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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
The dev_attrs field of struct class is going away soon, dev_groups should be used instead. This converts the pps class code to use the correct field. Cc: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
434 lines
10 KiB
C
434 lines
10 KiB
C
/*
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* PPS core file
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*
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*
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* Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/uaccess.h>
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#include <linux/idr.h>
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#include <linux/mutex.h>
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#include <linux/cdev.h>
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#include <linux/poll.h>
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#include <linux/pps_kernel.h>
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#include <linux/slab.h>
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#include "kc.h"
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/*
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* Local variables
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*/
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static dev_t pps_devt;
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static struct class *pps_class;
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static DEFINE_MUTEX(pps_idr_lock);
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static DEFINE_IDR(pps_idr);
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/*
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* Char device methods
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*/
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static unsigned int pps_cdev_poll(struct file *file, poll_table *wait)
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{
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struct pps_device *pps = file->private_data;
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poll_wait(file, &pps->queue, wait);
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return POLLIN | POLLRDNORM;
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}
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static int pps_cdev_fasync(int fd, struct file *file, int on)
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{
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struct pps_device *pps = file->private_data;
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return fasync_helper(fd, file, on, &pps->async_queue);
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}
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static long pps_cdev_ioctl(struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct pps_device *pps = file->private_data;
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struct pps_kparams params;
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void __user *uarg = (void __user *) arg;
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int __user *iuarg = (int __user *) arg;
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int err;
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switch (cmd) {
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case PPS_GETPARAMS:
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dev_dbg(pps->dev, "PPS_GETPARAMS\n");
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spin_lock_irq(&pps->lock);
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/* Get the current parameters */
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params = pps->params;
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spin_unlock_irq(&pps->lock);
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err = copy_to_user(uarg, ¶ms, sizeof(struct pps_kparams));
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if (err)
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return -EFAULT;
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break;
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case PPS_SETPARAMS:
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dev_dbg(pps->dev, "PPS_SETPARAMS\n");
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/* Check the capabilities */
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if (!capable(CAP_SYS_TIME))
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return -EPERM;
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err = copy_from_user(¶ms, uarg, sizeof(struct pps_kparams));
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if (err)
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return -EFAULT;
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if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
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dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
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params.mode);
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return -EINVAL;
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}
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/* Check for supported capabilities */
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if ((params.mode & ~pps->info.mode) != 0) {
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dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
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params.mode);
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return -EINVAL;
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}
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spin_lock_irq(&pps->lock);
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/* Save the new parameters */
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pps->params = params;
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/* Restore the read only parameters */
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if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
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/* section 3.3 of RFC 2783 interpreted */
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dev_dbg(pps->dev, "time format unspecified (%x)\n",
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params.mode);
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pps->params.mode |= PPS_TSFMT_TSPEC;
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}
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if (pps->info.mode & PPS_CANWAIT)
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pps->params.mode |= PPS_CANWAIT;
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pps->params.api_version = PPS_API_VERS;
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spin_unlock_irq(&pps->lock);
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break;
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case PPS_GETCAP:
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dev_dbg(pps->dev, "PPS_GETCAP\n");
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err = put_user(pps->info.mode, iuarg);
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if (err)
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return -EFAULT;
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break;
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case PPS_FETCH: {
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struct pps_fdata fdata;
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unsigned int ev;
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dev_dbg(pps->dev, "PPS_FETCH\n");
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err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
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if (err)
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return -EFAULT;
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ev = pps->last_ev;
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/* Manage the timeout */
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if (fdata.timeout.flags & PPS_TIME_INVALID)
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err = wait_event_interruptible(pps->queue,
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ev != pps->last_ev);
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else {
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unsigned long ticks;
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dev_dbg(pps->dev, "timeout %lld.%09d\n",
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(long long) fdata.timeout.sec,
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fdata.timeout.nsec);
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ticks = fdata.timeout.sec * HZ;
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ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
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if (ticks != 0) {
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err = wait_event_interruptible_timeout(
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pps->queue,
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ev != pps->last_ev,
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ticks);
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if (err == 0)
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return -ETIMEDOUT;
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}
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}
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/* Check for pending signals */
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if (err == -ERESTARTSYS) {
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dev_dbg(pps->dev, "pending signal caught\n");
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return -EINTR;
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}
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/* Return the fetched timestamp */
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spin_lock_irq(&pps->lock);
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fdata.info.assert_sequence = pps->assert_sequence;
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fdata.info.clear_sequence = pps->clear_sequence;
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fdata.info.assert_tu = pps->assert_tu;
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fdata.info.clear_tu = pps->clear_tu;
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fdata.info.current_mode = pps->current_mode;
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spin_unlock_irq(&pps->lock);
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err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
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if (err)
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return -EFAULT;
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break;
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}
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case PPS_KC_BIND: {
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struct pps_bind_args bind_args;
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dev_dbg(pps->dev, "PPS_KC_BIND\n");
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/* Check the capabilities */
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if (!capable(CAP_SYS_TIME))
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return -EPERM;
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if (copy_from_user(&bind_args, uarg,
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sizeof(struct pps_bind_args)))
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return -EFAULT;
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/* Check for supported capabilities */
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if ((bind_args.edge & ~pps->info.mode) != 0) {
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dev_err(pps->dev, "unsupported capabilities (%x)\n",
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bind_args.edge);
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return -EINVAL;
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}
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/* Validate parameters roughly */
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if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
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(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
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bind_args.consumer != PPS_KC_HARDPPS) {
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dev_err(pps->dev, "invalid kernel consumer bind"
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" parameters (%x)\n", bind_args.edge);
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return -EINVAL;
