From nobody Sun Nov 24 23:35:23 2024 Received: from smtpcmd15176.aruba.it (smtpcmd15176.aruba.it [62.149.156.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 915E4CA6B for ; Thu, 31 Oct 2024 16:38:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.156.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392706; cv=none; b=a8uQM0x5HZwhVpIj+H1qSNJxR7kAvAKYMNQecse0SSYRl1vRd58SYLYkr8ASnkYgUXbkkqgJFCIhNE9s08dDOPC7uFoXGzwKvnBQ0+Y07+OvotqxDgh23RmUw0/anaUvkAT3TUuIaSbKMlW0eKE97NHX3BHE6JsuFAUXd+zq7oo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392706; c=relaxed/simple; bh=9t+1HWKCNf6VucSYaxtleHwN/dP++t7UZJkLK4IDOcU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cajlc4VK1kgf0ypF0ubuCuz5BSKR/1tgBWDVnNv/jvsFYE0CiIigZjFhHiZk70gRfP7JhC0KzcS+7qf9cM2W3Jb4aF5OoeVF3p/vGXsXxAUjj6bk/twijW1ciFTGJ07DezNbf73jOvbW/ooYPBAXbrVYnY0n49kymn2UFocGRGI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com; spf=pass smtp.mailfrom=enneenne.com; dkim=temperror (0-bit key) header.d=aruba.it header.i=@aruba.it header.b=lTJyE8la; arc=none smtp.client-ip=62.149.156.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enneenne.com Authentication-Results: smtp.subspace.kernel.org; dkim=temperror (0-bit key) header.d=aruba.it header.i=@aruba.it header.b="lTJyE8la" Received: from polimar.everex.local ([79.0.204.227]) by Aruba Outgoing Smtp with ESMTPSA id 6Y8atb5dFqJRS6Y8dtNuHG; Thu, 31 Oct 2024 17:35:11 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1730392511; bh=9t+1HWKCNf6VucSYaxtleHwN/dP++t7UZJkLK4IDOcU=; h=From:To:Subject:Date:MIME-Version; b=lTJyE8laLgOkTAVKX4jEViJHvjp2hNQEw2jSn8qBi0kQcwZsTgukcuLbHWswfOh9M 7gIgNYvq9lOykzpFu/x+SqG/xlufjAs8GJYqUEIigtlW7/7ALtkLppY/FJ5wWnMm5I eZ6M8LCD0BkB4UP/6WRTfMQzleSVzWens2ejxUrfc7MHg/Nfwt7dmGZEoRXObbo3rF IkJLO1nXbpiEiB70QobdoAWj04VS3t3mGfJ/HhBKXD5c8Tpbc/XyKFa4Jp3Kon9bqk xWqDbu+Qd0FEaT+h60IhP10nJ7bW7+WuwhH4t43VVKWG3WjBLUeikiMJ9PpjaBKVa/ /Rs3qAareSzLQ== From: Rodolfo Giometti To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Greg KH , corbet@lwn.net, Hall Christopher S , Mohan Subramanian , tglx@linutronix.de, Andy Shevchenko , Dong Eddie , N Pandith , T R Thejesh Reddy , Zage David , Chinnadurai Srinivasan , Randy Dunlap , Rodolfo Giometti Subject: [V2 1/4] drivers pps: add PPS generators support Date: Thu, 31 Oct 2024 17:35:05 +0100 Message-Id: <20241031163508.259522-2-giometti@enneenne.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241031163508.259522-1-giometti@enneenne.com> References: <20241031163508.259522-1-giometti@enneenne.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMAE-Envelope: MS4xfN/FxSRnUHB8WmG0CP+7byCawZGM+hNWPsQQe7XCZ8BG6h94SNtY3v8NkMD6m77ludedH4mu/SejsdPh1Qkgnq1AJw6JrKoxc0lrTKjYyVfqMlpUFe0J 3oq2GuqyBUkU5oLMhfTNAVCtc+Al5t3aUP5HUvjw9PAM2CSeisVSFzou9hLuABhKbZ3IVj+MBZ1k+25gQ5Oh6FqegXlFpBt/io0nx7oqvSlInTAuwFFogD3c vOI2LlKHEGNKYY2PG7IPt+wlaLpb4GoJp83zTTESoeIKjJ6FKCTPmUAVYFT8jMM1QK11AsOIBoLRrQKJgtqeZpB1heIOQVCdAP4fNhX48724+P3M14egsyH7 O8iaJawf1h1CdTekqeFFEuaFzByUk5mkAH+C0U8KORUYtC/EnRkQnWATOZ1tcl40kAhOFlrj51GcjMqMNLiwWy/fkb/1qlTBVsTdesdZwATk3gvCFzO0wGme aXTRc3gosfDLpFZJHBM1ab9r6oC3sGqdWXnWHY+8QMOVS2fu+8QyBWbG3GYUfLuy06I7vBAE9orsTeyWb3sLvDBilrDlRN6B6gSgzCxms4J5nn99BwZSDH1a tVDqQp3i+W8DxdQv528GVGo8vDv49fo4UCJPrewkCygXz4Cm/zRPnKPnOOzLV5yfzihISGsyYe6XbXxMwomXLfns1uff/oqeGcslinXbBnV4/Ny1JXUMSssx Rljyh3qJkap2w+RiktjKn8PKh/nbf/tO Content-Type: text/plain; charset="utf-8" Sometimes one needs to be able not only to catch PPS signals but to produce them also. For example, running a distributed simulation, which requires computers' clock to be synchronized very tightly. This patch adds PPS generators