2019-05-20 03:19:02 -04:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
2011-02-01 08:52:35 -05:00
|
|
|
/*
|
|
|
|
* posix-clock.h - support for dynamic clock devices
|
|
|
|
*
|
|
|
|
* Copyright (C) 2010 OMICRON electronics GmbH
|
|
|
|
*/
|
|
|
|
#ifndef _LINUX_POSIX_CLOCK_H_
|
|
|
|
#define _LINUX_POSIX_CLOCK_H_
|
|
|
|
|
|
|
|
#include <linux/cdev.h>
|
|
|
|
#include <linux/fs.h>
|
|
|
|
#include <linux/poll.h>
|
|
|
|
#include <linux/posix-timers.h>
|
2011-03-30 09:24:21 -04:00
|
|
|
#include <linux/rwsem.h>
|
2011-02-01 08:52:35 -05:00
|
|
|
|
|
|
|
struct posix_clock;
|
2023-10-11 18:39:53 -04:00
|
|
|
struct posix_clock_context;
|
2011-02-01 08:52:35 -05:00
|
|
|
|
|
|
|
/**
|
|
|
|
* struct posix_clock_operations - functional interface to the clock
|
|
|
|
*
|
|
|
|
* Every posix clock is represented by a character device. Drivers may
|
|
|
|
* optionally offer extended capabilities by implementing the
|
|
|
|
* character device methods. The character device file operations are
|
|
|
|
* first handled by the clock device layer, then passed on to the
|
|
|
|
* driver by calling these functions.
|
|
|
|
*
|
|
|
|
* @owner: The clock driver should set to THIS_MODULE
|
|
|
|
* @clock_adjtime: Adjust the clock
|
|
|
|
* @clock_gettime: Read the current time
|
|
|
|
* @clock_getres: Get the clock resolution
|
|
|
|
* @clock_settime: Set the current time value
|
|
|
|
* @open: Optional character device open method
|
|
|
|
* @release: Optional character device release method
|
|
|
|
* @ioctl: Optional character device ioctl method
|
|
|
|
* @read: Optional character device read method
|
|
|
|
* @poll: Optional character device poll method
|
|
|
|
*/
|
|
|
|
struct posix_clock_operations {
|
|
|
|
struct module *owner;
|
|
|
|
|
2018-07-03 01:44:21 -04:00
|
|
|
int (*clock_adjtime)(struct posix_clock *pc, struct __kernel_timex *tx);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2017-03-26 15:04:13 -04:00
|
|
|
int (*clock_gettime)(struct posix_clock *pc, struct timespec64 *ts);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2017-03-26 15:04:13 -04:00
|
|
|
int (*clock_getres) (struct posix_clock *pc, struct timespec64 *ts);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
|
|
|
int (*clock_settime)(struct posix_clock *pc,
|
2017-03-26 15:04:13 -04:00
|
|
|
const struct timespec64 *ts);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Optional character device methods:
|
|
|
|
*/
|
2023-10-11 18:39:53 -04:00
|
|
|
long (*ioctl)(struct posix_clock_context *pccontext, unsigned int cmd,
|
|
|
|
unsigned long arg);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2023-10-11 18:39:53 -04:00
|
|
|
int (*open)(struct posix_clock_context *pccontext, fmode_t f_mode);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2023-10-11 18:39:53 -04:00
|
|
|
__poll_t (*poll)(struct posix_clock_context *pccontext, struct file *file,
|
|
|
|
poll_table *wait);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2023-10-11 18:39:53 -04:00
|
|
|
int (*release)(struct posix_clock_context *pccontext);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
2023-10-11 18:39:53 -04:00
|
|
|
ssize_t (*read)(struct posix_clock_context *pccontext, uint flags,
|
|
|
|
char __user *buf, size_t cnt);
|
2011-02-01 08:52:35 -05:00
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
|
|
* struct posix_clock - represents a dynamic posix clock
|
|
|
|
*
|
|
|
|
* @ops: Functional interface to the clock
|
|
|
|
* @cdev: Character device instance for this clock
|
2019-12-26 21:26:27 -05:00
|
|
|
* @dev: Pointer to the clock's device.
