u-boot dm驱动模型-udevice和driver
设备
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (c) 2013 Google, Inc
*
* (C) Copyright 2012
* Pavel Herrmann <morpheus.ibis@gmail.com>
* Marek Vasut <marex@denx.de>
*/
#ifndef _DM_DEVICE_H
#define _DM_DEVICE_H
#include <dm/ofnode.h>
#include <dm/uclass-id.h>
#include <fdtdec.h>
#include <linker_lists.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/printk.h>
struct driver_info;
/* Driver is active (probed). Cleared when it is removed */
#define DM_FLAG_ACTIVATED (1 << 0)
/* DM is responsible for allocating and freeing plat */
#define DM_FLAG_ALLOC_PDATA (1 << 1)
/* DM should init this device prior to relocation */
#define DM_FLAG_PRE_RELOC (1 << 2)
/* DM is responsible for allocating and freeing parent_plat */
#define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
/* DM is responsible for allocating and freeing uclass_plat */
#define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
/* Allocate driver private data on a DMA boundary */
#define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
/* Device is bound */
#define DM_FLAG_BOUND (1 << 6)
/* Device name is allocated and should be freed on unbind() */
#define DM_FLAG_NAME_ALLOCED (1 << 7)
/* Device has platform data provided by of-platdata */
#define DM_FLAG_OF_PLATDATA (1 << 8)
/*
* Call driver remove function to stop currently active DMA transfers or
* give DMA buffers back to the HW / controller. This may be needed for
* some drivers to do some final stage cleanup before the OS is called
* (U-Boot exit)
*/
#define DM_FLAG_ACTIVE_DMA (1 << 9)
/*
* Call driver remove function to do some final configuration, before
* U-Boot exits and the OS is started
*/
#define DM_FLAG_OS_PREPARE (1 << 10)
/* DM does not enable/disable the power domains corresponding to this device */
#define DM_FLAG_DEFAULT_PD_CTRL_OFF (1 << 11)
/* Driver plat has been read. Cleared when the device is removed */
#define DM_FLAG_PLATDATA_VALID (1 << 12)
/*
* Device is removed without switching off its power domain. This might
* be required, i. e. for serial console (debug) output when booting OS.
*/
#define DM_FLAG_LEAVE_PD_ON (1 << 13)
/*
* Device is vital to the operation of other devices. It is possible to remove
* removed this device after all regular devices are removed. This is useful
* e.g. for clock, which need to be active during the device-removal phase.
*/
#define DM_FLAG_VITAL (1 << 14)
/*
* One or multiple of these flags are passed to device_remove() so that
* a selective device removal as specified by the remove-stage and the
* driver flags can be done.
*
* DO NOT use these flags in your driver's @flags value...
* use the above DM_FLAG_... values instead
*/
enum {
/* Normal remove, remove all devices */
DM_REMOVE_NORMAL = 1 << 0,
/* Remove devices with active DMA */
DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
/* Remove devices which need some final OS preparation steps */
DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
/* Remove only devices that are not marked vital */
DM_REMOVE_NON_VITAL = DM_FLAG_VITAL,
/* Remove devices with any active flag */
DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
/* Don't power down any attached power domains */
DM_REMOVE_NO_PD = 1 << 1,
};
/**
* struct udevice - An instance of a driver
*
* This holds information about a device, which is a driver bound to a
* particular port or peripheral (essentially a driver instance).
*
* A device will come into existence through a 'bind' call, either due to
* a U_BOOT_DRVINFO() macro (in which case plat is non-NULL) or a node
* in the device tree (in which case of_offset is >= 0). In the latter case
* we translate the device tree information into plat in a function
* implemented by the driver of_to_plat method (called just before the
* probe method if the device has a device tree node.
*
* All three of plat, priv and uclass_priv can be allocated by the
* driver, or you can use the auto members of struct driver and
* struct uclass_driver to have driver model do this automatically.
