freebsd-dev/sys/kern/bus_if.m
Justin Hibbits 937a05ba81 Add necessary bits for Linux KPI to work correctly on powerpc
PowerPC, and possibly other architectures, use different address ranges for
PCI space vs physical address space, which is only mapped at resource
activation time, when the BAR gets written.  The DRM kernel modules do not
activate the rman resources, soas not to waste KVA, instead only mapping
parts of the PCI memory at a time.  This introduces a
BUS_TRANSLATE_RESOURCE() method, implemented in the Open Firmware/FDT PCI
driver, to perform this necessary translation without activating the
resource.

In addition to system KPI changes, LinuxKPI is updated to handle a
big-endian host, by adding proper endian swaps to the I/O functions.

Submitted by:	mmacy
Reported by:	hselasky
Differential Revision:	https://reviews.freebsd.org/D21096
2019-08-04 19:28:10 +00:00

935 lines
26 KiB
Objective-C

#-
# Copyright (c) 1998-2004 Doug Rabson
# All rights reserved.
#
# 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
#
# $FreeBSD$
#
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/bus.h>
/**
* @defgroup BUS bus - KObj methods for drivers of devices with children
* @brief A set of methods required device drivers that support
* child devices.
* @{
*/
INTERFACE bus;
#
# Default implementations of some methods.
#
CODE {
static struct resource *
null_alloc_resource(device_t dev, device_t child,
int type, int *rid, rman_res_t start, rman_res_t end,
rman_res_t count, u_int flags)
{
return (0);
}
static int
null_remap_intr(device_t bus, device_t dev, u_int irq)
{
if (dev != NULL)
return (BUS_REMAP_INTR(dev, NULL, irq));
return (ENXIO);
}
static device_t
null_add_child(device_t bus, int order, const char *name,
int unit)
{
panic("bus_add_child is not implemented");
}
static int null_reset_post(device_t bus, device_t dev)
{
return (0);
}
static int null_reset_prepare(device_t bus, device_t dev)
{
return (0);
}
static int
null_translate_resource(device_t bus, int type, rman_res_t start,
rman_res_t *newstart)
{
if (device_get_parent(bus) != NULL)
return (BUS_TRANSLATE_RESOURCE(device_get_parent(bus),
type, start, newstart));
*newstart = start;
return (0);
}
};
/**
* @brief Print a description of a child device
*
* This is called from system code which prints out a description of a
* device. It should describe the attachment that the child has with
* the parent. For instance the TurboLaser bus prints which node the
* device is attached to. See bus_generic_print_child() for more
* information.
*
* @param _dev the device whose child is being printed
* @param _child the child device to describe
*
* @returns the number of characters output.
*/
METHOD int print_child {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_print_child;
/**
* @brief Print a notification about an unprobed child device.
*
* Called for each child device that did not succeed in probing for a
* driver.
*
* @param _dev the device whose child was being probed
* @param _child the child device which failed to probe
*/
METHOD void probe_nomatch {
device_t _dev;
device_t _child;
};
/**
* @brief Read the value of a bus-specific attribute of a device
*
* This method, along with BUS_WRITE_IVAR() manages a bus-specific set
* of instance variables of a child device. The intention is that
* each different type of bus defines a set of appropriate instance
* variables (such as ports and irqs for ISA bus etc.)
*
* This information could be given to the child device as a struct but
* that makes it hard for a bus to add or remove variables without
* forcing an edit and recompile for all drivers which may not be
* possible for vendor supplied binary drivers.
*
* This method copies the value of an instance variable to the
* location specified by @p *_result.
*
* @param _dev the device whose child was being examined
* @param _child the child device whose instance variable is
* being read
* @param _index the instance variable to read
* @param _result a location to receive the instance variable
* value
*
* @retval 0 success
* @retval ENOENT no such instance variable is supported by @p
* _dev
*/
METHOD int read_ivar {
device_t _dev;
device_t _child;
int _index;
uintptr_t *_result;
};
/**
* @brief Write the value of a bus-specific attribute of a device
*
* This method sets the value of an instance variable to @p _value.
*
* @param _dev the device whose child was being updated
* @param _child the child device whose instance variable is
* being written
* @param _index the instance variable to write
* @param _value the value to write to that instance variable
*
* @retval 0 success
* @retval ENOENT no such instance variable is supported by @p
* _dev
* @retval EINVAL the instance variable was recognised but
* contains a read-only value
*/
METHOD int write_ivar {
device_t _dev;
device_t _child;
int _indx;
uintptr_t _value;
};
/**
* @brief Notify a bus that a child was deleted
*
* Called at the beginning of device_delete_child() to allow the parent
* to teardown any bus-specific state for the child.
