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