*
* @driver: The driver used by this device
* @name: Name of device, typically the FDT node name
* @plat_: Configuration data for this device (do not access outside driver
* model)
* @parent_plat_: The parent bus's configuration data for this device (do not
* access outside driver model)
* @uclass_plat_: The uclass's configuration data for this device (do not access
* outside driver model)
* @driver_data: Driver data word for the entry that matched this device with
* its driver
* @parent: Parent of this device, or NULL for the top level device
* @priv_: Private data for this device (do not access outside driver model)
* @uclass: Pointer to uclass for this device
* @uclass_priv_: The uclass's private data for this device (do not access
* outside driver model)
* @parent_priv_: The parent's private data for this device (do not access
* outside driver model)
* @uclass_node: Used by uclass to link its devices
* @child_head: List of children of this device
* @sibling_node: Next device in list of all devices
* @flags_: Flags for this device DM_FLAG_... (do not access outside driver
* model)
* @seq_: Allocated sequence number for this device (-1 = none). This is set up
* when the device is bound and is unique within the device's uclass. If the
* device has an alias in the devicetree then that is used to set the sequence
* number. Otherwise, the next available number is used. Sequence numbers are
* used by certain commands that need device to be numbered (e.g. 'mmc dev').
* (do not access outside driver model)
* @node_: Reference to device tree node for this device (do not access outside
* driver model)
* @devres_head: List of memory allocations associated with this device.
* When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
* add to this list. Memory so-allocated will be freed
* automatically when the device is removed / unbound
* @dma_offset: Offset between the physical address space (CPU's) and the
* device's bus address space
*/
struct udevice {
// 这个设备使用的driver
const struct driver *driver;
// 设备名，通常是FDT节点名
const char *name;
// 该设备的配置数据
void *plat_;
// 这个设备的父总线配置数据
void *parent_plat_;
// 这个设备的uclass配置数据
void *uclass_plat_;
// 此设备与匹配的驱动struct udevice_id中的data成员数据
ulong driver_data;
// 这个设备的父类，或者是顶级设备那么就为NULL。
struct udevice *parent;
// 此设备的私有数据
void *priv_;
// 指向这个设备uclass的指针
struct uclass *uclass;
// 对于这个设备uclass的私有数据
void *uclass_priv_;
// 对于这个设备parent的私有数据
void *parent_priv_;
// uclass通过它来链接设备（uclass_node可以获取当前udevice的地址，它被挂载在对应id uclass的uc->dev_head链表中，uclass_foreach_dev可以遍历对应id uclass的所有udevice。）
struct list_head uclass_node;
// 此设备的子设备列表（如果当前设备为parent，那么child的sibling_node将会在child_head链表上）
struct list_head child_head;
// 在设备列表中的下一个设备（sibling_node可以获取当前udevice的地址，通过它可以遍历挂在链表上的下一个udevice。）
struct list_head sibling_node;
#if !CONFIG_IS_ENABLED(OF_PLATDATA_RT)
// 此设备的标志，DM_FLAG_...开头，如：DM_FLAG_ALLOC_UCLASS_PDATA等
u32 flags_;
#endif
// 此设备请求的序列号(-1 = any)
int seq_;
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
//在设备树中的节点位置
ofnode node_;
#endif
#ifdef CONFIG_DEVRES
// 当CONFIG_DEVRES被定义时，devm_kmalloc()和friends会添加到这个列表中。这样分配的内存将在设备被移除/解除绑定时自动释放。
// 与此设备相关联的memory allocations列表。
struct list_head devres_head;
#endif
#if CONFIG_IS_ENABLED(DM_DMA)
ulong dma_offset;
#endif
};
/**
* udevice_rt - runtime information set up by U-Boot
*
* This is only used with OF_PLATDATA_RT
*
* There is one of these for every udevice in the linker list, indexed by
* the udevice_info idx value.
