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dm: core: Add functions to find parent and OF data
[people/ms/u-boot.git] / include / dm / device.h
1 /*
2 * Copyright (c) 2013 Google, Inc
3 *
4 * (C) Copyright 2012
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
6 * Marek Vasut <marex@denx.de>
7 *
8 * SPDX-License-Identifier: GPL-2.0+
9 */
10
11 #ifndef _DM_DEVICE_H
12 #define _DM_DEVICE_H
13
14 #include <dm/uclass-id.h>
15 #include <linker_lists.h>
16 #include <linux/list.h>
17
18 struct driver_info;
19
20 /* Driver is active (probed). Cleared when it is removed */
21 #define DM_FLAG_ACTIVATED (1 << 0)
22
23 /* DM is responsible for allocating and freeing platdata */
24 #define DM_FLAG_ALLOC_PDATA (1 << 1)
25
26 /* DM should init this device prior to relocation */
27 #define DM_FLAG_PRE_RELOC (1 << 2)
28
29 /**
30 * struct udevice - An instance of a driver
31 *
32 * This holds information about a device, which is a driver bound to a
33 * particular port or peripheral (essentially a driver instance).
34 *
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.
41 *
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.
45 *
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 * @of_id: Pointer to the udevice_id structure which created the device
51 * @parent: Parent of this device, or NULL for the top level device
52 * @priv: Private data for this device
53 * @uclass: Pointer to uclass for this device
54 * @uclass_priv: The uclass's private data for this device
55 * @parent_priv: The parent's private data for this device
56 * @uclass_node: Used by uclass to link its devices
57 * @child_head: List of children of this device
58 * @sibling_node: Next device in list of all devices
59 * @flags: Flags for this device DM_FLAG_...
60 * @req_seq: Requested sequence number for this device (-1 = any)
61 * @seq: Allocated sequence number for this device (-1 = none). This is set up
62 * when the device is probed and will be unique within the device's uclass.
63 */
64 struct udevice {
65 struct driver *driver;
66 const char *name;
67 void *platdata;
68 int of_offset;
69 const struct udevice_id *of_id;
70 struct udevice *parent;
71 void *priv;
72 struct uclass *uclass;
73 void *uclass_priv;
74 void *parent_priv;
75 struct list_head uclass_node;
76 struct list_head child_head;
77 struct list_head sibling_node;
78 uint32_t flags;
79 int req_seq;
80 int seq;
81 };
82
83 /* Maximum sequence number supported */
84 #define DM_MAX_SEQ 999
85
86 /* Returns the operations for a device */
87 #define device_get_ops(dev) (dev->driver->ops)
88
89 /* Returns non-zero if the device is active (probed and not removed) */
90 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
91
92 /**
93 * struct udevice_id - Lists the compatible strings supported by a driver
94 * @compatible: Compatible string
95 * @data: Data for this compatible string
96 */
97 struct udevice_id {
98 const char *compatible;
99 ulong data;
100 };
101
102 #ifdef CONFIG_OF_CONTROL
103 #define of_match_ptr(_ptr) (_ptr)
104 #else
105 #define of_match_ptr(_ptr) NULL
106 #endif /* CONFIG_OF_CONTROL */
107
108 /**
109 * struct driver - A driver for a feature or peripheral
110 *
111 * This holds methods for setting up a new device, and also removing it.
112 * The device needs information to set itself up - this is provided either
113 * by platdata or a device tree node (which we find by looking up
114 * matching compatible strings with of_match).
115 *
116 * Drivers all belong to a uclass, representing a class of devices of the
117 * same type. Common elements of the drivers can be implemented in the uclass,
118 * or the uclass can provide a consistent interface to the drivers within
119 * it.
120 *
121 * @name: Device name
122 * @id: Identiies the uclass we belong to
123 * @of_match: List of compatible strings to match, and any identifying data
124 * for each.
125 * @bind: Called to bind a device to its driver
126 * @probe: Called to probe a device, i.e. activate it
127 * @remove: Called to remove a device, i.e. de-activate it
128 * @unbind: Called to unbind a device from its driver
129 * @ofdata_to_platdata: Called before probe to decode device tree data
130 * @child_pre_probe: Called before a child device is probed. The device has
131 * memory allocated but it has not yet been probed.
132 * @child_post_remove: Called after a child device is removed. The device
133 * has memory allocated but its device_remove() method has been called.
134 * @priv_auto_alloc_size: If non-zero this is the size of the private data
135 * to be allocated in the device's ->priv pointer. If zero, then the driver
136 * is responsible for allocating any data required.
137 * @platdata_auto_alloc_size: If non-zero this is the size of the
138 * platform data to be allocated in the device's ->platdata pointer.
139 * This is typically only useful for device-tree-aware drivers (those with
140 * an of_match), since drivers which use platdata will have the data
141 * provided in the U_BOOT_DEVICE() instantiation.
142 * @per_child_auto_alloc_size: Each device can hold private data owned by
143 * its parent. If required this will be automatically allocated if this
144 * value is non-zero.
145 * TODO(sjg@chromium.org): I'm considering dropping this, and just having
146 * device_probe_child() pass it in. So far the use case for allocating it
147 * is SPI, but I found that unsatisfactory. Since it is here I will leave it
148 * until things are clearer.
149 * @ops: Driver-specific operations. This is typically a list of function
150 * pointers defined by the driver, to implement driver functions required by
151 * the uclass.
152 * @flags: driver flags - see DM_FLAGS_...
