LXR linux/drivers/iio/common/st_sensors/st_sensors

   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
  25static 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
  51irqreturn_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
  77st_sensors_get_buffer_element_error:
  78        iio_trigger_notify_done(indio_dev->trig);
  79
  80        return IRQ_HANDLED;
  81}
  82EXPORT_SYMBOL(st_sensors_trigger_handler);
  83
  84MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
  85MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer");
  86MODULE_LICENSE("GPL v2");
  87