*
* @param _dev the device whose child is being deleted
* @param _child the child device which is being deleted
*/
METHOD void child_deleted {
device_t _dev;
device_t _child;
};
/**
* @brief Notify a bus that a child was detached
*
* Called after the child's DEVICE_DETACH() method to allow the parent
* to reclaim any resources allocated on behalf of the child.
*
* @param _dev the device whose child changed state
* @param _child the child device which changed state
*/
METHOD void child_detached {
device_t _dev;
device_t _child;
};
/**
* @brief Notify a bus that a new driver was added
*
* Called when a new driver is added to the devclass which owns this
* bus. The generic implementation of this method attempts to probe and
* attach any un-matched children of the bus.
*
* @param _dev the device whose devclass had a new driver
* added to it
* @param _driver the new driver which was added
*/
METHOD void driver_added {
device_t _dev;
driver_t *_driver;
} DEFAULT bus_generic_driver_added;
/**
* @brief Create a new child device
*
* For buses which use use drivers supporting DEVICE_IDENTIFY() to
* enumerate their devices, this method is used to create new
* device instances. The new device will be added after the last
* existing child with the same order. Implementations of bus_add_child
* call device_add_child_ordered to add the child and often add
* a suitable ivar to the device specific to that bus.
*
* @param _dev the bus device which will be the parent of the
* new child device
* @param _order a value which is used to partially sort the
* children of @p _dev - devices created using
* lower values of @p _order appear first in @p
* _dev's list of children
* @param _name devclass name for new device or @c NULL if not
* specified
* @param _unit unit number for new device or @c -1 if not
* specified
*/
METHOD device_t add_child {
device_t _dev;
u_int _order;
const char *_name;
int _unit;
} DEFAULT null_add_child;
/**
* @brief Rescan the bus
*
* This method is called by a parent bridge or devctl to trigger a bus
* rescan. The rescan should delete devices no longer present and
* enumerate devices that have newly arrived.
*
* @param _dev the bus device
*/
METHOD int rescan {
device_t _dev;
}
/**
* @brief Allocate a system resource
*
* This method is called by child devices of a bus to allocate resources.
* The types are defined in <machine/resource.h>; the meaning of the
* resource-ID field varies from bus to bus (but @p *rid == 0 is always
* valid if the resource type is). If a resource was allocated and the
* caller did not use the RF_ACTIVE to specify that it should be
* activated immediately, the caller is responsible for calling
* BUS_ACTIVATE_RESOURCE() when it actually uses the resource.
*
* @param _dev the parent device of @p _child
* @param _child the device which is requesting an allocation
* @param _type the type of resource to allocate
* @param _rid a pointer to the resource identifier
* @param _start hint at the start of the resource range - pass
* @c 0 for any start address
* @param _end hint at the end of the resource range - pass
* @c ~0 for any end address
* @param _count hint at the size of range required - pass @c 1
* for any size
* @param _flags any extra flags to control the resource
* allocation - see @c RF_XXX flags in
* <sys/rman.h> for details
*
* @returns the resource which was allocated or @c NULL if no
* resource could be allocated
*/
METHOD struct resource * alloc_resource {
device_t _dev;
device_t _child;
int _type;
int *_rid;
rman_res_t _start;
rman_res_t _end;
rman_res_t _count;
u_int _flags;
} DEFAULT null_alloc_resource;
/**
* @brief Activate a resource
*
* Activate a resource previously allocated with
* BUS_ALLOC_RESOURCE(). This may enable decoding of this resource in a
* device for instance. It will also establish a mapping for the resource
* unless RF_UNMAPPED was set when allocating the resource.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _rid the resource identifier
* @param _r the resource to activate
*/
METHOD int activate_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
struct resource *_r;
};
/**
* @brief Map a resource
*
* Allocate a mapping for a range of an active resource. The mapping
* is described by a struct resource_map object. This may for instance
* map a memory region into the kernel's virtual address space.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _r the resource to map
* @param _args optional attributes of the mapping
* @param _map the mapping
*/
METHOD int map_resource {
device_t _dev;
device_t _child;
int _type;
struct resource *_r;
struct resource_map_request *_args;
struct resource_map *_map;
} DEFAULT bus_generic_map_resource;
/**
* @brief Unmap a resource
*
* Release a mapping previously allocated with
* BUS_MAP_RESOURCE(). This may for instance unmap a memory region
* from the kernel's virtual address space.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _r the resource
* @param _map the mapping to release
*/
METHOD int unmap_resource {
device_t _dev;
device_t _child;
int _type;
struct resource *_r;
struct resource_map *_map;
} DEFAULT bus_generic_unmap_resource;
/**
* @brief Deactivate a resource
*
* Deactivate a resource previously allocated with
* BUS_ALLOC_RESOURCE().