|
2011-03-30 09:24:21 -04:00
|
|
|
* @rwsem: Protects the 'zombie' field from concurrent access.
|
2011-02-01 08:52:35 -05:00
|
|
|
* @zombie: If 'zombie' is true, then the hardware has disappeared.
|
|
|
|
*
|
|
|
|
* Drivers should embed their struct posix_clock within a private
|
|
|
|
* structure, obtaining a reference to it during callbacks using
|
|
|
|
* container_of().
|
2019-12-26 21:26:27 -05:00
|
|
|
*
|
|
|
|
* Drivers should supply an initialized but not exposed struct device
|
|
|
|
* to posix_clock_register(). It is used to manage lifetime of the
|
|
|
|
* driver's private structure. It's 'release' field should be set to
|
|
|
|
* a release function for this private structure.
|
2011-02-01 08:52:35 -05:00
|
|
|
*/
|
|
|
|
struct posix_clock {
|
|
|
|
struct posix_clock_operations ops;
|
|
|
|
struct cdev cdev;
|
2019-12-26 21:26:27 -05:00
|
|
|
struct device *dev;
|
2011-03-30 09:24:21 -04:00
|
|
|
struct rw_semaphore rwsem;
|
2011-02-01 08:52:35 -05:00
|
|
|
bool zombie;
|
|
|
|
};
|
|
|
|
|
2023-10-11 18:39:53 -04:00
|
|
|
/**
|
|
|
|
* struct posix_clock_context - represents clock file operations context
|
|
|
|
*
|
|
|
|
* @clk: Pointer to the clock
|
|
|
|
* @private_clkdata: Pointer to user data
|
|
|
|
*
|
|
|
|
* Drivers should use struct posix_clock_context during specific character
|
|
|
|
* device file operation methods to access the posix clock.
|
|
|
|
*
|
|
|
|
* Drivers can store a private data structure during the open operation
|
|
|
|
* if they have specific information that is required in other file
|
|
|
|
* operations.
|
|
|
|
*/
|
|
|
|
struct posix_clock_context {
|
|
|
|
struct posix_clock *clk;
|
|
|
|
void *private_clkdata;
|
|
|
|
};
|
|
|
|
|
2011-02-01 08:52:35 -05:00
|
|
|
/**
|
|
|
|
* posix_clock_register() - register a new clock
|
2019-12-26 21:26:27 -05:00
|
|
|
* @clk: Pointer to the clock. Caller must provide 'ops' field
|
|
|
|
* @dev: Pointer to the initialized device. Caller must provide
|
|
|
|
* 'release' field
|
2011-02-01 08:52:35 -05:00
|
|
|
*
|
|
|
|
* A clock driver calls this function to register itself with the
|
|
|
|
* clock device subsystem. If 'clk' points to dynamically allocated
|
|
|
|
* memory, then the caller must provide a 'release' function to free
|
|
|
|
* that memory.
|
|
|
|
*
|
|
|
|
* Returns zero on success, non-zero otherwise.
|
|
|
|
*/
|
2019-12-26 21:26:27 -05:00
|
|
|
int posix_clock_register(struct posix_clock *clk, struct device *dev);
|
2011-02-01 08:52:35 -05:00
|
|
|
|
|
|
|
/**
|
|
|
|
* posix_clock_unregister() - unregister a clock
|
|
|
|
* @clk: Clock instance previously registered via posix_clock_register()
|
|
|
|
*
|
|
|
|
* A clock driver calls this function to remove itself from the clock
|
|
|
|
* device subsystem. The posix_clock itself will remain (in an
|
|
|
|
* inactive state) until its reference count drops to zero, at which
|
|
|
|
* point it will be deallocated with its 'release' method.
|
|
|
|
*/
|
|
|
|
void posix_clock_unregister(struct posix_clock *clk);
|
|
|
|
|
|
|
|
#endif
|