BHND_EROM(9)

NAME
bhnd_erom, bhnd_erom_alloc, bhnd_erom_dump, bhnd_erom_fini_static, bhnd_erom_free, bhnd_erom_free_core_table, bhnd_erom_get_core_table, bhnd_erom_init_static, bhnd_erom_io, bhnd_erom_io_fini, bhnd_erom_io_map, bhnd_erom_io_read, bhnd_erom_iobus_init, bhnd_erom_iores_new, bhnd_erom_lookup_core, bhnd_erom_lookup_core_addr, bhnd_erom_probe, bhnd_erom_probe_driver_classes - BHND device enumeration table parsing

SYNOPSIS
#include <dev/bhnd/bhnd.h>
#include <dev/bhnd/bhnd_erom.h>
typedef struct bhnd_erom bhnd_erom_t;
typedef struct kobj_class bhnd_erom_class_t;
typedef struct bhnd_erom_static bhnd_erom_static_t;
int
bhnd_erom_probe(bhnd_erom_class_t *cls, struct bhnd_erom_io *eio, const struct bhnd_chipid *hint, struct bhnd_chipid *cid);
bhnd_erom_class_t *
bhnd_erom_probe_driver_classes(devclass_t bus_devclass, struct bhnd_erom_io *eio, const struct bhnd_chipid *hint, struct bhnd_chipid *cid);
bhnd_erom_t *
bhnd_erom_alloc(bhnd_erom_class_t *cls, const struct bhnd_chipid *cid, struct bhnd_erom_io *eio);
void
bhnd_erom_free(bhnd_erom_t *erom);
int
bhnd_erom_init_static(bhnd_erom_class_t *cls, bhnd_erom_t *erom, size_t esize, const struct bhnd_chipid *cid, struct bhnd_erom_io *eio);
void
bhnd_erom_fini_static(bhnd_erom_t *erom);
int
bhnd_erom_dump(bhnd_erom_t *erom);
int
bhnd_erom_get_core_table(bhnd_erom_t *erom, struct bhnd_core_info **cores, u_int *num_cores);
void
bhnd_erom_free_core_table(bhnd_erom_t *erom, struct bhnd_core_info *cores);
int
bhnd_erom_lookup_core(bhnd_erom_t *erom, const struct bhnd_core_match *desc, struct bhnd_core_info *core);
int
bhnd_erom_lookup_core_addr(bhnd_erom_t *erom, const struct bhnd_core_match *desc, bhnd_port_type type, u_int port, u_int region, struct bhnd_core_info *core, bhnd_addr_t *addr, bhnd_size_t *size);

  Bus Space I/O
struct bhnd_erom_io *
bhnd_erom_iores_new(device_t dev, int rid);
int
bhnd_erom_iobus_init(struct bhnd_erom_iobus *iobus, bhnd_addr_t addr, bhnd_size_t size, bus_space_tag_t bst, bus_space_handle_t bsh);
void
bhnd_erom_io_fini(struct bhnd_erom_io *eio);
int
bhnd_erom_io_map(struct bhnd_erom_io *eio, bhnd_addr_t addr, bhnd_size_t size);
uint32_t
bhnd_erom_io_read(struct bhnd_erom_io *eio, bhnd_size_t offset, u_int width);
#include <dev/bhnd/bhnd_eromvar.h>

    struct bhnd_erom_io {
    	bhnd_erom_io_map_t	*map;
    	bhnd_erom_io_read_t	*read;
    	bhnd_erom_io_fini_t	*fini;
    };

typedef int
bhnd_erom_io_map_t(struct bhnd_erom_io *eio, bhnd_addr_t addr, bhnd_size_t size);
typedef uint32_t
bhnd_erom_io_read_t(struct bhnd_erom_io *eio, bhnd_size_t offset, u_int width);
typedef void
bhnd_erom_io_fini_t(struct bhnd_erom_io *eio);

DESCRIPTION
The bhnd_erom framework provides a common parser interface to the BHND device enumeration table formats supported by bhnd(4) bus drivers.

The bhnd_erom_probe() function is used to identify a bhnd(4) bus device and determine whether the erom class cls is capable of parsing its device enumeration table. If successful, the probed chip identification is written to the location pointed to by cid.

A pointer to a bus I/O instance mapping the device registers of the first hardware core must be provided using the eio argument. The registers can be mapped using bhnd_erom_io_map().

On devices that do not provide standard bhnd_chipc(4) chip identification registers via the first hardware core, a pointer to chip information for the device must be specified using the hint argument. Otherwise, the hint argument should be NULL.