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _rid the resource identifier
* @param _r the resource to deactivate
*/
METHOD int deactivate_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
struct resource *_r;
};
/**
* @brief Adjust a resource
*
* Adjust the start and/or end of a resource allocated by
* BUS_ALLOC_RESOURCE. At least part of the new address range must overlap
* with the existing address range. If the successful, the resource's range
* will be adjusted to [start, end] on return.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _res the resource to adjust
* @param _start the new starting address of the resource range
* @param _end the new ending address of the resource range
*/
METHOD int adjust_resource {
device_t _dev;
device_t _child;
int _type;
struct resource *_res;
rman_res_t _start;
rman_res_t _end;
};
/**
* @brief translate a resource value
*
*
* @param _dev the device associated with the resource
* @param _type the type of resource
* @param _start the starting address of the resource range
* @param _newstart the new starting address of the resource range
*/
METHOD int translate_resource {
device_t _dev;
int _type;
rman_res_t _start;
rman_res_t *_newstart;
} DEFAULT null_translate_resource;
/**
* @brief Release a resource
*
* Free a resource allocated by the BUS_ALLOC_RESOURCE. The @p _rid
* value must be the same as the one returned by BUS_ALLOC_RESOURCE()
* (which is not necessarily the same as the one the client passed).
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _type the type of resource
* @param _rid the resource identifier
* @param _r the resource to release
*/
METHOD int release_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
struct resource *_res;
};
/**
* @brief Install an interrupt handler
*
* This method is used to associate an interrupt handler function with
* an irq resource. When the interrupt triggers, the function @p _intr
* will be called with the value of @p _arg as its single
* argument. The value returned in @p *_cookiep is used to cancel the
* interrupt handler - the caller should save this value to use in a
* future call to BUS_TEARDOWN_INTR().
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
* @param _flags a set of bits from enum intr_type specifying
* the class of interrupt
* @param _intr the function to call when the interrupt
* triggers
* @param _arg a value to use as the single argument in calls
* to @p _intr
* @param _cookiep a pointer to a location to receive a cookie
* value that may be used to remove the interrupt
* handler
*/
METHOD int setup_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
int _flags;
driver_filter_t *_filter;
driver_intr_t *_intr;
void *_arg;
void **_cookiep;
};
/**
* @brief Uninstall an interrupt handler
*
* This method is used to disassociate an interrupt handler function
* with an irq resource. The value of @p _cookie must be the value
* returned from a previous call to BUS_SETUP_INTR().
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
* @param _cookie the cookie value returned when the interrupt
* was originally registered
*/
METHOD int teardown_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
void *_cookie;
};
/**
* @brief Suspend an interrupt handler
*
* This method is used to mark a handler as suspended in the case
* that the associated device is powered down and cannot be a source
* for the, typically shared, interrupt.
* The value of @p _irq must be the interrupt resource passed
* to a previous call to BUS_SETUP_INTR().
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
*/
METHOD int suspend_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
} DEFAULT bus_generic_suspend_intr;
/**
* @brief Resume an interrupt handler
*
* This method is used to clear suspended state of a handler when
* the associated device is powered up and can be an interrupt source
* again.
* The value of @p _irq must be the interrupt resource passed
* to a previous call to BUS_SETUP_INTR().
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
*/
METHOD int resume_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
} DEFAULT bus_generic_resume_intr;
/**
* @brief Define a resource which can be allocated with
* BUS_ALLOC_RESOURCE().
*
* This method is used by some buses (typically ISA) to allow a
* driver to describe a resource range that it would like to
* allocate. The resource defined by @p _type and @p _rid is defined
* to start at @p _start and to include @p _count indices in its
* range.
