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

349 lines
8.0 KiB
C

/*-
* SPDX-License-Identifier: Beerware
*
* ----------------------------------------------------------------------------
* "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
* ----------------------------------------------------------------------------
*
*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/sx.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/timepps.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <dev/ppbus/ppbconf.h>
#include "ppbus_if.h"
#include <dev/ppbus/ppbio.h>
#define PPS_NAME "pps" /* our official name */
#define PRVERBOSE(fmt, arg...) if (bootverbose) printf(fmt, ##arg);
struct pps_data {
struct ppb_device pps_dev;
struct pps_state pps[9];
struct cdev *devs[9];
device_t ppsdev;
device_t ppbus;
int busy;
struct callout timeout;
int lastdata;
struct sx lock;
struct resource *intr_resource; /* interrupt resource */
void *intr_cookie; /* interrupt registration cookie */
};
static void ppsintr(void *arg);
static void ppshcpoll(void *arg);
#define DEVTOSOFTC(dev) \
((struct pps_data *)device_get_softc(dev))
static d_open_t ppsopen;
static d_close_t ppsclose;
static d_ioctl_t ppsioctl;
static struct cdevsw pps_cdevsw = {
.d_version = D_VERSION,
.d_open = ppsopen,
.d_close = ppsclose,
.d_ioctl = ppsioctl,
.d_name = PPS_NAME,
};
static void
ppsidentify(driver_t *driver, device_t parent)
{
device_t dev;
dev = device_find_child(parent, PPS_NAME, -1);
if (!dev)
BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
}
static int
ppstry(device_t ppbus, int send, int expect)
{
int i;
ppb_wdtr(ppbus, send);
i = ppb_rdtr(ppbus);
PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
return (i != expect);
}
static int
ppsprobe(device_t ppsdev)
{
device_set_desc(ppsdev, "Pulse per second Timing Interface");
return (0);
}
static int
ppsattach(device_t dev)
{
struct pps_data *sc = DEVTOSOFTC(dev);
device_t ppbus = device_get_parent(dev);
struct cdev *d;
int error, i, unit, rid = 0;
/* declare our interrupt handler */
sc->intr_resource = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_SHAREABLE);
/* interrupts seem mandatory */
if (sc->intr_resource == NULL) {
device_printf(dev, "Unable to allocate interrupt resource\n");
return (ENXIO);
}
error = bus_setup_intr(dev, sc->intr_resource,
INTR_TYPE_TTY | INTR_MPSAFE, NULL, ppsintr,
sc, &sc->intr_cookie);
if (error) {
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->intr_resource);
device_printf(dev, "Unable to register interrupt handler\n");
return (error);
}
sx_init(&sc->lock, "pps");
ppb_init_callout(ppbus, &sc->timeout, 0);
sc->ppsdev = dev;
sc->ppbus = ppbus;
unit = device_get_unit(ppbus);
d = make_dev(&pps_cdevsw, unit,
UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
sc->devs[0] = d;
sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
sc->pps[0].driver_abi = PPS_ABI_VERSION;
sc->pps[0].driver_mtx = ppb_get_lock(ppbus);
d->si_drv1 = sc;
d->si_drv2 = (void*)0;
pps_init_abi(&sc->pps[0]);
ppb_lock(ppbus);
if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
ppb_unlock(ppbus);
return (0);
}
do {
i = ppb_set_mode(sc->ppbus, PPB_EPP);
PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
if (i == -1)
break;
i = 0;
ppb_wctr(ppbus, i);
if (ppstry(ppbus, 0x00, 0x00))
break;
if (ppstry(ppbus, 0x55, 0x55))
break;
if (ppstry(ppbus, 0xaa, 0xaa))
break;
if (ppstry(ppbus, 0xff, 0xff))
break;
i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
ppb_wctr(ppbus, i);
PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
if (ppstry(ppbus, 0x00, 0x00))
break;
if (ppstry(ppbus, 0x55, 0x00))
break;
if (ppstry(ppbus, 0xaa, 0x00))
break;
if (ppstry(ppbus, 0xff, 0x00))
break;
i = IRQENABLE | PCD | nINIT | SELECTIN;
ppb_wctr(ppbus, i);
PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
ppstry(ppbus, 0x00, 0xff);
ppstry(ppbus, 0x55, 0xff);
ppstry(ppbus, 0xaa, 0xff);
ppstry(ppbus, 0xff, 0xff);
ppb_unlock(ppbus);
for (i = 1; i < 9; i++) {
d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
sc->devs[i] = d;
sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
sc->pps[i].driver_abi = PPS_ABI_VERSION;
sc->pps[i].driver_mtx = ppb_get_lock(ppbus);
d->si_drv1 = sc;
d->si_drv2 = (void *)(intptr_t)i;
pps_init_abi(&sc->pps[i]);
}
ppb_lock(ppbus);
} while (0);
i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
ppb_release_bus(ppbus, dev);
ppb_unlock(ppbus);
return (0);
}
static int
ppsopen(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct pps_data *sc = dev->si_drv1;
device_t ppbus = sc->ppbus;
int subdev = (intptr_t)dev->si_drv2;
int i;
/*
* The sx lock is here solely to serialize open()'s to close
* the race of concurrent open()'s when pps(4) doesn't own the
* ppbus.
