cregit-Linux how code gets into the kernel

Release 4.14 drivers/pps/pps.c

Directory: drivers/pps
 * PPS core file
 * Copyright (C) 2005-2009   Rodolfo Giometti <>
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   GNU General Public License for more details.
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#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 unsigned int pps_cdev_poll(struct file *file, poll_table *wait) { struct pps_device *pps = file->private_data; poll_wait(file, &pps->queue, wait); return POLLIN | POLLRDNORM; }


Rodolfo Giometti42100.00%1100.00%

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); }


Rodolfo Giometti41100.00%1100.00%

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; dev_dbg(pps->dev, "timeout %lld.%09d\n", (long long) fdata->timeout.sec, fdata->timeout.nsec); ticks = fdata->timeout.sec * HZ; ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ); if (ticks != 0) { err = wait_event_interruptible_timeout( pps->queue, ev != pps->last_ev, ticks); if (err == 0) return -ETIMEDOUT; } } /* Check for pending signals */ if (err == -ERESTARTSYS) { dev_dbg(pps->dev, "pending signal caught\n"); return -EINTR; } return 0; }


Matthew Ranostay172100.00%1100.00%

static long pps_cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct pps_device *pps = file->private_data; struct pps_kparams params; void __user *uarg = (void __user *) arg; int __user *iuarg = (int __user *) arg; int err; switch (cmd) { case PPS_GETPARAMS: dev_dbg(pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); /* Get the current parameters */ params = pps->params; spin_unlock_irq(&pps->lock); err = copy_to_user(uarg, &params, sizeof(struct pps_kparams)); if (err) return -EFAULT; break; case PPS_SETPARAMS: dev_dbg(pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) return -EPERM; err = copy_from_user(&params, uarg, sizeof(struct pps_kparams)); if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { dev_dbg(pps->dev, "capture mode unspecified (%x)\n", params.mode); return -EINVAL; } /* Check for supported capabilities */ if ((params.mode & ~pps->info.mode) != 0) { dev_dbg(pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } spin_lock_irq(&pps->lock); /* Save the new parameters */ pps->params = params; /* Restore the read only parameters */ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { /* section 3.3 of RFC 2783 interpreted */ dev_dbg(pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } if (pps->info.mode & PPS_CANWAIT) pps->params.mode |= PPS_CANWAIT; pps->params.api_version = PPS_API_VERS; spin_unlock_irq(&pps->lock); break; case PPS_GETCAP: dev_dbg(pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) return -EFAULT; break; case PPS_FETCH: { struct pps_fdata fdata; dev_dbg(pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) return -EFAULT; err = pps_cdev_pps_fetch(pps, &fdata); if (err) return err; /* Return the fetched timestamp */ spin_lock_irq(&pps->lock); = pps->assert_sequence; = pps->clear_sequence; = pps->assert_tu; = pps->clear_tu; = pps->current_mode; spin_unlock_irq(&pps->lock); err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata)); if (err) return -EFAULT; break; } case PPS_KC_BIND: { struct pps_bind_args bind_args; dev_dbg(pps->dev, "PPS_KC_BIND\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) return -EPERM; if (copy_from_user(&bind_args, uarg, sizeof(struct pps_bind_args))) return -EFAULT; /* Check for supported capabilities */ if ((bind_args.edge & ~pps->info.mode) != 0) { dev_err(pps->dev, "unsupported capabilities (%x)\n", bind_args.edge); return -EINVAL; } /* Validate parameters roughly */ if (bind_args.tsformat != PPS_TSFMT_TSPEC || (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || bind_args.consumer != PPS_KC_HARDPPS) { dev_err(pps->dev, "invalid kernel consumer bind" " parameters (%x)\n", bind_args.edge); return -EINVAL; } err = pps_kc_bind(pps, &bind_args); if (err < 0) return err; break; } default: return -ENOTTY; } return 0; }


Rodolfo Giometti48971.60%233.33%
Alexander Gordeev19228.11%350.00%
Matthew Ranostay20.29%116.67%

static long pps_cdev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct pps_device *pps = file->private_data; void __user *uarg = (void __user *) arg; cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *)); if (cmd == PPS_FETCH) { struct pps_fdata_compat compat; struct pps_fdata fdata; int err; dev_dbg(pps->dev, "PPS_FETCH\n"); err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); if (err) return -EFAULT; memcpy(&fdata.timeout, &compat.timeout, sizeof(struct pps_ktime_compat)); err = pps_cdev_pps_fetch(pps, &fdata); if (err) return err; /* Return the fetched timestamp */ spin_lock_irq(&pps->lock); = pps->assert_sequence; = pps->clear_sequence; = pps->current_mode; memcpy(&, &pps->assert_tu, sizeof(struct pps_ktime_compat)); memcpy(&, &pps->clear_tu, sizeof(struct pps_ktime_compat)); spin_unlock_irq(&pps->lock); return copy_to_user(uarg, &compat, sizeof(struct pps_fdata_compat)) ? -EFAULT : 0; } return pps_cdev_ioctl(file, cmd, arg); }


Matthew Ranostay273100.00%2100.00%

#else #define pps_cdev_compat_ioctl NULL #endif
static int pps_cdev_open(struct inode *inode, struct file *file) { struct pps_device *pps = container_of(inode->i_cdev, struct pps_device, cdev); file->private_data = pps; kobject_get(&pps->dev->kobj); return 0; }


