xref: /openbmc/linux/drivers/iio/pressure/dlhl60d.c (revision 7cf15f42)
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 
35 enum dhl_ids {
36 	dlhl60d,
37 	dlhl60g,
38 };
39 
40 struct dlh_info {
41 	u8 osdig;           /* digital offset factor */
42 	unsigned int fss;   /* full scale span (inch H2O) */
43 };
44 
45 struct 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 
53 static 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 
dlh_cmd_start_single(struct dlh_state * st)65 static 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 
dlh_cmd_read_data(struct dlh_state * st)77 static 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 
dlh_start_capture_and_read(struct dlh_state * st)97 static 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 
dlh_read_direct(struct dlh_state * st,unsigned int * pressure,unsigned int * temperature)123 static 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 
dlh_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * value,int * value2,long mask)138 static 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 
208 static const struct iio_info dlh_info = {
209 	.read_raw = dlh_read_raw,
210 };
211 
212 static 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 
dlh_trigger_handler(int irq,void * private)246 static 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 
269 out:
270 	iio_trigger_notify_done(indio_dev->trig);
271 
272 	return IRQ_HANDLED;
273 }
274 
dlh_interrupt(int irq,void * private)275 static 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 
dlh_probe(struct i2c_client * client)285 static 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 
346 static const struct of_device_id dlh_of_match[] = {
347 	{ .compatible = "asc,dlhl60d" },
348 	{ .compatible = "asc,dlhl60g" },
349 	{}
350 };
351 MODULE_DEVICE_TABLE(of, dlh_of_match);
352 
353 static const struct i2c_device_id dlh_id[] = {
354 	{ "dlhl60d",    dlhl60d },
355 	{ "dlhl60g",    dlhl60g },
356 	{}
357 };
358 MODULE_DEVICE_TABLE(i2c, dlh_id);
359 
360 static 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 };
368 module_i2c_driver(dlh_driver);
369 
370 MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
371 MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
372 MODULE_LICENSE("GPL v2");
373