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(client: 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(client: st->client, buf: 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(x: &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(x: &st->completion,
110 timeout: 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(p: &st->rx_buf[1]);
133 *temperature = get_unaligned_be24(p: &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: &pressure, temperature: &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(dividend: 125LL * st->info.fss * 24909 * 100,
175 divisor: 1 << DLH_NUM_PR_BITS);
176 tmp = div_s64_rem(dividend: tmp, divisor: 1000000000LL, remainder: &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 }
265
266 iio_push_to_buffers(indio_dev, data: tmp_buf);
267
268out:
269 iio_trigger_notify_done(trig: indio_dev->trig);
270
271 return IRQ_HANDLED;
272}
273
274static irqreturn_t dlh_interrupt(int irq, void *private)
275{
276 struct iio_dev *indio_dev = private;
277 struct dlh_state *st = iio_priv(indio_dev);
278
279 complete(&st->completion);
280
281 return IRQ_HANDLED;
282};
283
284static int dlh_probe(struct i2c_client *client)
285{
286 const struct i2c_device_id *id = i2c_client_get_device_id(client);
287 struct dlh_state *st;
288 struct iio_dev *indio_dev;
289 int ret;
290
291 if (!i2c_check_functionality(adap: client->adapter,
292 I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
293 dev_err(&client->dev,
294 "adapter doesn't support required i2c functionality\n");
295 return -EOPNOTSUPP;
296 }
297
298 indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*st));
299 if (!indio_dev) {
300 dev_err(&client->dev, "failed to allocate iio device\n");
301 return -ENOMEM;
302 }
303
304 i2c_set_clientdata(client, data: indio_dev);
305
306 st = iio_priv(indio_dev);
307 st->info = dlh_info_tbl[id->driver_data];
308 st->client = client;
309 st->use_interrupt = false;
310
311 indio_dev->name = id->name;
312 indio_dev->info = &dlh_info;
313 indio_dev->modes = INDIO_DIRECT_MODE;
314 indio_dev->channels = dlh_channels;
315 indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
316
317 if (client->irq > 0) {
318 ret = devm_request_threaded_irq(dev: &client->dev, irq: client->irq,
319 handler: dlh_interrupt, NULL,
320 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
321 devname: id->name, dev_id: indio_dev);
322 if (ret) {
323 dev_err(&client->dev, "failed to allocate threaded irq");
324 return ret;
325 }
326
327 st->use_interrupt = true;
328 init_completion(x: &st->completion);
329 }
330
331 ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
332 NULL, &dlh_trigger_handler, NULL);
333 if (ret) {
334 dev_err(&client->dev, "failed to setup iio buffer\n");
335 return ret;
336 }
337
338 ret = devm_iio_device_register(&client->dev, indio_dev);
339 if (ret)
340 dev_err(&client->dev, "failed to register iio device\n");
341
342 return ret;
343}
344
345static const struct of_device_id dlh_of_match[] = {
346 { .compatible = "asc,dlhl60d" },
347 { .compatible = "asc,dlhl60g" },
348 {}
349};
350MODULE_DEVICE_TABLE(of, dlh_of_match);
351
352static const struct i2c_device_id dlh_id[] = {
353 { "dlhl60d", dlhl60d },
354 { "dlhl60g", dlhl60g },
355 {}
356};
357MODULE_DEVICE_TABLE(i2c, dlh_id);
358
359static struct i2c_driver dlh_driver = {
360 .driver = {
361 .name = "dlhl60d",
362 .of_match_table = dlh_of_match,
363 },
364 .probe = dlh_probe,
365 .id_table = dlh_id,
366};
367module_i2c_driver(dlh_driver);
368
369MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
370MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
371MODULE_LICENSE("GPL v2");
372

source code of linux/drivers/iio/pressure/dlhl60d.c