*
* @flags_: Flags for this device DM_FLAG_... (do not access outside driver
* model)
*/
struct udevice_rt {
u32 flags_;
};
/* Maximum sequence number supported and associated string length */
#define DM_MAX_SEQ 999
#define DM_MAX_SEQ_STR 3
/* Returns the operations for a device */
#define device_get_ops(dev) (dev->driver->ops)
#if CONFIG_IS_ENABLED(OF_PLATDATA_RT)
u32 dev_get_flags(const struct udevice *dev);
void dev_or_flags(const struct udevice *dev, u32 or);
void dev_bic_flags(const struct udevice *dev, u32 bic);
#else
static inline u32 dev_get_flags(const struct udevice *dev)
{
return dev->flags_;
}
static inline void dev_or_flags(struct udevice *dev, u32 or)
{
dev->flags_ |= or;
}
static inline void dev_bic_flags(struct udevice *dev, u32 bic)
{
dev->flags_ &= ~bic;
}
#endif /* OF_PLATDATA_RT */
/**
* dev_ofnode() - get the DT node reference associated with a udevice
*
* @dev: device to check
* @return reference of the the device's DT node
*/
static inline ofnode dev_ofnode(const struct udevice *dev)
{
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
return dev->node_;
#else
return ofnode_null();
#endif
}
/* Returns non-zero if the device is active (probed and not removed) */
#define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
#if CONFIG_IS_ENABLED(DM_DMA)
#define dev_set_dma_offset(_dev, _offset) _dev->dma_offset = _offset
#define dev_get_dma_offset(_dev) _dev->dma_offset
#else
#define dev_set_dma_offset(_dev, _offset)
#define dev_get_dma_offset(_dev) 0
#endif
static inline int dev_of_offset(const struct udevice *dev)
{
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
return ofnode_to_offset(dev_ofnode(dev));
#else
return -1;
#endif
}
static inline bool dev_has_ofnode(const struct udevice *dev)
{
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
return ofnode_valid(dev_ofnode(dev));
#else
return false;
#endif
}
static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
{
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
dev->node_ = node;
#endif
}
static inline int dev_seq(const struct udevice *dev)
{
return dev->seq_;
}
/**
* struct udevice_id - Lists the compatible strings supported by a driver
* @compatible: Compatible string
* @data: Data for this compatible string
*/
struct udevice_id {
const char *compatible;
ulong data;
};
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
#define of_match_ptr(_ptr) (_ptr)
#else
#define of_match_ptr(_ptr) NULL
#endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
/**
* struct driver - A driver for a feature or peripheral
*
* This holds methods for setting up a new device, and also removing it.
* The device needs information to set itself up - this is provided either
* by plat or a device tree node (which we find by looking up
* matching compatible strings with of_match).
*
* Drivers all belong to a uclass, representing a class of devices of the
* same type. Common elements of the drivers can be implemented in the uclass,
* or the uclass can provide a consistent interface to the drivers within
* it.
*
* @name: Device name
* @id: Identifies the uclass we belong to
* @of_match: List of compatible strings to match, and any identifying data
* for each.
* @bind: Called to bind a device to its driver
* @probe: Called to probe a device, i.e. activate it
* @remove: Called to remove a device, i.e. de-activate it
* @unbind: Called to unbind a device from its driver
* @of_to_plat: Called before probe to decode device tree data
* @child_post_bind: Called after a new child has been bound
* @child_pre_probe: Called before a child device is probed. The device has
* memory allocated but it has not yet been probed.
* @child_post_remove: Called after a child device is removed. The device
* has memory allocated but its device_remove() method has been called.
* @priv_auto: If non-zero this is the size of the private data
* to be allocated in the device's ->priv pointer. If zero, then the driver
* is responsible for allocating any data required.
* @plat_auto: If non-zero this is the size of the
* platform data to be allocated in the device's ->plat pointer.
* This is typically only useful for device-tree-aware drivers (those with
* an of_match), since drivers which use plat will have the data
* provided in the U_BOOT_DRVINFO() instantiation.
* @per_child_auto: Each device can hold private data owned by
* its parent. If required this will be automatically allocated if this
* value is non-zero.
* @per_child_plat_auto: A bus likes to store information about
* its children. If non-zero this is the size of this data, to be allocated
* in the child's parent_plat pointer.
* @ops: Driver-specific operations. This is typically a list of function
* pointers defined by the driver, to implement driver functions required by
* the uclass.
* @flags: driver flags - see DM_FLAGS_...
* @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
* allowing the device to add things to the ACPI tables passed to Linux
*/
struct driver {
char *name;
enum uclass_id id;
const struct udevice_id *of_match;
int (*bind)(struct udevice *dev);
int (*probe)(struct udevice *dev);
int (*remove)(struct udevice *dev);
int (*unbind)(struct udevice *dev);
int (*of_to_plat)(struct udevice *dev);
int (*child_post_bind)(struct udevice *dev);
int (*child_pre_probe)(struct udevice *dev);
int (*child_post_remove)(struct udevice *dev);
int priv_auto;
int plat_auto;
int per_child_auto;
// 一个总线习惯存储关于它的子节点的信息。如果非零，则分配该数据的大小空间，并将保存到子节点的parent_plat指针中。
//* @per_child_plat_auto: A bus likes to store information about its children. If non-zero this is the size of this data, to be allocated in the child's parent_plat pointer.