class in order to have a well-defined interface for these devices. Signed-off-by: Rodolfo Giometti --- .../userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 1 + drivers/pps/Makefile | 3 +- drivers/pps/generators/Kconfig | 13 +- drivers/pps/generators/Makefile | 3 + drivers/pps/generators/pps_gen.c | 344 ++++++++++++++++++ drivers/pps/generators/sysfs.c | 75 ++++ include/linux/pps_gen_kernel.h | 78 ++++ include/uapi/linux/pps_gen.h | 37 ++ 9 files changed, 553 insertions(+), 2 deletions(-) create mode 100644 drivers/pps/generators/pps_gen.c create mode 100644 drivers/pps/generators/sysfs.c create mode 100644 include/linux/pps_gen_kernel.h create mode 100644 include/uapi/linux/pps_gen.h diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documenta= tion/userspace-api/ioctl/ioctl-number.rst index e4be1378ba26..e4f7f798f091 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -283,6 +283,7 @@ Code Seq# Include File = Comments 'p' 80-9F linux/ppdev.h user-= space parport 'p' A1-A5 linux/pps.h Linux= PPS +'p' B1-B3 linux/pps-gen.h Linux= PPS 'q' 00-1F linux/serio.h 'q' 80-FF linux/telephony.h Inter= net PhoneJACK, Internet LineJACK diff --git a/MAINTAINERS b/MAINTAINERS index a097afd76ded..63871eb816eb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18536,6 +18536,7 @@ F: Documentation/devicetree/bindings/pps/pps-gpio.y= aml F: Documentation/driver-api/pps.rst F: drivers/pps/ F: include/linux/pps*.h +F: include/uapi/linux/pps-gen.h F: include/uapi/linux/pps.h =20 PPTP DRIVER 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 :=3D pps.o kapi.o sysfs.o pps_core-$(CONFIG_NTP_PPS) +=3D kc.o obj-$(CONFIG_PPS) :=3D pps_core.o -obj-y +=3D clients/ generators/ +obj-y +=3D clients/ +obj-$(CONFIG_PPS_GENERATOR) +=3D generators/ =20 ccflags-$(CONFIG_PPS_DEBUG) :=3D -DDEBUG diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig index d615e640fcad..5edbfdb8bd92 100644 --- a/drivers/pps/generators/Kconfig +++ b/drivers/pps/generators/Kconfig @@ -3,7 +3,16 @@ # PPS generators configuration # =20 -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.ko. + +if PPS_GENERATOR =20 config PPS_GENERATOR_PARPORT tristate "Parallel port PPS signal generator" @@ -12,3 +21,5 @@ 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/Makef= ile index 2589fd0f2481..034a78edfa26 100644 --- a/drivers/pps/generators/Makefile +++ b/drivers/pps/generators/Makefile @@ -3,6 +3,9 @@ # Makefile for PPS generators. # =20 +pps_gen_core-y :=3D pps_gen.o sysfs.o +obj-$(CONFIG_PPS_GENERATOR) :=3D pps_gen_core.o + obj-$(CONFIG_PPS_GENERATOR_PARPORT) +=3D pps_gen_parport.o =20 ccflags-$(CONFIG_PPS_DEBUG) :=3D -DDEBUG 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 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * 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 =3D 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 =3D 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 =3D file->private_data; + void __user *uarg =3D (void __user *) arg; + unsigned int __user *uiuarg =3D (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 =3D get_user(status, uiuarg); + if (ret) + return -EFAULT; + + ret =3D pps_gen->info.enable(pps_gen, status); + if (ret) + return ret; + pps_gen->enabled =3D status; + + break; + + case PPS_GEN_USESYSTEMCLOCK: + dev_dbg(pps_gen->dev, "PPS_GEN_USESYSTEMCLOCK\n"); + + ret =3D 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 =3D pps_gen->last_ev; + + dev_dbg(pps_gen->dev, "PPS_GEN_FETCHEVENT\n"); + + ret =3D wait_event_interruptible(pps_gen->queue, + ev !