diff options
Diffstat (limited to 'drivers/pps')
| -rw-r--r-- | drivers/pps/Makefile | 3 | ||||
| -rw-r--r-- | drivers/pps/clients/pps-gpio.c | 6 | ||||
| -rw-r--r-- | drivers/pps/generators/Kconfig | 22 | ||||
| -rw-r--r-- | drivers/pps/generators/Makefile | 4 | ||||
| -rw-r--r-- | drivers/pps/generators/pps_gen-dummy.c | 96 | ||||
| -rw-r--r-- | drivers/pps/generators/pps_gen.c | 344 | ||||
| -rw-r--r-- | drivers/pps/generators/sysfs.c | 75 |
7 files changed, 547 insertions, 3 deletions
diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile index ceaf65cc1f1d..0aea394d4e4d 100644 --- a/drivers/pps/Makefile +++ b/drivers/pps/Makefile @@ -6,6 +6,7 @@ pps_core-y := pps.o kapi.o sysfs.o pps_core-$(CONFIG_NTP_PPS) += kc.o obj-$(CONFIG_PPS) := pps_core.o -obj-y += clients/ generators/ +obj-y += clients/ +obj-$(CONFIG_PPS_GENERATOR) += generators/ ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index f77b19884f05..75c1bae30a7c 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -52,7 +52,9 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) info = data; - rising_edge = gpiod_get_value(info->gpio_pin); + /* Small trick to bypass the check on edge's direction when capture_clear is unset */ + rising_edge = info->capture_clear ? + gpiod_get_value(info->gpio_pin) : !info->assert_falling_edge; if ((rising_edge && !info->assert_falling_edge) || (!rising_edge && info->assert_falling_edge)) pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data); @@ -60,6 +62,8 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) ((rising_edge && info->assert_falling_edge) || (!rising_edge && !info->assert_falling_edge))) pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data); + else + dev_warn_ratelimited(&info->pps->dev, "IRQ did not trigger any PPS event\n"); return IRQ_HANDLED; } diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig index d615e640fcad..cd94bf3bfaf2 100644 --- a/drivers/pps/generators/Kconfig +++ b/drivers/pps/generators/Kconfig @@ -3,7 +3,25 @@ # PPS generators configuration # -comment "PPS generators support" +menuconfig PPS_GENERATOR + tristate "PPS generators support" + help + PPS generators are special hardware which are able to produce PPS + (Pulse Per Second) signals. + + To compile this driver as a module, choose M here: the module + will be called pps_gen_core. + +if PPS_GENERATOR + +config PPS_GENERATOR_DUMMY + tristate "Dummy PPS generator (Testing generator, use for debug)" + help + If you say yes here you get support for a PPS debugging generator + (which generates no PPS signal at all). + + This driver can also be built as a module. If so, the module + will be called pps_gen-dummy. config PPS_GENERATOR_PARPORT tristate "Parallel port PPS signal generator" @@ -12,3 +30,5 @@ config PPS_GENERATOR_PARPORT If you say yes here you get support for a PPS signal generator which utilizes STROBE pin of a parallel port to send PPS signals. It uses parport abstraction layer and hrtimers to precisely control the signal. + +endif # PPS_GENERATOR diff --git a/drivers/pps/generators/Makefile b/drivers/pps/generators/Makefile index 2589fd0f2481..dc1aa5a4688b 100644 --- a/drivers/pps/generators/Makefile +++ b/drivers/pps/generators/Makefile @@ -3,6 +3,10 @@ # Makefile for PPS generators. # +pps_gen_core-y := pps_gen.o sysfs.o +obj-$(CONFIG_PPS_GENERATOR) := pps_gen_core.o + +obj-$(CONFIG_PPS_GENERATOR_DUMMY) += pps_gen-dummy.o obj-$(CONFIG_PPS_GENERATOR_PARPORT) += pps_gen_parport.o ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/generators/pps_gen-dummy.c b/drivers/pps/generators/pps_gen-dummy.c new file mode 100644 index 000000000000..b284c200cbe5 --- /dev/null +++ b/drivers/pps/generators/pps_gen-dummy.