freebsd-skq/sys/dev/ppbus/pps.c

/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 *
 * $Id: pps.c,v 1.12 1998/12/07 21:58:16 archie Exp $
 *
 * This driver implements a draft-mogul-pps-api-02.txt PPS source.
 *
 * The input pin is pin#10 
 * The echo output pin is pin#14
 *
 */

#include "opt_devfs.h"
#include "opt_ntp.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/timepps.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif
#include <sys/malloc.h>

#include <dev/ppbus/ppbconf.h>
#include "pps.h"

#define PPS_NAME	"lppps"		/* our official name */

static struct pps_data {
	int	pps_unit;
	struct	ppb_device pps_dev;	
	pps_params_t	ppsparam;
	pps_info_t	ppsinfo;
} *softc[NPPS];

static int ppscap =
	PPS_CAPTUREASSERT |
#ifdef PPS_SYNC
	PPS_HARDPPSONASSERT | 
#endif /* PPS_SYNC */
	PPS_OFFSETASSERT | 
	PPS_ECHOASSERT |
	PPS_TSFMT_TSPEC;

static int npps;

/*
 * Make ourselves visible as a ppbus driver
 */

static struct ppb_device	*ppsprobe(struct ppb_data *ppb);
static int			ppsattach(struct ppb_device *dev);
static void			ppsintr(int unit);
static void			pps_drvinit(void *unused);

static struct ppb_driver ppsdriver = {
    ppsprobe, ppsattach, PPS_NAME
};

DATA_SET(ppbdriver_set, ppsdriver);

static	d_open_t	ppsopen;
static	d_close_t	ppsclose;
static	d_ioctl_t	ppsioctl;

#define CDEV_MAJOR 89
static struct cdevsw pps_cdevsw = 
	{ ppsopen,	ppsclose,	noread,		nowrite,
	  ppsioctl,	nullstop,	nullreset,	nodevtotty,
	  seltrue,	nommap,		nostrat,	PPS_NAME,
	  NULL,		-1 };

static struct ppb_device *
ppsprobe(struct ppb_data *ppb)
{
	struct pps_data *sc;

	sc = (struct pps_data *) malloc(sizeof(struct pps_data),
							M_TEMP, M_NOWAIT);
	if (!sc) {
		printf(PPS_NAME ": cannot malloc!\n");
		return (0);
	}
	bzero(sc, sizeof(struct pps_data));

	softc[npps] = sc;

	sc->pps_unit = npps++;

	sc->pps_dev.id_unit = sc->pps_unit;
	sc->pps_dev.ppb = ppb;
	sc->pps_dev.name = ppsdriver.name;
	sc->pps_dev.intr = ppsintr;

	return (&sc->pps_dev);
}

static int
ppsattach(struct ppb_device *dev)
{
	/*
	 * Report ourselves
	 */
	printf(PPS_NAME "%d: <Pulse per second Timing Interface> on ppbus %d\n",
	       dev->id_unit, dev->ppb->ppb_link->adapter_unit);

#ifdef DEVFS
	devfs_add_devswf(&pps_cdevsw,
		dev->id_unit, DV_CHR,
		UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", dev->id_unit);
#endif

	return (1);
}

static	int
ppsopen(dev_t dev, int flags, int fmt, struct proc *p)
{
	struct pps_data *sc;
	u_int unit = minor(dev);

	if ((unit >= npps))
		return (ENXIO);

	sc = softc[unit];

	if (ppb_request_bus(&sc->pps_dev, PPB_WAIT|PPB_INTR))
		return (EINTR);

	ppb_wctr(&sc->pps_dev, 0);
	ppb_wctr(&sc->pps_dev, IRQENABLE);

	return(0);
}

static	int
ppsclose(dev_t dev, int flags, int fmt, struct proc *p)
{
	struct pps_data *sc = softc[minor(dev)];

	sc->ppsparam.mode = 0;

	ppb_wdtr(&sc->pps_dev, 0);
	ppb_wctr(&sc->pps_dev, 0);

	ppb_release_bus(&sc->pps_dev);
	return(0);
}

static void
ppsintr(int unit)
{
	struct pps_data *sc = softc[unit];
	struct timespec tc;

	nanotime(&tc);
	if (!(ppb_rstr(&sc->pps_dev) & nACK))
		return;
	if (sc->ppsparam.mode & PPS_ECHOASSERT) 
		ppb_wctr(&sc->pps_dev, IRQENABLE | AUTOFEED);
	if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
		timespecadd(&tc, &sc->ppsparam.assert_offset);
		if (tc.tv_nsec < 0) {
			tc.tv_sec--;
			tc.tv_nsec += 1000000000;
		}
	}
	sc->ppsinfo.assert_timestamp = tc;
	sc->ppsinfo.assert_sequence++;
#ifdef PPS_SYNC
	if (sc->ppsparam.mode & PPS_HARDPPSONASSERT) {
		struct timeval tv;

		tv.tv_sec = tc.tv_sec;
		tv.tv_usec = tc.tv_nsec / 1000;
		hardpps(&tv, tv.tv_usec);
	}
#endif /* PPS_SYNC */
	if (sc->ppsparam.mode & PPS_ECHOASSERT) 
		ppb_wctr(&sc->pps_dev, IRQENABLE);
}

static int
ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
{
	struct pps_data *sc = softc[minor(dev)];

	return (std_pps_ioctl(cmd, data, &sc->ppsparam, &sc->ppsinfo, ppscap));
}

static pps_devsw_installed = 0;

static void
pps_drvinit(void *unused)
{
	dev_t dev;

	if( ! pps_devsw_installed ) {
		dev = makedev(CDEV_MAJOR, 0);
		cdevsw_add(&dev, &pps_cdevsw, NULL);
		pps_devsw_installed = 1;
    	}
}

SYSINIT(ppsdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,pps_drvinit,NULL)