File:  [DragonFly] / src / sys / bus / smbus / smb.c
Revision 1.7: download - view: text, annotated - select for diffs
Wed May 19 22:52:39 2004 UTC (10 years, 6 months ago) by dillon
Branches: MAIN
CVS tags: HEAD, DragonFly_Stable, DragonFly_Snap29Sep2004, DragonFly_Snap13Sep2004, DragonFly_RELEASE_1_6_Slip, DragonFly_RELEASE_1_6, DragonFly_RELEASE_1_4_Slip, DragonFly_RELEASE_1_4, DragonFly_RELEASE_1_2_Slip, DragonFly_RELEASE_1_2, DragonFly_1_0_REL, DragonFly_1_0_RC1, DragonFly_1_0A_REL
Device layer rollup commit.

* cdevsw_add() is now required.  cdevsw_add() and cdevsw_remove() may specify
  a mask/match indicating the range of supported minor numbers.  Multiple
  cdevsw_add()'s using the same major number, but distinctly different
  ranges, may be issued.  All devices that failed to call cdevsw_add() before
  now do.

* cdevsw_remove() now automatically marks all devices within its supported
  range as being destroyed.

* vnode->v_rdev is no longer resolved when the vnode is created.  Instead,
  only v_udev (a newly added field) is resolved.  v_rdev is resolved when
  the vnode is opened and cleared on the last close.

* A great deal of code was making rather dubious assumptions with regards
  to the validity of devices associated with vnodes, primarily due to
  the persistence of a device structure due to being indexed by (major, minor)
  instead of by (cdevsw, major, minor).  In particular, if you run a program
  which connects to a USB device and then you pull the USB device and plug
  it back in, the vnode subsystem will continue to believe that the device
  is open when, in fact, it isn't (because it was destroyed and recreated).

  In particular, note that all the VFS mount procedures now check devices
  via v_udev instead of v_rdev prior to calling VOP_OPEN(), since v_rdev
  is NULL prior to the first open.

* The disk layer's device interaction has been rewritten.  The disk layer
  (i.e. the slice and disklabel management layer) no longer overloads
  its data onto the device structure representing the underlying physical
  disk.  Instead, the disk layer uses the new cdevsw_add() functionality
  to register its own cdevsw using the underlying device's major number,
  and simply does NOT register the underlying device's cdevsw.  No
  confusion is created because the device hash is now based on
  (cdevsw,major,minor) rather then (major,minor).

  NOTE: This also means that underlying raw disk devices may use the entire
  device minor number instead of having to reserve the bits used by the disk
  layer, and also means that can we (theoretically) stack a fully
  disklabel-supported 'disk' on top of any block device.

* The new reference counting scheme prevents this by associating a device
  with a cdevsw and disconnecting the device from its cdevsw when the cdevsw
  is removed.  Additionally, all udev2dev() lookups run through the cdevsw
  mask/match and only successfully find devices still associated with an
  active cdevsw.

* Major work on MFS:  MFS no longer shortcuts vnode and device creation.  It
  now creates a real vnode and a real device and implements real open and
  close VOPs.  Additionally, due to the disk layer changes, MFS is no longer
  limited to 255 mounts.  The new limit is 16 million.  Since MFS creates a
  real device node, mount_mfs will now create a real /dev/mfs<PID> device
  that can be read from userland (e.g. so you can dump an MFS filesystem).

* BUF AND DEVICE STRATEGY changes.  The struct buf contains a b_dev field.
  In order to properly handle stacked devices we now require that the b_dev
  field be initialized before the device strategy routine is called.  This
  required some additional work in various VFS implementations.  To enforce
  this requirement, biodone() now sets b_dev to NODEV.  The new disk layer
  will adjust b_dev before forwarding a request to the actual physical
  device.

* A bug in the ISO CD boot sequence which resulted in a panic has been fixed.

Testing by: lots of people, but David Rhodus found the most aggregious bugs.

/*-
 * Copyright (c) 1998 Nicolas Souchu
 * 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 THE AUTHOR AND CONTRIBUTORS ``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.
 *
 * $FreeBSD: src/sys/dev/smbus/smb.c,v 1.20 1999/11/18 05:44:56 peter Exp $
 * $DragonFly: src/sys/bus/smbus/smb.c,v 1.7 2004/05/19 22:52:39 dillon Exp $
 *
 */
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/fcntl.h>

#include <machine/clock.h>

#include "smbconf.h"
#include "smbus.h"
#include <machine/smb.h>

#include "smbus_if.h"

#define BUFSIZE 1024

struct smb_softc {

	int sc_addr;			/* address on smbus */
	int sc_count;			/* >0 if device opened */

	char *sc_cp;			/* output buffer pointer */

	char sc_buffer[BUFSIZE];	/* output buffer */
	char sc_inbuf[BUFSIZE];		/* input buffer */
};

#define IIC_SOFTC(unit) \
	((struct smb_softc *)devclass_get_softc(smb_devclass, (unit)))

#define IIC_DEVICE(unit) \
	(devclass_get_device(smb_devclass, (unit)))

static int smb_probe(device_t);
static int smb_attach(device_t);

static devclass_t smb_devclass;

static device_method_t smb_methods[] = {
	/* device interface */
	DEVMETHOD(device_probe,		smb_probe),
	DEVMETHOD(device_attach,	smb_attach),

