include/linux/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
  21 struct 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  */
  32 struct 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 */
  45 struct pps_gen_device {
  46         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
  66 extern const struct attribute_group *pps_gen_groups[];
  67
  68 /*
  69  * Exported functions
  70  */
  71
  72 extern struct pps_gen_device *pps_gen_register_source(
  73                                 struct pps_gen_source_info *info);
  74 extern void pps_gen_unregister_source(struct pps_gen_device *pps_gen);
  75 extern void pps_gen_event(struct pps_gen_device *pps_gen,
  76                                 unsigned int event, void *data);
  77
  78 #endif /* LINUX_PPS_GEN_KERNEL_H */