diff options
Diffstat (limited to 'drivers/pps')
| -rw-r--r-- | drivers/pps/Kconfig | 33 | ||||
| -rw-r--r-- | drivers/pps/Makefile | 8 | ||||
| -rw-r--r-- | drivers/pps/kapi.c | 329 | ||||
| -rw-r--r-- | drivers/pps/pps.c | 312 | ||||
| -rw-r--r-- | drivers/pps/sysfs.c | 98 |
5 files changed, 780 insertions, 0 deletions
diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig new file mode 100644 index 000000000000..cc2eb8edb514 --- /dev/null +++ b/drivers/pps/Kconfig @@ -0,0 +1,33 @@ +# +# PPS support configuration +# + +menu "PPS support" + +config PPS + tristate "PPS support" + depends on EXPERIMENTAL + ---help--- + PPS (Pulse Per Second) is a special pulse provided by some GPS + antennae. Userland can use it to get a high-precision time + reference. + + Some antennae's PPS signals are connected with the CD (Carrier + Detect) pin of the serial line they use to communicate with the + host. In this case use the SERIAL_LINE client support. + + Some antennae's PPS signals are connected with some special host + inputs so you have to enable the corresponding client support. + + To compile this driver as a module, choose M here: the module + will be called pps_core.ko. + +config PPS_DEBUG + bool "PPS debugging messages" + depends on PPS + help + Say Y here if you want the PPS support to produce a bunch of debug + messages to the system log. Select this if you are having a + problem with PPS support and want to see more of what is going on. + +endmenu diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile new file mode 100644 index 000000000000..19ea582f431d --- /dev/null +++ b/drivers/pps/Makefile @@ -0,0 +1,8 @@ +# +# Makefile for the PPS core. +# + +pps_core-y := pps.o kapi.o sysfs.o +obj-$(CONFIG_PPS) := pps_core.o + +ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c new file mode 100644 index 000000000000..35a0b192d768 --- /dev/null +++ b/drivers/pps/kapi.c @@ -0,0 +1,329 @@ +/* + * kernel API + * + * + * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> + * + * 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 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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. + */ + + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/time.h> +#include <linux/spinlock.h> +#include <linux/idr.h> +#include <linux/fs.h> +#include <linux/pps_kernel.h> + +/* + * Global variables + */ + +DEFINE_SPINLOCK(pps_idr_lock); +DEFINE_IDR(pps_idr); + +/* + * Local functions + */ + +static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) +{ + ts->nsec += offset->nsec; + while (ts->nsec >= NSEC_PER_SEC) { + ts->nsec -= NSEC_PER_SEC; + ts->sec++; + } + while (ts->nsec < 0) { + ts->nsec += NSEC_PER_SEC; + ts->sec--; + } + ts->sec += offset->sec; +} + +/* + * Exported functions + */ + +/* pps_get_source - find a PPS source + * @source: the PPS source ID. + * + * This function is used to find an already registered PPS source into the + * system. + * + * The function returns NULL if found nothing, otherwise it returns a pointer + * to the PPS source data struct (the refcounter is incremented by 1). + */ + +struct pps_device *pps_get_source(int source) +{ + struct pps_device *pps; + unsigned long flags; + + spin_lock_irqsave(&pps_idr_lock, flags); + + pps = idr_find(&pps_idr, source); + if (pps != NULL) + atomic_inc(&pps->usage); + + spin_unlock_irqrestore(&pps_idr_lock, flags); + + return pps; +} + +/* pps_put_source - free the PPS source data + * @pps: a pointer to the PPS source. + * + * This function is used to free a PPS data struct if its refcount is 0. + */ + +void pps_put_source(struct pps_device *pps) +{ + unsigned long flags; + + spin_lock_irqsave(&pps_idr_lock, flags); + BUG_ON(atomic_read(&pps->usage) == 0); + + if (!atomic_dec_and_test(&pps->usage)) { + pps = NULL; + goto exit; + } + + /* No more reference to the PPS source. We can safely remove the + * PPS data struct. + */ + idr_remove(&pps_idr, pps->id); + +exit: + spin_unlock_irqrestore(&pps_idr_lock, flags); + kfree(pps); +} + +/* pps_register_source - add a PPS source in the system + * @info: the PPS info struct + * @default_params: the default PPS parameters of the new source + * + * This function is used to add a new PPS source in the system. The new + * source is described by info's fields and it will have, as default PPS + * parameters, the ones specified into default_params. + * + * The function returns, in case of success, the PPS source ID. + */ + +int pps_register_source(struct pps_source_info *info, int default_params) +{ + struct pps_device *pps; + int id; + int err; + + /* Sanity checks */ + if ((info->mode & default_params) != default_params) { + printk(KERN_ERR "pps: %s: unsupported default parameters\n", + info->name); + err = -EINVAL; + goto pps_register_source_exit; + } + if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 && + info->echo == NULL) { + printk(KERN_ERR "pps: %s: echo function is not defined\n", + info->name); + err = -EINVAL; + goto pps_register_source_exit; + } + if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { + printk(KERN_ERR "pps: %s: unspecified time format\n", + info->name); + err = -EINVAL; + goto pps_register_source_exit; + } + + /* Allocate memory for the new PPS source struct */ + pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL); + if (pps == NULL) { + err = -ENOMEM; + goto pps_register_source_exit; + } + + /* These initializations must be done before calling idr_get_new() + * in order to avoid reces into pps_event(). + */ + pps->params.api_version = PPS_API_VERS; + pps->params.mode = default_params; + pps->info = *info; + + init_waitqueue_head(&pps->queue); + spin_lock_init(&pps->lock); + atomic_set(&pps->usage, 1); + + /* Get new ID for the new PPS source */ + if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) { + err = -ENOMEM; + goto kfree_pps; + } + + spin_lock_irq(&pps_idr_lock); + + /* Now really allocate the PPS source. + * After idr_get_new() calling the new source will be freely available + * into the kernel. + */ + err = idr_get_new(&pps_idr, pps, &id); + if (err < 0) { + spin_unlock_irq(&pps_idr_lock); + goto kfree_pps; + } + + id = id & MAX_ID_MASK; + if (id >= PPS_MAX_SOURCES) { + spin_unlock_irq(&pps_idr_lock); + + printk(KERN_ERR "pps: %s: too many PPS sources in the system\n", + info->name); + err = -EBUSY; + goto free_idr; + } + pps->id = id; + + spin_unlock_irq(&pps_idr_lock); + + /* Create the char device */ + err = pps_register_cdev(pps); + if (err < 0) { + printk(KERN_ERR "pps: %s: unable to create char device\n", + info->name); + goto free_idr; + } + + pr_info("new PPS source %s at ID %d\n", info->name, id); + + return id; + +free_idr: + spin_lock_irq(&pps_idr_lock); + idr_remove(&pps_idr, id); + spin_unlock_irq(&pps_idr_lock); + +kfree_pps: + kfree(pps); + +pps_register_source_exit: + printk(KERN_ERR "pps: %s: unable to register source\n", info->name); + + return err; +} +EXPORT_SYMBOL(pps_register_source); + +/* pps_unregister_source - remove a PPS source from the system + * @source: the PPS source ID + * + * This function is used to remove a previously registered PPS source from + * the system. + */ + +void pps_unregister_source(int source) +{ + struct pps_device *pps; + + spin_lock_irq(&pps_idr_lock); + pps = idr_find(&pps_idr, source); + + if (!pps) { + BUG(); + spin_unlock_irq(&pps_idr_lock); + return; + } + spin_unlock_irq(&pps_idr_lock); + + pps_unregister_cdev(pps); + pps_put_source(pps); +} +EXPORT_SYMBOL(pps_unregister_source); + +/* pps_event - register a PPS event into the system + * @source: the PPS source ID + * @ts: the event timestamp + * @event: the event type + * @data: userdef pointer + * + * This function is used by each PPS client in order to register a new + * PPS event into the system (it's usually called inside an IRQ handler). + * + * If an echo function is associated with the PPS source it will be called + * as: + * pps->info.echo(source, event, data); + */ + +void pps_event(int source, struct pps_ktime *ts, int event, void *data) +{ + struct pps_device *pps; + unsigned long flags; + + if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) { + printk(KERN_ERR "pps: unknown event (%x) for source %d\n", + event, source); + return; + } + + pps = pps_get_source(source); + if (!pps) + return; + + pr_debug("PPS event on source %d at %llu.