=3D pps_gen->last_ev); + if (ret =3D=3D -ERESTARTSYS) { + dev_dbg(pps_gen->dev, "pending signal caught\n"); + return -EINTR; + } + + spin_lock_irq(&pps_gen->lock); + info.sequence =3D pps_gen->sequence; + info.event =3D pps_gen->event; + spin_unlock_irq(&pps_gen->lock); + + ret =3D 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 =3D container_of(inode->i_cdev, + struct pps_gen_device, cdev); + + get_device(pps_gen->dev); + file->private_data =3D pps_gen; + return 0; +} + +static int pps_gen_cdev_release(struct inode *inode, struct file *file) +{ + struct pps_gen_device *pps_gen =3D file->private_data; + + put_device(pps_gen->dev); + return 0; +} + +/* + * Char device stuff + */ + +static const struct file_operations pps_gen_cdev_fops =3D { + .owner =3D THIS_MODULE, + .poll =3D pps_gen_cdev_poll, + .fasync =3D pps_gen_cdev_fasync, + .unlocked_ioctl =3D pps_gen_cdev_ioctl, + .open =3D pps_gen_cdev_open, + .release =3D pps_gen_cdev_release, +}; + +static void pps_gen_device_destruct(struct device *dev) +{ + struct pps_gen_device *pps_gen =3D 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 =3D ida_alloc_max(&pps_gen_ida, PPS_GEN_MAX_SOURCES - 1, GFP_KERNEL); + if (err < 0) { + if (err =3D=3D -ENOSPC) { + pr_err("too many PPS sources in the system\n"); + err =3D -EBUSY; + } + return err; + } + pps_gen->id =3D err; + + devt =3D MKDEV(MAJOR(pps_gen_devt), pps_gen->id); + + cdev_init(&pps_gen->cdev, &pps_gen_cdev_fops); + pps_gen->cdev.owner =3D pps_gen->info.owner; + + err =3D 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 =3D 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 =3D PTR_ERR(pps_gen->dev); + goto del_cdev; + } + pps_gen->dev->release =3D 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 =3D kzalloc(sizeof(struct pps_gen_device), GFP_KERNEL); + if (pps_gen =3D=3D NULL) { + err =3D -ENOMEM; + goto pps_gen_register_source_exit; + } + pps_gen->info =3D *info; + pps_gen->enabled =3D false; + + init_waitqueue_head(&pps_gen->queue); + spin_lock_init(&pps_gen->lock); + + /* Create the char device */ + err =3D 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. Wh= en + * 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 =3D 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 =3D 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 =3D pps_gen_groups; + + err =3D 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 "); +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 + */ + +#include +#include +#include +#include + +/* + * Attribute functions + */ + +static ssize_t system_show(struct device *dev, struct device_attribute *at= tr, + char *buf) +{ + struct pps_gen_device *pps_gen =3D 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 =3D dev_get_drvdata(dev); + struct timespec64 time; + int ret; + + ret =3D 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 *a= ttr, + const char *buf, size_t count) +{ + struct pps_gen_device *pps_gen =3D dev_get_drvdata(dev); + bool status; + int ret; + + ret =3D kstrtobool(buf, &status); + if (ret) + return ret; + + ret =3D pps_gen->info.enable(pps_gen, status); + if (ret) + return ret; + pps_gen->enabled =3D status; + + return count; +} +static DEVICE_ATTR_WO(enable); + +static struct attribute *pps_gen_attrs[] =3D { + &dev_attr_enable.attr, + &dev_attr_time.attr, + &dev_attr_system.attr, + NULL, +}; + +static const struct attribute_group pps_gen_group =3D { + .attrs =3D pps_gen_attrs, +}; + +const struct attribute_group *pps_gen_groups[] =3D { + &pps_gen_group, + NULL, +}; diff --git a/include/linux/pps_gen_kernel.h b/include/linux/pps_gen_kernel.h new file mode 100644 index 000000000000..022ea0ac4440 --- /dev/null +++ b/include/linux/pps_gen_kernel.