Rodolfo Giometti4280.77%150.00%
George Spelvin1019.23%150.00%

static int pps_cdev_release(struct inode *inode, struct file *file) { struct pps_device *pps = container_of(inode->i_cdev, struct pps_device, cdev); kobject_put(&pps->dev->kobj); return 0; }


George Spelvin2758.70%150.00%
Rodolfo Giometti1941.30%150.00%

/* * Char device stuff */ static const struct file_operations pps_cdev_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .poll = pps_cdev_poll, .fasync = pps_cdev_fasync, .compat_ioctl = pps_cdev_compat_ioctl, .unlocked_ioctl = pps_cdev_ioctl, .open = pps_cdev_open, .release = pps_cdev_release, };
static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); cdev_del(&pps->cdev); /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); mutex_unlock(&pps_idr_lock); kfree(dev); kfree(pps); }


Alexander Gordeev5374.65%266.67%
George Spelvin1825.35%133.33%

int pps_register_cdev(struct pps_device *pps) { int err; dev_t devt; mutex_lock(&pps_idr_lock); /* * Get new ID for the new PPS source. After idr_alloc() calling * the new source will be freely available into the kernel. */ err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL); if (err < 0) { if (err == -ENOSPC) { pr_err("%s: too many PPS sources in the system\n", pps->; err = -EBUSY; } goto out_unlock; } pps->id = err; mutex_unlock(&pps_idr_lock); devt = MKDEV(MAJOR(pps_devt), pps->id); cdev_init(&pps->cdev, &pps_cdev_fops); pps->cdev.owner = pps->info.owner; err = cdev_add(&pps->cdev, devt, 1); if (err) { pr_err("%s: failed to add char device %d:%d\n", pps->, MAJOR(pps_devt), pps->id); goto free_idr; } pps->dev = device_create(pps_class, pps->, devt, pps, "pps%d", pps->id); if (IS_ERR(pps->dev)) { err = PTR_ERR(pps->dev); goto del_cdev; } /* Override the release function with our own */ pps->dev->release = pps_device_destruct; pr_debug("source %s got cdev (%d:%d)\n", pps->, MAJOR(pps_devt), pps->id); return 0; del_cdev: cdev_del(&pps->cdev); free_idr: mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); out_unlock: mutex_unlock(&pps_idr_lock); return err; }


Rodolfo Giometti15152.80%111.11%
Alexander Gordeev8931.12%444.44%
Tejun Heo289.79%111.11%
Emil Goode113.85%111.11%
Joonwoo Park62.10%111.11%
George Spelvin10.35%111.11%

void pps_unregister_cdev(struct pps_device *pps) { pr_debug("unregistering pps%d\n", pps->id); pps->lookup_cookie = NULL; device_destroy(pps_class, pps->dev->devt); }


Rodolfo Giometti1850.00%125.00%
George Spelvin1541.67%250.00%
Alexander Gordeev38.33%125.00%

/* * Look up a pps device by magic cookie. * The cookie is usually a pointer to some enclosing device, but this * code doesn't care; you should never be dereferencing it. * * This is a bit of a kludge that is currently used only by the PPS * serial line discipline. It may need to be tweaked when a second user * is found. * * There is no function interface for setting the lookup_cookie field. * It's initialized to NULL when the pps device is created, and if a * client wants to use it, just fill it in afterward. * * The cookie is automatically set to NULL in pps_unregister_source() * so that it will not be used again, even if the pps device cannot * be removed from the idr due to pending references holding the minor * number in use. */
struct pps_device *pps_lookup_dev(void const *cookie) { struct pps_device *pps; unsigned id; rcu_read_lock(); idr_for_each_entry(&pps_idr, pps, id) if (cookie == pps->lookup_cookie) break; rcu_read_unlock(); return pps; }


George Spelvin46100.00%1100.00%

EXPORT_SYMBOL(pps_lookup_dev); /* * Module stuff */
static void __exit pps_exit(void) { class_destroy(pps_class); unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); }


Rodolfo Giometti21100.00%1100.00%

static int __init pps_init(void) { int err; pps_class = class_create(THIS_MODULE, "pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); return PTR_ERR(pps_class); } pps_class->dev_groups = pps_groups; err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); if (err < 0) { pr_err("failed to allocate char device region\n"); goto remove_class; } pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS); pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti " "<>\n", PPS_VERSION); return 0; remove_class: class_destroy(pps_class); return err; }


Rodolfo Giometti9287.62%125.00%
Dan Carpenter76.67%125.00%
Alexander Gordeev43.81%125.00%
Greg Kroah-Hartman21.90%125.00%

subsys_initcall(pps_init); module_exit(pps_exit); MODULE_AUTHOR("Rodolfo Giometti <>"); MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION); MODULE_LICENSE("GPL");

Overall Contributors

Rodolfo Giometti102650.42%211.76%
Matthew Ranostay46322.75%211.76%
Alexander Gordeev36918.13%635.29%
George Spelvin1236.04%211.76%
Tejun Heo281.38%15.88%
Emil Goode110.54%15.88%
Dan Carpenter70.34%15.88%
Joonwoo Park60.29%15.88%
Greg Kroah-Hartman20.10%15.88%
Directory: drivers/pps
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