bhnd_bus_if.m

#-
# Copyright (c) 2015-2016 Landon Fuller <[email protected]>
# Copyright (c) 2017 The FreeBSD Foundation
# All rights reserved.
#
# Portions of this software were developed by Landon Fuller
# under sponsorship from the FreeBSD Foundation.
#
# 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 ``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.
#

#include <sys/types.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <dev/bhnd/bhnd_types.h>
#include <dev/bhnd/bhnd_erom_types.h>

INTERFACE bhnd_bus;

#
# bhnd(4) bus interface
#

HEADER {
	/* forward declarations */
	struct bhnd_board_info;
	struct bhnd_core_info;
	struct bhnd_chipid;
	struct bhnd_dma_translation;
	struct bhnd_devinfo;
	struct bhnd_resource;
}

CODE {
	#include <sys/systm.h>

	#include <dev/bhnd/bhndvar.h>

	static bhnd_erom_class_t *
	bhnd_bus_null_get_erom_class(driver_t *driver)
	{
		return (NULL);
	}

	static struct bhnd_chipid *
	bhnd_bus_null_get_chipid(device_t dev, device_t child)
	{
		panic("bhnd_bus_get_chipid unimplemented");
	}

	static int
	bhnd_bus_null_read_ioctl(device_t dev, device_t child, uint16_t *ioctl)
	{
		panic("bhnd_bus_read_ioctl unimplemented");
	}


	static int
	bhnd_bus_null_write_ioctl(device_t dev, device_t child, uint16_t value,
	    uint16_t mask)
	{
		panic("bhnd_bus_write_ioctl unimplemented");
	}


	static int
	bhnd_bus_null_read_iost(device_t dev, device_t child, uint16_t *iost)
	{
		panic("bhnd_bus_read_iost unimplemented");
	}

	static bool
	bhnd_bus_null_is_hw_suspended(device_t dev, device_t child)
	{
		panic("bhnd_bus_is_hw_suspended unimplemented");
	}

	static int
	bhnd_bus_null_reset_hw(device_t dev, device_t child, uint16_t ioctl,
	    uint16_t reset_ioctl)
	{
		panic("bhnd_bus_reset_hw unimplemented");
	}


	static int
	bhnd_bus_null_suspend_hw(device_t dev, device_t child)
	{
		panic("bhnd_bus_suspend_hw unimplemented");
	}

	static bhnd_attach_type
	bhnd_bus_null_get_attach_type(device_t dev, device_t child)
	{
		panic("bhnd_bus_get_attach_type unimplemented");
	}

	static int
	bhnd_bus_null_read_board_info(device_t dev, device_t child,
	    struct bhnd_board_info *info)
	{
		panic("bhnd_bus_read_boardinfo unimplemented");
	}

	static void
	bhnd_bus_null_child_added(device_t dev, device_t child)
	{
	}

	static int
	bhnd_bus_null_alloc_pmu(device_t dev, device_t child)
	{
		panic("bhnd_bus_alloc_pmu unimplemented");
	}

	static int
	bhnd_bus_null_release_pmu(device_t dev, device_t child)
	{
		panic("bhnd_bus_release_pmu unimplemented");
	}

	static int
	bhnd_bus_null_get_clock_latency(device_t dev, device_t child,
	    bhnd_clock clock, u_int *latency)
	{
		panic("bhnd_pmu_get_clock_latency unimplemented");
	}

	static int
	bhnd_bus_null_get_clock_freq(device_t dev, device_t child,
	    bhnd_clock clock, u_int *freq)
	{
		panic("bhnd_pmu_get_clock_freq unimplemented");
	}

	static int
	bhnd_bus_null_request_clock(device_t dev, device_t child,
	    bhnd_clock clock)
	{
		panic("bhnd_bus_request_clock unimplemented");
	}

	static int
	bhnd_bus_null_enable_clocks(device_t dev, device_t child,
	    uint32_t clocks)
	{
		panic("bhnd_bus_enable_clocks unimplemented");
	}
	
	static int
	bhnd_bus_null_request_ext_rsrc(device_t dev, device_t child,
	    u_int rsrc)
	{
		panic("bhnd_bus_request_ext_rsrc unimplemented");
	}

	static int
	bhnd_bus_null_release_ext_rsrc(device_t dev, device_t child,
	    u_int rsrc)
	{
		panic("bhnd_bus_release_ext_rsrc unimplemented");
	}

	static int
	bhnd_bus_null_read_config(device_t dev, device_t child,
	    bus_size_t offset, void *value, u_int width)
	{
		panic("bhnd_bus_null_read_config unimplemented");
	}

	static void
	bhnd_bus_null_write_config(device_t dev, device_t child,
	    bus_size_t offset, void *value, u_int width)
	{
		panic("bhnd_bus_null_write_config unimplemented");
	}

	static device_t
	bhnd_bus_null_find_hostb_device(device_t dev)
	{
		return (NULL);
	}

	static struct bhnd_service_registry *
	bhnd_bus_null_get_service_registry(device_t dev)
	{
		panic("bhnd_bus_get_service_registry unimplemented");
	}