int per_child_plat_auto;
const void *ops; /* driver-specific operations */
uint32_t flags;
#if CONFIG_IS_ENABLED(ACPIGEN)
struct acpi_ops *acpi_ops;
#endif
};
/* Declare a new U-Boot driver */
#define U_BOOT_DRIVER(__name) \
ll_entry_declare(struct driver, __name, driver)
/* Get a pointer to a given driver */
#define DM_DRIVER_GET(__name) \
ll_entry_get(struct driver, __name, driver)
/**
* DM_DRIVER_REF() - Get a reference to a driver
*
* This is useful in data structures and code for referencing a driver at
* build time. Before this is used, an extern U_BOOT_DRIVER() must have been
* declared.
*
* For example:
*
* extern U_BOOT_DRIVER(sandbox_fixed_clock);
*
* struct driver *drvs[] = {
* DM_DRIVER_REF(sandbox_fixed_clock),
* };
*
* @_name: Name of the driver. This must be a valid C identifier, used by the
* linker_list
* @returns struct driver * for the driver
*/
#define DM_DRIVER_REF(_name) \
ll_entry_ref(struct driver, _name, driver)
/**
* Declare a macro to state a alias for a driver name. This macro will
* produce no code but its information will be parsed by tools like
* dtoc
*/
#define DM_DRIVER_ALIAS(__name, __alias)
/**
* Declare a macro to indicate which phase of U-Boot this driver is fore.
*
*
* This macro produces no code but its information will be parsed by dtoc. The
* macro can be only be used once in a driver. Put it within the U_BOOT_DRIVER()
* declaration, e.g.:
*
* U_BOOT_DRIVER(cpu) = {
* .name = ...
* ...
* DM_PHASE(tpl)
* };
*/
#define DM_PHASE(_phase)
/**
* Declare a macro to declare a header needed for a driver. Often the correct
* header can be found automatically, but only for struct declarations. For
* enums and #defines used in the driver declaration and declared in a different
* header from the structs, this macro must be used.
*
* This macro produces no code but its information will be parsed by dtoc. The
* macro can be used multiple times with different headers, for the same driver.
* Put it within the U_BOOT_DRIVER() declaration, e.g.:
*
* U_BOOT_DRIVER(cpu) = {
* .name = ...
* ...
* DM_HEADER(<asm/cpu.h>)
* };
*/
#define DM_HEADER(_hdr)
/**
* dev_get_plat() - Get the platform data for a device
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return platform data, or NULL if none
*/
void *dev_get_plat(const struct udevice *dev);
/**
* dev_get_parent_plat() - Get the parent platform data for a device
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return parent's platform data, or NULL if none
*/
void *dev_get_parent_plat(const struct udevice *dev);
/**
* dev_get_uclass_plat() - Get the uclass platform data for a device
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return uclass's platform data, or NULL if none
*/
void *dev_get_uclass_plat(const struct udevice *dev);
/**
* dev_get_priv() - Get the private data for a device
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return private data, or NULL if none
*/
void *dev_get_priv(const struct udevice *dev);
/**
* dev_get_parent_priv() - Get the parent private data for a device
*
* The parent private data is data stored in the device but owned by the
* parent. For example, a USB device may have parent data which contains
* information about how to talk to the device over USB.
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return parent data, or NULL if none
*/
void *dev_get_parent_priv(const struct udevice *dev);
/**
* dev_get_uclass_priv() - Get the private uclass data for a device
*
* This checks that dev is not NULL, but no other checks for now
*
* @dev Device to check
* @return private uclass data for this device, or NULL if none
*/
void *dev_get_uclass_priv(const struct udevice *dev);
/**
* struct dev_get_parent() - Get the parent of a device
*
* @child: Child to check
* @return parent of child, or NULL if this is the root device
*/
struct udevice *dev_get_parent(const struct udevice *child);
/**
* dev_get_driver_data() - get the driver data used to bind a device
*
* When a device is bound using a device tree node, it matches a
* particular compatible string in struct udevice_id. This function
* returns the associated data value for that compatible string. This is
* the 'data' field in struct udevice_id.