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * PPS generator API kernel header + * + * Copyright (C) 2024 Rodolfo Giometti + */ + +#ifndef LINUX_PPS_GEN_KERNEL_H +#define LINUX_PPS_GEN_KERNEL_H + +#include +#include +#include + +/* + * Global defines + */ + +#define PPS_GEN_MAX_SOURCES 16 /* should be enough... */ + +struct pps_gen_device; + +/** + * struct pps_gen_source_info - the specific PPS generator info + * @use_system_clock: true, if the system clock is used to generate pulses + * @get_time: query the time stored into the generator clock + * @enable: enable/disable the PPS pulses generation + * + * This is the main generator struct where all needed information must be + * placed before calling the pps_gen_register_source(). + */ +struct pps_gen_source_info { + bool use_system_clock; + + int (*get_time)(struct pps_gen_device *pps_gen, + struct timespec64 *time); + int (*enable)(struct pps_gen_device *pps_gen, bool enable); + +/* private: internal use only */ + struct module *owner; + struct device *parent; /* for device_create */ +}; + +/* The main struct */ +struct pps_gen_device { + struct pps_gen_source_info info; /* PSS generator info */ + bool enabled; /* PSS generator status */ + + unsigned int event; + unsigned int sequence; + + unsigned int last_ev; /* last PPS event id */ + wait_queue_head_t queue; /* PPS event queue */ + + unsigned int id; /* PPS generator unique ID */ + struct cdev cdev; + struct device *dev; + struct fasync_struct *async_queue; /* fasync method */ + spinlock_t lock; +}; + +/* + * Global variables + */ + +extern const struct attribute_group *pps_gen_groups[]; + +/* + * Exported functions + */ + +extern struct pps_gen_device *pps_gen_register_source( + struct pps_gen_source_info *info); +extern void pps_gen_unregister_source(struct pps_gen_device *pps_gen); +extern void pps_gen_event(struct pps_gen_device *pps_gen, + unsigned int event, void *data); + +#endif /* LINUX_PPS_GEN_KERNEL_H */ diff --git a/include/uapi/linux/pps_gen.h b/include/uapi/linux/pps_gen.h new file mode 100644 index 000000000000..60a5d0fcfa68 --- /dev/null +++ b/include/uapi/linux/pps_gen.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * PPS generator API header + * + * Copyright (C) 2024 Rodolfo Giometti + */ + +#ifndef _PPS_GEN_H_ +#define _PPS_GEN_H_ + +#include +#include + +/** + * struct pps_gen_event - the PPS generator events + * @event: the event type + * @sequence: the event sequence number + * + * Userspace can get the last PPS generator event by using the + * ioctl(pps_gen, PPS_GEN_FETCHEVENT, ...) syscall. + * The sequence field can be used to save the last event ID, while in the + * event field is stored the last event type. Currently known event is: + * + * PPS_GEN_EVENT_MISSEDPULSE : last pulse was not generated + */ +struct pps_gen_event { + unsigned int event; + unsigned int sequence; +}; + +#define PPS_GEN_EVENT_MISSEDPULSE 1 + +#define PPS_GEN_SETENABLE _IOW('p', 0xb1, unsigned int *) +#define PPS_GEN_USESYSTEMCLOCK _IOR('p', 0xb2, unsigned int *) +#define PPS_GEN_FETCHEVENT _IOR('p', 0xb3, struct pps_gen_event *) + +#endif /* _PPS_GEN_H_ */ --=20 2.34.1 From nobody Sun Nov 24 23:35:23 2024 Received: from smtpcmd15176.aruba.it (smtpcmd15176.aruba.it [62.149.156.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9162A1974F4 for ; Thu, 31 Oct 2024 16:38:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.156.