	static bool
	bhnd_bus_null_is_hw_disabled(device_t dev, device_t child)
	{
		panic("bhnd_bus_is_hw_disabled unimplemented");
	}
	
	static int
	bhnd_bus_null_get_probe_order(device_t dev, device_t child)
	{
		panic("bhnd_bus_get_probe_order unimplemented");
	}

	static uintptr_t
	bhnd_bus_null_get_intr_domain(device_t dev, device_t child, bool self)
	{
		/* Unsupported */
		return (0);
	}

	static u_int
	bhnd_bus_null_get_intr_count(device_t dev, device_t child)
	{
		return (0);
	}

	static int
	bhnd_bus_null_get_intr_ivec(device_t dev, device_t child, u_int intr,
	    u_int *ivec)
	{
		panic("bhnd_bus_get_intr_ivec unimplemented");
	}
	
	static int
	bhnd_bus_null_map_intr(device_t dev, device_t child, u_int intr,
	    rman_res_t *irq)
	{
	    panic("bhnd_bus_map_intr unimplemented");
	}

	static int
	bhnd_bus_null_unmap_intr(device_t dev, device_t child, rman_res_t irq)
	{
	    panic("bhnd_bus_unmap_intr unimplemented");
	}

	static int
	bhnd_bus_null_get_port_rid(device_t dev, device_t child,
	    bhnd_port_type port_type, u_int port, u_int region)
	{
		return (-1);
	}
	
	static int
	bhnd_bus_null_decode_port_rid(device_t dev, device_t child, int type,
	    int rid, bhnd_port_type *port_type, u_int *port, u_int *region)
	{
		return (ENOENT);
	}

	static int
	bhnd_bus_null_get_region_addr(device_t dev, device_t child, 
	    bhnd_port_type type, u_int port, u_int region, bhnd_addr_t *addr,
	    bhnd_size_t *size)
	{
		return (ENOENT);
	}
	
	static int
	bhnd_bus_null_get_nvram_var(device_t dev, device_t child,
	    const char *name, void *buf, size_t *size, bhnd_nvram_type type)
	{
		return (ENODEV);
	}

}

/**
 * Return the bhnd(4) bus driver's device enumeration parser class.
 *
 * @param driver	The bhnd bus driver instance.
 */
STATICMETHOD bhnd_erom_class_t * get_erom_class {
	driver_t			*driver;
} DEFAULT bhnd_bus_null_get_erom_class;

/**
 * Register a shared bus @p provider for a given @p service.
 *
 * @param dev		The parent of @p child.
 * @param child		The requesting child device.
 * @param provider	The service provider to register.
 * @param service	The service for which @p provider will be registered.
 *
 * @retval 0		success
 * @retval EEXIST	if an entry for @p service already exists.
 * @retval non-zero	if registering @p provider otherwise fails, a regular
 *			unix error code will be returned.
 */
METHOD int register_provider {
	device_t dev;
	device_t child;
	device_t provider;
	bhnd_service_t service;
} DEFAULT bhnd_bus_generic_register_provider;

 /**
 * Attempt to remove the @p service provider registration for @p provider.
 *
 * @param dev		The parent of @p child.
 * @param child		The requesting child device.
 * @param provider	The service provider to be deregistered.
 * @param service	The service for which @p provider will be deregistered,
 *			or BHND_SERVICE_INVALID to remove all service
 *			registrations for @p provider.
 *
 * @retval 0		success
 * @retval EBUSY	if active references to @p provider exist; @see
 *			BHND_BUS_RETAIN_PROVIDER() and
 *			BHND_BUS_RELEASE_PROVIDER().
 */
METHOD int deregister_provider {
	device_t dev;
	device_t child;
	device_t provider;
	bhnd_service_t service;
} DEFAULT bhnd_bus_generic_deregister_provider;

/**
 * Retain and return a reference to the registered @p service provider, if any.
 *
 * @param dev		The parent of @p child.
 * @param child		The requesting child device.
 * @param service	The service for which a provider should be returned.
 *
 * On success, the caller assumes ownership the returned provider, and
 * is responsible for releasing this reference via
 * BHND_BUS_RELEASE_PROVIDER().
 *
 * @retval device_t	success
 * @retval NULL		if no provider is registered for @p service. 
 */
METHOD device_t retain_provider {
	device_t dev;
	device_t child;
	bhnd_service_t service;
} DEFAULT bhnd_bus_generic_retain_provider;

 /**
 * Release a reference to a service provider previously returned by
 * BHND_BUS_RETAIN_PROVIDER().
 *
 * @param dev		The parent of @p child.
 * @param child		The requesting child device.
 * @param provider	The provider to be released.
 * @param service	The service for which @p provider was previously
 *			retained.
 */
METHOD void release_provider {
	device_t dev;
	device_t child;
	device_t provider;
	bhnd_service_t service;
} DEFAULT bhnd_bus_generic_release_provider;

