FreeBSD的PCI驱动例子

/*
 * Simple KLD to play with the PCI functions.
 *
 * Murray Stokely
 */

#include <sys/param.h>        /* defines used in kernel.h */
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>        /* types used in module initialization */
#include <sys/conf.h>        /* cdevsw struct */
#include <sys/uio.h>        /* uio struct */
#include <sys/malloc.h>
#include <sys/bus.h>        /* structs, prototypes for pci bus stuff and DEVMETHOD macros! */

#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>

#include <dev/pci/pcivar.h>    /* For pci_get macros! */
#include <dev/pci/pcireg.h>

/* The softc holds our per-instance data. */
struct mypci_softc {
    device_t    my_dev;
    struct cdev    *my_cdev;
};

/* Function prototypes */
static d_open_t        mypci_open;
static d_close_t    mypci_close;
static d_read_t        mypci_read;
static d_write_t    mypci_write;

/* Character device entry points */

static struct cdevsw mypci_cdevsw = {
    .d_version =    D_VERSION,
    .d_open =    mypci_open,
    .d_close =    mypci_close,
    .d_read =    mypci_read,
    .d_write =    mypci_write,
    .d_name =    "mypci",
};

/*
 * In the cdevsw routines, we find our softc by using the si_drv1 member
 * of struct cdev.  We set this variable to point to our softc in our
 * attach routine when we create the /dev entry.
 */

int
mypci_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
    struct mypci_softc *sc;

    /* Look up our softc. */
    sc = dev->si_drv1;
    device_printf(sc->my_dev, "Opened successfully.
");
    return (0);
}

int
mypci_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
{
    struct mypci_softc *sc;

    /* Look up our softc. */
    sc = dev->si_drv1;
    device_printf(sc->my_dev, "Closed.
");
    return (0);
}

int
mypci_read(struct cdev *dev, struct uio *uio, int ioflag)
{
    struct mypci_softc *sc;

    /* Look up our softc. */
    sc = dev->si_drv1;
    device_printf(sc->my_dev, "Asked to read %zd bytes.
", uio->uio_resid);
    return (0);
}

int
mypci_write(struct cdev *dev, struct uio *uio, int ioflag)
{
    struct mypci_softc *sc;

    /* Look up our softc. */
    sc = dev->si_drv1;
    device_printf(sc->my_dev, "Asked to write %zd bytes.
", uio->uio_resid);
    return (0);
}

/* PCI Support Functions */

/*
 * Compare the device ID of this device against the IDs that this driver
 * supports.  If there is a match, set the description and return success.
 */
static int
mypci_probe(device_t dev)
{

    device_printf(dev, "MyPCI Probe
Vendor ID : 0x%x
Device ID : 0x%x
",
        pci_get_vendor(dev), pci_get_device(dev));

    if (pci_get_vendor(dev) == 0x11c1) {
        printf("We've got the Winmodem, probe successful!
");
        device_set_desc(dev, "WinModem");
        return (BUS_PROBE_DEFAULT);
    }
    return (ENXIO);
}

/* Attach function is only called if the probe is successful. */

static int
mypci_attach(device_t dev)
{
    struct mypci_softc *sc;

    printf("MyPCI Attach for : deviceID : 0x%x
", pci_get_devid(dev));

    /* Look up our softc and initialize its fields. */
    sc = device_get_softc(dev);
    sc->my_dev = dev;

    /*
     * Create a /dev entry for this device.  The kernel will assign us
     * a major number automatically.  We use the unit number of this
     * device as the minor number and name the character device
     * "mypci<unit>".
     */
    sc->my_cdev = make_dev(&mypci_cdevsw, device_get_unit(dev),
        UID_ROOT, GID_WHEEL, 0600, "mypci%u", device_get_unit(dev));
    sc->my_cdev->si_drv1 = sc;
    printf("Mypci device loaded.
");
    return (0);
}

/* Detach device. */

static int
mypci_detach(device_t dev)
{
    struct mypci_softc *sc;

    /* Teardown the state in our softc created in our attach routine. */
    sc = device_get_softc(dev);
    destroy_dev(sc->my_cdev);
    printf("Mypci detach!
");
    return (0);
}

/* Called during system shutdown after sync. */

static int
mypci_shutdown(device_t dev)
{

    printf("Mypci shutdown!
");
    return (0);
}

/*
 * Device suspend routine.
 */
static int
mypci_suspend(device_t dev)
{

    printf("Mypci suspend!
");
    return (0);
}

/*
 * Device resume routine.
 */
static int
mypci_resume(device_t dev)
{

    printf("Mypci resume!
");
    return (0);
}

static device_method_t mypci_methods[] = {
    /* Device interface */
    DEVMETHOD(device_probe,        mypci_probe),
    DEVMETHOD(device_attach,    mypci_attach),
    DEVMETHOD(device_detach,    mypci_detach),
    DEVMETHOD(device_shutdown,    mypci_shutdown),
    DEVMETHOD(device_suspend,    mypci_suspend),
    DEVMETHOD(device_resume,    mypci_resume),

    DEVMETHOD_END
};

static devclass_t mypci_devclass;

DEFINE_CLASS_0(mypci, mypci_driver, mypci_methods, sizeof(struct mypci_softc));
DRIVER_MODULE(mypci, pci, mypci_driver, mypci_devclass, 0, 0);

# Makefile for mypci driver

KMOD=    mypci
SRCS=    mypci.c
SRCS+=    device_if.h bus_if.h pci_if.h

.include <bsd.kmod.mk>

Chapter 11. PCI Devices (freebsd.org)上面代码链接地址

第 11 章 PCI设备 (freebsd.org)中文版链接地址

如果你将上面的源文件和 Makefile放入一个目录，你可以运行 make编译示例驱动程序。 还有，你可以运行make load 将驱动程序装载到当前正在运行的内核中，而make unload可在装载后卸载驱动程序。

注：如果make报错（“make” command: unable to locate the kernel source tree）或者其他的，请给系统安装源码