u-boot dm驱动模型-uclass和uclass_driver
#ifndef _DM_UCLASS_H
#define _DM_UCLASS_H
#include <dm/ofnode.h>
#include <dm/uclass-id.h>
#include <linker_lists.h>
#include <linux/list.h>
/**
* struct uclass - a U-Boot drive class, collecting together similar drivers
*
* A uclass provides an interface to a particular function, which is
* implemented by one or more drivers. Every driver belongs to a uclass even
* if it is the only driver in that uclass. An example uclass is GPIO, which
* provides the ability to change read inputs, set and clear outputs, etc.
* There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
* PMIC IO lines, all made available in a unified way through the uclass.
*
* @priv_: Private data for this uclass (do not access outside driver model)
* @uc_drv: The driver for the uclass itself, not to be confused with a
* 'struct driver'
* @dev_head: List of devices in this uclass (devices are attached to their
* uclass when their bind method is called)
* @sibling_node: Next uclass in the linked list of uclasses
*/
struct uclass {
// 这个uclass的私有数据
void *priv_;
// uclass本身的驱动程序，不要与“struct driver”混淆。
struct uclass_driver *uc_drv;
// 这个uclass中的设备列表（当设备的bind方法被调用时，设备被附加到它们的类上。
struct list_head dev_head;
// uclass链表中的下一个uclass
struct list_head sibling_node;
};
struct driver;
struct udevice;
/* Members of this uclass sequence themselves with aliases */
#define DM_UC_FLAG_SEQ_ALIAS (1 << 0)
/* Members of this uclass without aliases don't get a sequence number */
#define DM_UC_FLAG_NO_AUTO_SEQ (1 << 1)
/* Same as DM_FLAG_ALLOC_PRIV_DMA */
#define DM_UC_FLAG_ALLOC_PRIV_DMA (1 << 5)
/**
* struct uclass_driver - Driver for the uclass
*
* A uclass_driver provides a consistent interface to a set of related
* drivers.
*
* @name: Name of uclass driver
* @id: ID number of this uclass
* @post_bind: Called after a new device is bound to this uclass
* @pre_unbind: Called before a device is unbound from this uclass
* @pre_probe: Called before a new device is probed
* @post_probe: Called after a new device is probed
* @pre_remove: Called before a device is removed
* @child_post_bind: Called after a child is bound to a device in this uclass
* @child_pre_probe: Called before a child in this uclass is probed
* @child_post_probe: Called after a child in this uclass is probed
* @init: Called to set up the uclass
* @destroy: Called to destroy the uclass
* @priv_auto: If non-zero this is the size of the private data
* to be allocated in the uclass's ->priv pointer. If zero, then the uclass
* driver is responsible for allocating any data required.
* @per_device_auto: Each device can hold private data owned
* by the uclass. If required this will be automatically allocated if this
* value is non-zero.
* @per_device_plat_auto: Each device can hold platform data
* owned by the uclass as 'dev->uclass_plat'. If the value is non-zero,
* then this will be automatically allocated.
* @per_child_auto: Each child device (of a parent in this
* uclass) can hold parent data for the device/uclass. This value is only
* used as a fallback if this member is 0 in the driver.
* @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 device's parent_plat pointer. This value is only used as
* a fallback if this member is 0 in the driver.
* @flags: Flags for this uclass (DM_UC_...)
*/
struct uclass_driver {
// uclass driver的名称
const char *name;
// 这个uclass的ID号
enum uclass_id id;
// 在一个新设备绑定到这个uclass后被调用
int (*post_bind)(struct udevice *dev);
// 在设备从该uclass解绑定之前调用
int (*pre_unbind)(struct udevice *dev);
// 在probe一个新设备之前调用
int (*pre_probe)(struct udevice *dev);
// 在probe一个新设备之后调用
int (*post_probe)(struct udevice *dev);
// 在移除设备之前调用
int (*pre_remove)(struct udevice *dev);
// 在这个uclass的child绑定到一个设备之后被调用
int (*child_post_bind)(struct udevice *dev);
// 在这个uclass的child被probed之前被调用
int (*child_pre_probe)(struct udevice *dev);
// 在这个uclass的child被probed之后被调用
int (*child_post_probe)(struct udevice *dev);
// 在创建一个新的uclass时被调用
int (*init)(struct uclass *class);
// 在uclass被销毁时被调用
int (*destroy)(struct uclass *class);
// 如果非零，它就是"uclass->priv"指针中分配的私有数据的大小。如果为0，则uclass driver负责分配所需私有数据的空间。
int priv_auto;
// 每个device都可以将uclass拥有的私有数据保存在'dev->uclass_priv'。如果该值是非零，将自动分配该值大小的空间。
int per_device_auto;
// 每个device都可以将uclass拥有的平台数据保存在'dev->uclass_platdata'。如果该值是非零，将自动分配该值大小的空间。
int per_device_plat_auto;
// 每个子设备(在这个uclass中一个parent的child)可以保存device/uclass中的parent数据。地址为'dev->parent_priv'
int per_child_auto;
// 一个总线习惯保存关于它的子节点的信息。如果非零，将分配到子设备的'dev->parent_platdata'指针中。
int per_child_plat_auto;
// 这个uclass的标志(DM_UC_…)
uint32_t flags;
};
/* Declare a new uclass_driver */
#define UCLASS_DRIVER(__name) \
ll_entry_declare(struct uclass_driver, __name, uclass_driver)
/*
* These two macros DM_UCLASS_DRIVER_REF and DM_UCLASS_DRIVER_REF are only
* allowed in code generated by dtoc, because the ordering is important and if
* other instances creep in then they may mess up the ordering expected by dtoc.
