linux-imx

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * PPS core file

 *

 * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/uaccess.h>

#include <linux/idr.h>

#include <linux/mutex.h>

#include <linux/cdev.h>

#include <linux/poll.h>

#include <linux/pps_kernel.h>

#include <linux/slab.h>

​

#include "kc.h"

​

/*

 * Local variables

 */

​

static dev_t pps_devt;

static struct class *pps_class;

​

static DEFINE_MUTEX(pps_idr_lock);

static DEFINE_IDR(pps_idr);

​

/*

 * Char device methods

 */

​

static __poll_t pps_cdev_poll(struct file *file, poll_table *wait)

{

    struct pps_device *pps = file->private_data;

​

    poll_wait(file, &pps->queue, wait);

​

    return EPOLLIN | EPOLLRDNORM;

}

​

static int pps_cdev_fasync(int fd, struct file *file, int on)

{

    struct pps_device *pps = file->private_data;

    return fasync_helper(fd, file, on, &pps->async_queue);

}

​

static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)

{

    unsigned int ev = pps->last_ev;

    int err = 0;

​

    /* Manage the timeout */

    if (fdata->timeout.flags & PPS_TIME_INVALID)

        err = wait_event_interruptible(pps->queue,

                ev != pps->last_ev);

    else {

        unsigned long ticks;