_single(st);
101	if (ret)
102		return ret;
103
104	if (st->use_interrupt) {
105		ret = wait_for_completion_timeout(&st->completion,
106			msecs_to_jiffies(DLH_SINGLE_DUT_MS));
107		if (!ret) {
108			dev_err(&st->client->dev,
109				"%s: conversion timed out\n", __func__);
110			return -ETIMEDOUT;
111		}
112	} else {
113		mdelay(DLH_SINGLE_DUT_MS);
114	}
115
116	return dlh_cmd_read_data(st);
117}
118
119static int dlh_read_direct(struct dlh_state *st,
120	unsigned int *pressure, unsigned int *temperature)
121{
122	int ret;
123
124	ret = dlh_start_capture_and_read(st);
125	if (ret)
126		return ret;
127
128	*pressure = get_unaligned_be24(&st->rx_buf[1]);
129	*temperature = get_unaligned_be24(&st->rx_buf[4]);
130
131	return 0;
132}
133
134static int dlh_read_raw(struct iio_dev *indio_dev,
135	struct iio_chan_spec const *channel, int *value,
136	int *value2, long mask)
137{
138	struct dlh_state *st = iio_priv(indio_dev);
139	unsigned int pressure, temperature;
140	int ret;
141	s64 tmp;
142	s32 rem;
143
144	switch (mask) {
145	case IIO_CHAN_INFO_RAW:
146		if (!iio_device_claim_direct(indio_dev))
147			return -EBUSY;
148
149		ret = dlh_read_direct(st, &pressure, &temperature);
150		iio_device_release_direct(indio_dev);
151		if (ret)
152			return ret;
153
154		switch (channel->type) {
155		case IIO_PRESSURE:
156			*value = pressure;
157			return IIO_VAL_INT;
158
159		case IIO_TEMP:
160			*value = temperature;
161			return IIO_VAL_INT;
162
163		default:
164			return -EINVAL;
165		}
166	case IIO_CHAN_INFO_SCALE:
167		switch (channel->type) {
168		case IIO_PRESSURE:
169			tmp = div_s64(125LL * st->info->fss * 24909 * 100,
170				1 << DLH_NUM_PR_BITS);
171			tmp = div_s64_rem(tmp, 1000000000LL, &rem);
172			*value = tmp;
173			*value2 = rem;
174			return IIO_VAL_INT_PLUS_NANO;
175
176		case IIO_TEMP:
177			*value = 125 * 1000;
178			*value2 = DLH_NUM_TEMP_BITS;
179			return IIO_VAL_FRACTIONAL_LOG2;
180
181		default:
182			return -EINVAL;
183		}
184	case IIO_CHAN_INFO_OFFSET:
185		switch (channel->type) {
186		case IIO_PRESSURE:
187			*value = -125 * st->info->fss * 24909;
188			*value2 = 100 * st->info->osdig * 100000;
189			return IIO_VAL_FRACTIONAL;
190
191		case IIO_TEMP:
192			*value = -40 * 1000;
193			return IIO_VAL_INT;
194
195		default:
196			return -EINVAL;
197		}
198	}
199
200	return -EINVAL;
201}
202
203static const struct iio_info dlh_info = {
204	.read_raw = dlh_read_raw,
205};
206
207static const struct iio_chan_spec dlh_channels[] = {
208	{
209		.type = IIO_PRESSURE,
210		.indexed = 1,
211		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
212		.info_mask_shared_by_type =
213			BIT(IIO_CHAN_INFO_SCALE) |
214			BIT(IIO_CHAN_INFO_OFFSET),
215		.scan_index = 0,
216		.scan_type = {
217			.sign = 'u',
218			.realbits = DLH_NUM_PR_BITS,
219			.storagebits = 32,
220			.shift = 8,
221			.endianness = IIO_BE,
222		},
223	}, {
224		.type = IIO_TEMP,
225		.indexed = 1,
226		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
227		.info_mask_shared_by_type =
228			BIT(IIO_CHAN_INFO_SCALE) |
229			BIT(IIO_CHAN_INFO_OFFSET),
230		.scan_index = 1,
231		.scan_type = {
232			.sign = 'u',
233			.realbits = DLH_NUM_TEMP_BITS,
234			.storagebits = 32,
235			.shift = 8,
236			.endianness = IIO_BE,
237		},
238	}
239};
240