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392704; cv=none; b=APxLKVjIW2K51SXuxvhphULgugORHVeLhlMo4rywwEEjKq23j0xxmGpQXdvxzFK/XretHO5N516BDrCNrCkYg9RMBGkf8St/or0EElSR6T7Y1kXhBpu1nchhsTBrIvu8h6KJWychWJMweY+pyPJ6D5TfcYWAyF0re6L7s60mk0U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392704; c=relaxed/simple; bh=5IQJhOIfU2KprQEe0yBeY1XeFR4R80mFeIeQJwMngZI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=NRcYPd0rzvPVDFiJMgaD64HXVl+GHu3N551F8f9ovowo4wekyMbLWgfybk365BfX1mXbnCOFt1A3lHMrWPIppYsS7KScsgJt7qbNSJSG9ecaeP2LQjvmnkMeTgylNZkcIWnSRjTIDO1B83ZRPZE/oOZMI0vpyxYaGZY11J88a68= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com; spf=pass smtp.mailfrom=enneenne.com; dkim=temperror (0-bit key) header.d=aruba.it header.i=@aruba.it header.b=Qx+RlTjx; arc=none smtp.client-ip=62.149.156.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enneenne.com Authentication-Results: smtp.subspace.kernel.org; dkim=temperror (0-bit key) header.d=aruba.it header.i=@aruba.it header.b="Qx+RlTjx" Received: from polimar.everex.local ([79.0.204.227]) by Aruba Outgoing Smtp with ESMTPSA id 6Y8atb5dFqJRS6Y8dtNuHf; Thu, 31 Oct 2024 17:35:12 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1730392512; bh=5IQJhOIfU2KprQEe0yBeY1XeFR4R80mFeIeQJwMngZI=; h=From:To:Subject:Date:MIME-Version; b=Qx+RlTjxmlHSQWs5u7S0Ia577Z48+ZVb3Bv3A+wuwz1acA78LUJpqIqyO5Qt1lGPL 2ore0wUdBinWbvO5bCWNqC38mswKsDtN0pRnJmzmpKJQmpdZ530RXZm38zv11oPIsu /G8UaRZl27P3V74rUPeFDFjDfCDKrL8WzCfBj+ccEOBPn6YVY7sNxU6UtOif04u3cI m7+QNR4PEMwgr0zYI7JDuf4fbhAQEqjMaebN84K0Us/DWmBlfuNk09v/6gE7Cv/00J o4d6WBmtBVkolKI5WcXV+k4l1jed6ldH2lYcdGfrr7WedWLdXPqpDmuVEJzP4uRZFf 3AxZESP30fVfQ== From: Rodolfo Giometti To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Greg KH , corbet@lwn.net, Hall Christopher S , Mohan Subramanian , tglx@linutronix.de, Andy Shevchenko , Dong Eddie , N Pandith , T R Thejesh Reddy , Zage David , Chinnadurai Srinivasan , Randy Dunlap , Rodolfo Giometti Subject: [V2 2/4] drivers pps/generators: add dummy PPS generator Date: Thu, 31 Oct 2024 17:35:06 +0100 Message-Id: <20241031163508.259522-3-giometti@enneenne.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241031163508.259522-1-giometti@enneenne.com> References: <20241031163508.259522-1-giometti@enneenne.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMAE-Envelope: MS4xfC4xJUzpyCeO512MKewBUXNC4nAmGrgTaZrYRB09ByD5SuetG3jKHT7f5+pLMj3x/nDQx7PZ0NY7Kh6FUgquTM9fs7rlt107VMFkASeI8bDdaPuVagbg s0CZ/4bJTUgvzoajhk4OOsSPNcjk/X0Pj4udoZ1NXVVBqdW+suT6YjOI9qmJYZDZ4Jgk18DKXOIfYHaWjPITDdNDYgL6MLKPuLcuFLsY6fZJQkAF6lVSuyAp crDj6HfPLJO+YNzhokInuNKmoNBpeKTgV+6V3h8ErcugLoTCLKxceqEEnaDssY6/2Tw5nFYGb0DdDct5JMH+ILgmo3QiIMvKCJ6gpR1gsA3FRehLK5+vzSdn Q6p697yL76leu9kKsMpZ+UmdFJVLFpBsEAiri+mZTiw4y91p8yAEy8MggacEerUONWK3I+ODfN1vWlg0QZ6uEoc34/ZOVOHY/VtJGjBmrY68+grEyaMleQxw zvYEJM3GHEKDdTpYcJdGYWnRmCjsxkRPACFx0vh87UUKFpIUaLFeHvE+3vS3jxLsB3r1/l7VfhpxIsUA3ar8rCjLl68cpwZU4Cef0Njt2zUxRU2RWEKxOePO HZyU6oMvz+nqGyftZZQbL8woxAP7LlKgtw/0JS+yA54Ucnc+VVnBcO7XY15uqUB0TZOf4wkJf7xjtKkPvDEevwBE4HEWEXSDiXTJJXSWNtKriaxMPHF5yF5T zigl0OuO8O1mHUXLSuO50dlTWEARQLXe Content-Type: text/plain; charset="utf-8" This dummy PPS generator can be used for debugging and documentation purposes. Signed-off-by: Rodolfo Giometti --- drivers/pps/generators/Kconfig | 9 +++ drivers/pps/generators/Makefile | 1 + drivers/pps/generators/pps_gen-dummy.c | 96 ++++++++++++++++++++++++++ 3 files changed, 106 insertions(+) create mode 100644 drivers/pps/generators/pps_gen-dummy.c diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig index 5edbfdb8bd92..51c05b090d94 100644 --- a/drivers/pps/generators/Kconfig +++ b/drivers/pps/generators/Kconfig @@ -14,6 +14,15 @@ menuconfig PPS_GENERATOR =20 if PPS_GENERATOR =20 +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" depends on PARPORT && BROKEN