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ptp: Added a brand new class driver for ptp clocks.

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This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.

The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Richard Cochran 2011-04-22 12:03:08 +02:00 • committed by John Stultz
parent caebc160ce
commit d94ba80ebb
16 changed files with 1695 additions and 0 deletions
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139
include/linux/ptp_clock_kernel.h Normal file
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/*
* PTP 1588 clock support
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _PTP_CLOCK_KERNEL_H_
#define _PTP_CLOCK_KERNEL_H_
#include <linux/ptp_clock.h>
struct ptp_clock_request {
enum {
PTP_CLK_REQ_EXTTS,
PTP_CLK_REQ_PEROUT,
PTP_CLK_REQ_PPS,
} type;
union {
struct ptp_extts_request extts;
struct ptp_perout_request perout;
};
};
/**
* struct ptp_clock_info - decribes a PTP hardware clock
*
* @owner: The clock driver should set to THIS_MODULE.
* @name: A short name to identify the clock.
* @max_adj: The maximum possible frequency adjustment, in parts per billon.
* @n_alarm: The number of programmable alarms.
* @n_ext_ts: The number of external time stamp channels.
* @n_per_out: The number of programmable periodic signals.
* @pps: Indicates whether the clock supports a PPS callback.
*
* clock operations
*
* @adjfreq: Adjusts the frequency of the hardware clock.
* parameter delta: Desired period change in parts per billion.
*
* @adjtime: Shifts the time of the hardware clock.
* parameter delta: Desired change in nanoseconds.
*
* @gettime: Reads the current time from the hardware clock.
* parameter ts: Holds the result.
*
* @settime: Set the current time on the hardware clock.
* parameter ts: Time value to set.
*
* @enable: Request driver to enable or disable an ancillary feature.
* parameter request: Desired resource to enable or disable.
* parameter on: Caller passes one to enable or zero to disable.
*
* Drivers should embed their ptp_clock_info within a private
* structure, obtaining a reference to it using container_of().
*
* The callbacks must all return zero on success, non-zero otherwise.
*/
struct ptp_clock_info {
struct module *owner;
char name[16];
s32 max_adj;
int n_alarm;
int n_ext_ts;
int n_per_out;
int pps;
int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
int (*gettime)(struct ptp_clock_info *ptp, struct timespec *ts);
int (*settime)(struct ptp_clock_info *ptp, const struct timespec *ts);
int (*enable)(struct ptp_clock_info *ptp,
struct ptp_clock_request *request, int on);
};
struct ptp_clock;
/**
* ptp_clock_register() - register a PTP hardware clock driver
*
* @info: Structure describing the new clock.
*/
extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info);
/**
* ptp_clock_unregister() - unregister a PTP hardware clock driver
*
* @ptp: The clock to remove from service.
*/
extern int ptp_clock_unregister(struct ptp_clock *ptp);
enum ptp_clock_events {
PTP_CLOCK_ALARM,
PTP_CLOCK_EXTTS,
PTP_CLOCK_PPS,
};
/**
* struct ptp_clock_event - decribes a PTP hardware clock event
*
* @type: One of the ptp_clock_events enumeration values.
* @index: Identifies the source of the event.
* @timestamp: When the event occured.
*/
struct ptp_clock_event {
int type;
int index;
u64 timestamp;
};
/**
* ptp_clock_event() - notify the PTP layer about an event
*
* @ptp: The clock obtained from ptp_clock_register().
* @event: Message structure describing the event.
*/
extern void ptp_clock_event(struct ptp_clock *ptp,
struct ptp_clock_event *event);
#endif