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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 <giometti@enneenne.com> Link: https://lore.kernel.org/r/20241108073115.759039-2-giometti@enneenne.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* PPS generators sysfs support
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*
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* Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com>
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/pps_gen_kernel.h>
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/*
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* Attribute functions
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*/
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static ssize_t system_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
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return sysfs_emit(buf, "%d\n", pps_gen->info.use_system_clock);
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}
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static DEVICE_ATTR_RO(system);
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static ssize_t time_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
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struct timespec64 time;
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int ret;
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ret = pps_gen->info.get_time(pps_gen, &time);
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if (ret)
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return ret;
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return sysfs_emit(buf, "%llu %09lu\n", time.tv_sec, time.tv_nsec);
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}
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static DEVICE_ATTR_RO(time);
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static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
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bool status;
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int ret;
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ret = kstrtobool(buf, &status);
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if (ret)
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return ret;
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ret = pps_gen->info.enable(pps_gen, status);
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if (ret)
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return ret;
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pps_gen->enabled = status;
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return count;
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}
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static DEVICE_ATTR_WO(enable);
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static struct attribute *pps_gen_attrs[] = {
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&dev_attr_enable.attr,
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&dev_attr_time.attr,
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&dev_attr_system.attr,
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NULL,
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};
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static const struct attribute_group pps_gen_group = {
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.attrs = pps_gen_attrs,
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};
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const struct attribute_group *pps_gen_groups[] = {
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&pps_gen_group,
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NULL,
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};
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