/**
 * Return a struct bhnd_service_registry.
 *
 * Used by drivers which use bhnd_bus_generic_sr_register_provider() etc.
 * to implement service provider registration. It should return a service
 * registry that may be used to resolve provider requests from @p child.
 *
 * @param dev		The parent of @p child.
 * @param child		The requesting child device.
 */
METHOD struct bhnd_service_registry * get_service_registry {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_get_service_registry;

/**
 * Return the active host bridge core for the bhnd bus, if any.
 *
 * @param dev The bhnd bus device.
 *
 * @retval device_t if a hostb device exists
 * @retval NULL if no hostb device is found.
 */
METHOD device_t find_hostb_device {
	device_t dev;
} DEFAULT bhnd_bus_null_find_hostb_device;

/**
 * Return true if the hardware components required by @p child are unpopulated
 * or otherwise unusable.
 *
 * In some cases, enumerated devices may have pins that are left floating, or
 * the hardware may otherwise be non-functional; this method allows a parent
 * device to explicitly specify if a successfully enumerated @p child should
 * be disabled.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 */
METHOD bool is_hw_disabled {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_is_hw_disabled;

/**
 * Return the probe (and attach) order for @p child. 
 *
 * All devices on the bhnd(4) bus will be probed, attached, or resumed in
 * ascending order; they will be suspended, shutdown, and detached in
 * descending order.
 *
 * The following device methods will be dispatched in ascending probe order
 * by the bus:
 *
 * - DEVICE_PROBE()
 * - DEVICE_ATTACH()
 * - DEVICE_RESUME()
 *
 * The following device methods will be dispatched in descending probe order
 * by the bus:
 *
 * - DEVICE_SHUTDOWN()
 * - DEVICE_DETACH()
 * - DEVICE_SUSPEND()
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 *
 * Refer to BHND_PROBE_* and BHND_PROBE_ORDER_* for the standard set of
 * priorities.
 */
METHOD int get_probe_order {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_get_probe_order;

/**
 * Return the BHND chip identification for the parent bus.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 */
METHOD const struct bhnd_chipid * get_chipid {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_get_chipid;

/**
 * Return the BHND attachment type of the parent bus.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 *
 * @retval BHND_ATTACH_ADAPTER if the bus is resident on a bridged adapter,
 * such as a WiFi chipset.
 * @retval BHND_ATTACH_NATIVE if the bus provides hardware services (clock,
 * CPU, etc) to a directly attached native host.
 */
METHOD bhnd_attach_type get_attach_type {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_get_attach_type;


/**
 * Find the best available DMA address translation capable of mapping a
 * physical host address to a BHND DMA device address of @p width with
 * @p flags.
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting the DMA address translation.
 * @param width The address width within which the translation window must
 * reside (see BHND_DMA_ADDR_*).
 * @param flags Required translation flags (see BHND_DMA_TRANSLATION_*).
 * @param[out] dmat On success, will be populated with a DMA tag specifying the
 * @p translation DMA address restrictions. This argment may be NULL if the DMA
 * tag is not desired.
 * the set of valid host DMA addresses reachable via @p translation.
 * @param[out] translation On success, will be populated with a DMA address
 * translation descriptor for @p child. This argment may be NULL if the
 * descriptor is not desired.
 *
 * @retval 0 success
 * @retval ENODEV If DMA is not supported.
 * @retval ENOENT If no DMA translation matching @p width and @p flags is
 * available.
 * @retval non-zero If determining the DMA address translation for @p child
 * otherwise fails, a regular unix error code will be returned.
 */
METHOD int get_dma_translation {
	device_t dev;
	device_t child;
	u_int width;
	uint32_t flags;
	bus_dma_tag_t *dmat;
	struct bhnd_dma_translation *translation;
} DEFAULT bhnd_bus_generic_get_dma_translation;

/**
 * Attempt to read the BHND board identification from the parent bus.
 *
 * This relies on NVRAM access, and will fail if a valid NVRAM device cannot
 * be found, or is not yet attached.
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting board info.
 * @param[out] info On success, will be populated with the bhnd(4) device's
 * board information.
 *
 * @retval 0 success
 * @retval ENODEV	No valid NVRAM source could be found.
 * @retval non-zero	If reading @p name otherwise fails, a regular unix
 *			error code will be returned.
 */
METHOD int read_board_info {
	device_t dev;
	device_t child;
	struct bhnd_board_info *info;
} DEFAULT bhnd_bus_null_read_board_info;

/**
 * Notify a bhnd bus that a child was added.
 *
 * This method must be called by concrete bhnd(4) driver impementations
 * after @p child's bus state is fully initialized.
 *
 * @param dev The bhnd bus whose child is being added.
 * @param child The child added to @p dev.
 */
METHOD void child_added {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_child_added;

