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 
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 
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