.\" Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
.\" Copyright (c) 2017 The FreeBSD Foundation
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.\" Portions of this documentation were written by Landon Fuller
.\" under sponsorship from the FreeBSD Foundation.
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.Dd November 9, 2017
.Dt BHND_EROM 9
.Os
.Sh NAME
.Nm bhnd_erom ,
.Nm bhnd_erom_alloc ,
.Nm bhnd_erom_dump ,
.Nm bhnd_erom_fini_static ,
.Nm bhnd_erom_free ,
.Nm bhnd_erom_free_core_table ,
.Nm bhnd_erom_get_core_table ,
.Nm bhnd_erom_init_static ,
.Nm bhnd_erom_io ,
.Nm bhnd_erom_io_fini ,
.Nm bhnd_erom_io_map ,
.Nm bhnd_erom_io_read ,
.Nm bhnd_erom_iobus_init ,
.Nm bhnd_erom_iores_new ,
.Nm bhnd_erom_lookup_core ,
.Nm bhnd_erom_lookup_core_addr ,
.Nm bhnd_erom_probe ,
.Nm bhnd_erom_probe_driver_classes
.Nd BHND device enumeration table parsing
.Sh SYNOPSIS
.In dev/bhnd/bhnd.h
.In dev/bhnd/bhnd_erom.h
.\"
.Vt typedef struct bhnd_erom bhnd_erom_t ;
.Vt typedef struct kobj_class bhnd_erom_class_t ;
.Vt typedef struct bhnd_erom_static bhnd_erom_static_t ;
.Ft int
.Fo bhnd_erom_probe
.Fa "bhnd_erom_class_t *cls"
.Fa "struct bhnd_erom_io *eio"
.Fa "const struct bhnd_chipid *hint"
.Fa "struct bhnd_chipid *cid"
.Fc
.Ft bhnd_erom_class_t *
.Fo bhnd_erom_probe_driver_classes
.Fa "devclass_t bus_devclass"
.Fa "struct bhnd_erom_io *eio"
.Fa "const struct bhnd_chipid *hint"
.Fa "struct bhnd_chipid *cid"
.Fc
.Ft bhnd_erom_t *
.Fo bhnd_erom_alloc
.Fa "bhnd_erom_class_t *cls"
.Fa "const struct bhnd_chipid *cid"
.Fa "struct bhnd_erom_io *eio"
.Fc
.Ft void
.Fo bhnd_erom_free
.Fa "bhnd_erom_t *erom"
.Fc
.Ft int
.Fo bhnd_erom_init_static
.Fa "bhnd_erom_class_t *cls"
.Fa "bhnd_erom_t *erom"
.Fa "size_t esize"
.Fa "const struct bhnd_chipid *cid"
.Fa "struct bhnd_erom_io *eio"
.Fc
.Ft void
.Fo bhnd_erom_fini_static
.Fa "bhnd_erom_t *erom"
.Fc
.Ft int
.Fo bhnd_erom_dump
.Fa "bhnd_erom_t *erom"
.Fc
.Ft int
.Fo bhnd_erom_get_core_table
.Fa "bhnd_erom_t *erom"
.Fa "struct bhnd_core_info **cores"
.Fa "u_int *num_cores"
.Fc
.Ft void
.Fo bhnd_erom_free_core_table
.Fa "bhnd_erom_t *erom"
.Fa "struct bhnd_core_info *cores"
.Fc
.Ft int
.Fo bhnd_erom_lookup_core
.Fa "bhnd_erom_t *erom"
.Fa "const struct bhnd_core_match *desc"
.Fa "struct bhnd_core_info *core"
.Fc
.Ft int
.Fo bhnd_erom_lookup_core_addr
.Fa "bhnd_erom_t *erom"
.Fa "const struct bhnd_core_match *desc"
.Fa "bhnd_port_type type"
.Fa "u_int port"
.Fa "u_int region"
.Fa "struct bhnd_core_info *core"
.Fa "bhnd_addr_t *addr"
.Fa "bhnd_size_t *size"
.Fc
.\"
.Ss Bus Space I/O
.Ft struct bhnd_erom_io *
.Fo bhnd_erom_iores_new
.Fa "device_t dev"
.Fa "int rid"
.Fc
.Ft int
.Fo bhnd_erom_iobus_init
.Fa "struct bhnd_erom_iobus *iobus"
.Fa "bhnd_addr_t addr"
.Fa "bhnd_size_t size"
.Fa "bus_space_tag_t bst"
.Fa "bus_space_handle_t bsh"
.Fc
.Ft void
.Fo bhnd_erom_io_fini
.Fa "struct bhnd_erom_io *eio"
.Fc
.Ft int
.Fo bhnd_erom_io_map
.Fa "struct bhnd_erom_io *eio"
.Fa "bhnd_addr_t addr"
.Fa "bhnd_size_t size"
.Fc
.Ft uint32_t
.Fo bhnd_erom_io_read
.Fa "struct bhnd_erom_io *eio"
.Fa "bhnd_size_t offset"
.Fa "u_int width"
.Fc
.In dev/bhnd/bhnd_eromvar.h
.Bd -literal
struct bhnd_erom_io {
	bhnd_erom_io_map_t	*map;
	bhnd_erom_io_read_t	*read;
	bhnd_erom_io_fini_t	*fini;
};
.Ed
.Ft typedef int
.Fo \*(lpbhnd_erom_io_map_t\*(rp