	/* smbus interface */
	DEVMETHOD(smbus_intr,		smbus_generic_intr),

	{ 0, 0 }
};

static driver_t smb_driver = {
	"smb",
	smb_methods,
	sizeof(struct smb_softc),
};

static	d_open_t	smbopen;
static	d_close_t	smbclose;
static	d_write_t	smbwrite;
static	d_read_t	smbread;
static	d_ioctl_t	smbioctl;

#define CDEV_MAJOR 106
static struct cdevsw smb_cdevsw = {
	/* name */	"smb",
	/* maj */	CDEV_MAJOR,
	/* flags */	0,
	/* port */	NULL,
	/* clone */	NULL,

	/* open */	smbopen,
	/* close */	smbclose,
	/* read */	smbread,
	/* write */	smbwrite,
	/* ioctl */	smbioctl,
	/* poll */	nopoll,
	/* mmap */	nommap,
	/* strategy */	nostrategy,
	/* dump */	nodump,
	/* psize */	nopsize
};

/*
 * smbprobe()
 */
static int
smb_probe(device_t dev)
{
	struct smb_softc *sc = (struct smb_softc *)device_get_softc(dev);

	sc->sc_addr = smbus_get_addr(dev);

	/* XXX detect chip with start/stop conditions */

	return (0);
}
	
/*
 * smbattach()
 */
static int
smb_attach(device_t dev)
{
	cdevsw_add(&smb_cdevsw, -1, device_get_unit(dev));
	make_dev(&smb_cdevsw, device_get_unit(dev),	/* XXX cleanup */
			UID_ROOT, GID_WHEEL,
			0600, "smb%d", device_get_unit(dev));
	return (0);
}

static int
smbopen (dev_t dev, int flags, int fmt, struct thread *td)
{
	struct smb_softc *sc = IIC_SOFTC(minor(dev));

	if (!sc)
		return (EINVAL);

	if (sc->sc_count)
		return (EBUSY);

	sc->sc_count++;

	return (0);
}

static int
smbclose(dev_t dev, int flags, int fmt, struct thread *td)
{
	struct smb_softc *sc = IIC_SOFTC(minor(dev));

	if (!sc)
		return (EINVAL);

	if (!sc->sc_count)
		return (EINVAL);

	sc->sc_count--;

	return (0);
}

static int
smbwrite(dev_t dev, struct uio * uio, int ioflag)
{
	/* not supported */

	return (EINVAL);
}

static int
smbread(dev_t dev, struct uio * uio, int ioflag)
{
	/* not supported */

	return (EINVAL);
}

static int
smbioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
{
	device_t smbdev = IIC_DEVICE(minor(dev));
	struct smb_softc *sc = IIC_SOFTC(minor(dev));
	device_t parent = device_get_parent(smbdev);

	int error = 0;
	struct smbcmd *s = (struct smbcmd *)data;

	if (!sc || !s)
		return (EINVAL);

	/* allocate the bus */
	if ((error = smbus_request_bus(parent, smbdev,
			(flags & O_NONBLOCK) ? SMB_DONTWAIT : (SMB_WAIT | SMB_INTR))))
		return (error);

	switch (cmd) {
	case SMB_QUICK_WRITE:
		error = smbus_error(smbus_quick(parent, s->slave, SMB_QWRITE));
		break;

	case SMB_QUICK_READ:
		error = smbus_error(smbus_quick(parent, s->slave, SMB_QREAD));
		break;

	case SMB_SENDB:
		error = smbus_error(smbus_sendb(parent, s->slave, s->cmd));
		break;

	case SMB_RECVB:
		error = smbus_error(smbus_recvb(parent, s->slave, &s->cmd));
		break;

	case SMB_WRITEB:
		error = smbus_error(smbus_writeb(parent, s->slave, s->cmd,
						s->data.byte));
		break;

	case SMB_WRITEW:
		error = smbus_error(smbus_writew(parent, s->slave,
						s->cmd, s->data.word));
		break;

	case SMB_READB:
		if (s->data.byte_ptr)
			error = smbus_error(smbus_readb(parent, s->slave,
						s->cmd, s->data.byte_ptr));
		break;

	case SMB_READW:
		if (s->data.word_ptr)
			error = smbus_error(smbus_readw(parent, s->slave,
						s->cmd, s->data.word_ptr));
		break;

	case SMB_PCALL:
		if (s->data.process.rdata)
			error = smbus_error(smbus_pcall(parent, s->slave, s->cmd,
				s->data.process.sdata, s->data.process.rdata));
		break;

	case SMB_BWRITE:
		if (s->count && s->data.byte_ptr)
			error = smbus_error(smbus_bwrite(parent, s->slave,
						s->cmd, s->count, s->data.byte_ptr));
		break;

	case SMB_BREAD:
		if (s->count && s->data.byte_ptr)
			error = smbus_error(smbus_bread(parent, s->slave,
						s->cmd, s->count, s->data.byte_ptr));
		break;
		
	default:
		error = ENODEV;
	}

	/* release the bus */
	smbus_release_bus(parent, smbdev);

	return (error);
}

DRIVER_MODULE(smb, smbus, smb_driver, smb_devclass, 0, 0);