[linux.git] / drivers / pps / kc.c

/*
 * PPS kernel consumer API
 *
 * Copyright (C) 2009-2010   Alexander Gordeev <[email protected]>
 *
 *   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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/pps_kernel.h>

#include "kc.h"

/*
 * Global variables
 */

/* state variables to bind kernel consumer */
DEFINE_SPINLOCK(pps_kc_hardpps_lock);
/* PPS API (RFC 2783): current source and mode for kernel consumer */
struct pps_device *pps_kc_hardpps_dev;	/* unique pointer to device */
int pps_kc_hardpps_mode;		/* mode bits for kernel consumer */

/* pps_kc_bind - control PPS kernel consumer binding
 * @pps: the PPS source
 * @bind_args: kernel consumer bind parameters
 *
 * This function is used to bind or unbind PPS kernel consumer according to
 * supplied parameters. Should not be called in interrupt context.
 */
int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args)
{
	/* Check if another consumer is already bound */
	spin_lock_irq(&pps_kc_hardpps_lock);

	if (bind_args->edge == 0)
		if (pps_kc_hardpps_dev == pps) {
			pps_kc_hardpps_mode = 0;
			pps_kc_hardpps_dev = NULL;
			spin_unlock_irq(&pps_kc_hardpps_lock);
			dev_info(pps->dev, "unbound kernel"
					" consumer\n");
		} else {
			spin_unlock_irq(&pps_kc_hardpps_lock);
			dev_err(pps->dev, "selected kernel consumer"
					" is not bound\n");
			return -EINVAL;
		}
	else
		if (pps_kc_hardpps_dev == NULL ||
				pps_kc_hardpps_dev == pps) {
			pps_kc_hardpps_mode = bind_args->edge;
			pps_kc_hardpps_dev = pps;
			spin_unlock_irq(&pps_kc_hardpps_lock);
			dev_info(pps->dev, "bound kernel consumer: "
				"edge=0x%x\n", bind_args->edge);
		} else {
			spin_unlock_irq(&pps_kc_hardpps_lock);
			dev_err(pps->dev, "another kernel consumer"
					" is already bound\n");
			return -EINVAL;
		}

	return 0;
}

/* pps_kc_remove - unbind kernel consumer on PPS source removal
 * @pps: the PPS source
 *
 * This function is used to disable kernel consumer on PPS source removal
 * if this source was bound to PPS kernel consumer. Can be called on any
 * source safely. Should not be called in interrupt context.
 */
void pps_kc_remove(struct pps_device *pps)
{
	spin_lock_irq(&pps_kc_hardpps_lock);
	if (pps == pps_kc_hardpps_dev) {
		pps_kc_hardpps_mode = 0;
		pps_kc_hardpps_dev = NULL;
		spin_unlock_irq(&pps_kc_hardpps_lock);
		dev_info(pps->dev, "unbound kernel consumer"
				" on device removal\n");
	} else
		spin_unlock_irq(&pps_kc_hardpps_lock);
}

/* pps_kc_event - call hardpps() on PPS event
 * @pps: the PPS source
 * @ts: PPS event timestamp
 * @event: PPS event edge
 *
 * This function calls hardpps() when an event from bound PPS source occurs.
 */
void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts,
		int event)
{
	unsigned long flags;

	/* Pass some events to kernel consumer if activated */
	spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
	if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
		hardpps(&ts->ts_real, &ts->ts_raw);
	spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
}
Commit	Line	Data
717c0336 AG	1	/*
	2	* PPS kernel consumer API
	3	*
	4	* Copyright (C) 2009-2010 Alexander Gordeev <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
	21	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	22
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/device.h>
	26	#include <linux/init.h>
	27	#include <linux/spinlock.h>
	28	#include <linux/pps_kernel.h>
	29
	30	#include "kc.h"
	31
	32	/*
	33	* Global variables
	34	*/
	35
	36	/* state variables to bind kernel consumer */
	37	DEFINE_SPINLOCK(pps_kc_hardpps_lock);
	38	/* PPS API (RFC 2783): current source and mode for kernel consumer */
	39	struct pps_device pps_kc_hardpps_dev; / unique pointer to device */
	40	int pps_kc_hardpps_mode; /* mode bits for kernel consumer */
	41
	42	/* pps_kc_bind - control PPS kernel consumer binding
	43	* @pps: the PPS source
	44	* @bind_args: kernel consumer bind parameters
	45	*
	46	* This function is used to bind or unbind PPS kernel consumer according to
	47	* supplied parameters. Should not be called in interrupt context.
	48	*/
	49	int pps_kc_bind(struct pps_device pps, struct pps_bind_args bind_args)
	50	{
	51	/* Check if another consumer is already bound */
	52	spin_lock_irq(&pps_kc_hardpps_lock);
	53
	54	if (bind_args->edge == 0)
	55	if (pps_kc_hardpps_dev == pps) {
	56	pps_kc_hardpps_mode = 0;
	57	pps_kc_hardpps_dev = NULL;
	58	spin_unlock_irq(&pps_kc_hardpps_lock);
	59	dev_info(pps->dev, "unbound kernel"
	60	" consumer\n");
	61	} else {
	62	spin_unlock_irq(&pps_kc_hardpps_lock);
	63	dev_err(pps->dev, "selected kernel consumer"
	64	" is not bound\n");
65	return -EINVAL;
66	}
67	else
68	if (pps_kc_hardpps_dev == NULL \|\|
69	pps_kc_hardpps_dev == pps) {
70	pps_kc_hardpps_mode = bind_args->edge;
71	pps_kc_hardpps_dev = pps;
72	spin_unlock_irq(&pps_kc_hardpps_lock);
73	dev_info(pps->dev, "bound kernel consumer: "
74	"edge=0x%x\n", bind_args->edge);
75	} else {
76	spin_unlock_irq(&pps_kc_hardpps_lock);
77	dev_err(pps->dev, "another kernel consumer"
78	" is already bound\n");
79	return -EINVAL;
80	}
81
82	return 0;
83	}
84
85	/* pps_kc_remove - unbind kernel consumer on PPS source removal
86	* @pps: the PPS source
87	*
88	* This function is used to disable kernel consumer on PPS source removal
89	* if this source was bound to PPS kernel consumer. Can be called on any
90	* source safely. Should not be called in interrupt context.
91	*/
92	void pps_kc_remove(struct pps_device *pps)
93	{
94	spin_lock_irq(&pps_kc_hardpps_lock);
95	if (pps == pps_kc_hardpps_dev) {
96	pps_kc_hardpps_mode = 0;
97	pps_kc_hardpps_dev = NULL;
98	spin_unlock_irq(&pps_kc_hardpps_lock);
99	dev_info(pps->dev, "unbound kernel consumer"
100	" on device removal\n");
101	} else
102	spin_unlock_irq(&pps_kc_hardpps_lock);
103	}
104
105	/* pps_kc_event - call hardpps() on PPS event
106	* @pps: the PPS source
107	* @ts: PPS event timestamp
108	* @event: PPS event edge
109	*
110	* This function calls hardpps() when an event from bound PPS source occurs.
111	*/
112	void pps_kc_event(struct pps_device pps, struct pps_event_time ts,
113	int event)
114	{
115	unsigned long flags;
116
117	/* Pass some events to kernel consumer if activated */
118	spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
119	if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
120	hardpps(&ts->ts_real, &ts->ts_raw);
121	spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
122	}