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PPS dummy generator + * + * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/time.h> +#include <linux/timer.h> +#include <linux/random.h> +#include <linux/pps_gen_kernel.h> + +static struct pps_gen_device *pps_gen; +static struct timer_list ktimer; + +static unsigned int get_random_delay(void) +{ + unsigned int delay = get_random_u8() & 0x0f; + + return (delay + 1) * HZ; +} + +/* + * The kernel timer + */ + +static void pps_gen_ktimer_event(struct timer_list *unused) +{ + pps_gen_event(pps_gen, PPS_GEN_EVENT_MISSEDPULSE, NULL); +} + +/* + * PPS Generator methods + */ + +static int pps_gen_dummy_get_time(struct pps_gen_device *pps_gen, + struct timespec64 *time) +{ + struct system_time_snapshot snap; + + ktime_get_snapshot(&snap); + *time = ktime_to_timespec64(snap.real); + + return 0; +} + +static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enable) +{ + if (enable) + mod_timer(&ktimer, jiffies + get_random_delay()); + else + del_timer_sync(&ktimer); + + return 0; +} + +/* + * The PPS info struct + */ + +static struct pps_gen_source_info pps_gen_dummy_info = { + .use_system_clock = true, + .get_time = pps_gen_dummy_get_time, + .enable = pps_gen_dummy_enable, +}; + +/* + * Module staff + */ + +static void __exit pps_gen_dummy_exit(void) +{ + del_timer_sync(&ktimer); + pps_gen_unregister_source(pps_gen); +} + +static int __init pps_gen_dummy_init(void) +{ + pps_gen = pps_gen_register_source(&pps_gen_dummy_info); + if (IS_ERR(pps_gen)) + return PTR_ERR(pps_gen); + + timer_setup(&ktimer, pps_gen_ktimer_event, 0); + + return 0; +} + +module_init(pps_gen_dummy_init); +module_exit(pps_gen_dummy_exit); + +MODULE_AUTHOR("Rodolfo Giometti <giometti@enneenne.com>"); +MODULE_DESCRIPTION("LinuxPPS dummy generator"); +MODULE_LICENSE("GPL"); diff --git a/drivers/pps/generators/pps_gen.c b/drivers/pps/generators/pps_gen.c new file mode 100644 index 000000000000..ca592f1736f4 --- /dev/null +++ b/drivers/pps/generators/pps_gen.c @@ -0,0 +1,344 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PPS generators core file + * + * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com> + */ + +#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/time.h> +#include <linux/timex.h> +#include <linux/uaccess.h> +#include <linux/idr.h> +#include <linux/cdev.h> +#include <linux/poll.h> +#include <linux/fs.h> +#include <linux/pps_gen_kernel.h> +#include <linux/slab.h> + +/* + * Local variables + */ + +static dev_t pps_gen_devt; +static struct class *pps_gen_class; + +static DEFINE_IDA(pps_gen_ida); + +/* + * Char device methods + */ + +static __poll_t pps_gen_cdev_poll(struct file *file, poll_table *wait) +{ + struct pps_gen_device *pps_gen = file->private_data; + + poll_wait(file, &pps_gen->queue, wait); + return EPOLLIN | EPOLLRDNORM; +} + +static int pps_gen_cdev_fasync(int fd, struct file *file, int on) +{ + struct pps_gen_device *pps_gen = file->private_data; + + return fasync_helper(fd, file, on, &pps_gen->async_queue); +} + +static long pps_gen_cdev_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct pps_gen_device *pps_gen = file->private_data; + void __user *uarg = (void __user *) arg; + unsigned int __user *uiuarg = (unsigned int __user *) arg; + unsigned int status; + int ret; + + switch (cmd) { + case PPS_GEN_SETENABLE: + dev_dbg(pps_gen->dev, "PPS_GEN_SETENABLE\n"); + + ret = get_user(status, uiuarg); + if (ret) + return -EFAULT; + + ret = pps_gen->info.enable(pps_gen, status); + if (ret) + return ret; + pps_gen->enabled = status; + + break; + + case PPS_GEN_USESYSTEMCLOCK: + dev_dbg(pps_gen->dev, "PPS_GEN_USESYSTEMCLOCK\n"); + + ret = put_user(pps_gen->info.use_system_clock, uiuarg); + if (ret) + return -EFAULT; + + break; + + case PPS_GEN_FETCHEVENT: { + struct pps_gen_event info; + unsigned int ev = pps_gen->last_ev; + + dev_dbg(pps_gen->dev, "PPS_GEN_FETCHEVENT\n"); + + ret = wait_event_interruptible(pps_gen->queue, + ev != pps_gen->last_ev); + if (ret == -ERESTARTSYS) { + dev_dbg(pps_gen->dev, "pending signal caught\n"); + return -EINTR; + } + + spin_lock_irq(&pps_gen->lock); + info.sequence = pps_gen->sequence; + info.event = pps_gen->event; + spin_unlock_irq(&pps_gen->lock); + + ret = copy_to_user(uarg, &info, sizeof(struct pps_gen_event)); + if (ret) + return -EFAULT; + + break; + } + default: + return -ENOTTY; + } + + return 0; +} + +static int pps_gen_cdev_open(struct inode *inode, struct file *file) +{ + struct pps_gen_device *pps_gen = container_of(inode->i_cdev, + struct pps_gen_device, cdev); + + get_device(pps_gen->dev); + file->private_data = pps_gen; + return 0; +} + +static int pps_gen_cdev_release(struct inode *inode, struct file *file) +{ + struct pps_gen_device *pps_gen = file->private_data; + + put_device(pps_gen->dev); + return 0; +} + +/* + * Char device stuff + */ + +static const struct file_operations pps_gen_cdev_fops = { + .owner = THIS_MODULE, + .poll = pps_gen_cdev_poll, + .fasync = pps_gen_cdev_fasync, + .unlocked_ioctl = pps_gen_cdev_ioctl, + .open = pps_gen_cdev_open, + .release = pps_gen_cdev_release, +}; + +static void pps_gen_device_destruct(struct device *dev) +{ + struct pps_gen_device *pps_gen = dev_get_drvdata(dev); + + cdev_del(&pps_gen->cdev); + + pr_debug("deallocating pps-gen%d\n", pps_gen->id); + ida_free(&pps_gen_ida, pps_gen->id); + + kfree(dev); + kfree(pps_gen); +} + +static int pps_gen_register_cdev(struct pps_gen_device *pps_gen) +{ + int err; + dev_t devt; + + err = ida_alloc_max(&pps_gen_ida, PPS_GEN_MAX_SOURCES - 1, GFP_KERNEL); + if (err < 0) { + if (err == -ENOSPC) { + pr_err("too many PPS sources in the system\n"); + err = -EBUSY; + } + return err; + } + pps_gen->id = err; + + devt = MKDEV(MAJOR(pps_gen_devt), pps_gen->id); + + cdev_init(&pps_gen->cdev, &pps_gen_cdev_fops); + pps_gen->cdev.owner = pps_gen->info.owner; + + err = cdev_add(&pps_gen->cdev, devt, 1); + if (err) { + pr_err("failed to add char device %d:%d\n", + MAJOR(pps_gen_devt), pps_gen->id); + goto free_ida; + } + pps_gen->dev = device_create(pps_gen_class, pps_gen->info.parent, devt, + pps_gen, "pps-gen%d", pps_gen->id); + if (IS_ERR(pps_gen->dev)) { + err = PTR_ERR(pps_gen->dev); + goto del_cdev; + } + pps_gen->dev->release = pps_gen_device_destruct; + dev_set_drvdata(pps_gen->dev, pps_gen); + + pr_debug("generator got cdev (%d:%d)\n", + MAJOR(pps_gen_devt), pps_gen->id); + + return 0; + +del_cdev: + cdev_del(&pps_gen->cdev); +free_ida: + ida_free(&pps_gen_ida, pps_gen->id); + return err; +} + +static void pps_gen_unregister_cdev(struct pps_gen_device *pps_gen) +{ + pr_debug("unregistering pps-gen%d\n", pps_gen->id); + device_destroy(pps_gen_class, pps_gen->dev->devt); +} + +/* + * Exported functions + */ + +/** + * pps_gen_register_source() - add a PPS generator in the system + * @info: the PPS generator info struct + * + * This function is used to register a new PPS generator in the system. + * When it returns successfully the new generator is up and running, and + * it can be managed by the userspace. + * + * Return: the PPS generator device in case of success, and ERR_PTR(errno) + * otherwise. + */ +struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info) +{ + struct pps_gen_device *pps_gen; + int err; + + pps_gen = kzalloc(sizeof(struct pps_gen_device), GFP_KERNEL); + if (pps_gen == NULL) { + err = -ENOMEM; + goto pps_gen_register_source_exit; + } + pps_gen->info = *info; + pps_gen->enabled = false; + + init_waitqueue_head(&pps_gen->queue); + spin_lock_init(&pps_gen->lock); + + /* Create the char device */ + err = pps_gen_register_cdev(pps_gen); + if (err < 0) { + pr_err(" unable to create char device\n"); + goto kfree_pps_gen; + } + + return pps_gen; + +kfree_pps_gen: + kfree(pps_gen); + +pps_gen_register_source_exit: + pr_err("unable to register generator\n"); + + return