diff --git a/drivers/pps/generators/Makefile b/drivers/pps/generators/Makef= ile index 034a78edfa26..dc1aa5a4688b 100644 --- a/drivers/pps/generators/Makefile +++ b/drivers/pps/generators/Makefile @@ -6,6 +6,7 @@ pps_gen_core-y :=3D pps_gen.o sysfs.o obj-$(CONFIG_PPS_GENERATOR) :=3D pps_gen_core.o =20 +obj-$(CONFIG_PPS_GENERATOR_DUMMY) +=3D pps_gen-dummy.o obj-$(CONFIG_PPS_GENERATOR_PARPORT) +=3D pps_gen_parport.o =20 ccflags-$(CONFIG_PPS_DEBUG) :=3D -DDEBUG diff --git a/drivers/pps/generators/pps_gen-dummy.c b/drivers/pps/generator= s/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 + */ + +#include +#include +#include +#include +#include +#include +#include + +static struct pps_gen_device *pps_gen; +static struct timer_list ktimer; + +static unsigned int get_random_delay(void) +{ + unsigned int delay =3D 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 =3D ktime_to_timespec64(snap.real); + + return 0; +} + +static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enabl= e) +{ + 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 =3D { + .use_system_clock =3D true, + .get_time =3D pps_gen_dummy_get_time, + .enable =3D 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 =3D 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 "); +MODULE_DESCRIPTION("LinuxPPS dummy generator"); +MODULE_LICENSE("GPL"); --=20 2.34.1 From nobody Sun Nov 24 23:35:23 2024 Received: from smtpcmd15176.aruba.it (smtpcmd15176.aruba.it [62.149.156.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1613B1BC092 for ; Thu, 31 Oct 2024 16:38:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.156.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392705; cv=none; b=V0I/ziu8KRJvYkLhGaB3/VQpwX9MGf43OKacDtEXReZqXUjMSx1lS9XW+/WUN3wVZeGUL+kLeDjfFy7Qfk0S/vxNyJWJWvRxel8K7PNdzWzMNmIS2kGiEU6Y4ij2LTnssYAaTVItNr+evebyy/jRMokwLo7z10LqZGQqONGjFXA= ARC-Message-Signature: i=1; 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Thu, 31 Oct 2024 17:35:12 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1730392512; bh=VFMn6ViOGXV/RBm2wpEduDTGHwJW7KOXv7vL9E399kg=; h=From:To:Subject:Date:MIME-Version; b=PP3IWnShM85Pc794Fy9G7m5usfsR7PN3DslIheGNAhAKkxSj8HIEIwiIidtSJqVSH oJz+wiUsS1BBqp6kJQnpfRuUdAc1EzdvRkC1eTTTMzeOZHwuRpkXDuL1lkiQT+E+wP j9DFS3nPh3YPcQbyNsq/q4mb/l4MamBBLwKGGCD/dIoStB15PrU9dweuftXD30533X 8UtLkcMavTHFBnclaZxwiMS6dzCxjiy4WbQg4HS1cwReUh2MnSFXWUXCpyob/mlFWR Z4pngbdg5gsxfUaXnGcUpWCYtzJC11zhPu+UBZPKc/fYBqrNf3hGk2I/SM6fdXHwC/ +0+KQ99UrIJ5A== From: Rodolfo Giometti To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Greg KH , corbet@lwn.net, Hall Christopher S , Mohan Subramanian , tglx@linutronix.de, Andy Shevchenko , Dong Eddie , N Pandith , T R Thejesh Reddy , Zage David , Chinnadurai Srinivasan , Randy Dunlap , Rodolfo Giometti Subject: [V2 3/4] Documentation pps.rst: add PPS generators documentation Date: Thu, 31 Oct 2024 17:35:07 +0100 Message-Id: <20241031163508.259522-4-giometti@enneenne.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241031163508.259522-1-giometti@enneenne.com> References: <20241031163508.259522-1-giometti@enneenne.