f2f45a5364
With the recent 'iio_dev_opaque' variable name, these two functions are looking a bit ugly. This change uses an 'ev_int' variable for the iio_device_{un}register_eventset functions to make the code a little easier to read. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20200921103156.194748-1-alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
565 lines
15 KiB
C
565 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Industrial I/O event handling
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*
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* Copyright (c) 2008 Jonathan Cameron
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*
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* Based on elements of hwmon and input subsystems.
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*/
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#include <linux/anon_inodes.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/kernel.h>
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#include <linux/kfifo.h>
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#include <linux/module.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/wait.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/iio-opaque.h>
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#include "iio_core.h"
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#include <linux/iio/sysfs.h>
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#include <linux/iio/events.h>
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/**
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* struct iio_event_interface - chrdev interface for an event line
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* @wait: wait queue to allow blocking reads of events
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* @det_events: list of detected events
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* @dev_attr_list: list of event interface sysfs attribute
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* @flags: file operations related flags including busy flag.
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* @group: event interface sysfs attribute group
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* @read_lock: lock to protect kfifo read operations
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*/
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struct iio_event_interface {
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wait_queue_head_t wait;
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DECLARE_KFIFO(det_events, struct iio_event_data, 16);
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struct list_head dev_attr_list;
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unsigned long flags;
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struct attribute_group group;
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struct mutex read_lock;
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};
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bool iio_event_enabled(const struct iio_event_interface *ev_int)
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{
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return !!test_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
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}
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/**
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* iio_push_event() - try to add event to the list for userspace reading
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* @indio_dev: IIO device structure
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* @ev_code: What event
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* @timestamp: When the event occurred
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*
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* Note: The caller must make sure that this function is not running
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* concurrently for the same indio_dev more than once.
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*
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* This function may be safely used as soon as a valid reference to iio_dev has
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* been obtained via iio_device_alloc(), but any events that are submitted
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* before iio_device_register() has successfully completed will be silently
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* discarded.
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**/
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int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
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{
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
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struct iio_event_data ev;
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int copied;
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if (!ev_int)
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return 0;
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/* Does anyone care? */
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if (iio_event_enabled(ev_int)) {
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ev.id = ev_code;
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ev.timestamp = timestamp;
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copied = kfifo_put(&ev_int->det_events, ev);
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if (copied != 0)
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wake_up_poll(&ev_int->wait, EPOLLIN);
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}
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return 0;
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}
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EXPORT_SYMBOL(iio_push_event);
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/**
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* iio_event_poll() - poll the event queue to find out if it has data
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* @filep: File structure pointer to identify the device
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* @wait: Poll table pointer to add the wait queue on
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*
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* Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
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* or a negative error code on failure
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*/
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static __poll_t iio_event_poll(struct file *filep,
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struct poll_table_struct *wait)
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{
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struct iio_dev *indio_dev = filep->private_data;
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
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__poll_t events = 0;
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if (!indio_dev->info)
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return events;
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poll_wait(filep, &ev_int->wait, wait);
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if (!kfifo_is_empty(&ev_int->det_events))
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events = EPOLLIN | EPOLLRDNORM;
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return events;
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}
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static ssize_t iio_event_chrdev_read(struct file *filep,
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char __user *buf,
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size_t count,
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loff_t *f_ps)
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{
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struct iio_dev *indio_dev = filep->private_data;
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
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unsigned int copied;
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int ret;
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if (!indio_dev->info)
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return -ENODEV;
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if (count < sizeof(struct iio_event_data))
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return -EINVAL;
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do {
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if (kfifo_is_empty(&ev_int->det_events)) {
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if (filep->f_flags & O_NONBLOCK)
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return -EAGAIN;
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ret = wait_event_interruptible(ev_int->wait,
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!kfifo_is_empty(&ev_int->det_events) ||
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indio_dev->info == NULL);
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if (ret)
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return ret;
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if (indio_dev->info == NULL)
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return -ENODEV;
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}
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if (mutex_lock_interruptible(&ev_int->read_lock))
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return -ERESTARTSYS;
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ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
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mutex_unlock(&ev_int->read_lock);
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if (ret)
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return ret;
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/*
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* If we couldn't read anything from the fifo (a different
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* thread might have been faster) we either return -EAGAIN if
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* the file descriptor is non-blocking, otherwise we go back to
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* sleep and wait for more data to arrive.