*
* It is OK to use them with 'extern' though, since that does not actually
* add a new record to the linker_list.
*/
/**
* DM_UCLASS_DRIVER_REF() - Get a reference to a uclass driver
*
* This is useful in data structures and code for referencing a uclass_driver at
* build time. Before this is used, an extern UCLASS_DRIVER() must have been
* declared.
*
* For example:
*
* extern UCLASS_DRIVER(clk);
*
* struct uclass_driver *drvs[] = {
* DM_UCLASS_DRIVER_REF(clk),
* };
*
* @_name: Name of the uclass_driver. This must be a valid C identifier, used by
* the linker_list.
* @returns struct uclass_driver * for the uclass driver
*/
#define DM_UCLASS_DRIVER_REF(_name) \
ll_entry_ref(struct uclass_driver, _name, uclass_driver)
/**
* uclass_get_priv() - Get the private data for a uclass
*
* @uc Uclass to check
* @return private data, or NULL if none
*/
void *uclass_get_priv(const struct uclass *uc);
/**
* uclass_get() - Get a uclass based on an ID, creating it if needed
*
* Every uclass is identified by an ID, a number from 0 to n-1 where n is
* the number of uclasses. This function allows looking up a uclass by its
* ID.
*
* @key: ID to look up
* @ucp: Returns pointer to uclass (there is only one per ID)
* @return 0 if OK, -EDEADLK if driver model is not yet inited, other -ve on
* other error
*/
int uclass_get(enum uclass_id key, struct uclass **ucp);
/**
* uclass_get_name() - Get the name of a uclass driver
*
* @id: ID to look up
* @returns the name of the uclass driver for that ID, or NULL if none
*/
const char *uclass_get_name(enum uclass_id id);
/**
* uclass_get_by_name() - Look up a uclass by its driver name
*
* @name: Name to look up
* @returns the associated uclass ID, or UCLASS_INVALID if not found
*/
enum uclass_id uclass_get_by_name(const char *name);
/**
* uclass_get_device() - Get a uclass device based on an ID and index
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @index: Device number within that uclass (0=first)
* @devp: Returns pointer to device (there is only one per for each ID)
* @return 0 if OK, -ve on error
*/
int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
/**
* uclass_get_device_by_name() - Get a uclass device by its name
*
* This searches the devices in the uclass for one with the exactly given name.
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @name: name of a device to get
* @devp: Returns pointer to device (the first one with the name)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_name(enum uclass_id id, const char *name,
struct udevice **devp);
/**
* uclass_get_device_by_seq() - Get a uclass device based on an ID and 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.
*
* @id: ID to look up
* @seq: Sequence number to find (0=first)
* @devp: Returns pointer to device (there is only one for each seq)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
/**
* uclass_get_device_by_of_offset() - Get a uclass device by device tree node
*
* This searches the devices in the uclass for one attached to the given
* device tree node.
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @node: Device tree offset to search for (if -ve then -ENODEV is returned)
* @devp: Returns pointer to device (there is only one for each node)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_of_offset(enum uclass_id id, int node,
struct udevice **devp);
/**
* uclass_get_device_by_ofnode() - Get a uclass device by device tree node
*
* This searches the devices in the uclass for one attached to the given
* device tree node.
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @np: Device tree node to search for (if NULL then -ENODEV is returned)
* @devp: Returns pointer to device (there is only one for each node)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
struct udevice **devp);
/**
* uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
*
* This searches the devices in the uclass for one with the given phandle id.
*
* The device is probed to activate it ready for use.
*
* @id: uclass ID to look up
* @phandle_id: the phandle id to look up
* @devp: Returns pointer to device (there is only one for each node). NULL if
* there is no such device.
* @return 0 if OK, -ENODEV if there is no device match the phandle, other
* -ve on error
*/
int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
struct udevice **devp);
/**
* uclass_get_device_by_phandle() - Get a uclass device by phandle
*
* This searches the devices in the uclass for one with the given phandle.
*
* The device is probed to activate it ready for use.
*
* @id: uclass ID to look up
* @parent: Parent device containing the phandle pointer
* @name: Name of property in the parent device node
* @devp: Returns pointer to device (there is only one for each node)
* @return 0 if OK, -ENOENT if there is no @name present in the node, other
* -ve on error
*/
int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
const char *name, struct udevice **devp);
/**
* uclass_get_device_by_driver() - Get a uclass device for a driver
*
* This searches the devices in the uclass for one that uses the given
* driver. Use DM_DRIVER_GET(name) for the @drv argument, where 'name' is
* the driver name - as used in U_BOOT_DRIVER(name).
