121 lines
3.0 KiB
C
121 lines
3.0 KiB
C
/*
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* This file is part of the Xilinx DMA IP Core driver for Linux
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*
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* Copyright (c) 2016-present, Xilinx, Inc.
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* All rights reserved.
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*
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* This source code is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* The full GNU General Public License is included in this distribution in
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* the file called "COPYING".
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
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#include "xdma_cdev.h"
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/*
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* character device file operations for events
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*/
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static ssize_t char_events_read(struct file *file, char __user *buf,
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size_t count, loff_t *pos)
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{
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int rv;
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struct xdma_user_irq *user_irq;
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struct xdma_cdev *xcdev = (struct xdma_cdev *)file->private_data;
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u32 events_user;
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unsigned long flags;
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rv = xcdev_check(__func__, xcdev, 0);
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if (rv < 0)
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return rv;
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user_irq = xcdev->user_irq;
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if (!user_irq) {
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pr_info("xcdev 0x%p, user_irq NULL.\n", xcdev);
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return -EINVAL;
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}
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if (count != 4)
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return -EPROTO;
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if (*pos & 3)
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return -EPROTO;
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/*
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* sleep until any interrupt events have occurred,
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* or a signal arrived
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*/
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rv = wait_event_interruptible(user_irq->events_wq,
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user_irq->events_irq != 0);
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if (rv)
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dbg_sg("wait_event_interruptible=%d\n", rv);
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/* wait_event_interruptible() was interrupted by a signal */
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if (rv == -ERESTARTSYS)
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return -ERESTARTSYS;
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/* atomically decide which events are passed to the user */
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spin_lock_irqsave(&user_irq->events_lock, flags);
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events_user = user_irq->events_irq;
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user_irq->events_irq = 0;
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spin_unlock_irqrestore(&user_irq->events_lock, flags);
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rv = copy_to_user(buf, &events_user, 4);
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if (rv)
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dbg_sg("Copy to user failed but continuing\n");
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return 4;
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}
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static unsigned int char_events_poll(struct file *file, poll_table *wait)
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{
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struct xdma_user_irq *user_irq;
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struct xdma_cdev *xcdev = (struct xdma_cdev *)file->private_data;
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unsigned long flags;
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unsigned int mask = 0;
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int rv;
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rv = xcdev_check(__func__, xcdev, 0);
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if (rv < 0)
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return rv;
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user_irq = xcdev->user_irq;
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if (!user_irq) {
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pr_info("xcdev 0x%p, user_irq NULL.\n", xcdev);
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return -EINVAL;
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}
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poll_wait(file, &user_irq->events_wq, wait);
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spin_lock_irqsave(&user_irq->events_lock, flags);
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if (user_irq->events_irq)
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mask = POLLIN | POLLRDNORM; /* readable */
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spin_unlock_irqrestore(&user_irq->events_lock, flags);
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return mask;
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}
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/*
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* character device file operations for the irq events
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*/
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static const struct file_operations events_fops = {
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.owner = THIS_MODULE,
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.open = char_open,
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.release = char_close,
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.read = char_events_read,
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.poll = char_events_poll,
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};
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void cdev_event_init(struct xdma_cdev *xcdev)
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{
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xcdev->user_irq = &(xcdev->xdev->user_irq[xcdev->bar]);
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cdev_init(&xcdev->cdev, &events_fops);
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}
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