/**
 * Read the current value of @p child's I/O control register.
 *
 * @param dev The bhnd bus parent of @p child.
 * @param child The bhnd device for which the I/O control register should be
 * read.
 * @param[out] ioctl On success, the I/O control register value.
 *
 * @retval 0 success
 * @retval EINVAL If @p child is not a direct child of @p dev.
 * @retval ENODEV If agent/config space for @p child is unavailable.
 * @retval non-zero If reading the IOCTL register otherwise fails, a regular
 * unix error code will be returned.
 */
METHOD int read_ioctl {
	device_t dev;
	device_t child;
	uint16_t *ioctl;
} DEFAULT bhnd_bus_null_read_ioctl;

/**
 * Write @p value with @p mask to @p child's I/O control register.
 * 
 * @param dev The bhnd bus parent of @p child.
 * @param child The bhnd device for which the I/O control register should
 * be updated.
 * @param value The value to be written (see also BHND_IOCTL_*).
 * @param mask Only the bits defined by @p mask will be updated from @p value.
 * 
 * @retval 0 success
 * @retval EINVAL If @p child is not a direct child of @p dev.
 * @retval ENODEV If agent/config space for @p child is unavailable.
 * @retval non-zero If writing the IOCTL register otherwise fails, a regular
 * unix error code will be returned.
 */
METHOD int write_ioctl {
	device_t dev;
	device_t child;
	uint16_t value;
	uint16_t mask;
} DEFAULT bhnd_bus_null_write_ioctl;

/**
 * Read the current value of @p child's I/O status register.
 *
 * @param dev The bhnd bus parent of @p child.
 * @param child The bhnd device for which the I/O status register should be
 * read.
 * @param[out] iost On success, the I/O status register value.
 * 
 * @retval 0 success
 * @retval EINVAL If @p child is not a direct child of @p dev.
 * @retval ENODEV If agent/config space for @p child is unavailable.
 * @retval non-zero If reading the IOST register otherwise fails, a regular
 * unix error code will be returned.
 */
METHOD int read_iost {
	device_t dev;
	device_t child;
	uint16_t *iost;
} DEFAULT bhnd_bus_null_read_iost;


/**
 * Return true if the given bhnd device's hardware is currently held
 * in a RESET state or otherwise not clocked (BHND_IOCTL_CLK_EN).
 * 
 * @param dev The bhnd bus parent of @p child.
 * @param child The device to query.
 *
 * @retval true If @p child is held in RESET or not clocked (BHND_IOCTL_CLK_EN),
 * or an error occurred determining @p child's hardware state.
 * @retval false If @p child is clocked and is not held in RESET.
 */
METHOD bool is_hw_suspended {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_is_hw_suspended;

/**
 * Place the bhnd(4) device's hardware into a low-power RESET state with
 * the @p reset_ioctl I/O control flags set, and then bring the hardware out of
 * RESET with the @p ioctl I/O control flags set.
 * 
 * Any clock or resource PMU requests previously made by @p child will be
 * invalidated.
 *
 * @param dev The bhnd bus parent of @p child.
 * @param child The device to be reset.
 * @param ioctl Device-specific I/O control flags to be set when bringing
 * the core out of its RESET state (see BHND_IOCTL_*).
 * @param reset_ioctl Device-specific I/O control flags to be set when placing
 * the core into its RESET state.
 *
 * @retval 0 success
 * @retval non-zero error
 */
METHOD int reset_hw {
	device_t dev;
	device_t child;
	uint16_t ioctl;
	uint16_t reset_ioctl;
} DEFAULT bhnd_bus_null_reset_hw;

/**
 * Suspend @p child's hardware in a low-power RESET state.
 *
 * Any clock or resource PMU requests previously made by @p dev will be
 * invalidated.
 *
 * The hardware may be brought out of RESET via bhnd_reset_hw().
 *
 * @param dev The bhnd bus parent of @p child.
 * @param dev The device to be suspended.
 * @param ioctl Device-specific I/O control flags to be set when placing
 * the core into its RESET state (see BHND_IOCTL_*).
 *
 * @retval 0 success
 * @retval non-zero error
 */
METHOD int suspend_hw {
	device_t dev;
	device_t child;
	uint16_t ioctl;
} DEFAULT bhnd_bus_null_suspend_hw;

/**
 * Allocate per-core PMU resources and enable PMU request handling for @p child.
 *
 * The region containing the core's PMU register block (if any) must be
 * allocated via bus_alloc_resource(9) (or bhnd_alloc_resource) before
 * calling BHND_BUS_ALLOC_PMU(), and must not be released until after
 * calling BHND_BUS_RELEASE_PMU().
 *
 * @param dev The parent of @p child.
 * @param child The requesting bhnd device.
 *
 * @retval 0		success
 * @retval non-zero	if enabling per-core PMU request handling fails, a
 *			regular unix error code will be returned.
 */
METHOD int alloc_pmu {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_alloc_pmu;

/**
 * Release per-core PMU resources allocated for @p child. Any
 * outstanding PMU requests are discarded.
 *
 * @param dev The parent of @p child.
 * @param child The requesting bhnd device.
 */
METHOD int release_pmu {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_release_pmu;