*
* As an example, consider this structure:
* static const struct udevice_id tegra_i2c_ids[] = {
* { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
* { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
* { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
* { }
* };
*
* When driver model finds a driver for this it will store the 'data' value
* corresponding to the compatible string it matches. This function returns
* that value. This allows the driver to handle several variants of a device.
*
* For USB devices, this is the driver_info field in struct usb_device_id.
*
* @dev: Device to check
* @return driver data (0 if none is provided)
*/
ulong dev_get_driver_data(const struct udevice *dev);
/**
* dev_get_driver_ops() - get the device's driver's operations
*
* This checks that dev is not NULL, and returns the pointer to device's
* driver's operations.
*
* @dev: Device to check
* @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
*/
const void *dev_get_driver_ops(const struct udevice *dev);
/**
* device_get_uclass_id() - return the uclass ID of a device
*
* @dev: Device to check
* @return uclass ID for the device
*/
enum uclass_id device_get_uclass_id(const struct udevice *dev);
/**
* dev_get_uclass_name() - return the uclass name of a device
*
* This checks that dev is not NULL.
*
* @dev: Device to check
* @return pointer to the uclass name for the device
*/
const char *dev_get_uclass_name(const struct udevice *dev);
/**
* device_get_child() - Get the child of a device by index
*
* Returns the numbered child, 0 being the first. This does not use
* sequence numbers, only the natural order.
*
* @dev: Parent device to check
* @index: Child index
* @devp: Returns pointer to device
* @return 0 if OK, -ENODEV if no such device, other error if the device fails
* to probe
*/
int device_get_child(const struct udevice *parent, int index,
struct udevice **devp);
/**
* device_get_child_count() - Get the available child count of a device
*
* Returns the number of children to a device.
*
* @parent: Parent device to check
*/
int device_get_child_count(const struct udevice *parent);
/**
* device_find_child_by_seq() - Find a child device based on a sequence
*
* This searches for a device with the given seq.
*
* @parent: Parent device
* @seq: Sequence number to find (0=first)
* @devp: Returns pointer to device (there is only one per for each seq).
* Set to NULL if none is found
* @return 0 if OK, -ENODEV if not found
*/
int device_find_child_by_seq(const struct udevice *parent, int seq,
struct udevice **devp);
/**
* device_get_child_by_seq() - Get a child device based on a sequence
*
* If an active device has this sequence it will be returned. If there is no
* such device then this will check for a device that is requesting this
* sequence.
*
* The device is probed to activate it ready for use.
*
* @parent: Parent device
* @seq: Sequence number to find (0=first)
* @devp: Returns pointer to device (there is only one per for each seq)
* Set to NULL if none is found
* @return 0 if OK, -ve on error
*/
int device_get_child_by_seq(const struct udevice *parent, int seq,
struct udevice **devp);
/**
* device_find_child_by_of_offset() - Find a child device based on FDT offset
*
* Locates a child device by its device tree offset.
*
* @parent: Parent device
* @of_offset: Device tree offset to find
* @devp: Returns pointer to device if found, otherwise this is set to NULL
* @return 0 if OK, -ve on error
*/
int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
struct udevice **devp);
/**
* device_get_child_by_of_offset() - Get a child device based on FDT offset
*
* Locates a child device by its device tree offset.
*
* The device is probed to activate it ready for use.
*
* @parent: Parent device
* @of_offset: Device tree offset to find
* @devp: Returns pointer to device if found, otherwise this is set to NULL
* @return 0 if OK, -ve on error
*/
int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
struct udevice **devp);
/**
* device_find_global_by_ofnode() - Get a device based on ofnode
*
* Locates a device by its device tree ofnode, searching globally throughout
* the all driver model devices.
*
* The device is NOT probed
*
* @node: Device tree ofnode to find
* @devp: Returns pointer to device if found, otherwise this is set to NULL
* @return 0 if OK, -ve on error
*/
int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
/**
* device_get_global_by_ofnode() - Get a device based on ofnode
*
* Locates a device by its device tree ofnode, searching globally throughout
* the all driver model devices.
*
* The device is probed to activate it ready for use.