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}
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err = pps_kc_bind(pps, &bind_args);
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if (err < 0)
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return err;
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break;
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}
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static int pps_cdev_open(struct inode *inode, struct file *file)
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{
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struct pps_device *pps = container_of(inode->i_cdev,
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struct pps_device, cdev);
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file->private_data = pps;
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kobject_get(&pps->dev->kobj);
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return 0;
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}
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static int pps_cdev_release(struct inode *inode, struct file *file)
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{
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struct pps_device *pps = container_of(inode->i_cdev,
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struct pps_device, cdev);
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kobject_put(&pps->dev->kobj);
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return 0;
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}
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/*
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* Char device stuff
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*/
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static const struct file_operations pps_cdev_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.poll = pps_cdev_poll,
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.fasync = pps_cdev_fasync,
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.unlocked_ioctl = pps_cdev_ioctl,
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.open = pps_cdev_open,
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.release = pps_cdev_release,
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};
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static void pps_device_destruct(struct device *dev)
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{
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struct pps_device *pps = dev_get_drvdata(dev);
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cdev_del(&pps->cdev);
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/* Now we can release the ID for re-use */
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pr_debug("deallocating pps%d\n", pps->id);
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mutex_lock(&pps_idr_lock);
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idr_remove(&pps_idr, pps->id);
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mutex_unlock(&pps_idr_lock);
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kfree(dev);
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kfree(pps);
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}
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int pps_register_cdev(struct pps_device *pps)
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{
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int err;
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dev_t devt;
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mutex_lock(&pps_idr_lock);
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/*
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* Get new ID for the new PPS source. After idr_alloc() calling
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* the new source will be freely available into the kernel.
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*/
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err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
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if (err < 0) {
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if (err == -ENOSPC) {
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pr_err("%s: too many PPS sources in the system\n",
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pps->info.name);
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err = -EBUSY;
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}
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goto out_unlock;
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}
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pps->id = err;
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mutex_unlock(&pps_idr_lock);
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devt = MKDEV(MAJOR(pps_devt), pps->id);
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cdev_init(&pps->cdev, &pps_cdev_fops);
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pps->cdev.owner = pps->info.owner;
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err = cdev_add(&pps->cdev, devt, 1);
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if (err) {
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pr_err("%s: failed to add char device %d:%d\n",
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pps->info.name, MAJOR(pps_devt), pps->id);
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goto free_idr;
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}
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pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
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"pps%d", pps->id);
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if (IS_ERR(pps->dev)) {
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err = PTR_ERR(pps->dev);
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goto del_cdev;
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}
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/* Override the release function with our own */
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pps->dev->release = pps_device_destruct;
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pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
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MAJOR(pps_devt), pps->id);
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return 0;
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del_cdev:
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cdev_del(&pps->cdev);
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free_idr:
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mutex_lock(&pps_idr_lock);
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idr_remove(&pps_idr, pps->id);
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out_unlock:
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mutex_unlock(&pps_idr_lock);
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return err;
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}
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void pps_unregister_cdev(struct pps_device *pps)
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{
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pr_debug("unregistering pps%d\n", pps->id);
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pps->lookup_cookie = NULL;
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device_destroy(pps_class, pps->dev->devt);
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}
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/*
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* Look up a pps device by magic cookie.
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* The cookie is usually a pointer to some enclosing device, but this
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* code doesn't care; you should never be dereferencing it.
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*
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* This is a bit of a kludge that is currently used only by the PPS
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* serial line discipline. It may need to be tweaked when a second user
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* is found.
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*
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* There is no function interface for setting the lookup_cookie field.
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* It's initialized to NULL when the pps device is created, and if a
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* client wants to use it, just fill it in afterward.
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*
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* The cookie is automatically set to NULL in pps_unregister_source()
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* so that it will not be used again, even if the pps device cannot
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* be removed from the idr due to pending references holding the minor
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* number in use.
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*/
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struct pps_device *pps_lookup_dev(void const *cookie)
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{
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struct pps_device *pps;
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unsigned id;
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rcu_read_lock();
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idr_for_each_entry(&pps_idr, pps, id)
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if (cookie == pps->lookup_cookie)
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break;
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rcu_read_unlock();
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return pps;
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}
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EXPORT_SYMBOL(pps_lookup_dev);
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/*
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* Module stuff
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*/
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static void __exit pps_exit(void)
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{
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class_destroy(pps_class);
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unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
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}
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static int __init pps_init(void)
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{
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int err;
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pps_class = class_create(THIS_MODULE, "pps");
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if (IS_ERR(pps_class)) {
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pr_err("failed to allocate class\n");
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return PTR_ERR(pps_class);
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}
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pps_class->dev_groups = pps_groups;
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err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
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if (err < 0) {
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pr_err("failed to allocate char device region\n");
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goto remove_class;
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}
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pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
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pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
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"<giometti@linux.it>\n", PPS_VERSION);
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return 0;
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remove_class:
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class_destroy(pps_class);
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return err;
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}
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subsys_initcall(pps_init);
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module_exit(pps_exit);
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MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
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MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
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MODULE_LICENSE("GPL");
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