DRVCTL(4)

NAME
drvctl - driver control device

SYNOPSIS
pseudo-device drvctl

DESCRIPTION
The drvctl driver allows to control some autoconf(9) operations from userland through the /dev/drvctl device and the drvctl(8) command.

The driver supports the following ioctl(2) operations.

DRVSUSPENDDEV
DRVRESUMEDEV
    Invoke power management functions for a named driver that has registered itself with the pmf(9) framework. The ioctl argument specifies the driver name as:

        struct devpmargs {
                char devname[16];
                uint32_t flags;
        };

    The flag DEVPM_F_SUBTREE lets the function recurse over all children of that driver.

DRVLISTDEV
    Return a list of child devices attached to the named driver. The ioctl argument specifies the driver name as:

        struct devlistargs {
                char l_devname[16];
                char (*l_childname)[16];
                size_t l_children;
        };

    The names for up to l_children child devices are copied to the l_childname array. If there is no error, the ioctl returns the total number of children. Normally you would call DRVLISTDEV once with l_children set to zero, allocate a buffer for enough 16-character strings and call DRVLISTDEV again to fill the buffer.

DRVDETACHDEV
    Detach the named driver and all its autoconfigured children. The ioctl argument specifies the driver name as:

        struct devdetachargs {
                char devname[16];
        };

DRVSCANBUS
    Invoke the rescan method of the named driver to locate child devices. The ioctl argument specifies the driver name as:

        struct devrescanargs {
                char busname[16];
                char ifattr[16];
                unsigned int numlocators;
                int *locators;
        };

    Some device drivers attach children to specific interface attributes, a zero length ifattr represents that no interface attribute should be used. The rescan can also be limited to driver-specific locators.

DRVCTLCOMMAND
    Send a command formatted as a property list. The property list includes all arguments like the driver name, the result is again a property list. Currently the only supported command is "get-properties", the property list is constructed like:

        const char *device = "sd0";
        const char *command = "get-properties";
        prop_string_t s;
        prop_dictionary_t c, a;
        c = prop_dictionary_create();
        a = prop_dictionary_create();
        s = prop_string_create_cstring_nocopy(command);
        prop_dictionary_set(c, "drvctl-command", s);
        prop_object_release(s);
        s = prop_string_create_cstring(device);
        prop_dictionary_set(a, "device-name", s);
        prop_object_release(s);
        prop_dictionary_set(c, "drvctl-arguments", a);
        prop_object_release(a);

    The command must be sent with prop_dictionary_sendrecv_ioctl(3). The resulting property list contains the numeric attribute drvctl-error, which corresponds to an errno value, and the dictionary drvctl-result-data. The contents of the dictionary depends on the queried driver.

DRVGETEVENT
    Return the next queued autoconfig event formatted as a property list. The request needs to be sent with prop_dictionary_recv_ioctl(3). The resulting property list contains the string attributes event, device and parent. Currently the events "device-attach" and "device-detach" are generated by the autoconf(9) framework.

    If /dev/drvctl was opened with O_NONBLOCK and there is no event queued, the call returns immediately with EWOULDBLOCK, otherwise it waits for the next event.

All names used in the ioctl arguments are zero-terminated strings. A driver name is the name of a driver instance with the appended unit number like sd0, atabus3, ...

FILES

/dev/drvctl
    drvctl access device

SEE ALSO
ioctl(2), prop_send_ioctl(3), proplib(3), devpubd(8), drvctl(8), autoconf(9)

HISTORY
The /dev/drvctl device appeared in NetBSD 3.0 but was only added to the GENERIC configuration in NetBSD 5.0.