2 * Copyright (c) 2013 Google, Inc
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
6 * Marek Vasut <marex@denx.de>
8 * SPDX-License-Identifier: GPL-2.0+
14 #include <dm/uclass-id.h>
15 #include <linker_lists.h>
16 #include <linux/list.h>
20 /* Driver is active (probed). Cleared when it is removed */
21 #define DM_FLAG_ACTIVATED (1 << 0)
23 /* DM is responsible for allocating and freeing platdata */
24 #define DM_FLAG_ALLOC_PDATA (1 << 1)
26 /* DM should init this device prior to relocation */
27 #define DM_FLAG_PRE_RELOC (1 << 2)
30 * struct udevice - An instance of a driver
32 * This holds information about a device, which is a driver bound to a
33 * particular port or peripheral (essentially a driver instance).
35 * A device will come into existence through a 'bind' call, either due to
36 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
37 * in the device tree (in which case of_offset is >= 0). In the latter case
38 * we translate the device tree information into platdata in a function
39 * implemented by the driver ofdata_to_platdata method (called just before the
40 * probe method if the device has a device tree node.
42 * All three of platdata, priv and uclass_priv can be allocated by the
43 * driver, or you can use the auto_alloc_size members of struct driver and
44 * struct uclass_driver to have driver model do this automatically.
46 * @driver: The driver used by this device
47 * @name: Name of device, typically the FDT node name
48 * @platdata: Configuration data for this device
49 * @of_offset: Device tree node offset for this device (- for none)
50 * @parent: Parent of this device, or NULL for the top level device
51 * @priv: Private data for this device
52 * @uclass: Pointer to uclass for this device
53 * @uclass_priv: The uclass's private data for this device
54 * @parent_priv: The parent's private data for this device
55 * @uclass_node: Used by uclass to link its devices
56 * @child_head: List of children of this device
57 * @sibling_node: Next device in list of all devices
58 * @flags: Flags for this device DM_FLAG_...
59 * @req_seq: Requested sequence number for this device (-1 = any)
60 * @seq: Allocated sequence number for this device (-1 = none)
63 struct driver *driver;
67 struct udevice *parent;
69 struct uclass *uclass;
72 struct list_head uclass_node;
73 struct list_head child_head;
74 struct list_head sibling_node;
80 /* Maximum sequence number supported */
81 #define DM_MAX_SEQ 999
83 /* Returns the operations for a device */
84 #define device_get_ops(dev) (dev->driver->ops)
86 /* Returns non-zero if the device is active (probed and not removed) */
87 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
90 * struct udevice_id - Lists the compatible strings supported by a driver
91 * @compatible: Compatible string
92 * @data: Data for this compatible string
95 const char *compatible;
99 #ifdef CONFIG_OF_CONTROL
100 #define of_match_ptr(_ptr) (_ptr)
102 #define of_match_ptr(_ptr) NULL
103 #endif /* CONFIG_OF_CONTROL */
106 * struct driver - A driver for a feature or peripheral
108 * This holds methods for setting up a new device, and also removing it.
109 * The device needs information to set itself up - this is provided either
110 * by platdata or a device tree node (which we find by looking up
111 * matching compatible strings with of_match).
113 * Drivers all belong to a uclass, representing a class of devices of the
114 * same type. Common elements of the drivers can be implemented in the uclass,
115 * or the uclass can provide a consistent interface to the drivers within
119 * @id: Identiies the uclass we belong to
120 * @of_match: List of compatible strings to match, and any identifying data
122 * @bind: Called to bind a device to its driver
123 * @probe: Called to probe a device, i.e. activate it
124 * @remove: Called to remove a device, i.e. de-activate it
125 * @unbind: Called to unbind a device from its driver
126 * @ofdata_to_platdata: Called before probe to decode device tree data
127 * @child_pre_probe: Called before a child device is probed. The device has
128 * memory allocated but it has not yet been probed.
129 * @child_post_remove: Called after a child device is removed. The device
130 * has memory allocated but its device_remove() method has been called.
131 * @priv_auto_alloc_size: If non-zero this is the size of the private data
132 * to be allocated in the device's ->priv pointer. If zero, then the driver
133 * is responsible for allocating any data required.
134 * @platdata_auto_alloc_size: If non-zero this is the size of the
135 * platform data to be allocated in the device's ->platdata pointer.
136 * This is typically only useful for device-tree-aware drivers (those with
137 * an of_match), since drivers which use platdata will have the data
138 * provided in the U_BOOT_DEVICE() instantiation.
