u-boot/include/dm/device.h
Simon Glass c5785673bc dm: core: Add device children and sibling functions
Add some utility functions to check for children and for the last sibling in
a device's parent.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>
2015-04-18 11:11:19 -06:00

413 lines
14 KiB
C

/*
* Copyright (c) 2013 Google, Inc
*
* (C) Copyright 2012
* Pavel Herrmann <morpheus.ibis@gmail.com>
* Marek Vasut <marex@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DM_DEVICE_H
#define _DM_DEVICE_H
#include <dm/uclass-id.h>
#include <fdtdec.h>
#include <linker_lists.h>
#include <linux/list.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 platdata */
#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_platdata */
#define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
/* Allocate driver private data on a DMA boundary */
#define DM_FLAG_ALLOC_PRIV_DMA (1 << 4)
/**
* 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_DEVICE() macro (in which case platdata 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 platdata in a function
* implemented by the driver ofdata_to_platdata method (called just before the
* probe method if the device has a device tree node.
*
* All three of platdata, priv and uclass_priv can be allocated by the
* driver, or you can use the auto_alloc_size 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
* @platdata: Configuration data for this device
* @parent_platdata: The parent bus's configuration data for this device
* @of_offset: Device tree node offset for this device (- for none)
* @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
* @uclass: Pointer to uclass for this device
* @uclass_priv: The uclass's private data for this device
* @parent_priv: The parent's private data for this device
* @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_...
* @req_seq: Requested sequence number for this device (-1 = any)
* @seq: Allocated sequence number for this device (-1 = none). This is set up
* when the device is probed and will be unique within the device's uclass.
*/
struct udevice {
const struct driver *driver;
const char *name;
void *platdata;
void *parent_platdata;
int of_offset;
ulong driver_data;
struct udevice *parent;
void *priv;
struct uclass *uclass;
void *uclass_priv;
void *parent_priv;
struct list_head uclass_node;
struct list_head child_head;
struct list_head sibling_node;
uint32_t flags;
int req_seq;
int seq;
};
/* Maximum sequence number supported */
#define DM_MAX_SEQ 999
/* Returns the operations for a device */
#define device_get_ops(dev) (dev->driver->ops)
/* Returns non-zero if the device is active (probed and not removed) */
#define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
/**
* 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;
};
#ifdef CONFIG_OF_CONTROL
#define of_match_ptr(_ptr) (_ptr)
#else
#define of_match_ptr(_ptr) NULL
#endif /* CONFIG_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 platdata 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: Identiies 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
* @ofdata_to_platdata: 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_alloc_size: 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.
* @platdata_auto_alloc_size: If non-zero this is the size of the
* platform data to be allocated in the device's ->platdata pointer.
* This is typically only useful for device-tree-aware drivers (those with
* an of_match), since drivers which use platdata will have the data
* provided in the U_BOOT_DEVICE() instantiation.
* @per_child_auto_alloc_size: Each device can hold private data owned by
* its parent. If required this will be automatically allocated if this
* value is non-zero.
* TODO(sjg@chromium.org): I'm considering dropping this, and just having
* device_probe_child() pass it in. So far the use case for allocating it
* is SPI, but I found that unsatisfactory. Since it is here I will leave it
* until things are clearer.
* @per_child_platdata_auto_alloc_size: 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_platdata 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_...
*/
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 (*ofdata_to_platdata)(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_alloc_size;
int platdata_auto_alloc_size;
int per_child_auto_alloc_size;
int per_child_platdata_auto_alloc_size;
const void *ops; /* driver-specific operations */
uint32_t flags;
};
/* Declare a new U-Boot driver */
#define U_BOOT_DRIVER(__name) \
ll_entry_declare(struct driver, __name, driver)
/**
* dev_get_platdata() - 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_platdata(struct udevice *dev);
/**
* dev_get_parent_platdata() - 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_platdata(struct udevice *dev);
/**
* dev_get_parentdata() - Get the parent data for a device
*
* The parent 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_parentdata(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(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(struct udevice *child);
/**
* 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(struct udevice *dev);
/**
* 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 as in struct udevice_id. This function
* returns the associated data value for that compatible string. This is
* the 'data' field in struct udevice_id.
*
* For USB devices, this is the driver_info field in struct usb_device_id.
*
* @dev: Device to check
*/
ulong dev_get_driver_data(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(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
*/
int device_get_child(struct udevice *parent, int index, struct udevice **devp);
/**
* device_find_child_by_seq() - Find a child device based on a sequence
*
* This searches for a device with the given seq or req_seq.
*
* For seq, if an active device has this sequence it will be returned.
* If there is no such device then this will return -ENODEV.
*
* For req_seq, if a device (whether activated or not) has this req_seq
* value, that device will be returned. This is a strong indication that
* the device will receive that sequence when activated.
*
* @parent: Parent device
* @seq_or_req_seq: Sequence number to find (0=first)
* @find_req_seq: true to find req_seq, false to find seq
* @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_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
bool find_req_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(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(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(struct udevice *parent, int seq,
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(struct udevice *parent, struct udevice **devp);
/**
* device_find_first_child() - Find the first 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);
/**
* dev_get_addr() - Get the reg property of a device
*
* @dev: Pointer to a device
*
* @return addr
*/
fdt_addr_t dev_get_addr(struct udevice *dev);
/**
* 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(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(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(struct udevice *dev);
#endif