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
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 if (!iio_device_claim_direct(indio_dev))
151 return -EBUSY;
152
153 ret = dlh_read_direct(st, &pressure, &temperature);
154 iio_device_release_direct(indio_dev);
155 if (ret)
156 return ret;
157
158 switch (channel->type) {
159 case IIO_PRESSURE:
160 *value = pressure;
161 return IIO_VAL_INT;
162
163 case IIO_TEMP:
164 *value = temperature;
165 return IIO_VAL_INT;
166
167 default:
168 return -EINVAL;
169 }
170 case IIO_CHAN_INFO_SCALE:
171 switch (channel->type) {
172 case IIO_PRESSURE:
173 tmp = div_s64(125LL * st->info.fss * 24909 * 100,
174 1 << DLH_NUM_PR_BITS);
175 tmp = div_s64_rem(tmp, 1000000000LL, &rem);
176 *value = tmp;
177 *value2 = rem;
178 return IIO_VAL_INT_PLUS_NANO;
179
180 case IIO_TEMP:
181 *value = 125 * 1000;
182 *value2 = DLH_NUM_TEMP_BITS;
183 return IIO_VAL_FRACTIONAL_LOG2;
184
185 default:
186 return -EINVAL;
187 }
188 case IIO_CHAN_INFO_OFFSET:
189 switch (channel->type) {
190 case IIO_PRESSURE:
191 *value = -125 * st->info.fss * 24909;
192 *value2 = 100 * st->info.osdig * 100000;
193 return IIO_VAL_FRACTIONAL;
194
195 case IIO_TEMP:
196 *value = -40 * 1000;
197 return IIO_VAL_INT;
198
199 default:
200 return -EINVAL;
201 }
202 }
203
204 return -EINVAL;
205 }
206
207 static const struct iio_info dlh_info = {
208 .read_raw = dlh_read_raw,
209 };
210
211 static const struct iio_chan_spec dlh_channels[] = {
212 {
213 .type = IIO_PRESSURE,
214 .indexed = 1,
215 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
216 .info_mask_shared_by_type =
217 BIT(IIO_CHAN_INFO_SCALE) |
218 BIT(IIO_CHAN_INFO_OFFSET),
219 .scan_index = 0,
220 .scan_type = {
221 .sign = 'u',
222 .realbits = DLH_NUM_PR_BITS,
223 .storagebits = 32,
224 .shift = 8,
225 .endianness = IIO_BE,
226 },
227 }, {
228 .type = IIO_TEMP,
229 .indexed = 1,
230 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
231 .info_mask_shared_by_type =
232 BIT(IIO_CHAN_INFO_SCALE) |
233 BIT(IIO_CHAN_INFO_OFFSET),
234 .scan_index = 1,
235 .scan_type = {
236 .sign = 'u',
237 .realbits = DLH_NUM_TEMP_BITS,
238 .storagebits = 32,
239 .shift = 8,
240 .endianness = IIO_BE,
241 },
242 }
243 };
244
dlh_trigger_handler(int irq,void * private)245 static irqreturn_t dlh_trigger_handler(int irq, void *private)
246 {
247 struct iio_poll_func *pf = private;
248 struct iio_dev *indio_dev = pf->indio_dev;
249 struct dlh_state *st = iio_priv(indio_dev);
250 int ret;
251 unsigned int chn, i = 0;
252 __be32 tmp_buf[2] = { };
253
254 ret = dlh_start_capture_and_read(st);
255 if (ret)
256 goto out;
257
258 iio_for_each_active_channel(indio_dev, chn) {
259 memcpy(&tmp_buf[i++],
260 &st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
261 DLH_NUM_DATA_BYTES);
262 }
263
264 iio_push_to_buffers(indio_dev, tmp_buf);
265
266 out:
267 iio_trigger_notify_done(indio_dev->trig);
268
269 return IRQ_HANDLED;
270 }
271
dlh_interrupt(int irq,void * private)272 static irqreturn_t dlh_interrupt(int irq, void *private)
273 {
274 struct iio_dev *indio_dev = private;
275 struct dlh_state *st = iio_priv(indio_dev);
276
277 complete(&st->completion);
278
279 return IRQ_HANDLED;
280 };
281
dlh_probe(struct i2c_client * client)282 static int dlh_probe(struct i2c_client *client)
283 {
284 const struct i2c_device_id *id = i2c_client_get_device_id(client);
285 struct dlh_state *st;
286 struct iio_dev *indio_dev;
287 int ret;
288
289 if (!i2c_check_functionality(client->adapter,
290 I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
291 dev_err(&client->dev,
292 "adapter doesn't support required i2c functionality\n");
293 return -EOPNOTSUPP;
294 }
295
296 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
297 if (!indio_dev) {
298 dev_err(&client->dev, "failed to allocate iio device\n");
299 return -ENOMEM;
300 }
301
302 i2c_set_clientdata(client, indio_dev);
303
304 st = iio_priv(indio_dev);
305 st->info = dlh_info_tbl[id->driver_data];
306 st->client = client;
307 st->use_interrupt = false;
308
309 indio_dev->name = id->name;
310 indio_dev->info = &dlh_info;
311 indio_dev->modes = INDIO_DIRECT_MODE;
312 indio_dev->channels = dlh_channels;
313 indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
314
315 if (client->irq > 0) {
316 ret = devm_request_threaded_irq(&client->dev, client->irq,
317 dlh_interrupt, NULL,
318 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
319 id->name, indio_dev);
320 if (ret) {
321 dev_err(&client->dev, "failed to allocate threaded irq");
322 return ret;
323 }
324
325 st->use_interrupt = true;
326 init_completion(&st->completion);
327 }
328
329 ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
330 NULL, &dlh_trigger_handler, NULL);
331 if (ret) {
332 dev_err(&client->dev, "failed to setup iio buffer\n");
333 return ret;
334 }
335
336 ret = devm_iio_device_register(&client->dev, indio_dev);
337 if (ret)
338 dev_err(&client->dev, "failed to register iio device\n");
339
340 return ret;
341 }
342
343 static const struct of_device_id dlh_of_match[] = {
344 { .compatible = "asc,dlhl60d" },
345 { .compatible = "asc,dlhl60g" },
346 { }
347 };
348 MODULE_DEVICE_TABLE(of, dlh_of_match);
349
350 static const struct i2c_device_id dlh_id[] = {
351 { "dlhl60d", dlhl60d },
352 { "dlhl60g", dlhl60g },
353 { }
354 };
355 MODULE_DEVICE_TABLE(i2c, dlh_id);
356
357 static struct i2c_driver dlh_driver = {
358 .driver = {
359 .name = "dlhl60d",
360 .of_match_table = dlh_of_match,
361 },
362 .probe = dlh_probe,
363 .id_table = dlh_id,
364 };
365 module_i2c_driver(dlh_driver);
366
367 MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
368 MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
369 MODULE_LICENSE("GPL v2");
370