NAME
ISAPNP
,
isapnp_devmatch
,
isapnp_config
,
isapnp_unconfig
—
Plug 'n' Play ISA bus
SYNOPSIS
#include
<sys/bus.h>
#include <dev/isa/isareg.h>
#include <dev/isa/isavar.h>
#include
<dev/isapnp/isapnpreg.h>
#include
<dev/isapnp/isapnpvar.h>
#include
<dev/isapnp/isapnpdevs.h>
int
isapnp_devmatch
(const
struct isapnp_attach_args *ipa,
const struct isapnp_devinfo
*dinfo, int
*variant);
int
isapnp_config
(bus_space_tag_t
iot, bus_space_tag_t
memt, struct
isapnp_attach_args *ipa);
void
isapnp_unconfig
(bus_space_tag_t
iot, bus_space_tag_t
memt, struct
isapnp_attach_args *ipa);
DESCRIPTION
The machine-independent ISAPNP
subsystem
provides support for ISAPNP devices. ISAPNP devices were developed to
support "plug and play" connection on the ISA bus. In all other
aspects, the ISAPNP bus is same as the ISA bus (see
isa(9)).
Devices on the ISAPNP bus are uniquely identified by a 7-character string. Resources, such as I/O address space and interrupts, should be allocated to the devices by the machine firmware. On some machine the firmware seems doesn't work correctly and NetBSD will attempt to allocate resources as necessary.
DATA TYPES
Drivers attached to the ISAPNP bus will make use of the following data types:
- struct isapnp_matchinfo
- NetBSD kernel contains a database of known ISAPNP
devices. Each entry in the database has a struct
isapnp_matchinfo. It contains the following members:
const char *name; /* device id string */ int variant; /* variant flag */
- struct isapnp_devinfo
- Defines the devices supported by a driver. It contains pointer to an array
of supported struct isapnp_matchinfo structures and a
pointer to another array of compatibility devices. It contains the
following members:
struct isapnp_matchinfo *devlogic; int nlogic; struct isapnp_matchinfo *devcompat; int ncompat;
- struct isapnp_region
- Describes ISAPNP bus-space regions. It contains the following members:
bus_space_handle_t h; uint32_t base; uint32_t length;
- struct isapnp_pin
- Describes the wiring of interrupts and DMA pins from the ISAPNP bus onto
the host processor. It contains the following members:
uint8_t num; uint8_t flags:4; uint8_t type:4; uint16_t bits;
- struct isapnp_attach_args
- A structure used to inform the driver of the device properties. It
contains the following members:
bus_space_tag_t ipa_iot; /* isa i/o space tag */ bus_space_tag_t ipa_memt; /* isa mem space tag */ bus_dma_tag_t ipa_dmat; /* isa dma tag */ isa_chipset_tag_t ipa_ic; struct isapnp_region ipa_io[ISAPNP_NUM_IO]; struct isapnp_region ipa_mem[ISAPNP_NUM_MEM]; struct isapnp_region ipa_mem32[ISAPNP_NUM_MEM32]; struct isapnp_pin ipa_irq[ISAPNP_NUM_IRQ]; struct isapnp_pin ipa_drq[ISAPNP_NUM_DRQ];
FUNCTIONS
isapnp_devmatch
(ipa, dinfo, variant)- Matches the device described by the attachment ipa
with the device-match information in dinfo. If the
device is matched,
isapnp_devmatch
() returns a non-zero value and variant is the flag describing the device variant.isapnp_devmatch
() returns zero if the device is not found. isapnp_config
(iot, memt, ipa)- Allocate device resources specified by ipa. The
device is mapped into the I/O and memory bus spaces specified by bus-space
tags iot and memt
respectively. The ipa_io,
ipa_mem, ipa_mem32,
ipa_irq, and ipa_drq members
of ipa are updated to reflect the allocated and
mapped resources.
isapnp_config
() returns zero on success and non-zero on error. isapnp_unconfig
(iot, memt, ipa)- Free the resources allocated by
isapnp_config
().
AUTOCONFIGURATION
During autoconfiguration, an ISAPNP driver will receive a pointer
to struct isapnp_attach_args describing the device
attached to the ISAPNP bus. Drivers match the device using
ispnp_devmatch
().
During the driver attach step, driver should
initially allocate and map resources using
isapnp_config
().
The I/O (memory) bus-space resources can be accessed using the bus-space tag
ipa_iot (ipa_memt) and the
bus-space handle ipa_io[0].h
(ipa_mem[0].h) members of
ipa.
Interrupts should be established using
isa_intr_establish
()
(see isa(9)) with the IRQ specified by the
ipa_irq[0].num member of ipa.
Similarly, the standard
isa(9) DMA interface should be used with the
ipa_drq[0].num member of
ipa.
DMA SUPPORT
Extensive DMA facilities are provided through the isa(9) DMA facilities.
CODE REFERENCES
The ISAPNP
subsystem itself is implemented
within the file sys/dev/isapnp/isapnp.c. The
database of the known devices exists within the file
sys/dev/isapnp/isapnpdevs.c and is generated
automatically from the file
sys/dev/isapnp/isapnpdevs. New devices should be
added to this file. The database can be regenerated using the Makefile
sys/dev/isapnp/Makefile.isapnpdevs.
SEE ALSO
isa(4), isapnp(4), pnpbios(4), autoconf(9), bus_dma(9), bus_space(9), driver(9), isa(9)
Plug and Play ISA Specification V1.0a, May 5 1994.
HISTORY
The machine-independent ISAPNP subsystem appear in NetBSD 1.3.