cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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st_sensors_buffer.c (2214B)

      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
     22static 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
     48irqreturn_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
     74st_sensors_get_buffer_element_error:
     75	iio_trigger_notify_done(indio_dev->trig);
     76
     77	return IRQ_HANDLED;
     78}
     79EXPORT_SYMBOL_NS(st_sensors_trigger_handler, IIO_ST_SENSORS);