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMAE-Envelope: MS4xfC4xJUzpyCeO512MKewBUXNC4nAmGrgTaZrYRB09ByD5SuetG3jKHT7f5+pLMj3x/nDQx7PZ0NY7Kh6FUgquTM9fs7rlt107VMFkASeI8bDdaPuVagbg s0CZ/4bJTUgvzoajhk4OOsSPNcjk/X0Pj4udoZ1NXVVBqdW+suT6YjOI9qmJYZDZ4Jgk18DKXOIfYHaWjPITDdNDYgL6MLKPuLcuFLsY6fZJQkAF6lVSuyAp crDj6HfPLJO+YNzhokInuNKmoNBpeKTgV+6V3h8ErcugLoTCLKxceqEEnaDssY6/2Tw5nFYGb0DdDct5JMH+ILgmo3QiIMvKCJ6gpR1gsA3FRehLK5+vzSdn Q6p697yL76leu9kKsMpZ+UmdFJVLFpBsEAiri+mZTiw4y91p8yAEy8MggacEerUONWK3I+ODfN1vWlg0QZ6uEoc34/ZOVOHY/VtJGjBmrY68+grEyaMleQxw zvYEJM3GHEKDdTpYcJdGYWnRmCjsxkRPACFx0vh87UUKFpIUaLFeHvE+3vS3jxLsB3r1/l7VfhpxIsUA3ar8rCjLl68cpwZU4Cef0Njt2zUxRU2RWEKxOePO HZyU6oMvz+nqGyftZZQbL8woxAP7LlKgtw/0JS+yA54Ucnc+VVnBcO7XY15uqUB0TZOf4wkJf7xjtKkPvDEevwBE4HEWEXSDiXTJJXSWNtKriaxMPHF5yF5T zigl0OuO8O1mHUXLSuO50dlTWEARQLXe Content-Type: text/plain; charset="utf-8" This patch adds some examples about how to register a new PPS generator in the system, and how to manage it. Signed-off-by: Rodolfo Giometti --- Documentation/driver-api/pps.rst | 40 ++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/Documentation/driver-api/pps.rst b/Documentation/driver-api/pp= s.rst index 78dded03e5d8..dffa06ed919f 100644 --- a/Documentation/driver-api/pps.rst +++ b/Documentation/driver-api/pps.rst @@ -202,6 +202,46 @@ Sometimes one needs to be able not only to catch PPS s= ignals but to produce them also. For example, running a distributed simulation, which requires computers' clock to be synchronized very tightly. =20 +To do so the class pps-gen has been added. PPS generators can be +registered in the kernel by defining a struct pps_gen_source_info as +follows:: + + static struct pps_gen_source_info pps_gen_dummy_info =3D { + .name =3D "dummy", + .use_system_clock =3D true, + .get_time =3D pps_gen_dummy_get_time, + .enable =3D pps_gen_dummy_enable, + }; + +Where the use_system_clock states if the generator uses the system +clock to generate its pulses, or from a peripheral device +clock. Method get_time() is used to query the time stored into the +generator clock, while the method enable() is used to enable or +disable the PPS pulse generation. + +Then calling the function pps_gen_register_source() in your +initialization routine as follows creates a new generator in the +system:: + + pps_gen =3D pps_gen_register_source(&pps_gen_dummy_info); + +Generators SYSFS support +------------------------ + +If the SYSFS filesystem is enabled in the kernel it provides a new class:: + + $ ls /sys/class/pps-gen/ + pps-gen0/ pps-gen1/ pps-gen2/ + +Every directory is the ID of a PPS generator defined in the system and +inside you find several files:: + + $ ls -F /sys/class/pps-gen/pps-gen0/ + dev enable name power/ subsystem@ system time uevent + +To enable the PPS signal generation you can use the command below:: + + $ echo 1 > /sys/class/pps-gen/pps-gen0/enable =20 Parallel port generator ------------------------ --=20 2.34.1 From nobody Sun Nov 24 23:35:23 2024 Received: from smtpcmd15176.aruba.it (smtpcmd15176.aruba.it [62.149.156.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8BD31BC07D for ; 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arc=none smtp.client-ip=62.149.156.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enneenne.com Authentication-Results: smtp.subspace.kernel.org; dkim=temperror (0-bit key) header.d=aruba.it header.i=@aruba.it header.b="WfGYJXTP" Received: from polimar.everex.local ([79.0.204.227]) by Aruba Outgoing Smtp with ESMTPSA id 6Y8atb5dFqJRS6Y8etNuId; Thu, 31 Oct 2024 17:35:13 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1730392513; bh=gTLrUi+ogGOSBZjhzxkPXbV+MjJz+x1w78sA14AoOAM=; h=From:To:Subject:Date:MIME-Version; b=WfGYJXTPSxrAUzlYPckcXdb3KYzMYApZzbnDFq1DbOKyzwqtqGEDdT5HFia3MQECE qe+Qzo6GYg7KSRR8DljHmGd/+YdQqK23QiKTwHe4PhAu6dr7gk5bb/+xQULnia2P0r hUeb29DM3eFkHCbFSXt7IWzB6eg+xgfRLb8MJSI56K3dh3+p0ZHorG4R940kHEca1m g4YQ3eeQix/KHGQvG9+uSsuzueqqtyGtnNhGTwvDi6dl4h9+AmhD7se2ChRkhggVZ/ etGsM5wYZJi+fugfDzeAlXnzwMcVz1HOuuvsW2Gk4xtPHTFPFjQT8LgDpXUlzLWfe5 Wqqh6xDwK7J4w== From: Rodolfo Giometti To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Greg KH , corbet@lwn.net, Hall Christopher S , Mohan Subramanian , tglx@linutronix.de, Andy Shevchenko , Dong Eddie , N Pandith , T R Thejesh Reddy , Zage David , Chinnadurai Srinivasan , Randy Dunlap , Rodolfo Giometti Subject: [V2 4/4] Documentation ABI: add PPS generators documentation Date: Thu, 31 Oct 2024 17:35:08 +0100 Message-Id: <20241031163508.259522-5-giometti@enneenne.