%06u\n", + pps->id, (unsigned long long) ts->sec, ts->nsec); + + spin_lock_irqsave(&pps->lock, flags); + + /* Must call the echo function? */ + if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR))) + pps->info.echo(source, event, data); + + /* Check the event */ + pps->current_mode = pps->params.mode; + if (event & PPS_CAPTUREASSERT) { + /* We have to add an offset? */ + if (pps->params.mode & PPS_OFFSETASSERT) + pps_add_offset(ts, &pps->params.assert_off_tu); + + /* Save the time stamp */ + pps->assert_tu = *ts; + pps->assert_sequence++; + pr_debug("capture assert seq #%u for source %d\n", + pps->assert_sequence, source); + } + if (event & PPS_CAPTURECLEAR) { + /* We have to add an offset? */ + if (pps->params.mode & PPS_OFFSETCLEAR) + pps_add_offset(ts, &pps->params.clear_off_tu); + + /* Save the time stamp */ + pps->clear_tu = *ts; + pps->clear_sequence++; + pr_debug("capture clear seq #%u for source %d\n", + pps->clear_sequence, source); + } + + pps->go = ~0; + wake_up_interruptible(&pps->queue); + + kill_fasync(&pps->async_queue, SIGIO, POLL_IN); + + spin_unlock_irqrestore(&pps->lock, flags); + + /* Now we can release the PPS source for (possible) deregistration */ + pps_put_source(pps); +} +EXPORT_SYMBOL(pps_event); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c new file mode 100644 index 000000000000..ac8cc8cea1e3 --- /dev/null +++ b/drivers/pps/pps.c @@ -0,0 +1,312 @@ +/* + * PPS core file + * + * + * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> + * + * 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 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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. + */ + + +#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/cdev.h> +#include <linux/poll.h> +#include <linux/pps_kernel.h> + +/* + * Local variables + */ + +static dev_t pps_devt; +static struct class *pps_class; + +/* + * 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; +} + +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 long pps_cdev_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct pps_device *pps = file->private_data; + struct pps_kparams params; + struct pps_fdata fdata; + unsigned long ticks; + void __user *uarg = (void __user *) arg; + int __user *iuarg = (int __user *) arg; + int err; + + switch (cmd) { + case PPS_GETPARAMS: + pr_debug("PPS_GETPARAMS: source %d\n", pps->id); + + /* Return current parameters */ + err = copy_to_user(uarg, &pps->params, + sizeof(struct pps_kparams)); + if (err) + return -EFAULT; + + break; + + case PPS_SETPARAMS: + pr_debug("PPS_SETPARAMS: source %d\n", pps->id); + + /* 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))) { + pr_debug("capture mode unspecified (%x)\n", + params.mode); + return -EINVAL; + } + + /* Check for supported capabilities */ + if ((params.mode & ~pps->info.mode) != 0) { + pr_debug("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 */ + pr_debug("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: + pr_debug("PPS_GETCAP: source %d\n", pps->id); + + err = put_user(pps->info.mode, iuarg); + if (err) + return -EFAULT; + + break; + + case PPS_FETCH: + pr_debug("PPS_FETCH: source %d\n", pps->id); + + err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); + if (err) + return -EFAULT; + + pps->go = 0; + + /* Manage the timeout */ + if (fdata.timeout.flags & PPS_TIME_INVALID) + err = wait_event_interruptible(pps->queue, pps->go); + else { + pr_debug("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, pps->go, ticks); + if (err == 0) + return -ETIMEDOUT; + } + } + + /* Check for pending signals */ + if (err == -ERESTARTSYS) { + pr_debug("pending signal caught\n"); + return -EINTR; + } + + /* 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; + + default: + return -ENOTTY; + break; + } + + return 0; +} + +static int pps_cdev_open(struct inode *inode, struct file *file) +{ + struct pps_device *pps = container_of(inode->i_cdev, + struct pps_device, cdev); + int found; + + found = pps_get_source(pps->id) != 0; + if (!found) + return -ENODEV; + + file->private_data = pps; + + return 0; +} + +static int pps_cdev_release(struct inode *inode, struct file *file) +{ + struct pps_device *pps = file->private_data; + + /* Free the PPS source and wake up (possible) deregistration */ + pps_put_source(pps); + + 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, + .unlocked_ioctl = pps_cdev_ioctl, + .open = pps_cdev_open, + .release = pps_cdev_release, +}; + +int pps_register_cdev(struct pps_device *pps) +{ + int err; + + pps->devno = MKDEV(MAJOR(pps_devt), pps->id); + cdev_init(&pps->cdev, &pps_cdev_fops); + pps->cdev.owner = pps->info.owner; + + err = cdev_add(&pps->cdev, pps->devno, 1); + if (err) { + printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n", + pps->info.name, MAJOR(pps_devt), pps->id); + return err; + } + pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL, + "pps%d", pps->id); + if (err) + goto del_cdev; + dev_set_drvdata(pps->dev, pps); + + 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); + + return err; +} + +void pps_unregister_cdev(struct pps_device *pps) +{ + device_destroy(pps_class, pps->devno); + cdev_del(&pps->cdev); +} + +/* + * 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 (!pps_class) { + printk(KERN_ERR "pps: failed to allocate class\n"); + return -ENOMEM; + } + pps_class->dev_attrs = pps_attrs; + + err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); + if (err < 0) { + printk(KERN_ERR "pps: 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"); diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c new file mode 100644 index 000000000000..ef0978c71eee --- /dev/null +++ b/drivers/pps/sysfs.c @@ -0,0 +1,98 @@ +/* + * PPS sysfs support + * + * + * Copyright (C) 2007-2009 Rodolfo Giometti <giometti@linux.it> + * + * 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 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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. + */ + + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/pps_kernel.h> + +/* + * Attribute functions + */ + +static ssize_t pps_show_assert(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + if (!(pps->info.mode & PPS_CAPTUREASSERT)) + return 0; + + return sprintf(buf, "%lld.%09d#%d\n", + (long long) pps->assert_tu.sec, pps->assert_tu.nsec, + pps->assert_sequence); +} + +static ssize_t pps_show_clear(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + if (!(pps->info.mode & PPS_CAPTURECLEAR)) + return 0; + + return sprintf(buf, "%lld.%09d#%d\n", + (long long) pps->clear_tu.sec, pps->clear_tu.nsec, + pps->clear_sequence); +} + +static ssize_t pps_show_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + return sprintf(buf, "%4x\n", pps->info.mode); +} + +static ssize_t pps_show_echo(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", !!pps->info.echo); +} + +static ssize_t pps_show_name(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", pps->info.name); +} + +static ssize_t pps_show_path(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", pps->info.path); +} + +struct device_attribute pps_attrs[] = { + __ATTR(assert, S_IRUGO, pps_show_assert, NULL), + __ATTR(clear, S_IRUGO, pps_show_clear, NULL), + __ATTR(mode, S_IRUGO, pps_show_mode, NULL), + __ATTR(echo, S_IRUGO, pps_show_echo, NULL), + __ATTR(name, S_IRUGO, pps_show_name, NULL), + __ATTR(path, S_IRUGO, pps_show_path, NULL), + __ATTR_NULL, +}; |