484 lines
12 KiB
C
484 lines
12 KiB
C
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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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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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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/module.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 "iio.h"
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#include "iio_core.h"
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#include "sysfs.h"
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#include "events.h"
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/**
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* struct iio_detected_event_list - list element for events that have occurred
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* @list: linked list header
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* @ev: the event itself
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*/
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struct iio_detected_event_list {
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struct list_head list;
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struct iio_event_data ev;
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};
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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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* @event_list_lock: mutex to protect the list of detected events
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* @det_events: list of detected events
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* @max_events: maximum number of events before new ones are dropped
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* @current_events: number of events in detected list
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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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*/
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struct iio_event_interface {
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wait_queue_head_t wait;
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struct mutex event_list_lock;
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struct list_head det_events;
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int max_events;
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int current_events;
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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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};
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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_event_interface *ev_int = indio_dev->event_interface;
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struct iio_detected_event_list *ev;
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int ret = 0;
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/* Does anyone care? */
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mutex_lock(&ev_int->event_list_lock);
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if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
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if (ev_int->current_events == ev_int->max_events) {
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mutex_unlock(&ev_int->event_list_lock);
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return 0;
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}
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ev = kmalloc(sizeof(*ev), GFP_KERNEL);
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if (ev == NULL) {
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ret = -ENOMEM;
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mutex_unlock(&ev_int->event_list_lock);
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goto error_ret;
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}
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ev->ev.id = ev_code;
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ev->ev.timestamp = timestamp;
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list_add_tail(&ev->list, &ev_int->det_events);
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ev_int->current_events++;
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mutex_unlock(&ev_int->event_list_lock);
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wake_up_interruptible(&ev_int->wait);
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} else
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mutex_unlock(&ev_int->event_list_lock);
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error_ret:
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return ret;
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}
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EXPORT_SYMBOL(iio_push_event);
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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_event_interface *ev_int = filep->private_data;
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struct iio_detected_event_list *el;
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size_t len = sizeof(el->ev);
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int ret;
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if (count < len)
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return -EINVAL;
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mutex_lock(&ev_int->event_list_lock);
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if (list_empty(&ev_int->det_events)) {
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if (filep->f_flags & O_NONBLOCK) {
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ret = -EAGAIN;
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goto error_mutex_unlock;
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}
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mutex_unlock(&ev_int->event_list_lock);
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/* Blocking on device; waiting for something to be there */
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ret = wait_event_interruptible(ev_int->wait,
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!list_empty(&ev_int
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->det_events));
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if (ret)
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goto error_ret;
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/* Single access device so no one else can get the data */
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mutex_lock(&ev_int->event_list_lock);
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}
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el = list_first_entry(&ev_int->det_events,
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struct iio_detected_event_list,
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list);
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if (copy_to_user(buf, &(el->ev), len)) {
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ret = -EFAULT;
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goto error_mutex_unlock;
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}
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list_del(&el->list);
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ev_int->current_events--;
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mutex_unlock(&ev_int->event_list_lock);
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kfree(el);
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return len;
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error_mutex_unlock:
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mutex_unlock(&ev_int->event_list_lock);
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error_ret:
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return ret;
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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_event_interface *ev_int = filep->private_data;
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struct iio_detected_event_list *el, *t;
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mutex_lock(&ev_int->event_list_lock);
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clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
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/*
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* In order to maintain a clean state for reopening,
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* clear out any awaiting events. The mask will prevent
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* any new __iio_push_event calls running.
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*/
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list_for_each_entry_safe(el, t, &ev_int->det_events, list) {
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list_del(&el->list);
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kfree(el);
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}
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ev_int->current_events = 0;
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mutex_unlock(&ev_int->event_list_lock);
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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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.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_event_interface *ev_int = indio_dev->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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mutex_lock(&ev_int->event_list_lock);
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if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
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mutex_unlock(&ev_int->event_list_lock);
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return -EBUSY;
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}
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mutex_unlock(&ev_int->event_list_lock);
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fd = anon_inode_getfd("iio:event",
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&iio_event_chrdev_fileops, ev_int, O_RDONLY);
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if (fd < 0) {
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mutex_lock(&ev_int->event_list_lock);
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clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
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mutex_unlock(&ev_int->event_list_lock);