241static irqreturn_t dlh_trigger_handler(int irq, void *private)
242{
243	struct iio_poll_func *pf = private;
244	struct iio_dev *indio_dev = pf->indio_dev;
245	struct dlh_state *st = iio_priv(indio_dev);
246	int ret;
247	unsigned int chn, i = 0;
248	__be32 tmp_buf[2] = { };
249
250	ret = dlh_start_capture_and_read(st);
251	if (ret)
252		goto out;
253
254	iio_for_each_active_channel(indio_dev, chn) {
255		memcpy(&tmp_buf[i++],
256			&st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
257			DLH_NUM_DATA_BYTES);
258	}
259
260	iio_push_to_buffers(indio_dev, tmp_buf);
261
262out:
263	iio_trigger_notify_done(indio_dev->trig);
264
265	return IRQ_HANDLED;
266}
267
268static irqreturn_t dlh_interrupt(int irq, void *private)
269{
270	struct iio_dev *indio_dev = private;
271	struct dlh_state *st = iio_priv(indio_dev);
272
273	complete(&st->completion);
274
275	return IRQ_HANDLED;
276};
277
278static int dlh_probe(struct i2c_client *client)
279{
280	struct dlh_state *st;
281	struct iio_dev *indio_dev;
282	int ret;
283
284	if (!i2c_check_functionality(client->adapter,
285		I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
286		dev_err(&client->dev,
287			"adapter doesn't support required i2c functionality\n");
288		return -EOPNOTSUPP;
289	}
290
291	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
292	if (!indio_dev)
293		return -ENOMEM;
294
295	i2c_set_clientdata(client, indio_dev);
296
297	st = iio_priv(indio_dev);
298	st->info = i2c_get_match_data(client);
299	st->client = client;
300	st->use_interrupt = false;
301
302	indio_dev->name = st->info->name;
303	indio_dev->info = &dlh_info;
304	indio_dev->modes = INDIO_DIRECT_MODE;
305	indio_dev->channels =  dlh_channels;
306	indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
307
308	if (client->irq > 0) {
309		ret = devm_request_threaded_irq(&client->dev, client->irq,
310			dlh_interrupt, NULL,
311			IRQF_TRIGGER_RISING | IRQF_ONESHOT,
312			st->info->name, indio_dev);
313		if (ret) {
314			dev_err(&client->dev, "failed to allocate threaded irq");
315			return ret;
316		}
317
318		st->use_interrupt = true;
319		init_completion(&st->completion);
320	}
321
322	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
323		NULL, &dlh_trigger_handler, NULL);
324	if (ret) {
325		dev_err(&client->dev, "failed to setup iio buffer\n");
326		return ret;
327	}
328
329	ret = devm_iio_device_register(&client->dev, indio_dev);
330	if (ret)
331		dev_err(&client->dev, "failed to register iio device\n");
332
333	return ret;
334}
335
336static const struct of_device_id dlh_of_match[] = {
337	{ .compatible = "asc,dlhl60d", .data = &dlhl60d_info },
338	{ .compatible = "asc,dlhl60g", .data = &dlhl60g_info },
339	{ }
340};
341MODULE_DEVICE_TABLE(of, dlh_of_match);
342
343static const struct i2c_device_id dlh_id[] = {
344	{ "dlhl60d", (kernel_ulong_t)&dlhl60d_info },
345	{ "dlhl60g", (kernel_ulong_t)&dlhl60g_info },
346	{ }
347};
348MODULE_DEVICE_TABLE(i2c, dlh_id);
349
350static struct i2c_driver dlh_driver = {
351	.driver = {
352		.name = "dlhl60d",
353		.of_match_table = dlh_of_match,
354	},
355	.probe = dlh_probe,
356	.id_table = dlh_id,
357};
358module_i2c_driver(dlh_driver);
359
360MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
361MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
362MODULE_LICENSE("GPL v2");