From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- drivers/pps/pps.c | 489 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 489 insertions(+) create mode 100644 drivers/pps/pps.c (limited to 'drivers/pps/pps.c') diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c new file mode 100644 index 000000000..22a65ad4e --- /dev/null +++ b/drivers/pps/pps.c @@ -0,0 +1,489 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PPS core file + * + * Copyright (C) 2005-2009 Rodolfo Giometti + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; + + 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; +} + +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, ¶ms, 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(¶ms, 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; + + /* + * Clear unused fields of pps_kparams to avoid leaking + * uninitialized data of the PPS_SETPARAMS caller via + * PPS_GETPARAMS + */ + pps->params.assert_off_tu.flags = 0; + pps->params.clear_off_tu.flags = 0; + + 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); + + fdata.info.assert_sequence = pps->assert_sequence; + fdata.info.clear_sequence = pps->clear_sequence; + fdata.info.assert_tu = pps->assert_tu; + fdata.info.clear_tu = pps->clear_tu; + fdata.info.current_mode = 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; +} + +#ifdef CONFIG_COMPAT +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); + + compat.info.assert_sequence = pps->assert_sequence; + compat.info.clear_sequence = pps->clear_sequence; + compat.info.current_mode = pps->current_mode; + + memcpy(&compat.info.assert_tu, &pps->assert_tu, + sizeof(struct pps_ktime_compat)); + memcpy(&compat.info.clear_tu, &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); +} +#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; +} + +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; +} + +/* + * 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); +} + +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->info.name); + 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->info.name, MAJOR(pps_devt), pps->id); + goto free_idr; + } + pps->dev = device_create(pps_class, pps->info.dev, 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->info.name, + 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; +} + +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); +} + +/* + * 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; +} +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); +} + +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; +} + +subsys_initcall(pps_init); +module_exit(pps_exit); + +MODULE_AUTHOR("Rodolfo Giometti "); +MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION); +MODULE_LICENSE("GPL"); -- cgit v1.2.3