freebsd-skq/sys/dev/ppbus/pcfclock.c
jhb 879505d4df Add locking to ppc and ppbus and mark the whole lot MPSAFE:
- To avoid having a bunch of locks that end up always getting acquired as
  a group, give each ppc(4) device a mutex which it shares with all the
  child devices including ppbus(4), lpt(4), plip(4), etc.  This mutex
  is then used for all the locking.
- Rework the interrupt handling stuff yet again.  Now ppbus drivers setup
  their interrupt handler during attach and tear it down during detach
  like most other drivers.  ppbus(4) only invokes the interrupt handler
  of the device that currently owns the bus (if any) when an interrupt
  occurs, however.  Also, interrupt handlers in general now accept their
  softc pointers as their argument rather than the device_t.  Another
  feature of the ppbus interrupt handlers is that they are called with
  the parent ppc device's lock already held.  This minimizes the number
  of lock operations during an interrupt.
- Mark plip(4), lpt(4), pcfclock(4), ppi(4), vpo(4) MPSAFE.
- lpbb(4) uses the ppc lock instead of Giant.
- Other plip(4) changes:
  - Add a mutex to protect the global tables in plip(4) and free them on
    module unload.
  - Add a detach routine.
  - Split out the init/stop code from the ioctl routine into separate
    functions.
- Other lpt(4) changes:
  - Use device_printf().
  - Use a dedicated callout for the lptout timer.
  - Allocate the I/O buffers at attach and detach rather than during
    open and close as this simplifies the locking at the cost of
    1024+32 bytes when the driver is attached.
- Other ppi(4) changes:
  - Use an sx lock to serialize open and close.
  - Remove unused HADBUS flag.
  - Add a detach routine.
  - Use a malloc'd buffer for each read and write to avoid races with
    concurrent read/write.
- Other pps(4) changes:
  - Use a callout rather than a callout handle with timeout().
  - Conform to the new ppbus requirements (regular mutex, non-filter
    interrupt handler).  pps(4) is probably going to have to become a
    standalone driver that doesn't use ppbus(4) to satisfy it's
    requirements for low latency as a result.
  - Use an sx lock to serialize open and close.
- Other vpo(4) changes:
  - Use the parent ppc device's lock to create the CAM sim instead of
    Giant.
- Other ppc(4) changes:
  - Fix ppc_isa's detach method to detach instead of calling attach.