.Fa "struct bhnd_erom_io *eio"
.Fa "bhnd_addr_t addr"
.Fa "bhnd_size_t size"
.Fc
.Ft typedef uint32_t
.Fo \*(lpbhnd_erom_io_read_t\*(rp
.Fa "struct bhnd_erom_io *eio"
.Fa "bhnd_size_t offset"
.Fa "u_int width"
.Fc
.Ft typedef void
.Fo "\*(lpbhnd_erom_io_fini_t\*(rp
.Fa "struct bhnd_erom_io *eio"
.Fc
.\"
.Sh DESCRIPTION
The
.Nm
framework provides a common parser interface to the BHND device enumeration
table formats supported by
.Xr bhnd 4
bus drivers.
.Pp
The
.Fn bhnd_erom_probe
function is used to identify a
.Xr bhnd 4
bus device and determine whether the erom class
.Fa cls
is capable of parsing its device enumeration table.
If successful, the probed chip identification is written to the location
pointed to by
.Fa cid .
.Pp
A pointer to a bus I/O instance mapping the device registers of the first
hardware core must be provided using the
.Fa eio
argument.
The registers can be mapped using
.Xr bhnd_erom_io_map 9 .
.Pp
On devices that do not provide standard
.Xr bhnd_chipc 4
chip identification registers via the first hardware core, a pointer to chip
information for the device must be specified using the
.Fa hint
argument.
Otherwise, the
.Fa hint
argument should be
.Dv NULL .
.Pp
The
.Fn bhnd_erom_probe_driver_classes
function is a convenience wrapper for
.Fn bhnd_erom_probe .
This function will iterate over all drivers instances in the device class
.Fa bus_devclass ,
using
.Xr bhnd_driver_get_erom_class 9
to fetch each driver's erom class and probe the hardware core mapped by
.Fa eio .
A pointer to the erom class with the highest probe priority is returned on
success.
If there are no successful probe results from the erom classes,
.Dv NULL
is returned.
.Pp
The
.Fn bhnd_erom_alloc
function allocates and returns a new parser instance of the device enumeration
class
.Fa cls
for the chip identified by
.Fa cid ,
using the bus I/O instance
.Fa eio
to map and read the device table.
On success, the returned
.Vt bhnd_erom_t
assumes ownership of
.Fa eio .
.Pp
The
.Fn bhnd_erom_free
function releases all resources held by an erom parser successfully allocated
using
.Fn bhnd_erom_alloc .
.Pp
Clients can manage the allocation of memory themselves with
.Fn bhnd_erom_init_static .
This is useful in cases like performing device enumeration before
.Xr malloc 9
initialization.
.Fn bhnd_erom_init_static
is called with
.Fa erom
set to a pointer to the memory for the instance, and the total available bytes
in
.Fa esize .
.Pp
The
.Vt bhnd_erom_static
structure is large enough to statically allocate any supported parser class
instance state.
Pointers to a
.Vt bhnd_erom_static
structure can be cast to
.Vt bhnd_erom_t .
.Pp
The
.Fn bhnd_erom_fini_static
function releases all resources held by an erom parser successfully
initialized using
.Fn bhnd_erom_init_static .
.Pp
The
.Fn bhnd_erom_dump
function enumerates and prints all device table entries in
.Fa erom .
.Pp
The
.Fn bhnd_erom_get_core_table
function enumerates all device table entries in
.Fa erom ,
returning a table of core information structures in
.Fa cores
and the count in
.Fa num_cores .
The memory allocated for the table must be freed using
.Fn bhnd_erom_free_core_table .
.Pp
The
.Fn bhnd_erom_free_core_table
function frees any memory allocated in a previous call to
.Fn bhnd_erom_get_core_table .