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*/
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if (copied == 0 && (filep->f_flags & O_NONBLOCK))
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return -EAGAIN;
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} while (copied == 0);
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return copied;
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}
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static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
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{
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struct iio_dev *indio_dev = filep->private_data;
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
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clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
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iio_device_put(indio_dev);
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return 0;
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}
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static const struct file_operations iio_event_chrdev_fileops = {
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.read = iio_event_chrdev_read,
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.poll = iio_event_poll,
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.release = iio_event_chrdev_release,
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.owner = THIS_MODULE,
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.llseek = noop_llseek,
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};
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int iio_event_getfd(struct iio_dev *indio_dev)
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{
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
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int fd;
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if (ev_int == NULL)
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return -ENODEV;
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fd = mutex_lock_interruptible(&indio_dev->mlock);
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if (fd)
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return fd;
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if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
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fd = -EBUSY;
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goto unlock;
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}
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iio_device_get(indio_dev);
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fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
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indio_dev, O_RDONLY | O_CLOEXEC);
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if (fd < 0) {
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clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
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iio_device_put(indio_dev);
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} else {
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kfifo_reset_out(&ev_int->det_events);
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}
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unlock:
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mutex_unlock(&indio_dev->mlock);
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return fd;
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}
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static const char * const iio_ev_type_text[] = {
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[IIO_EV_TYPE_THRESH] = "thresh",
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[IIO_EV_TYPE_MAG] = "mag",
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[IIO_EV_TYPE_ROC] = "roc",
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[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
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[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
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[IIO_EV_TYPE_CHANGE] = "change",
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};
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static const char * const iio_ev_dir_text[] = {
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[IIO_EV_DIR_EITHER] = "either",
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[IIO_EV_DIR_RISING] = "rising",
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[IIO_EV_DIR_FALLING] = "falling"
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};
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static const char * const iio_ev_info_text[] = {
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[IIO_EV_INFO_ENABLE] = "en",
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[IIO_EV_INFO_VALUE] = "value",
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[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
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[IIO_EV_INFO_PERIOD] = "period",
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[IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
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[IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
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};
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static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
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{
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return attr->c->event_spec[attr->address & 0xffff].dir;
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}
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static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
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{
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return attr->c->event_spec[attr->address & 0xffff].type;
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}
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static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
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{
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return (attr->address >> 16) & 0xffff;
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}
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static ssize_t iio_ev_state_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int ret;
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bool val;
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ret = strtobool(buf, &val);
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if (ret < 0)
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return ret;
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ret = indio_dev->info->write_event_config(indio_dev,
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this_attr->c, iio_ev_attr_type(this_attr),
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iio_ev_attr_dir(this_attr), val);
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return (ret < 0) ? ret : len;
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}
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static ssize_t iio_ev_state_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int val;
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val = indio_dev->info->read_event_config(indio_dev,
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this_attr->c, iio_ev_attr_type(this_attr),
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iio_ev_attr_dir(this_attr));
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if (val < 0)
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return val;
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else
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return sprintf(buf, "%d\n", val);
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}
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static ssize_t iio_ev_value_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int val, val2, val_arr[2];
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int ret;
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ret = indio_dev->info->read_event_value(indio_dev,
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this_attr->c, iio_ev_attr_type(this_attr),
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iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
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&val, &val2);
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if (ret < 0)
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return ret;
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val_arr[0] = val;
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val_arr[1] = val2;
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return iio_format_value(buf, ret, 2, val_arr);
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}
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static ssize_t iio_ev_value_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int val, val2;
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int ret;
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if (!indio_dev->info->write_event_value)
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return -EINVAL;
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ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
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if (ret)
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return ret;
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ret = indio_dev->info->write_event_value(indio_dev,
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this_attr->c, iio_ev_attr_type(this_attr),
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iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
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val, val2);
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if (ret < 0)
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return ret;
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return len;
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}
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static int iio_device_add_event(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, unsigned int spec_index,
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enum iio_event_type type, enum iio_event_direction dir,
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enum iio_shared_by shared_by, const unsigned long *mask)
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{
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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ssize_t (*show)(struct device *, struct device_attribute *, char *);
