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/module.h>
12 #include <linux/slab.h>
13 #include <linux/iio/iio.h>
14 #include <linux/iio/trigger.h>
15 #include <linux/interrupt.h>
16 #include <linux/iio/buffer.h>
17 #include <linux/iio/trigger_consumer.h>
18 #include <linux/iio/triggered_buffer.h>
19 #include <linux/irqreturn.h>
20 #include <linux/regmap.h>
21
22 #include <linux/iio/common/st_sensors.h>
23
24
st_sensors_get_buffer_element(struct iio_dev * indio_dev,u8 * buf)25 static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
26 {
27 struct st_sensor_data *sdata = iio_priv(indio_dev);
28 unsigned int num_data_channels = sdata->num_data_channels;
29 int i;
30
31 for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
32 const struct iio_chan_spec *channel = &indio_dev->channels[i];
33 unsigned int bytes_to_read =
34 DIV_ROUND_UP(channel->scan_type.realbits +
35 channel->scan_type.shift, 8);
36 unsigned int storage_bytes =
37 channel->scan_type.storagebits >> 3;
38
39 buf = PTR_ALIGN(buf, storage_bytes);
40 if (regmap_bulk_read(sdata->regmap, channel->address,
41 buf, bytes_to_read) < 0)
42 return -EIO;
43
44 /* Advance the buffer pointer */
45 buf += storage_bytes;
46 }
47
48 return 0;
49 }
50
st_sensors_trigger_handler(int irq,void * p)51 irqreturn_t st_sensors_trigger_handler(int irq, void *p)
52 {
53 int len;
54 struct iio_poll_func *pf = p;
55 struct iio_dev *indio_dev = pf->indio_dev;
56 struct st_sensor_data *sdata = iio_priv(indio_dev);
57 s64 timestamp;
58
59 /*
60 * If we do timetamping here, do it before reading the values, because
61 * once we've read the values, new interrupts can occur (when using
62 * the hardware trigger) and the hw_timestamp may get updated.
63 * By storing it in a local variable first, we are safe.
64 */
65 if (iio_trigger_using_own(indio_dev))
66 timestamp = sdata->hw_timestamp;
67 else
68 timestamp = iio_get_time_ns(indio_dev);
69
70 len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
71 if (len < 0)
72 goto st_sensors_get_buffer_element_error;
73
74 iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
75 timestamp);
76
77 st_sensors_get_buffer_element_error:
78 iio_trigger_notify_done(indio_dev->trig);
79
80 return IRQ_HANDLED;
81 }
82 EXPORT_SYMBOL(st_sensors_trigger_handler);
83
84 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
85 MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer");
86 MODULE_LICENSE("GPL v2");
87