.Pp
The
.Fn bhnd_erom_lookup_core
function locates the first device table entry in
.Fa erom
that matches core match descriptor
.Fa desc ,
writing the core information of the matching entry to
.Fa core .
.Pp
The
.Fn bhnd_erom_lookup_core_addr
function locates the first device table entry in
.Fa erom
that matches core match descriptor
.Fa desc ,
fetching the base address and size of the memory region
.Fa region
mapped to the port
.Fa port
of type
.Fa type .
On success, the core information of the matching entry is written to
.Fa core ,
the base address of the port region is written to
.Fa addr ,
and the total size of the port region is written to
.Fa size .
If the core information is not desired, set
.Fa core
to
.Dv NULL .
.Ss Bus Space I/O
The
.Vt bhnd_erom_io
structure provides a set of I/O callbacks used by
.Nm
to map and read the device enumeration table.
Clients may either use the existing
.Fn bhnd_erom_iores_new
or
.Fn bhnd_erom_iobus_init
functions to allocate a bus I/O instance, or implement the
.Vt bhnd_erom_io
callbacks directly.
.Pp
The
.Vt bhnd_erom_io
structure contains these required fields:
.Bl -tag -width "read" -offset indent
.It Fa map
A function implementing
.Fn bhnd_erom_io_map .
.It Fa read
A function implementing
.Fn bhnd_erom_io_read .
.It Fa fini
A function implementing
.Fn bhnd_erom_io_fini .
.El
.Pp
The
.Fn bhnd_erom_iores_new
function allocates and returns a new bus I/O instance that will perform mapping
by using
.Xr bhnd_alloc_resource 9
to allocate
.Dv SYS_RES_MEMORY
bus resources on demand from the device
.Fa dev
using a resource ID of
.Fa rid .
.Pp
The
.Fn bhnd_erom_iobus_init
function initializes a caller-allocated bus I/O instance
.Fa iobus
that will perform bus I/O using the bus space tag
.Fa bst
and handle
.Fa bsh .
The base address and total size mapped by
.Fa bsh
should be specified using the
.Fa addr
and
.Fa size
arguments.
.Pp
The
.Fn bhnd_erom_io_fini
function frees all resources held by the bus I/O instance
.Fa eio .
.Pp
The
.Fn bhnd_erom_io_map
function is used to request that the bus I/O instance
.Fa eio
map
.Xr bhnd 4
bus space at bus address
.Fa addr
with a mapping of size
.Fa size .
.Pp
The
.Fn bhnd_erom_io_read
function is used to read a data item of
.Fa width
bytes from the bus I/O instance
.Fa eio
at
.Fa offset ,
relative to the bus address previously mapped using
.Fn bhnd_erom_io_map .
.Pp
The
.Fa width
must be one of 1, 2, or 4 bytes.
.Sh RETURN VALUES
The
.Fn bhnd_erom_probe
function returns a standard
.Xr DEVICE_PROBE 9
result.
.Pp
A return value equal to or less than zero indicates success.
Values greater than zero indicates an error, and will be an appropriate error
code.
For values less than or equal to zero, the erom class returning the highest
value should be used to parse the erom table.
.Er ENXIO
is returned if the device is not supported by the parser.
.Pp
The
.Fn bhnd_erom_probe_driver_classes
function returns a pointer to the probed
.Vt bhnd_erom_class_t
instance on success, a null pointer otherwise.
.Pp
The
.Fn bhnd_erom_alloc
function returns a pointer to
.Vt bhnd_erom_t
on success, or
.Dv NULL
if an error occurred allocating or initializing the EROM parser.
.Pp
The
.Fn bhnd_erom_init_static
function returns 0 on success,
.Er ENOMEM
if the allocation size is smaller than required by the erom class, or
an appropriate error code if initialization otherwise fails.
.Pp
The
.Fn bhnd_erom_lookup_core
function returns 0 on success,
.Er ENOENT
if no matching core is found, or an appropriate error code if parsing the device
table otherwise fails.
.Pp
The
.Fn bhnd_erom_dump ,
.Fn bhnd_erom_get_core_table ,
.Fn bhnd_erom_iobus_init ,
.Fn bhnd_erom_io_map ,
functions return 0 on success, otherwise an appropriate error code is returned.
.Sh SEE ALSO
.Xr bhnd 4 ,
.Xr bhnd 9 ,
.Xr bhnd_alloc_resource 9 ,
.Xr bhnd_driver_get_erom_class 9 ,
.Xr bus_space 9
.Sh AUTHORS
.An -nosplit
The
.Nm
framework and this manual page were written by
.An Landon Fuller Aq Mt landonf@FreeBSD.org .