pps_gen_kernel.h

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * PPS generator API kernel header
 4 *
 5 * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com>
 6 */
 7
 8#ifndef LINUX_PPS_GEN_KERNEL_H
 9#define LINUX_PPS_GEN_KERNEL_H
10
11#include <linux/pps_gen.h>
12#include <linux/cdev.h>
13#include <linux/device.h>
14
15/*
16 * Global defines
17 */
18
19#define PPS_GEN_MAX_SOURCES	16		/* should be enough... */
20
21struct pps_gen_device;
22
23/**
24 * struct pps_gen_source_info - the specific PPS generator info
25 * @use_system_clock: true, if the system clock is used to generate pulses
26 * @get_time: query the time stored into the generator clock
27 * @enable: enable/disable the PPS pulses generation
28 *
29 * This is the main generator struct where all needed information must be
30 * placed before calling the pps_gen_register_source().
31 */
32struct pps_gen_source_info {
33	bool use_system_clock;
34
35	int (*get_time)(struct pps_gen_device *pps_gen,
36					struct timespec64 *time);
37	int (*enable)(struct pps_gen_device *pps_gen, bool enable);
38
39/* private: internal use only */
40	struct module *owner;
41	struct device *parent;			/* for device_create */
42};
43
44/* The main struct */
45struct pps_gen_device {
46	const struct pps_gen_source_info *info;	/* PSS generator info */
47	bool enabled;				/* PSS generator status */
48
49	unsigned int event;
50	unsigned int sequence;
51
52	unsigned int last_ev;			/* last PPS event id */
53	wait_queue_head_t queue;		/* PPS event queue */
54
55	unsigned int id;			/* PPS generator unique ID */
56	struct cdev cdev;
57	struct device *dev;
58	struct fasync_struct *async_queue;	/* fasync method */
59	spinlock_t lock;
60};
61
62/*
63 * Global variables
64 */
65
66extern const struct attribute_group *pps_gen_groups[];
67
68/*
69 * Exported functions
70 */
71
72extern struct pps_gen_device *pps_gen_register_source(
73				const struct pps_gen_source_info *info);
74extern void pps_gen_unregister_source(struct pps_gen_device *pps_gen);
75extern void pps_gen_event(struct pps_gen_device *pps_gen,
76				unsigned int event, void *data);
77
78#endif /* LINUX_PPS_GEN_KERNEL_H */