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/*
* This file is part of the Xilinx DMA IP Core driver for Linux
*
* Copyright (c) 2016-present, Xilinx, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
#include "xdma_cdev.h"
/*
* character device file operations for events
*/
static ssize_t char_events_read(struct file *file, char __user *buf,
size_t count, loff_t *pos)
{
int rv;
struct xdma_user_irq *user_irq;
struct xdma_cdev *xcdev = (struct xdma_cdev *)file->private_data;
u32 events_user;
unsigned long flags;
rv = xcdev_check(__func__, xcdev, 0);
if (rv < 0)
return rv;
user_irq = xcdev->user_irq;
if (!user_irq) {
pr_info("xcdev 0x%p, user_irq NULL.\n", xcdev);
return -EINVAL;
}
if (count != 4)
return -EPROTO;
if (*pos & 3)
return -EPROTO;
/*
* sleep until any interrupt events have occurred,
* or a signal arrived
*/
rv = wait_event_interruptible(user_irq->events_wq,
user_irq->events_irq != 0);
if (rv)
dbg_sg("wait_event_interruptible=%d\n", rv);
/* wait_event_interruptible() was interrupted by a signal */
if (rv == -ERESTARTSYS)
return -ERESTARTSYS;
/* atomically decide which events are passed to the user */
spin_lock_irqsave(&user_irq->events_lock, flags);
events_user = user_irq->events_irq;
user_irq->events_irq = 0;
spin_unlock_irqrestore(&user_irq->events_lock, flags);
rv = copy_to_user(buf, &events_user, 4);
if (rv)
dbg_sg("Copy to user failed but continuing\n");
return 4;
}
static unsigned int char_events_poll(struct file *file, poll_table *wait)
{
struct xdma_user_irq *user_irq;
struct xdma_cdev *xcdev = (struct xdma_cdev *)file->private_data;
unsigned long flags;
unsigned int mask = 0;
int rv;
rv = xcdev_check(__func__, xcdev, 0);
if (rv < 0)
return rv;
user_irq = xcdev->user_irq;
if (!user_irq) {
pr_info("xcdev 0x%p, user_irq NULL.\n", xcdev);
return -EINVAL;
}
poll_wait(file, &user_irq->events_wq, wait);
spin_lock_irqsave(&user_irq->events_lock, flags);
if (user_irq->events_irq)
mask = POLLIN | POLLRDNORM; /* readable */
spin_unlock_irqrestore(&user_irq->events_lock, flags);
return mask;
}
/*
* character device file operations for the irq events
*/
static const struct file_operations events_fops = {
.owner = THIS_MODULE,
.open = char_open,
.release = char_close,
.read = char_events_read,
.poll = char_events_poll,
};
void cdev_event_init(struct xdma_cdev *xcdev)
{
xcdev->user_irq = &(xcdev->xdev->user_irq[xcdev->bar]);
cdev_init(&xcdev->cdev, &events_fops);
}
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