/**
 * Return the transition latency required for @p clock in microseconds, if
 * known.
 *
 * The BHND_CLOCK_HT latency value is suitable for use as the D11 core's
 * 'fastpwrup_dly' value. 
 *
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before querying PMU clocks.
 *
 * @param dev The parent of @p child.
 * @param child The requesting bhnd device.
 * @param clock	The clock to be queried for transition latency.
 * @param[out] latency On success, the transition latency of @p clock in
 * microseconds.
 * 
 * @retval 0		success
 * @retval ENODEV	If the transition latency for @p clock is not available.
 */
METHOD int get_clock_latency {
	device_t dev;
	device_t child;
	bhnd_clock clock;
	u_int *latency;
} DEFAULT bhnd_bus_null_get_clock_latency;

/**
 * Return the frequency for @p clock in Hz, if known.
 *
 * @param dev The parent of @p child.
 * @param child The requesting bhnd device.
 * @param clock The clock to be queried.
 * @param[out] freq On success, the frequency of @p clock in Hz.
 *
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before querying PMU clocks.
 * 
 * @retval 0		success
 * @retval ENODEV	If the frequency for @p clock is not available.
 */
METHOD int get_clock_freq {
	device_t dev;
	device_t child;
	bhnd_clock clock;
	u_int *freq;
} DEFAULT bhnd_bus_null_get_clock_freq;

/** 
 * Request that @p clock (or faster) be routed to @p child.
 * 
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before it can request clock resources.
 *
 * @note Any outstanding PMU clock requests will be discarded upon calling
 * BHND_BUS_RESET_HW() or BHND_BUS_SUSPEND_HW().
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting @p clock.
 * @param clock The requested clock source.
 *
 * @retval 0		success
 * @retval ENODEV	If an unsupported clock was requested.
 * @retval ETIMEDOUT	If the clock request succeeds, but the clock is not
 *			detected as ready within the PMU's maximum transition
 *			delay. This should not occur in normal operation.
 */
METHOD int request_clock {
	device_t dev;
	device_t child;
	bhnd_clock clock;
} DEFAULT bhnd_bus_null_request_clock;

/**
 * Request that @p clocks be powered on behalf of @p child.
 *
 * This will power on clock sources (e.g. XTAL, PLL, etc) required for
 * @p clocks and wait until they are ready, discarding any previous
 * requests by @p child.
 *
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before it can request clock resources.
 *
 * @note Any outstanding PMU clock requests will be discarded upon calling
 * BHND_BUS_RESET_HW() or BHND_BUS_SUSPEND_HW().
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting @p clock.
 * @param clock The requested clock source.
 *
 * @retval 0		success
 * @retval ENODEV	If an unsupported clock was requested.
 * @retval ETIMEDOUT	If the clock request succeeds, but the clock is not
 *			detected as ready within the PMU's maximum transition
 *			delay. This should not occur in normal operation.
 */
METHOD int enable_clocks {
	device_t dev;
	device_t child;
	uint32_t clocks;
} DEFAULT bhnd_bus_null_enable_clocks;

/**
 * Power up an external PMU-managed resource assigned to @p child.
 * 
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before it can request PMU resources.
 *
 * @note Any outstanding PMU resource requests will be released upon calling
 * BHND_BUS_RESET_HW() or BHND_BUS_SUSPEND_HW().
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting @p rsrc.
 * @param rsrc The core-specific external resource identifier.
 *
 * @retval 0		success
 * @retval ENODEV	If the PMU does not support @p rsrc.
 * @retval ETIMEDOUT	If the clock request succeeds, but the clock is not
 *			detected as ready within the PMU's maximum transition
 *			delay. This should not occur in normal operation.
 */
METHOD int request_ext_rsrc {
	device_t dev;
	device_t child;
	u_int rsrc;
} DEFAULT bhnd_bus_null_request_ext_rsrc;

/**
 * Power down an external PMU-managed resource assigned to @p child.
 * 
 * @note A driver must ask the bhnd bus to allocate PMU request state
 * via BHND_BUS_ALLOC_PMU() before it can request PMU resources.
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device requesting @p rsrc.
 * @param rsrc The core-specific external resource number.
 *
 * @retval 0		success
 * @retval ENODEV	If the PMU does not support @p rsrc.
 * @retval ETIMEDOUT	If the clock request succeeds, but the clock is not
 *			detected as ready within the PMU's maximum transition
 *			delay. This should not occur in normal operation.
 */
METHOD int release_ext_rsrc {
	device_t dev;
	device_t child;
	u_int rsrc;
} DEFAULT bhnd_bus_null_release_ext_rsrc;