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ssize_t (*store)(struct device *, struct device_attribute *,
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const char *, size_t);
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unsigned int attrcount = 0;
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unsigned int i;
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char *postfix;
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int ret;
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for_each_set_bit(i, mask, sizeof(*mask)*8) {
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if (i >= ARRAY_SIZE(iio_ev_info_text))
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return -EINVAL;
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if (dir != IIO_EV_DIR_NONE)
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postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
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iio_ev_type_text[type],
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iio_ev_dir_text[dir],
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iio_ev_info_text[i]);
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else
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postfix = kasprintf(GFP_KERNEL, "%s_%s",
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iio_ev_type_text[type],
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iio_ev_info_text[i]);
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if (postfix == NULL)
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return -ENOMEM;
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if (i == IIO_EV_INFO_ENABLE) {
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show = iio_ev_state_show;
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store = iio_ev_state_store;
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} else {
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show = iio_ev_value_show;
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store = iio_ev_value_store;
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}
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ret = __iio_add_chan_devattr(postfix, chan, show, store,
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(i << 16) | spec_index, shared_by, &indio_dev->dev,
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&iio_dev_opaque->event_interface->dev_attr_list);
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kfree(postfix);
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if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
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continue;
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if (ret)
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return ret;
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attrcount++;
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}
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return attrcount;
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}
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static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan)
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{
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int ret = 0, i, attrcount = 0;
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enum iio_event_direction dir;
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enum iio_event_type type;
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for (i = 0; i < chan->num_event_specs; i++) {
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type = chan->event_spec[i].type;
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dir = chan->event_spec[i].dir;
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ret = iio_device_add_event(indio_dev, chan, i, type, dir,
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IIO_SEPARATE, &chan->event_spec[i].mask_separate);
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if (ret < 0)
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return ret;
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attrcount += ret;
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ret = iio_device_add_event(indio_dev, chan, i, type, dir,
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IIO_SHARED_BY_TYPE,
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&chan->event_spec[i].mask_shared_by_type);
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if (ret < 0)
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return ret;
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attrcount += ret;
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ret = iio_device_add_event(indio_dev, chan, i, type, dir,
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IIO_SHARED_BY_DIR,
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&chan->event_spec[i].mask_shared_by_dir);
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if (ret < 0)
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return ret;
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attrcount += ret;
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ret = iio_device_add_event(indio_dev, chan, i, type, dir,
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IIO_SHARED_BY_ALL,
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&chan->event_spec[i].mask_shared_by_all);
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if (ret < 0)
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return ret;
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attrcount += ret;
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}
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ret = attrcount;
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return ret;
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}
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static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
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{
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int j, ret, attrcount = 0;
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/* Dynamically created from the channels array */
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for (j = 0; j < indio_dev->num_channels; j++) {
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ret = iio_device_add_event_sysfs(indio_dev,
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&indio_dev->channels[j]);
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if (ret < 0)
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return ret;
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attrcount += ret;
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}
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return attrcount;
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}
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static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
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{
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int j;
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for (j = 0; j < indio_dev->num_channels; j++) {
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if (indio_dev->channels[j].num_event_specs != 0)
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return true;
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}
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return false;
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}
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static void iio_setup_ev_int(struct iio_event_interface *ev_int)
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{
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INIT_KFIFO(ev_int->det_events);
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init_waitqueue_head(&ev_int->wait);
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mutex_init(&ev_int->read_lock);
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}
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static const char *iio_event_group_name = "events";
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int iio_device_register_eventset(struct iio_dev *indio_dev)
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{
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
|
|
struct iio_event_interface *ev_int;
|
|
struct iio_dev_attr *p;
|
|
int ret = 0, attrcount_orig = 0, attrcount, attrn;
|
|
struct attribute **attr;
|
|
|
|
if (!(indio_dev->info->event_attrs ||
|
|
iio_check_for_dynamic_events(indio_dev)))
|
|
return 0;
|
|
|
|
ev_int = kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
|
|
if (ev_int == NULL)
|
|
return -ENOMEM;
|
|
|
|
iio_dev_opaque->event_interface = ev_int;
|
|
|
|
INIT_LIST_HEAD(&ev_int->dev_attr_list);
|
|
|
|
iio_setup_ev_int(ev_int);
|
|
if (indio_dev->info->event_attrs != NULL) {
|
|
attr = indio_dev->info->event_attrs->attrs;
|
|
while (*attr++ != NULL)
|
|
attrcount_orig++;
|
|
}
|
|
attrcount = attrcount_orig;
|
|
if (indio_dev->channels) {
|
|
ret = __iio_add_event_config_attrs(indio_dev);
|
|
if (ret < 0)
|
|
goto error_free_setup_event_lines;
|
|
attrcount += ret;
|
|
}
|
|
|
|
ev_int->group.name = iio_event_group_name;
|
|
ev_int->group.attrs = kcalloc(attrcount + 1,
|
|
sizeof(ev_int->group.attrs[0]),
|
|
GFP_KERNEL);
|
|
if (ev_int->group.attrs == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_free_setup_event_lines;
|
|
}
|
|
if (indio_dev->info->event_attrs)
|
|
memcpy(ev_int->group.attrs,
|
|
indio_dev->info->event_attrs->attrs,
|
|
sizeof(ev_int->group.attrs[0]) * attrcount_orig);
|
|
attrn = attrcount_orig;
|
|
/* Add all elements from the list. */
|
|
list_for_each_entry(p, &ev_int->dev_attr_list, l)
|
|
ev_int->group.attrs[attrn++] = &p->dev_attr.attr;
|
|
indio_dev->groups[indio_dev->groupcounter++] = &ev_int->group;
|
|
|
|
return 0;
|
|
|
|
error_free_setup_event_lines:
|
|
iio_free_chan_devattr_list(&ev_int->dev_attr_list);
|
|
kfree(ev_int);
|
|
iio_dev_opaque->event_interface = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* iio_device_wakeup_eventset - Wakes up the event waitqueue
|
|
* @indio_dev: The IIO device
|
|
*
|
|
* Wakes up the event waitqueue used for poll() and blocking read().
|
|
* Should usually be called when the device is unregistered.
|
|
*/
|
|
void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
|
|
|
|
if (iio_dev_opaque->event_interface == NULL)
|
|
return;
|
|
wake_up(&iio_dev_opaque->event_interface->wait);
|
|
}
|
|
|
|
void iio_device_unregister_eventset(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
|
|
struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
|
|
|
|
if (ev_int == NULL)
|
|
return;
|
|
iio_free_chan_devattr_list(&ev_int->dev_attr_list);
|
|
kfree(ev_int->group.attrs);
|
|
kfree(ev_int);
|
|
}
|