1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics sensors buffer library driver
4 *
5 * Copyright 2012-2013 STMicroelectronics Inc.
6 *
7 * Denis Ciocca <denis.ciocca@st.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/iio/iio.h>
12 #include <linux/iio/trigger.h>
13 #include <linux/interrupt.h>
14 #include <linux/iio/buffer.h>
15 #include <linux/iio/trigger_consumer.h>
16 #include <linux/irqreturn.h>
17 #include <linux/regmap.h>
18
19 #include <linux/iio/common/st_sensors.h>
20
21
st_sensors_get_buffer_element(struct iio_dev * indio_dev,u8 * buf)22 static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
23 {
24 struct st_sensor_data *sdata = iio_priv(indio_dev);
25 unsigned int num_data_channels = sdata->num_data_channels;
26 int i;
27
28 for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
29 const struct iio_chan_spec *channel = &indio_dev->channels[i];
30 unsigned int bytes_to_read =
31 DIV_ROUND_UP(channel->scan_type.realbits +
32 channel->scan_type.shift, 8);
33 unsigned int storage_bytes =
34 channel->scan_type.storagebits >> 3;
35
36 buf = PTR_ALIGN(buf, storage_bytes);
37 if (regmap_bulk_read(sdata->regmap, channel->address,
38 buf, bytes_to_read) < 0)
39 return -EIO;
40
41 /* Advance the buffer pointer */
42 buf += storage_bytes;
43 }
44
45 return 0;
46 }
47
st_sensors_trigger_handler(int irq,void * p)48 irqreturn_t st_sensors_trigger_handler(int irq, void *p)
49 {
50 int len;
51 struct iio_poll_func *pf = p;
52 struct iio_dev *indio_dev = pf->indio_dev;
53 struct st_sensor_data *sdata = iio_priv(indio_dev);
54 s64 timestamp;
55
56 /*
57 * If we do timestamping here, do it before reading the values, because
58 * once we've read the values, new interrupts can occur (when using
59 * the hardware trigger) and the hw_timestamp may get updated.
60 * By storing it in a local variable first, we are safe.
61 */
62 if (iio_trigger_using_own(indio_dev))
63 timestamp = sdata->hw_timestamp;
64 else
65 timestamp = iio_get_time_ns(indio_dev);
66
67 len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
68 if (len < 0)
69 goto st_sensors_get_buffer_element_error;
70
71 iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
72 timestamp);
73
74 st_sensors_get_buffer_element_error:
75 iio_trigger_notify_done(indio_dev->trig);
76
77 return IRQ_HANDLED;
78 }
79 EXPORT_SYMBOL_NS(st_sensors_trigger_handler, IIO_ST_SENSORS);
80