*
* @param _dev the parent device of @p _child
* @param _child the device which owns the resource
* @param _type the type of resource
* @param _rid the resource identifier
* @param _start the start of the resource range
* @param _count the size of the resource range
*/
METHOD int set_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
rman_res_t _start;
rman_res_t _count;
};
/**
* @brief Describe a resource
*
* This method allows a driver to examine the range used for a given
* resource without actually allocating it.
*
* @param _dev the parent device of @p _child
* @param _child the device which owns the resource
* @param _type the type of resource
* @param _rid the resource identifier
* @param _start the address of a location to receive the start
* index of the resource range
* @param _count the address of a location to receive the size
* of the resource range
*/
METHOD int get_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
rman_res_t *_startp;
rman_res_t *_countp;
};
/**
* @brief Delete a resource.
*
* Use this to delete a resource (possibly one previously added with
* BUS_SET_RESOURCE()).
*
* @param _dev the parent device of @p _child
* @param _child the device which owns the resource
* @param _type the type of resource
* @param _rid the resource identifier
*/
METHOD void delete_resource {
device_t _dev;
device_t _child;
int _type;
int _rid;
};
/**
* @brief Return a struct resource_list.
*
* Used by drivers which use bus_generic_rl_alloc_resource() etc. to
* implement their resource handling. It should return the resource
* list of the given child device.
*
* @param _dev the parent device of @p _child
* @param _child the device which owns the resource list
*/
METHOD struct resource_list * get_resource_list {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_get_resource_list;
/**
* @brief Is the hardware described by @p _child still attached to the
* system?
*
* This method should return 0 if the device is not present. It
* should return -1 if it is present. Any errors in determining
* should be returned as a normal errno value. Client drivers are to
* assume that the device is present, even if there is an error
* determining if it is there. Buses are to try to avoid returning
* errors, but newcard will return an error if the device fails to
* implement this method.
*
* @param _dev the parent device of @p _child
* @param _child the device which is being examined
*/
METHOD int child_present {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_child_present;
/**
* @brief Returns the pnp info for this device.
*
* Return it as a string. If the storage is insufficient for the
* string, then return EOVERFLOW.
*
* The string must be formatted as a space-separated list of
* name=value pairs. Names may only contain alphanumeric characters,
* underscores ('_') and hyphens ('-'). Values can contain any
* non-whitespace characters. Values containing whitespace can be
* quoted with double quotes ('"'). Double quotes and backslashes in
* quoted values can be escaped with backslashes ('\').
*
* @param _dev the parent device of @p _child
* @param _child the device which is being examined
* @param _buf the address of a buffer to receive the pnp
* string
* @param _buflen the size of the buffer pointed to by @p _buf
*/
METHOD int child_pnpinfo_str {
device_t _dev;
device_t _child;
char *_buf;
size_t _buflen;
};
/**
* @brief Returns the location for this device.
*
* Return it as a string. If the storage is insufficient for the
* string, then return EOVERFLOW.
*
* The string must be formatted as a space-separated list of
* name=value pairs. Names may only contain alphanumeric characters,
* underscores ('_') and hyphens ('-'). Values can contain any
* non-whitespace characters. Values containing whitespace can be
* quoted with double quotes ('"'). Double quotes and backslashes in
* quoted values can be escaped with backslashes ('\').
*
* @param _dev the parent device of @p _child
* @param _child the device which is being examined
* @param _buf the address of a buffer to receive the location
* string
* @param _buflen the size of the buffer pointed to by @p _buf
*/
METHOD int child_location_str {
device_t _dev;
device_t _child;
char *_buf;
size_t _buflen;
};
/**
* @brief Allow drivers to request that an interrupt be bound to a specific
* CPU.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
* @param _cpu the CPU to bind the interrupt to
*/
METHOD int bind_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
int _cpu;
} DEFAULT bus_generic_bind_intr;
/**
* @brief Allow (bus) drivers to specify the trigger mode and polarity
* of the specified interrupt.
*
* @param _dev the bus device
* @param _irq the interrupt number to modify
* @param _trig the trigger mode required
* @param _pol the interrupt polarity required
*/
METHOD int config_intr {
device_t _dev;
int _irq;
enum intr_trigger _trig;
enum intr_polarity _pol;
} DEFAULT bus_generic_config_intr;
/**
* @brief Allow drivers to associate a description with an active
* interrupt handler.