The bhnd_erom_probe_driver_classes() function is a convenience wrapper for bhnd_erom_probe(). This function will iterate over all drivers instances in the device class bus_devclass, using bhnd_driver_get_erom_class(9) to fetch each driver's erom class and probe the hardware core mapped by 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, NULL is returned.

The bhnd_erom_alloc() function allocates and returns a new parser instance of the device enumeration class cls for the chip identified by cid, using the bus I/O instance eio to map and read the device table. On success, the returned bhnd_erom_t assumes ownership of eio.

The bhnd_erom_free() function releases all resources held by an erom parser successfully allocated using bhnd_erom_alloc().

Clients can manage the allocation of memory themselves with bhnd_erom_init_static(). This is useful in cases like performing device enumeration before malloc(9) initialization. bhnd_erom_init_static() is called with erom set to a pointer to the memory for the instance, and the total available bytes in esize.

The bhnd_erom_static structure is large enough to statically allocate any supported parser class instance state. Pointers to a bhnd_erom_static structure can be cast to bhnd_erom_t.

The bhnd_erom_fini_static() function releases all resources held by an erom parser successfully initialized using bhnd_erom_init_static().

The bhnd_erom_dump() function enumerates and prints all device table entries in erom.

The bhnd_erom_get_core_table() function enumerates all device table entries in erom, returning a table of core information structures in cores and the count in num_cores. The memory allocated for the table must be freed using bhnd_erom_free_core_table().

The bhnd_erom_free_core_table() function frees any memory allocated in a previous call to bhnd_erom_get_core_table().

The bhnd_erom_lookup_core() function locates the first device table entry in erom that matches core match descriptor desc, writing the core information of the matching entry to core.

The bhnd_erom_lookup_core_addr() function locates the first device table entry in erom that matches core match descriptor desc, fetching the base address and size of the memory region region mapped to the port port of type type. On success, the core information of the matching entry is written to core, the base address of the port region is written to addr, and the total size of the port region is written to size. If the core information is not desired, set core to NULL.

  Bus Space I/O
The bhnd_erom_io structure provides a set of I/O callbacks used by bhnd_erom to map and read the device enumeration table. Clients may either use the existing bhnd_erom_iores_new() or bhnd_erom_iobus_init() functions to allocate a bus I/O instance, or implement the bhnd_erom_io callbacks directly.

The bhnd_erom_io structure contains these required fields:

map A function implementing bhnd_erom_io_map().

read
    A function implementing bhnd_erom_io_read().

fini
    A function implementing bhnd_erom_io_fini().

The bhnd_erom_iores_new() function allocates and returns a new bus I/O instance that will perform mapping by using bhnd_alloc_resource(9) to allocate SYS_RES_MEMORY bus resources on demand from the device dev using a resource ID of rid.

The bhnd_erom_iobus_init() function initializes a caller-allocated bus I/O instance iobus that will perform bus I/O using the bus space tag bst and handle bsh. The base address and total size mapped by bsh should be specified using the addr and size arguments.

The bhnd_erom_io_fini() function frees all resources held by the bus I/O instance eio.

The bhnd_erom_io_map() function is used to request that the bus I/O instance eio map bhnd(4) bus space at bus address addr with a mapping of size size.

The bhnd_erom_io_read() function is used to read a data item of width bytes from the bus I/O instance eio at offset, relative to the bus address previously mapped using bhnd_erom_io_map().

The width must be one of 1, 2, or 4 bytes.

RETURN VALUES
The bhnd_erom_probe() function returns a standard DEVICE_PROBE(9) result.

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. ENXIO is returned if the device is not supported by the parser.

The bhnd_erom_probe_driver_classes() function returns a pointer to the probed bhnd_erom_class_t instance on success, a null pointer otherwise.

The bhnd_erom_alloc() function returns a pointer to bhnd_erom_t on success, or NULL if an error occurred allocating or initializing the EROM parser.

The bhnd_erom_init_static() function returns 0 on success, ENOMEM if the allocation size is smaller than required by the erom class, or an appropriate error code if initialization otherwise fails.

The bhnd_erom_lookup_core() function returns 0 on success, ENOENT if no matching core is found, or an appropriate error code if parsing the device table otherwise fails.

The bhnd_erom_dump(), bhnd_erom_get_core_table(), bhnd_erom_iobus_init(), bhnd_erom_io_map(), functions return 0 on success, otherwise an appropriate error code is returned.

SEE ALSO
bhnd(4), bhnd(9), bhnd_alloc_resource(9), bhnd_driver_get_erom_class(9), bus_space(9)

AUTHORS
-nosplit The bhnd_erom framework and this manual page were written by Landon Fuller <landonf@FreeBSD.org>.