*/
sx_xlock(&sc->lock);
ppb_lock(ppbus);
if (!sc->busy) {
device_t ppsdev = sc->ppsdev;
if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR)) {
ppb_unlock(ppbus);
sx_xunlock(&sc->lock);
return (EINTR);
}
i = ppb_set_mode(sc->ppbus, PPB_PS2);
PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
i = IRQENABLE | PCD | nINIT | SELECTIN;
ppb_wctr(ppbus, i);
}
if (subdev > 0 && !(sc->busy & ~1)) {
/* XXX: Timeout of 1? hz/100 instead perhaps? */
callout_reset(&sc->timeout, 1, ppshcpoll, sc);
sc->lastdata = ppb_rdtr(sc->ppbus);
}
sc->busy |= (1 << subdev);
ppb_unlock(ppbus);
sx_xunlock(&sc->lock);
return(0);
}
static int
ppsclose(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct pps_data *sc = dev->si_drv1;
int subdev = (intptr_t)dev->si_drv2;
sx_xlock(&sc->lock);
sc->pps[subdev].ppsparam.mode = 0; /* PHK ??? */
ppb_lock(sc->ppbus);
sc->busy &= ~(1 << subdev);
if (subdev > 0 && !(sc->busy & ~1))
callout_stop(&sc->timeout);
if (!sc->busy) {
device_t ppsdev = sc->ppsdev;
device_t ppbus = sc->ppbus;
ppb_wdtr(ppbus, 0);
ppb_wctr(ppbus, 0);
ppb_set_mode(ppbus, PPB_COMPATIBLE);
ppb_release_bus(ppbus, ppsdev);
}
ppb_unlock(sc->ppbus);
sx_xunlock(&sc->lock);
return(0);
}
static void
ppshcpoll(void *arg)
{
struct pps_data *sc = arg;
int i, j, k, l;
KASSERT(sc->busy & ~1, ("pps polling w/o opened devices"));
i = ppb_rdtr(sc->ppbus);
if (i == sc->lastdata)
return;
l = sc->lastdata ^ i;
k = 1;
for (j = 1; j < 9; j ++) {
if (l & k) {
pps_capture(&sc->pps[j]);
pps_event(&sc->pps[j],
i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
}
k += k;
}
sc->lastdata = i;
callout_reset(&sc->timeout, 1, ppshcpoll, sc);
}
static void
ppsintr(void *arg)
{
struct pps_data *sc = (struct pps_data *)arg;
ppb_assert_locked(sc->ppbus);
pps_capture(&sc->pps[0]);
if (!(ppb_rstr(sc->ppbus) & nACK))
return;
if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
ppb_wctr(sc->ppbus, IRQENABLE | AUTOFEED);
pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
ppb_wctr(sc->ppbus, IRQENABLE);
}
static int
ppsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
{
struct pps_data *sc = dev->si_drv1;
int subdev = (intptr_t)dev->si_drv2;
int err;
ppb_lock(sc->ppbus);
err = pps_ioctl(cmd, data, &sc->pps[subdev]);
ppb_unlock(sc->ppbus);
return (err);
}
static device_method_t pps_methods[] = {
/* device interface */
DEVMETHOD(device_identify, ppsidentify),
DEVMETHOD(device_probe, ppsprobe),
DEVMETHOD(device_attach, ppsattach),
{ 0, 0 }
};
static driver_t pps_driver = {
PPS_NAME,
pps_methods,
sizeof(struct pps_data),
};
DRIVER_MODULE(pps, ppbus, pps_driver, 0, 0);
MODULE_DEPEND(pps, ppbus, 1, 1, 1);