/**
 * Read @p width bytes at @p offset from the bus-specific agent/config
 * space of @p child.
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device for which @p offset should be read.
 * @param offset The offset to be read.
 * @param[out] value On success, the bytes read at @p offset.
 * @param width The size of the access. Must be 1, 2 or 4 bytes.
 *
 * The exact behavior of this method is bus-specific. On a bcma(4) bus, this
 * method provides access to the first agent port of @p child; on a siba(4) bus,
 * this method provides access to the core's CFG0 register block.
 *
 * @note Device drivers should only use this API for functionality
 * that is not available via another bhnd(4) function.
 *
 * @retval 0 success
 * @retval EINVAL If @p child is not a direct child of @p dev.
 * @retval EINVAL If @p width is not one of 1, 2, or 4 bytes.
 * @retval ENODEV If accessing agent/config space for @p child is unsupported.
 * @retval EFAULT If reading @p width at @p offset exceeds the bounds of
 * the mapped agent/config space  for @p child.
 */
METHOD int read_config {
	device_t dev;
	device_t child;
	bus_size_t offset;
	void *value;
	u_int width;
} DEFAULT bhnd_bus_null_read_config;

/**
 * Read @p width bytes at @p offset from the bus-specific agent/config
 * space of @p child.
 *
 * @param dev The parent of @p child.
 * @param child The bhnd device for which @p offset should be read.
 * @param offset The offset to be written.
 * @param value A pointer to the value to be written.
 * @param width The size of @p value. Must be 1, 2 or 4 bytes.
 *
 * The exact behavior of this method is bus-specific. In the case of
 * bcma(4), this method provides access to the first agent port of @p child.
 *
 * @note Device drivers should only use this API for functionality
 * that is not available via another bhnd(4) function.
 *
 * @retval 0 success
 * @retval EINVAL If @p child is not a direct child of @p dev.
 * @retval EINVAL If @p width is not one of 1, 2, or 4 bytes.
 * @retval ENODEV If accessing agent/config space for @p child is unsupported.
 * @retval EFAULT If reading @p width at @p offset exceeds the bounds of
 * the mapped agent/config space  for @p child.
 */
METHOD int write_config {
	device_t dev;
	device_t child;
	bus_size_t offset;
	const void *value;
	u_int width;
} DEFAULT bhnd_bus_null_write_config;

/**
 * Allocate a bhnd resource.
 *
 * This method's semantics are functionally identical to the bus API of the same
 * name; refer to BUS_ALLOC_RESOURCE for complete documentation.
 */
METHOD struct bhnd_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 bhnd_bus_generic_alloc_resource;

/**
 * Release a bhnd resource.
 *
 * This method's semantics are functionally identical to the bus API of the same
 * name; refer to BUS_RELEASE_RESOURCE for complete documentation.
 */
METHOD int release_resource {
	device_t dev;
	device_t child;
	struct bhnd_resource *res;
} DEFAULT bhnd_bus_generic_release_resource;

/**
 * Activate a bhnd resource.
 *
 * This method's semantics are functionally identical to the bus API of the same
 * name; refer to BUS_ACTIVATE_RESOURCE for complete documentation.
 */
METHOD int activate_resource {
	device_t dev;
        device_t child;
        struct bhnd_resource *r;
} DEFAULT bhnd_bus_generic_activate_resource;

/**
 * Deactivate a bhnd resource.
 *
 * This method's semantics are functionally identical to the bus API of the same
 * name; refer to BUS_DEACTIVATE_RESOURCE for complete documentation.
 */
METHOD int deactivate_resource {
        device_t dev;
        device_t child;
        struct bhnd_resource *r;
} DEFAULT bhnd_bus_generic_deactivate_resource;

/**
 * Return the interrupt domain.
 *
 * This globally unique value may be used as the interrupt controller 'xref'
 * on targets that support INTRNG.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 * @param self If true, return @p child's interrupt domain, rather than the
 * domain in which @p child resides.
 *
 * On Non-OFW targets, this should either return:
 *   - The pointer address of a device that can uniquely identify @p child's
 *     interrupt domain (e.g., the bhnd bus' device_t address), or
 *   - 0 if unsupported by the bus.
 *
 * On OFW (including FDT) targets, this should return the @p child's iparent
 * property's xref if @p self is false, the child's own node xref value if
 * @p self is true, or 0 if no interrupt parent is found.
 */
METHOD uintptr_t get_intr_domain {
	device_t dev;
	device_t child;
	bool self;
} DEFAULT bhnd_bus_null_get_intr_domain;
 
/**
 * Return the number of interrupt lines assigned to @p child.
 * 
 * @param dev The bhnd device whose child is being examined.
 * @param child The child device.
 */
METHOD u_int get_intr_count {
	device_t dev;
	device_t child;
} DEFAULT bhnd_bus_null_get_intr_count;

/**
 * Get the backplane interrupt vector of the @p intr line attached to @p child.
 * 
 * @param dev The device whose child is being examined.
 * @param child The child device.
 * @param intr The index of the interrupt line being queried.
 * @param[out] ivec On success, the assigned hardware interrupt vector will be
 * written to this pointer.
 *
 * On bcma(4) devices, this returns the OOB bus line assigned to the
 * interrupt.
 *
 * On siba(4) devices, this returns the target OCP slave flag number assigned
 * to the interrupt.
 *
 * @retval 0		success
 * @retval ENXIO	If @p intr exceeds the number of interrupt lines
 *			assigned to @p child.
 */
METHOD int get_intr_ivec {
	device_t dev;
	device_t child;
	u_int intr;
	u_int *ivec;
} DEFAULT bhnd_bus_null_get_intr_ivec;

