1 files changed, 489 insertions, 0 deletions

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 0000000000..5d19baae6a
--- /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 <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;
+
+		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, &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;
+
+		/*
+		 * 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("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 "
+		"<giometti@linux.it>\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 <giometti@linux.it>");
+MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
+MODULE_LICENSE("GPL");