139 * @per_child_auto_alloc_size: Each device can hold private data owned by
140 * its parent. If required this will be automatically allocated if this
142 * @ops: Driver-specific operations. This is typically a list of function
143 * pointers defined by the driver, to implement driver functions required by
145 * @flags: driver flags - see DM_FLAGS_...
150 const struct udevice_id *of_match;
151 int (*bind)(struct udevice *dev);
152 int (*probe)(struct udevice *dev);
153 int (*remove)(struct udevice *dev);
154 int (*unbind)(struct udevice *dev);
155 int (*ofdata_to_platdata)(struct udevice *dev);
156 int (*child_pre_probe)(struct udevice *dev);
157 int (*child_post_remove)(struct udevice *dev);
158 int priv_auto_alloc_size;
159 int platdata_auto_alloc_size;
160 int per_child_auto_alloc_size;
161 const void *ops; /* driver-specific operations */
165 /* Declare a new U-Boot driver */
166 #define U_BOOT_DRIVER(__name) \
167 ll_entry_declare(struct driver, __name, driver)
170 * dev_get_platdata() - Get the platform data for a device
172 * This checks that dev is not NULL, but no other checks for now
174 * @dev Device to check
175 * @return platform data, or NULL if none
177 void *dev_get_platdata(struct udevice *dev);
180 * dev_get_parentdata() - Get the parent data for a device
182 * The parent data is data stored in the device but owned by the parent.
183 * For example, a USB device may have parent data which contains information
184 * about how to talk to the device over USB.
186 * This checks that dev is not NULL, but no other checks for now
188 * @dev Device to check
189 * @return parent data, or NULL if none
191 void *dev_get_parentdata(struct udevice *dev);
194 * dev_get_priv() - Get the private data for a device
196 * This checks that dev is not NULL, but no other checks for now
198 * @dev Device to check
199 * @return private data, or NULL if none
201 void *dev_get_priv(struct udevice *dev);
204 * device_get_child() - Get the child of a device by index
206 * Returns the numbered child, 0 being the first. This does not use
207 * sequence numbers, only the natural order.
209 * @dev: Parent device to check
210 * @index: Child index
211 * @devp: Returns pointer to device
213 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
216 * device_find_child_by_seq() - Find a child device based on a sequence
218 * This searches for a device with the given seq or req_seq.
220 * For seq, if an active device has this sequence it will be returned.
221 * If there is no such device then this will return -ENODEV.
223 * For req_seq, if a device (whether activated or not) has this req_seq
224 * value, that device will be returned. This is a strong indication that
225 * the device will receive that sequence when activated.
227 * @parent: Parent device
228 * @seq_or_req_seq: Sequence number to find (0=first)
229 * @find_req_seq: true to find req_seq, false to find seq
230 * @devp: Returns pointer to device (there is only one per for each seq).
231 * Set to NULL if none is found
232 * @return 0 if OK, -ve on error
234 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
235 bool find_req_seq, struct udevice **devp);
238 * device_get_child_by_seq() - Get a child device based on a sequence
240 * If an active device has this sequence it will be returned. If there is no
241 * such device then this will check for a device that is requesting this
244 * The device is probed to activate it ready for use.
246 * @parent: Parent device
247 * @seq: Sequence number to find (0=first)
248 * @devp: Returns pointer to device (there is only one per for each seq)
249 * Set to NULL if none is found
250 * @return 0 if OK, -ve on error
252 int device_get_child_by_seq(struct udevice *parent, int seq,
253 struct udevice **devp);
256 * device_find_child_by_of_offset() - Find a child device based on FDT offset
258 * Locates a child device by its device tree offset.
260 * @parent: Parent device
261 * @of_offset: Device tree offset to find
262 * @devp: Returns pointer to device if found, otherwise this is set to NULL
263 * @return 0 if OK, -ve on error
265 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
266 struct udevice **devp);
269 * device_get_child_by_of_offset() - Get a child device based on FDT offset
271 * Locates a child device by its device tree offset.
273 * The device is probed to activate it ready for use.
275 * @parent: Parent device
276 * @of_offset: Device tree offset to find
277 * @devp: Returns pointer to device if found, otherwise this is set to NULL
278 * @return 0 if OK, -ve on error
280 int device_get_child_by_of_offset(struct udevice *parent, int seq,
281 struct udevice **devp);
284 * device_find_first_child() - Find the first child of a device
286 * @parent: Parent device to search
287 * @devp: Returns first child device, or NULL if none
290 int device_find_first_child(struct udevice *parent, struct udevice **devp);
293 * device_find_first_child() - Find the first child of a device
295 * @devp: Pointer to previous child device on entry. Returns pointer to next
296 * child device, or NULL if none
299 int device_find_next_child(struct udevice **devp);