153 */
154 struct driver {
155 char *name;
156 enum uclass_id id;
157 const struct udevice_id *of_match;
158 int (*bind)(struct udevice *dev);
159 int (*probe)(struct udevice *dev);
160 int (*remove)(struct udevice *dev);
161 int (*unbind)(struct udevice *dev);
162 int (*ofdata_to_platdata)(struct udevice *dev);
163 int (*child_pre_probe)(struct udevice *dev);
164 int (*child_post_remove)(struct udevice *dev);
165 int priv_auto_alloc_size;
166 int platdata_auto_alloc_size;
167 int per_child_auto_alloc_size;
168 const void *ops; /* driver-specific operations */
169 uint32_t flags;
170 };
171
172 /* Declare a new U-Boot driver */
173 #define U_BOOT_DRIVER(__name) \
174 ll_entry_declare(struct driver, __name, driver)
175
176 /**
177 * dev_get_platdata() - Get the platform data for a device
178 *
179 * This checks that dev is not NULL, but no other checks for now
180 *
181 * @dev Device to check
182 * @return platform data, or NULL if none
183 */
184 void *dev_get_platdata(struct udevice *dev);
185
186 /**
187 * dev_get_parentdata() - Get the parent data for a device
188 *
189 * The parent data is data stored in the device but owned by the parent.
190 * For example, a USB device may have parent data which contains information
191 * about how to talk to the device over USB.
192 *
193 * This checks that dev is not NULL, but no other checks for now
194 *
195 * @dev Device to check
196 * @return parent data, or NULL if none
197 */
198 void *dev_get_parentdata(struct udevice *dev);
199
200 /**
201 * dev_get_priv() - Get the private data for a device
202 *
203 * This checks that dev is not NULL, but no other checks for now
204 *
205 * @dev Device to check
206 * @return private data, or NULL if none
207 */
208 void *dev_get_priv(struct udevice *dev);
209
210 /**
211 * struct dev_get_parent() - Get the parent of a device
212 *
213 * @child: Child to check
214 * @return parent of child, or NULL if this is the root device
215 */
216 struct udevice *dev_get_parent(struct udevice *child);
217
218 /**
219 * dev_get_of_data() - get the device tree data used to bind a device
220 *
221 * When a device is bound using a device tree node, it matches a
222 * particular compatible string as in struct udevice_id. This function
223 * returns the associated data value for that compatible string
224 */
225 ulong dev_get_of_data(struct udevice *dev);
226
227 /**
228 * device_get_child() - Get the child of a device by index
229 *
230 * Returns the numbered child, 0 being the first. This does not use
231 * sequence numbers, only the natural order.
232 *
233 * @dev: Parent device to check
234 * @index: Child index
235 * @devp: Returns pointer to device
236 */
237 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
238
239 /**
240 * device_find_child_by_seq() - Find a child device based on a sequence
241 *
242 * This searches for a device with the given seq or req_seq.
243 *
244 * For seq, if an active device has this sequence it will be returned.
245 * If there is no such device then this will return -ENODEV.
246 *
247 * For req_seq, if a device (whether activated or not) has this req_seq
248 * value, that device will be returned. This is a strong indication that
249 * the device will receive that sequence when activated.
250 *
251 * @parent: Parent device
252 * @seq_or_req_seq: Sequence number to find (0=first)
253 * @find_req_seq: true to find req_seq, false to find seq
254 * @devp: Returns pointer to device (there is only one per for each seq).
255 * Set to NULL if none is found
256 * @return 0 if OK, -ve on error
257 */
258 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
259 bool find_req_seq, struct udevice **devp);
260
261 /**
262 * device_get_child_by_seq() - Get a child device based on a sequence
263 *
264 * If an active device has this sequence it will be returned. If there is no
265 * such device then this will check for a device that is requesting this
266 * sequence.
267 *
268 * The device is probed to activate it ready for use.
269 *
270 * @parent: Parent device
271 * @seq: Sequence number to find (0=first)
272 * @devp: Returns pointer to device (there is only one per for each seq)
273 * Set to NULL if none is found
274 * @return 0 if OK, -ve on error
275 */
276 int device_get_child_by_seq(struct udevice *parent, int seq,
277 struct udevice **devp);
278
279 /**
280 * device_find_child_by_of_offset() - Find a child device based on FDT offset
281 *
282 * Locates a child device by its device tree offset.
283 *
284 * @parent: Parent device
285 * @of_offset: Device tree offset to find
286 * @devp: Returns pointer to device if found, otherwise this is set to NULL
287 * @return 0 if OK, -ve on error
288 */
289 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
290 struct udevice **devp);
291
292 /**
293 * device_get_child_by_of_offset() - Get a child device based on FDT offset
294 *
295 * Locates a child device by its device tree offset.
296 *
297 * The device is probed to activate it ready for use.
298 *
299 * @parent: Parent device
300 * @of_offset: Device tree offset to find
301 * @devp: Returns pointer to device if found, otherwise this is set to NULL
302 * @return 0 if OK, -ve on error
303 */
304 int device_get_child_by_of_offset(struct udevice *parent, int seq,
305 struct udevice **devp);
306
307 /**
308 * device_find_first_child() - Find the first child of a device
309 *
310 * @parent: Parent device to search
311 * @devp: Returns first child device, or NULL if none
312 * @return 0
313 */
314 int device_find_first_child(struct udevice *parent, struct udevice **devp);
315
316 /**
317 * device_find_first_child() - Find the first child of a device
318 *
319 * @devp: Pointer to previous child device on entry. Returns pointer to next
320 * child device, or NULL if none
321 * @return 0
322 */
323 int device_find_next_child(struct udevice **devp);
324
325 #endif