diff options
Diffstat (limited to 'static/freebsd/man9/bus_activate_resource.9')
| -rw-r--r-- | static/freebsd/man9/bus_activate_resource.9 | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/static/freebsd/man9/bus_activate_resource.9 b/static/freebsd/man9/bus_activate_resource.9 new file mode 100644 index 00000000..7b87197b --- /dev/null +++ b/static/freebsd/man9/bus_activate_resource.9 @@ -0,0 +1,126 @@ +.\" -*- nroff -*- +.\" +.\" Copyright (c) 2003 M. Warner Losh <imp@FreeBSD.org> +.\" +.\" 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 DEVELOPERS ``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 DEVELOPERS 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. +.\" +.Dd March 13, 2024 +.Dt BUS_ACTIVATE_RESOURCE 9 +.Os +.Sh NAME +.Nm bus_activate_resource , bus_deactivate_resource +.Nd activate or deactivate a resource +.Sh SYNOPSIS +.In sys/param.h +.In sys/bus.h +.Pp +.In machine/bus.h +.In sys/rman.h +.In machine/resource.h +.Ft int +.Fo bus_activate_resource +.Fa "device_t dev" "struct resource *r" +.Fc +.Ft int +.Fo bus_deactivate_resource +.Fa "device_t dev" "struct resource *r" +.Fc +.Sh DESCRIPTION +These functions activate or deactivate a previously allocated resource. +In general, resources must be activated before they can be accessed by +the driver. +Bus drivers may perform additional actions to ensure that the resource is +ready to be accessed. +For example, +the PCI bus driver enables memory decoding in a PCI device's command register +when activating a memory resource. +.Pp +The arguments are as follows: +.Bl -tag -width indent +.It Fa dev +The device that requests ownership of the resource. +Before allocation, the resource is owned by the parent bus. +.It Fa r +A pointer to the +.Vt "struct resource" +returned by +.Xr bus_alloc_resource 9 . +.El +.Ss Resource Mapping +Resources which can be mapped for CPU access by a +.Xr bus_space 9 +tag and handle will create a mapping of the entire resource when activated. +The tag and handle for this mapping are stored in +.Fa r +and can be retrieved via +.Xr rman_get_bustag 9 +and +.Xr rman_get_bushandle 9 . +These can be used with the +.Xr bus_space 9 +API to access device registers or memory described by +.Fa r . +If the mapping is associated with a virtual address, +the virtual address can be retrieved via +.Xr rman_get_virtual 9 . +.Pp +This implicit mapping can be disabled by passing the +.Dv RF_UNMAPPED +flag to +.Xr bus_alloc_resource 9 . +A driver may use this if it wishes to allocate its own mappings of a resource +using +.Xr bus_map_resource 9 . +.Pp +A wrapper API for +.Xr bus_space 9 +is also provided that accepts the associated resource as the first argument +in place of the +.Xr bus_space 9 +tag and handle. +The functions in this wrapper API are named similarly to the +.Xr bus_space 9 +API except that +.Dq _space +is removed from their name. +For example, +.Fn bus_read_4 +can be used in place of +.Fn bus_space_read_4 . +The wrapper API is preferred in new drivers. +.Pp +These two statements both read a 32-bit register at the start of a +resource: +.Bd -literal + bus_space_read_4(rman_get_bustag(res), rman_get_bushandle(res), 0); + bus_read_4(res, 0); +.Ed +.Sh RETURN VALUES +Zero is returned on success, otherwise an error is returned. +.Sh SEE ALSO +.Xr bus_alloc_resource 9 , +.Xr bus_map_resource 9 , +.Xr bus_space 9 , +.Xr device 9 , +.Xr driver 9 +.Sh AUTHORS +This manual page was written by +.An Warner Losh Aq Mt imp@FreeBSD.org . |