/**
 * Map the given @p intr to an IRQ number; until unmapped, this IRQ may be used
 * to allocate a resource of type SYS_RES_IRQ.
 * 
 * On success, the caller assumes ownership of the interrupt mapping, and
 * is responsible for releasing the mapping via BHND_BUS_UNMAP_INTR().
 * 
 * @param dev The bhnd bus device.
 * @param child The requesting child device.
 * @param intr The interrupt being mapped.
 * @param[out] irq On success, the bus interrupt value mapped for @p intr.
 *
 * @retval 0		If an interrupt was assigned.
 * @retval non-zero	If mapping an interrupt otherwise fails, a regular
 *			unix error code will be returned.
 */
METHOD int map_intr {
	device_t dev;
	device_t child;
	u_int intr;
	rman_res_t *irq;
} DEFAULT bhnd_bus_null_map_intr;

/**
 * Unmap an bus interrupt previously mapped via BHND_BUS_MAP_INTR().
 * 
 * @param dev The bhnd bus device.
 * @param child The requesting child device.
 * @param intr The interrupt number being unmapped. This is equivalent to the
 * bus resource ID for the interrupt.
 */
METHOD void unmap_intr {
	device_t dev;
	device_t child;
	rman_res_t irq;
} DEFAULT bhnd_bus_null_unmap_intr;

/**
 * Return true if @p region_num is a valid region on @p port_num of
 * @p type attached to @p child.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 * @param type The port type being queried.
 * @param port_num The port number being queried.
 * @param region_num The region number being queried.
 */
METHOD bool is_region_valid {
	device_t dev;
	device_t child;
	bhnd_port_type type;
	u_int port_num;
	u_int region_num;
};

/**
 * Return the number of ports of type @p type attached to @p child.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 * @param type The port type being queried.
 */
METHOD u_int get_port_count {
	device_t dev;
	device_t child;
	bhnd_port_type type;
};

/**
 * Return the number of memory regions mapped to @p child @p port of
 * type @p type.
 *
 * @param dev The device whose child is being examined.
 * @param child The child device.
 * @param port The port number being queried.
 * @param type The port type being queried.
 */
METHOD u_int get_region_count {
	device_t dev;
	device_t child;
	bhnd_port_type type;
	u_int port;
};

/**
 * Return the SYS_RES_MEMORY resource-ID for a port/region pair attached to
 * @p child.
 *
 * @param dev The bus device.
 * @param child The bhnd child.
 * @param port_type The port type.
 * @param port_num The index of the child interconnect port.
 * @param region_num The index of the port-mapped address region.
 *
 * @retval -1 No such port/region found.
 */
METHOD int get_port_rid {
	device_t dev;
	device_t child;
	bhnd_port_type port_type;
	u_int port_num;
	u_int region_num;
} DEFAULT bhnd_bus_null_get_port_rid;


/**
 * Decode a port / region pair on @p child defined by @p type and @p rid.
 *
 * @param dev The bus device.
 * @param child The bhnd child.
 * @param type The resource type.
 * @param rid The resource ID.
 * @param[out] port_type The port's type.
 * @param[out] port The port identifier.
 * @param[out] region The identifier of the memory region on @p port.
 * 
 * @retval 0 success
 * @retval non-zero No matching type/rid found.
 */
METHOD int decode_port_rid {
	device_t dev;
	device_t child;
	int type;
	int rid;
	bhnd_port_type *port_type;
	u_int *port;
	u_int *region;
} DEFAULT bhnd_bus_null_decode_port_rid;

/**
 * Get the address and size of @p region on @p port.
 *
 * @param dev The bus device.
 * @param child The bhnd child.
 * @param port_type The port type.
 * @param port The port identifier.
 * @param region The identifier of the memory region on @p port.
 * @param[out] region_addr The region's base address.
 * @param[out] region_size The region's size.
 *
 * @retval 0 success
 * @retval non-zero No matching port/region found.
 */
METHOD int get_region_addr {
	device_t dev;
	device_t child;
	bhnd_port_type port_type;
	u_int port;
	u_int region;
	bhnd_addr_t *region_addr;
	bhnd_size_t *region_size;
} DEFAULT bhnd_bus_null_get_region_addr;