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241031163508.259522-1-giometti@enneenne.com> References: <20241031163508.259522-1-giometti@enneenne.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMAE-Envelope: MS4xfNhVFdCIMPZv4rJQzhVFX9H/8YBNU08/9vZg6hF6quaO1eE2OdPxa5VADHxuLCumXOV3o4UFolahD17uxS4sUes1ubmxYIUk7zbKUg0Q+x3FMW8wFRpO L4N8racZWsKP2tsNLHO+ED4cHYXeRv38d45Bmmy7QEhLPu+EonmztyOW9ghKGuF+/faCR2w8bnZuESScE2Y2l1XiakZOjjTorGt9i89j7J76h8YvbOvIEhBF J7ibHw2cISki4TX2MJ5VkDZV/17TDsjLNclweSLCLl1zY5ivGEc5NNhGP4PyGwd1r7bq8Mm/w/DkIu3Nj12C/jS6Ob/l5qBQZDmrkx4L/AuxZBexw1ZV9jhq UWNj2JXfRaBLZZVPlIYDRAl79n8X9DvZG/y50htuwOVzSHseTvGgxHB0VU7ePbpZUeJmPwyNL7S031xaoFE4Vc4VPo1qFP+iWwv8lr+9sSjapPUq751UJKCX O+qV4KmC+tuVkWlptYNbITew0bAjQNDMNKw3VHDwqqMGKCf5gxpGpCW+re4KP/XBzT5i4dDMrC7+IBdPgE1xUivHXmcuulXVFvu8T/E8ToaZS/bz+s+1WK3K Ps98DQUWEanMc4WlLU5W97kzPEfDiMmcGDseDJDZiEBehB1uqANfe/rVS4un29RIEDSDK89Qg6rq9TvdT9hLi1aKTZzaYBrSZxgOuPdz1zCW8DfK7EGofU8s N8V816dXZDDtDpTUt5y/6CgixI/YHw2g Content-Type: text/plain; charset="utf-8" This patch adds the documentation for the ABI between the Linux kernel and userspace regarding the PPS generators. Signed-off-by: Rodolfo Giometti --- Documentation/ABI/testing/sysfs-pps-gen | 38 +++++++++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 39 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-pps-gen diff --git a/Documentation/ABI/testing/sysfs-pps-gen b/Documentation/ABI/te= sting/sysfs-pps-gen new file mode 100644 index 000000000000..7effe495d062 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-pps-gen @@ -0,0 +1,38 @@ +What: /sys/class/pps-gen/ +Date: February 2025 +Contact: Rodolfo Giometti +Description: + The /sys/class/pps-gen/ directory contains files and + directories that provide a unified interface to the PPS + generators. + +What: /sys/class/pps-gen/pps-genX/ +Date: February 2025 +Contact: Rodolfo Giometti +Description: + The /sys/class/pps-gen/pps-genX/ directory is related to X-th + PPS generator in the system. Each directory contain files to + manage and control its PPS generator. + +What: /sys/class/pps-gen/pps-genX/enable +Date: February 2025 +Contact: Rodolfo Giometti +Description: + This write-only file enables or disables generation of the + PPS signal. + +What: /sys/class/pps-gen/pps-genX/system +Date: February 2025 +Contact: Rodolfo Giometti +Description: + This read-only file returns "1" if the generator takes the + timing from the system clock, while it returns "0" if not + (i.e. from a peripheral device clock). + +What: /sys/class/pps-gen/pps-genX/time +Date: February 2025 +Contact: Rodolfo Giometti +Description: + This read-only file contains the current time stored into the + generator clock as two integers representing the current time + seconds and nanoseconds. diff --git a/MAINTAINERS b/MAINTAINERS index 63871eb816eb..d0b628c973f7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18532,6 +18532,7 @@ L: linuxpps@ml.enneenne.com (subscribers-only) S: Maintained W: http://wiki.enneenne.com/index.php/LinuxPPS_support F: Documentation/ABI/testing/sysfs-pps +F: Documentation/ABI/testing/sysfs-pps-gen F: Documentation/devicetree/bindings/pps/pps-gpio.yaml F: Documentation/driver-api/pps.rst F: drivers/pps/ --=20 2.34.1