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @drv: Driver to look for
* @devp: Returns pointer to the first device with that driver
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
struct udevice **devp);
/**
* uclass_first_device() - Get the first device in a uclass
*
* The device returned is probed if necessary, and ready for use
*
* This function is useful to start iterating through a list of devices which
* are functioning correctly and can be probed.
*
* @id: Uclass ID to look up
* @devp: Returns pointer to the first device in that uclass if no error
* occurred, or NULL if there is no first device, or an error occurred with
* that device.
* @return 0 if OK (found or not found), other -ve on error
*/
int uclass_first_device(enum uclass_id id, struct udevice **devp);
/**
* uclass_first_device_err() - Get the first device in a uclass
*
* The device returned is probed if necessary, and ready for use
*
* @id: Uclass ID to look up
* @devp: Returns pointer to the first device in that uclass, or NULL if none
* @return 0 if found, -ENODEV if not found, other -ve on error
*/
int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
/**
* uclass_next_device() - Get the next device in a uclass
*
* The device returned is probed if necessary, and ready for use
*
* This function is useful to iterate through a list of devices which
* are functioning correctly and can be probed.
*
* @devp: On entry, pointer to device to lookup. On exit, returns pointer
* to the next device in the uclass if no error occurred, or NULL if there is
* no next device, or an error occurred with that next device.
* @return 0 if OK (found or not found), other -ve on error
*/
int uclass_next_device(struct udevice **devp);
/**
* uclass_next_device_err() - Get the next device in a uclass
*
* 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 device in the uclass if no error occurred, or -ENODEV if
* there is no next device.
* @return 0 if found, -ENODEV if not found, other -ve on error
*/
int uclass_next_device_err(struct udevice **devp);
/**
* uclass_first_device_check() - Get the first device in a uclass
*
* The device returned is probed if necessary, and ready for use
*
* This function is useful to start iterating through a list of devices which
* are functioning correctly and can be probed.
*
* @id: Uclass ID to look up
* @devp: Returns pointer to the first device in that uclass, or NULL if there
* is no first device
* @return 0 if OK (found or not found), other -ve on error. If an error occurs
* it is still possible to move to the next device.
*/
int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
/**
* uclass_next_device_check() - Get the next device in a uclass
*
* The device returned is probed if necessary, and ready for use
*
* This function is useful to start iterating through a list of devices which
* are functioning correctly and can be probed.
*
* @devp: On entry, pointer to device to lookup. On exit, returns pointer
* to the next device in the uclass if any
* @return 0 if OK (found or not found), other -ve on error. If an error occurs
* it is still possible to move to the next device.
*/
int uclass_next_device_check(struct udevice **devp);
/**
* uclass_first_device_drvdata() - Find the first device with given driver data
*
* This searches through the devices for a particular uclass looking for one
* that has the given driver data.
*
* @id: Uclass ID to check
* @driver_data: Driver data to search for
* @devp: Returns pointer to the first matching device in that uclass, if found
* @return 0 if found, -ENODEV if not found, other -ve on error
*/
int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
struct udevice **devp);
/**
* uclass_probe_all() - Probe all devices based on an uclass ID
*
* This function probes all devices associated with a uclass by
* looking for its ID.
*
* @id: uclass ID to look up
* @return 0 if OK, other -ve on error
*/
int uclass_probe_all(enum uclass_id id);
/**
* uclass_id_foreach_dev() - Helper function to iteration through devices
*
* This creates a for() loop which works through the available devices in
* a uclass ID in order from start to end.
*
* If for some reason the uclass cannot be found, this does nothing.
*
* @id: enum uclass_id ID to use
* @pos: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
* @uc: temporary uclass variable (struct uclass *)
*/
#define uclass_id_foreach_dev(id, pos, uc) \
if (!uclass_get(id, &uc)) \
list_for_each_entry(pos, &uc->dev_head, uclass_node)
/**
* uclass_foreach_dev() - Helper function to iteration through devices
*
* This creates a for() loop which works through the available devices in
* a uclass in order from start to end.
*
* @pos: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
* @uc: uclass to scan
*/
#define uclass_foreach_dev(pos, uc) \
list_for_each_entry(pos, &uc->dev_head, uclass_node)
/**
* uclass_foreach_dev_safe() - Helper function to safely iteration through devs
*
* This creates a for() loop which works through the available devices in
* a uclass in order from start to end. Inside the loop, it is safe to remove
* @pos if required.
*
* @pos: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
* @next: struct udevice * to hold the next next
* @uc: uclass to scan
*/
#define uclass_foreach_dev_safe(pos, next, uc) \
list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
/**
* uclass_foreach_dev_probe() - Helper function to iteration through devices
* of given uclass
*
* This creates a for() loop which works through the available devices in
* a uclass in order from start to end. Devices are probed if necessary,
* and ready for use.
*
* @id: Uclass ID
* @dev: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
*/
#define uclass_foreach_dev_probe(id, dev) \
for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \
_ret = uclass_next_device_err(&dev))
#endif