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}
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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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};
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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 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_get_drvdata(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->address,
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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_get_drvdata(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int val = indio_dev->info->read_event_config(indio_dev,
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this_attr->address);
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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_get_drvdata(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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int val, ret;
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ret = indio_dev->info->read_event_value(indio_dev,
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this_attr->address, &val);
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if (ret < 0)
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return ret;
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return sprintf(buf, "%d\n", val);
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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_get_drvdata(dev);
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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unsigned long val;
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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 = strict_strtoul(buf, 10, &val);
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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, this_attr->address,
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val);
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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_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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u64 mask = 0;
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char *postfix;
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if (!chan->event_mask)
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return 0;
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for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
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postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
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iio_ev_type_text[i/IIO_EV_DIR_MAX],
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iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
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if (postfix == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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if (chan->modified)
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mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
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i/IIO_EV_DIR_MAX,
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i%IIO_EV_DIR_MAX);
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else if (chan->differential)
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mask = IIO_EVENT_CODE(chan->type,
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0, 0,
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i%IIO_EV_DIR_MAX,
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i/IIO_EV_DIR_MAX,
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0,
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chan->channel,
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chan->channel2);
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else
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mask = IIO_UNMOD_EVENT_CODE(chan->type,
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chan->channel,
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i/IIO_EV_DIR_MAX,
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i%IIO_EV_DIR_MAX);
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ret = __iio_add_chan_devattr(postfix,
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chan,
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&iio_ev_state_show,
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iio_ev_state_store,
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mask,
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0,
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&indio_dev->dev,
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&indio_dev->event_interface->
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dev_attr_list);
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kfree(postfix);
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if (ret)
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goto error_ret;
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attrcount++;
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postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
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iio_ev_type_text[i/IIO_EV_DIR_MAX],
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iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
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if (postfix == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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ret = __iio_add_chan_devattr(postfix, chan,
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iio_ev_value_show,
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iio_ev_value_store,
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mask,
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0,
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&indio_dev->dev,
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&indio_dev->event_interface->
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dev_attr_list);
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kfree(postfix);
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if (ret)
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goto error_ret;
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attrcount++;
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}
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ret = attrcount;
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error_ret:
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return ret;
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}
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static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
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{
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struct iio_dev_attr *p, *n;
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list_for_each_entry_safe(p, n,
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&indio_dev->event_interface->
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dev_attr_list, l) {
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kfree(p->dev_attr.attr.name);
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kfree(p);
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}
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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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|
{
|
||
|
|
int j, ret, attrcount = 0;
|
||
|
|
|
||
|
|
INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
|
||
|
|
/* Dynically created from the channels array */
|
||
|
|
for (j = 0; j < indio_dev->num_channels; j++) {
|
||
|
|
ret = iio_device_add_event_sysfs(indio_dev,
|
||
|
|
&indio_dev->channels[j]);
|
||
|
|
if (ret < 0)
|
||
|
|
goto error_clear_attrs;
|
||
|
|
attrcount += ret;
|
||
|
|
}
|
||
|
|
return attrcount;
|
||
|
|
|
||
|
|
error_clear_attrs:
|
||
|
|
__iio_remove_event_config_attrs(indio_dev);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
|
||
|
|
{
|
||
|
|
int j;
|
||
|
|
|
||
|
|
for (j = 0; j < indio_dev->num_channels; j++)
|
||
|
|
if (indio_dev->channels[j].event_mask != 0)
|
||
|
|
return true;
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void iio_setup_ev_int(struct iio_event_interface *ev_int)
|
||
|
|
{
|
||
|
|
mutex_init(&ev_int->event_list_lock);
|
||
|
|
/* discussion point - make this variable? */
|
||
|
|
ev_int->max_events = 10;
|
||
|
|
ev_int->current_events = 0;
|
||
|
|
INIT_LIST_HEAD(&ev_int->det_events);
|
||
|
|
init_waitqueue_head(&ev_int->wait);
|
||
|
|
}
|
||
|
|
|
||
|
|
static const char *iio_event_group_name = "events";
|
||
|
|
int iio_device_register_eventset(struct iio_dev *indio_dev)
|
||
|
|
{
|
||
|
|
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;
|
||
|
|
|
||
|
|
indio_dev->event_interface =
|
||
|
|
kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
|
||
|
|
if (indio_dev->event_interface == NULL) {
|
||
|
|
ret = -ENOMEM;
|
||
|
|
goto error_ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
iio_setup_ev_int(indio_dev->event_interface);
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
indio_dev->event_interface->group.name = iio_event_group_name;
|
||
|
|
indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
|
||
|
|
sizeof(indio_dev->event_interface->group.attrs[0]),
|
||
|
|
GFP_KERNEL);
|
||
|
|
if (indio_dev->event_interface->group.attrs == NULL) {
|
||
|
|
ret = -ENOMEM;
|
||
|
|
goto error_free_setup_event_lines;
|
||
|
|
}
|
||
|
|
if (indio_dev->info->event_attrs)
|
||
|
|
memcpy(indio_dev->event_interface->group.attrs,
|
||
|
|
indio_dev->info->event_attrs->attrs,
|
||
|
|
sizeof(indio_dev->event_interface->group.attrs[0])
|
||
|
|
*attrcount_orig);
|
||
|
|
attrn = attrcount_orig;
|
||
|
|
/* Add all elements from the list. */
|
||
|
|
list_for_each_entry(p,
|
||
|
|
&indio_dev->event_interface->dev_attr_list,
|
||
|
|
l)
|
||
|
|
indio_dev->event_interface->group.attrs[attrn++] =
|
||
|
|
&p->dev_attr.attr;
|
||
|
|
indio_dev->groups[indio_dev->groupcounter++] =
|
||
|
|
&indio_dev->event_interface->group;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
error_free_setup_event_lines:
|
||
|
|
__iio_remove_event_config_attrs(indio_dev);
|
||
|
|
kfree(indio_dev->event_interface);
|
||
|
|
error_ret:
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
void iio_device_unregister_eventset(struct iio_dev *indio_dev)
|
||
|
|
{
|
||
|
|
if (indio_dev->event_interface == NULL)
|
||
|
|
return;
|
||
|
|
__iio_remove_event_config_attrs(indio_dev);
|
||
|
|
kfree(indio_dev->event_interface->group.attrs);
|
||
|
|
kfree(indio_dev->event_interface);
|
||
|
|
}
|