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 * TODO(sjg@chromium.org): I'm considering dropping this, and just having
143 * device_probe_child() pass it in. So far the use case for allocating it
144 * is SPI, but I found that unsatisfactory. Since it is here I will leave it
145 * until things are clearer.
146 * @ops: Driver-specific operations. This is typically a list of function
147 * pointers defined by the driver, to implement driver functions required by
149 * @flags: driver flags - see DM_FLAGS_...
154 const struct udevice_id *of_match;
155 int (*bind)(struct udevice *dev);
156 int (*probe)(struct udevice *dev);
157 int (*remove)(struct udevice *dev);
158 int (*unbind)(struct udevice *dev);
159 int (*ofdata_to_platdata)(struct udevice *dev);
160 int (*child_pre_probe)(struct udevice *dev);
161 int (*child_post_remove)(struct udevice *dev);
162 int priv_auto_alloc_size;
163 int platdata_auto_alloc_size;
164 int per_child_auto_alloc_size;
165 const void *ops; /* driver-specific operations */
169 /* Declare a new U-Boot driver */
170 #define U_BOOT_DRIVER(__name) \
171 ll_entry_declare(struct driver, __name, driver)
174 * dev_get_platdata() - Get the platform data for a device
176 * This checks that dev is not NULL, but no other checks for now
178 * @dev Device to check
179 * @return platform data, or NULL if none
181 void *dev_get_platdata(struct udevice *dev);
184 * dev_get_parentdata() - Get the parent data for a device
186 * The parent data is data stored in the device but owned by the parent.
187 * For example, a USB device may have parent data which contains information
188 * about how to talk to the device over USB.
190 * This checks that dev is not NULL, but no other checks for now
192 * @dev Device to check
193 * @return parent data, or NULL if none
195 void *dev_get_parentdata(struct udevice *dev);
198 * dev_get_priv() - Get the private data for a device
200 * This checks that dev is not NULL, but no other checks for now
202 * @dev Device to check
203 * @return private data, or NULL if none
205 void *dev_get_priv(struct udevice *dev);
208 * device_get_child() - Get the child of a device by index
210 * Returns the numbered child, 0 being the first. This does not use
211 * sequence numbers, only the natural order.
213 * @dev: Parent device to check
214 * @index: Child index
215 * @devp: Returns pointer to device
217 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
220 * device_find_child_by_seq() - Find a child device based on a sequence
222 * This searches for a device with the given seq or req_seq.
224 * For seq, if an active device has this sequence it will be returned.
225 * If there is no such device then this will return -ENODEV.
227 * For req_seq, if a device (whether activated or not) has this req_seq
228 * value, that device will be returned. This is a strong indication that
229 * the device will receive that sequence when activated.
231 * @parent: Parent device
232 * @seq_or_req_seq: Sequence number to find (0=first)
233 * @find_req_seq: true to find req_seq, false to find seq
234 * @devp: Returns pointer to device (there is only one per for each seq).
235 * Set to NULL if none is found
236 * @return 0 if OK, -ve on error
238 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
239 bool find_req_seq, struct udevice **devp);
242 * device_get_child_by_seq() - Get a child device based on a sequence
244 * If an active device has this sequence it will be returned. If there is no
245 * such device then this will check for a device that is requesting this
248 * The device is probed to activate it ready for use.
250 * @parent: Parent device
251 * @seq: Sequence number to find (0=first)
252 * @devp: Returns pointer to device (there is only one per for each seq)
253 * Set to NULL if none is found
254 * @return 0 if OK, -ve on error
256 int device_get_child_by_seq(struct udevice *parent, int seq,
257 struct udevice **devp);
260 * device_find_child_by_of_offset() - Find a child device based on FDT offset
262 * Locates a child device by its device tree offset.
264 * @parent: Parent device
265 * @of_offset: Device tree offset to find
266 * @devp: Returns pointer to device if found, otherwise this is set to NULL
267 * @return 0 if OK, -ve on error
269 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
270 struct udevice **devp);
273 * device_get_child_by_of_offset() - Get a child device based on FDT offset
275 * Locates a child device by its device tree offset.
277 * The device is probed to activate it ready for use.
279 * @parent: Parent device
280 * @of_offset: Device tree offset to find
281 * @devp: Returns pointer to device if found, otherwise this is set to NULL
282 * @return 0 if OK, -ve on error
284 int device_get_child_by_of_offset(struct udevice *parent, int seq,
285 struct udevice **devp);
288 * device_find_first_child() - Find the first child of a device
290 * @parent: Parent device to search
291 * @devp: Returns first child device, or NULL if none
294 int device_find_first_child(struct udevice *parent, struct udevice **devp);
297 * device_find_first_child() - Find the first child of a device
299 * @devp: Pointer to previous child device on entry. Returns pointer to next
300 * child device, or NULL if none
303 int device_find_next_child(struct udevice **devp);