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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143/* SPDX-License-Identifier: GPL-2.0-or-later *//* * 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>#include <linux/rwsem.h>
struct posix_clock;struct posix_clock_context;
/** * 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;
int (*clock_adjtime)(struct posix_clock *pc, struct __kernel_timex *tx);
int (*clock_gettime)(struct posix_clock *pc, struct timespec64 *ts);
int (*clock_getres) (struct posix_clock *pc, struct timespec64 *ts);
int (*clock_settime)(struct posix_clock *pc, const struct timespec64 *ts);
/* * Optional character device methods: */ long (*ioctl)(struct posix_clock_context *pccontext, unsigned int cmd, unsigned long arg);
int (*open)(struct posix_clock_context *pccontext, fmode_t f_mode);
__poll_t (*poll)(struct posix_clock_context *pccontext, struct file *file, poll_table *wait);
int (*release)(struct posix_clock_context *pccontext);
ssize_t (*read)(struct posix_clock_context *pccontext, uint flags, char __user *buf, size_t cnt);};
/** * struct posix_clock - represents a dynamic posix clock * * @ops: Functional interface to the clock * @cdev: Character device instance for this clock * @dev: Pointer to the clock's device. * @rwsem: Protects the 'zombie' field from concurrent access. * @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(). * * 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. */struct posix_clock { struct posix_clock_operations ops; struct cdev cdev; struct device *dev; struct rw_semaphore rwsem; bool zombie;};
/** * struct posix_clock_context - represents clock file operations context * * @clk: Pointer to the clock * @fp: Pointer to the file used to open 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. In particular, * the file pointer can be used to verify correct access mode for ioctl() * calls. * * 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; struct file *fp; void *private_clkdata;};
/** * posix_clock_register() - register a new clock * @clk: Pointer to the clock. Caller must provide 'ops' field * @dev: Pointer to the initialized device. Caller must provide * 'release' field * * 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. */int posix_clock_register(struct posix_clock *clk, struct device *dev);
/** * 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