/**
 * Read an NVRAM variable.
 * 
 * It is the responsibility of the bus to delegate this request to
 * the appropriate NVRAM child device, or to a parent bus implementation.
 *
 * @param		dev	The bus device.
 * @param		child	The requesting device.
 * @param		name	The NVRAM variable name.
 * @param[out]		buf	On success, the requested value will be written
 *				to this buffer. This argment may be NULL if
 *				the value is not desired.
 * @param[in,out]	size	The capacity of @p buf. On success, will be set
 *				to the actual size of the requested value.
 * @param		type	The data type to be written to @p buf.
 *
 * @retval 0		success
 * @retval ENOENT	The requested variable was not found.
 * @retval ENOMEM	If @p buf is non-NULL and a buffer of @p size is too
 *			small to hold the requested value.
 * @retval ENODEV	No valid NVRAM source could be found.
 * @retval EFTYPE	If the @p name's data type cannot be coerced to @p type.
 * @retval ERANGE	If value coercion would overflow @p type.
 * @retval non-zero	If reading @p name otherwise fails, a regular unix
 *			error code will be returned.
 */
METHOD int get_nvram_var {
	device_t	 dev;
	device_t	 child;
	const char	*name;
	void		*buf;
	size_t		*size;
	bhnd_nvram_type	 type;
} DEFAULT bhnd_bus_null_get_nvram_var;


/** An implementation of bus_read_1() compatible with bhnd_resource */
METHOD uint8_t read_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_read_2() compatible with bhnd_resource */
METHOD uint16_t read_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_read_4() compatible with bhnd_resource */
METHOD uint32_t read_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_write_1() compatible with bhnd_resource */
METHOD void write_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t value;
}

/** An implementation of bus_write_2() compatible with bhnd_resource */
METHOD void write_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t value;
}

/** An implementation of bus_write_4() compatible with bhnd_resource */
METHOD void write_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t value;
}

/** An implementation of bus_read_stream_1() compatible with bhnd_resource */
METHOD uint8_t read_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_read_stream_2() compatible with bhnd_resource */
METHOD uint16_t read_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_read_stream_4() compatible with bhnd_resource */
METHOD uint32_t read_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
}

/** An implementation of bus_write_stream_1() compatible with bhnd_resource */
METHOD void write_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t value;
}

/** An implementation of bus_write_stream_2() compatible with bhnd_resource */
METHOD void write_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t value;
}

/** An implementation of bus_write_stream_4() compatible with bhnd_resource */
METHOD void write_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t value;
}

/** An implementation of bus_read_multi_1() compatible with bhnd_resource */
METHOD void read_multi_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_multi_2() compatible with bhnd_resource */
METHOD void read_multi_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_multi_4() compatible with bhnd_resource */
METHOD void read_multi_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_1() compatible with bhnd_resource */
METHOD void write_multi_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_2() compatible with bhnd_resource */
METHOD void write_multi_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_4() compatible with bhnd_resource */
METHOD void write_multi_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_multi_stream_1() compatible
 *  bhnd_resource */
METHOD void read_multi_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_multi_stream_2() compatible
 *  bhnd_resource */
METHOD void read_multi_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_multi_stream_4() compatible
 *  bhnd_resource */
METHOD void read_multi_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_stream_1() compatible
 *  bhnd_resource */
METHOD void write_multi_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_stream_2() compatible with
 *  bhnd_resource */
METHOD void write_multi_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_multi_stream_4() compatible with
 *  bhnd_resource */
METHOD void write_multi_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_set_multi_1() compatible with bhnd_resource */
METHOD void set_multi_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t value;
	bus_size_t count;
}

/** An implementation of bus_set_multi_2() compatible with bhnd_resource */
METHOD void set_multi_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t value;
	bus_size_t count;
}

/** An implementation of bus_set_multi_4() compatible with bhnd_resource */
METHOD void set_multi_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t value;
	bus_size_t count;
}

/** An implementation of bus_set_region_1() compatible with bhnd_resource */
METHOD void set_region_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t value;
	bus_size_t count;
}

/** An implementation of bus_set_region_2() compatible with bhnd_resource */
METHOD void set_region_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t value;
	bus_size_t count;
}

/** An implementation of bus_set_region_4() compatible with bhnd_resource */
METHOD void set_region_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t value;
	bus_size_t count;
}

/** An implementation of bus_read_region_1() compatible with bhnd_resource */
METHOD void read_region_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_region_2() compatible with bhnd_resource */
METHOD void read_region_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_region_4() compatible with bhnd_resource */
METHOD void read_region_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_region_stream_1() compatible with
  * bhnd_resource */
METHOD void read_region_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_region_stream_2() compatible with
  * bhnd_resource */
METHOD void read_region_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_read_region_stream_4() compatible with
  * bhnd_resource */
METHOD void read_region_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_1() compatible with bhnd_resource */
METHOD void write_region_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_2() compatible with bhnd_resource */
METHOD void write_region_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_4() compatible with bhnd_resource */
METHOD void write_region_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_stream_1() compatible with
  * bhnd_resource */
METHOD void write_region_stream_1 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint8_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_stream_2() compatible with
  * bhnd_resource */
METHOD void write_region_stream_2 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint16_t *datap;
	bus_size_t count;
}

/** An implementation of bus_write_region_stream_4() compatible with
  * bhnd_resource */
METHOD void write_region_stream_4 {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	uint32_t *datap;
	bus_size_t count;
}

/** An implementation of bus_barrier() compatible with bhnd_resource */
METHOD void barrier {
	device_t dev;
	device_t child;
	struct bhnd_resource *r;
	bus_size_t offset;
	bus_size_t length;
	int flags;
}