Tested by:	  no one :-(
2009-01-21 23:10:06 +00:00

335 lines
7.5 KiB
C

/*-
* Copyright (c) 2000 Sascha Schumann. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY SASCHA SCHUMANN ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_pcfclock.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <dev/ppbus/ppbconf.h>
#include <dev/ppbus/ppb_msq.h>
#include <dev/ppbus/ppbio.h>
#include "ppbus_if.h"
#define PCFCLOCK_NAME "pcfclock"
struct pcfclock_data {
device_t dev;
struct cdev *cdev;
};
static devclass_t pcfclock_devclass;
static d_open_t pcfclock_open;
static d_close_t pcfclock_close;
static d_read_t pcfclock_read;
static struct cdevsw pcfclock_cdevsw = {
.d_version = D_VERSION,
.d_open = pcfclock_open,
.d_close = pcfclock_close,
.d_read = pcfclock_read,
.d_name = PCFCLOCK_NAME,
};
#ifndef PCFCLOCK_MAX_RETRIES
#define PCFCLOCK_MAX_RETRIES 10
#endif
#define AFC_HI 0
#define AFC_LO AUTOFEED
/* AUTO FEED is used as clock */
#define AUTOFEED_CLOCK(val) \
ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
/* SLCT is used as clock */
#define CLOCK_OK \
((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
/* PE is used as data */
#define BIT_SET (ppb_rstr(ppbus)&PERROR)
/* the first byte sent as reply must be 00001001b */
#define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
#define NR(buf, off) (buf[off+1]*10+buf[off])
/* check for correct input values */
#define PCFCLOCK_CORRECT_FORMAT(buf) (\
NR(buf, 14) <= 99 && \
NR(buf, 12) <= 12 && \
NR(buf, 10) <= 31 && \
NR(buf, 6) <= 23 && \
NR(buf, 4) <= 59 && \
NR(buf, 2) <= 59)
#define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
#define PCFCLOCK_CMD_TIME 0 /* send current time */
#define PCFCLOCK_CMD_COPY 7 /* copy received signal to PC */
static void
pcfclock_identify(driver_t *driver, device_t parent)
{
device_t dev;
dev = device_find_child(parent, PCFCLOCK_NAME, -1);
if (!dev)
BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
}
static int
pcfclock_probe(device_t dev)
{
device_set_desc(dev, "PCF-1.0");
return (0);
}
static int
pcfclock_attach(device_t dev)
{
struct pcfclock_data *sc = device_get_softc(dev);
int unit;
unit = device_get_unit(dev);
sc->dev = dev;
sc->cdev = make_dev(&pcfclock_cdevsw, unit,
UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
if (sc->cdev == NULL) {
device_printf(dev, "Failed to create character device\n");
return (ENXIO);
}
sc->cdev->si_drv1 = sc;
return (0);
}
static int
pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t pcfclockdev = sc->dev;
device_t ppbus = device_get_parent(pcfclockdev);
int res;
if (!sc)
return (ENXIO);
ppb_lock(ppbus);
res = ppb_request_bus(ppbus, pcfclockdev,
(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT);
ppb_unlock(ppbus);
return (res);
}
static int
pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t pcfclockdev = sc->dev;
device_t ppbus = device_get_parent(pcfclockdev);
ppb_lock(ppbus);
ppb_release_bus(ppbus, pcfclockdev);
ppb_unlock(ppbus);
return (0);
}
static void
pcfclock_write_cmd(struct cdev *dev, unsigned char command)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t pcfclockdev = sc->dev;
device_t ppbus = device_get_parent(pcfclockdev);
unsigned char ctr = 14;
char i;
for (i = 0; i <= 7; i++) {
ppb_wdtr(ppbus, i);
AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
DELAY(3000);
}
ppb_wdtr(ppbus, command);
AUTOFEED_CLOCK(AFC_LO);
DELAY(3000);
AUTOFEED_CLOCK(AFC_HI);
}
static void
pcfclock_display_data(struct cdev *dev, char buf[18])
{
struct pcfclock_data *sc = dev->si_drv1;
#ifdef PCFCLOCK_VERBOSE
int year;
year = NR(buf, 14);
if (year < 70)
year += 100;
device_printf(sc->dev, "%02d.%02d.%4d %02d:%02d:%02d, "
"battery status: %s\n",
NR(buf, 10), NR(buf, 12), 1900 + year,
NR(buf, 6), NR(buf, 4), NR(buf, 2),
PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
#else
if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
device_printf(sc->dev, "BATTERY STATUS LOW ON\n");
#endif
}
static int
pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t pcfclockdev = sc->dev;
device_t ppbus = device_get_parent(pcfclockdev);
int i;
char waitfor;
int offset;
/* one byte per four bits */
bzero(buf, ((bits + 3) >> 2) + 1);
waitfor = 100;
for (i = 0; i <= bits; i++) {
/* wait for clock, maximum (waitfor*100) usec */
while (!CLOCK_OK && --waitfor > 0)
DELAY(100);
/* timed out? */
if (!waitfor)
return (EIO);
waitfor = 100; /* reload */
/* give it some time */
DELAY(500);
/* calculate offset into buffer */
offset = i >> 2;
buf[offset] <<= 1;
if (BIT_SET)
buf[offset] |= 1;
}
return (0);
}
static int
pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t pcfclockdev = sc->dev;
device_t ppbus = device_get_parent(pcfclockdev);
int error = 0;
ppb_set_mode(ppbus, PPB_COMPATIBLE);
while (--maxretries > 0) {
pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
if (pcfclock_read_data(dev, buf, 68))
continue;
if (!PCFCLOCK_CORRECT_SYNC(buf))
continue;
if (!PCFCLOCK_CORRECT_FORMAT(buf))
continue;
break;
}
if (!maxretries)
error = EIO;
return (error);
}
static int
pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
{
struct pcfclock_data *sc = dev->si_drv1;
device_t ppbus;
char buf[18];
int error = 0;
if (uio->uio_resid < 18)
return (ERANGE);
ppbus = device_get_parent(sc->dev);
ppb_lock(ppbus);
error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
ppb_unlock(ppbus);
if (error) {
device_printf(sc->dev, "no PCF found\n");
} else {
pcfclock_display_data(dev, buf);
uiomove(buf, 18, uio);
}
return (error);
}
static device_method_t pcfclock_methods[] = {
/* device interface */
DEVMETHOD(device_identify, pcfclock_identify),
DEVMETHOD(device_probe, pcfclock_probe),
DEVMETHOD(device_attach, pcfclock_attach),
{ 0, 0 }
};
static driver_t pcfclock_driver = {
PCFCLOCK_NAME,
pcfclock_methods,
sizeof(struct pcfclock_data),
};
DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);