*
* @node: Device tree ofnode to find
* @devp: Returns pointer to device if found, otherwise this is set to NULL
* @return 0 if OK, -ve on error
*/
int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
/**
* device_get_by_ofplat_idx() - Get a device based on of-platdata index
*
* Locates a device by either its struct driver_info index, or its
* struct udevice index. The latter is used with OF_PLATDATA_INST, since we have
* a list of build-time instantiated struct udevice records, The former is used
* with !OF_PLATDATA_INST since in that case we have a list of
* struct driver_info records.
*
* The index number is written into the idx field of struct phandle_1_arg, etc.
* It is the position of this driver_info/udevice in its linker list.
*
* The device is probed to activate it ready for use.
*
* @idx: Index number of the driver_info/udevice structure (0=first)
* @devp: Returns pointer to device if found, otherwise this is set to NULL
* @return 0 if OK, -ve on error
*/
int device_get_by_ofplat_idx(uint idx, struct udevice **devp);
/**
* device_find_first_child() - Find the first child of a device
*
* @parent: Parent device to search
* @devp: Returns first child device, or NULL if none
* @return 0
*/
int device_find_first_child(const struct udevice *parent,
struct udevice **devp);
/**
* device_find_next_child() - Find the next child of a device
*
* @devp: Pointer to previous child device on entry. Returns pointer to next
* child device, or NULL if none
* @return 0
*/
int device_find_next_child(struct udevice **devp);
/**
* device_find_first_inactive_child() - Find the first inactive child
*
* This is used to locate an existing child of a device which is of a given
* uclass.
*
* The device is NOT probed
*
* @parent: Parent device to search
* @uclass_id: Uclass to look for
* @devp: Returns device found, if any
* @return 0 if found, else -ENODEV
*/
int device_find_first_inactive_child(const struct udevice *parent,
enum uclass_id uclass_id,
struct udevice **devp);
/**
* device_find_first_child_by_uclass() - Find the first child of a device in uc
*
* @parent: Parent device to search
* @uclass_id: Uclass to look for
* @devp: Returns first child device in that uclass, if any
* @return 0 if found, else -ENODEV
*/
int device_find_first_child_by_uclass(const struct udevice *parent,
enum uclass_id uclass_id,
struct udevice **devp);
/**
* device_find_child_by_name() - Find a child by device name
*
* @parent: Parent device to search
* @name: Name to look for
* @devp: Returns device found, if any
* @return 0 if found, else -ENODEV
*/
int device_find_child_by_name(const struct udevice *parent, const char *name,
struct udevice **devp);
/**
* device_first_child_ofdata_err() - Find the first child and reads its plat
*
* The of_to_plat() method is called on the child before it is returned,
* but the child is not probed.
*
* @parent: Parent to check
* @devp: Returns child that was found, if any
* @return 0 on success, -ENODEV if no children, other -ve on error
*/
int device_first_child_ofdata_err(struct udevice *parent,
struct udevice **devp);
/*
* device_next_child_ofdata_err() - Find the next child and read its plat
*
* The of_to_plat() method is called on the child before it is returned,
* but the child is not probed.
*
* @devp: On entry, points to the previous child; on exit returns the child that
* was found, if any
* @return 0 on success, -ENODEV if no children, other -ve on error
*/
int device_next_child_ofdata_err(struct udevice **devp);
/**
* device_first_child_err() - Get the first child of a device
*
* The device returned is probed if necessary, and ready for use
*
* @parent: Parent device to search
* @devp: Returns device found, if any
* @return 0 if found, -ENODEV if not, -ve error if device failed to probe
*/
int device_first_child_err(struct udevice *parent, struct udevice **devp);
/**
* device_next_child_err() - Get the next child of a parent device
*
* The device returned is probed if necessary, and ready for use
*
* @devp: On entry, pointer to device to lookup. On exit, returns pointer
* to the next sibling if no error occurred
* @return 0 if found, -ENODEV if not, -ve error if device failed to probe
*/
int device_next_child_err(struct udevice **devp);
/**
* device_has_children() - check if a device has any children
*
* @dev: Device to check
* @return true if the device has one or more children
*/
bool device_has_children(const struct udevice *dev);
/**
* device_has_active_children() - check if a device has any active children
*
* @dev: Device to check
* @return true if the device has one or more children and at least one of
* them is active (probed).
*/
bool device_has_active_children(const struct udevice *dev);
/**
* device_is_last_sibling() - check if a device is the last sibling
*
* This function can be useful for display purposes, when special action needs
* to be taken when displaying the last sibling. This can happen when a tree
* view of devices is being displayed.