ERR_PTR(err); +} +EXPORT_SYMBOL(pps_gen_register_source); + +/** + * pps_gen_unregister_source() - remove a PPS generator from the system + * @pps_gen: the PPS generator device to be removed + * + * This function is used to deregister a PPS generator from the system. When + * called, it disables the generator so no pulses are generated anymore. + */ +void pps_gen_unregister_source(struct pps_gen_device *pps_gen) +{ + pps_gen_unregister_cdev(pps_gen); +} +EXPORT_SYMBOL(pps_gen_unregister_source); + +/* pps_gen_event - register a PPS generator event into the system + * @pps: the PPS generator device + * @event: the event type + * @data: userdef pointer + * + * This function is used by each PPS generator in order to register a new + * PPS event into the system (it's usually called inside an IRQ handler). + */ +void pps_gen_event(struct pps_gen_device *pps_gen, + unsigned int event, void *data) +{ + unsigned long flags; + + dev_dbg(pps_gen->dev, "PPS generator event %u\n", event); + + spin_lock_irqsave(&pps_gen->lock, flags); + + pps_gen->event = event; + pps_gen->sequence++; + + pps_gen->last_ev++; + wake_up_interruptible_all(&pps_gen->queue); + kill_fasync(&pps_gen->async_queue, SIGIO, POLL_IN); + + spin_unlock_irqrestore(&pps_gen->lock, flags); +} +EXPORT_SYMBOL(pps_gen_event); + +/* + * Module stuff + */ + +static void __exit pps_gen_exit(void) +{ + class_destroy(pps_gen_class); + unregister_chrdev_region(pps_gen_devt, PPS_GEN_MAX_SOURCES); +} + +static int __init pps_gen_init(void) +{ + int err; + + pps_gen_class = class_create("pps-gen"); + if (IS_ERR(pps_gen_class)) { + pr_err("failed to allocate class\n"); + return PTR_ERR(pps_gen_class); + } + pps_gen_class->dev_groups = pps_gen_groups; + + err = alloc_chrdev_region(&pps_gen_devt, 0, + PPS_GEN_MAX_SOURCES, "pps-gen"); + if (err < 0) { + pr_err("failed to allocate char device region\n"); + goto remove_class; + } + + return 0; + +remove_class: + class_destroy(pps_gen_class); + return err; +} + +subsys_initcall(pps_gen_init); +module_exit(pps_gen_exit); + +MODULE_AUTHOR("Rodolfo Giometti <giometti@enneenne.com>"); +MODULE_DESCRIPTION("LinuxPPS generators support"); +MODULE_LICENSE("GPL"); diff --git a/drivers/pps/generators/sysfs.c b/drivers/pps/generators/sysfs.c new file mode 100644 index 000000000000..faf8b1c6d202 --- /dev/null +++ b/drivers/pps/generators/sysfs.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PPS generators sysfs support + * + * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com> + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/pps_gen_kernel.h> + +/* + * Attribute functions + */ + +static ssize_t system_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pps_gen_device *pps_gen = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%d\n", pps_gen->info.use_system_clock); +} +static DEVICE_ATTR_RO(system); + +static ssize_t time_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pps_gen_device *pps_gen = dev_get_drvdata(dev); + struct timespec64 time; + int ret; + + ret = pps_gen->info.get_time(pps_gen, &time); + if (ret) + return ret; + + return sysfs_emit(buf, "%llu %09lu\n", time.tv_sec, time.tv_nsec); +} +static DEVICE_ATTR_RO(time); + +static ssize_t enable_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pps_gen_device *pps_gen = dev_get_drvdata(dev); + bool status; + int ret; + + ret = kstrtobool(buf, &status); + if (ret) + return ret; + + ret = pps_gen->info.enable(pps_gen, status); + if (ret) + return ret; + pps_gen->enabled = status; + + return count; +} +static DEVICE_ATTR_WO(enable); + +static struct attribute *pps_gen_attrs[] = { + &dev_attr_enable.attr, + &dev_attr_time.attr, + &dev_attr_system.attr, + NULL, +}; + +static const struct attribute_group pps_gen_group = { + .attrs = pps_gen_attrs, +}; + +const struct attribute_group *pps_gen_groups[] = { + &pps_gen_group, + NULL, +}; |