*
* @param _dev the parent device of @p _child
* @param _child the device which allocated the resource
* @param _irq the resource representing the interrupt
* @param _cookie the cookie value returned when the interrupt
* was originally registered
* @param _descr the description to associate with the interrupt
*/
METHOD int describe_intr {
device_t _dev;
device_t _child;
struct resource *_irq;
void *_cookie;
const char *_descr;
} DEFAULT bus_generic_describe_intr;
/**
* @brief Notify a (bus) driver about a child that the hints mechanism
* believes it has discovered.
*
* The bus is responsible for then adding the child in the right order
* and discovering other things about the child. The bus driver is
* free to ignore this hint, to do special things, etc. It is all up
* to the bus driver to interpret.
*
* This method is only called in response to the parent bus asking for
* hinted devices to be enumerated.
*
* @param _dev the bus device
* @param _dname the name of the device w/o unit numbers
* @param _dunit the unit number of the device
*/
METHOD void hinted_child {
device_t _dev;
const char *_dname;
int _dunit;
};
/**
* @brief Returns bus_dma_tag_t for use w/ devices on the bus.
*
* @param _dev the parent device of @p _child
* @param _child the device to which the tag will belong
*/
METHOD bus_dma_tag_t get_dma_tag {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_get_dma_tag;
/**
* @brief Returns bus_space_tag_t for use w/ devices on the bus.
*
* @param _dev the parent device of @p _child
* @param _child the device to which the tag will belong
*/
METHOD bus_space_tag_t get_bus_tag {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_get_bus_tag;
/**
* @brief Allow the bus to determine the unit number of a device.
*
* @param _dev the parent device of @p _child
* @param _child the device whose unit is to be wired
* @param _name the name of the device's new devclass
* @param _unitp a pointer to the device's new unit value
*/
METHOD void hint_device_unit {
device_t _dev;
device_t _child;
const char *_name;
int *_unitp;
};
/**
* @brief Notify a bus that the bus pass level has been changed
*
* @param _dev the bus device
*/
METHOD void new_pass {
device_t _dev;
} DEFAULT bus_generic_new_pass;
/**
* @brief Notify a bus that specified child's IRQ should be remapped.
*
* @param _dev the bus device
* @param _child the child device
* @param _irq the irq number
*/
METHOD int remap_intr {
device_t _dev;
device_t _child;
u_int _irq;
} DEFAULT null_remap_intr;
/**
* @brief Suspend a given child
*
* @param _dev the parent device of @p _child
* @param _child the device to suspend
*/
METHOD int suspend_child {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_suspend_child;
/**
* @brief Resume a given child
*
* @param _dev the parent device of @p _child
* @param _child the device to resume
*/
METHOD int resume_child {
device_t _dev;
device_t _child;
} DEFAULT bus_generic_resume_child;
/**
* @brief Get the VM domain handle for the given bus and child.
*
* @param _dev the bus device
* @param _child the child device
* @param _domain a pointer to the bus's domain handle identifier
*/
METHOD int get_domain {
device_t _dev;
device_t _child;
int *_domain;
} DEFAULT bus_generic_get_domain;
/**
* @brief Request a set of CPUs
*
* @param _dev the bus device
* @param _child the child device
* @param _op type of CPUs to request
* @param _setsize the size of the set passed in _cpuset
* @param _cpuset a pointer to a cpuset to receive the requested
* set of CPUs
*/
METHOD int get_cpus {
device_t _dev;
device_t _child;
enum cpu_sets _op;
size_t _setsize;
struct _cpuset *_cpuset;
} DEFAULT bus_generic_get_cpus;
/**
* @brief Prepares the given child of the bus for reset
*
* Typically bus detaches or suspends children' drivers, and then
* calls this method to save bus-specific information, for instance,
* PCI config space, which is damaged by reset.
*
* The bus_helper_reset_prepare() helper is provided to ease
* implementing bus reset methods.
*
* @param _dev the bus device
* @param _child the child device
*/
METHOD int reset_prepare {
device_t _dev;
device_t _child;
} DEFAULT null_reset_prepare;
/**
* @brief Restores the child operations after the reset
*
* The bus_helper_reset_post() helper is provided to ease
* implementing bus reset methods.
*
* @param _dev the bus device
* @param _child the child device
*/
METHOD int reset_post {
device_t _dev;
device_t _child;
} DEFAULT null_reset_post;
/**
* @brief Performs reset of the child
*
* @param _dev the bus device
* @param _child the child device
* @param _flags DEVF_RESET_ flags
*/
METHOD int reset_child {
device_t _dev;
device_t _child;
int _flags;
};