*
* @dev: Device to check
* @return true if there are no more siblings after this one - i.e. is it
* last in the list.
*/
bool device_is_last_sibling(const struct udevice *dev);
/**
* device_set_name() - set the name of a device
*
* This must be called in the device's bind() method and no later. Normally
* this is unnecessary but for probed devices which don't get a useful name
* this function can be helpful.
*
* The name is allocated and will be freed automatically when the device is
* unbound.
*
* @dev: Device to update
* @name: New name (this string is allocated new memory and attached to
* the device)
* @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
* string
*/
int device_set_name(struct udevice *dev, const char *name);
/**
* device_set_name_alloced() - note that a device name is allocated
*
* This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
* unbound the name will be freed. This avoids memory leaks.
*
* @dev: Device to update
*/
void device_set_name_alloced(struct udevice *dev);
/**
* device_is_compatible() - check if the device is compatible with the compat
*
* This allows to check whether the device is comaptible with the compat.
*
* @dev: udevice pointer for which compatible needs to be verified.
* @compat: Compatible string which needs to verified in the given
* device
* @return true if OK, false if the compatible is not found
*/
bool device_is_compatible(const struct udevice *dev, const char *compat);
/**
* of_machine_is_compatible() - check if the machine is compatible with
* the compat
*
* This allows to check whether the machine is comaptible with the compat.
*
* @compat: Compatible string which needs to verified
* @return true if OK, false if the compatible is not found
*/
bool of_machine_is_compatible(const char *compat);
/**
* dev_disable_by_path() - Disable a device given its device tree path
*
* @path: The device tree path identifying the device to be disabled
* @return 0 on success, -ve on error
*/
int dev_disable_by_path(const char *path);
/**
* dev_enable_by_path() - Enable a device given its device tree path
*
* @path: The device tree path identifying the device to be enabled
* @return 0 on success, -ve on error
*/
int dev_enable_by_path(const char *path);
/**
* device_is_on_pci_bus - Test if a device is on a PCI bus
*
* @dev: device to test
* @return: true if it is on a PCI bus, false otherwise
*/
static inline bool device_is_on_pci_bus(const struct udevice *dev)
{
return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
}
/**
* device_foreach_child_safe() - iterate through child devices safely
*
* This allows the @pos child to be removed in the loop if required.
*
* @pos: struct udevice * for the current device
* @next: struct udevice * for the next device
* @parent: parent device to scan
*/
#define device_foreach_child_safe(pos, next, parent) \
list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
/**
* device_foreach_child() - iterate through child devices
*
* @pos: struct udevice * for the current device
* @parent: parent device to scan
*/
#define device_foreach_child(pos, parent) \
list_for_each_entry(pos, &parent->child_head, sibling_node)
/**
* device_foreach_child_of_to_plat() - iterate through children
*
* This stops when it gets an error, with @pos set to the device that failed to
* read ofdata.
* This creates a for() loop which works through the available children of
* a device in order from start to end. Device ofdata is read by calling
* device_of_to_plat() on each one. The devices are not probed.
*
* @pos: struct udevice * for the current device
* @parent: parent device to scan
*/
#define device_foreach_child_of_to_plat(pos, parent) \
for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
_ret = device_next_child_ofdata_err(&dev))
/**
* device_foreach_child_probe() - iterate through children, probing them
*
* This creates a for() loop which works through the available children of
* a device in order from start to end. Devices are probed if necessary,
* and ready for use.
*
* This stops when it gets an error, with @pos set to the device that failed to
* probe
*
* @pos: struct udevice * for the current device
* @parent: parent device to scan
*/
#define device_foreach_child_probe(pos, parent) \
for (int _ret = device_first_child_err(parent, &dev); !_ret; \
_ret = device_next_child_err(&dev))
/**
* dm_scan_fdt_dev() - Bind child device in the device tree
*
* This handles device which have sub-nodes in the device tree. It scans all
* sub-nodes and binds drivers for each node where a driver can be found.
*
* If this is called prior to relocation, only pre-relocation devices will be
* bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
* the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
* be bound.
*
* @dev: Device to scan
* @return 0 if OK, -ve on error
*/
int dm_scan_fdt_dev(struct udevice *dev);
#endif
