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>
16 #include <linker_lists.h>
17 #include <linux/list.h>
21 /* Driver is active (probed). Cleared when it is removed */
22 #define DM_FLAG_ACTIVATED (1 << 0)
24 /* DM is responsible for allocating and freeing platdata */
25 #define DM_FLAG_ALLOC_PDATA (1 << 1)
27 /* DM should init this device prior to relocation */
28 #define DM_FLAG_PRE_RELOC (1 << 2)
30 /* DM is responsible for allocating and freeing parent_platdata */
31 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
33 /* DM is responsible for allocating and freeing uclass_platdata */
34 #define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
36 /* Allocate driver private data on a DMA boundary */
37 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
40 * struct udevice - An instance of a driver
42 * This holds information about a device, which is a driver bound to a
43 * particular port or peripheral (essentially a driver instance).
45 * A device will come into existence through a 'bind' call, either due to
46 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
47 * in the device tree (in which case of_offset is >= 0). In the latter case
48 * we translate the device tree information into platdata in a function
49 * implemented by the driver ofdata_to_platdata method (called just before the
50 * probe method if the device has a device tree node.
52 * All three of platdata, priv and uclass_priv can be allocated by the
53 * driver, or you can use the auto_alloc_size members of struct driver and
54 * struct uclass_driver to have driver model do this automatically.
56 * @driver: The driver used by this device
57 * @name: Name of device, typically the FDT node name
58 * @platdata: Configuration data for this device
59 * @parent_platdata: The parent bus's configuration data for this device
60 * @uclass_platdata: The uclass's configuration data for this device
61 * @of_offset: Device tree node offset for this device (- for none)
62 * @driver_data: Driver data word for the entry that matched this device with
64 * @parent: Parent of this device, or NULL for the top level device
65 * @priv: Private data for this device
66 * @uclass: Pointer to uclass for this device
67 * @uclass_priv: The uclass's private data for this device
68 * @parent_priv: The parent's private data for this device
69 * @uclass_node: Used by uclass to link its devices
70 * @child_head: List of children of this device
71 * @sibling_node: Next device in list of all devices
72 * @flags: Flags for this device DM_FLAG_...
73 * @req_seq: Requested sequence number for this device (-1 = any)
74 * @seq: Allocated sequence number for this device (-1 = none). This is set up
75 * when the device is probed and will be unique within the device's uclass.
78 const struct driver *driver;
81 void *parent_platdata;
82 void *uclass_platdata;
85 struct udevice *parent;
87 struct uclass *uclass;
90 struct list_head uclass_node;
91 struct list_head child_head;
92 struct list_head sibling_node;
98 /* Maximum sequence number supported */
99 #define DM_MAX_SEQ 999
101 /* Returns the operations for a device */
102 #define device_get_ops(dev) (dev->driver->ops)
104 /* Returns non-zero if the device is active (probed and not removed) */
105 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
108 * struct udevice_id - Lists the compatible strings supported by a driver
109 * @compatible: Compatible string
110 * @data: Data for this compatible string
113 const char *compatible;
117 #ifdef CONFIG_OF_CONTROL
118 #define of_match_ptr(_ptr) (_ptr)
120 #define of_match_ptr(_ptr) NULL
121 #endif /* CONFIG_OF_CONTROL */
124 * struct driver - A driver for a feature or peripheral
126 * This holds methods for setting up a new device, and also removing it.
127 * The device needs information to set itself up - this is provided either
128 * by platdata or a device tree node (which we find by looking up
129 * matching compatible strings with of_match).
131 * Drivers all belong to a uclass, representing a class of devices of the
132 * same type. Common elements of the drivers can be implemented in the uclass,
133 * or the uclass can provide a consistent interface to the drivers within
137 * @id: Identiies the uclass we belong to
138 * @of_match: List of compatible strings to match, and any identifying data
140 * @bind: Called to bind a device to its driver
141 * @probe: Called to probe a device, i.e. activate it
142 * @remove: Called to remove a device, i.e. de-activate it
143 * @unbind: Called to unbind a device from its driver
144 * @ofdata_to_platdata: Called before probe to decode device tree data
145 * @child_post_bind: Called after a new child has been bound
146 * @child_pre_probe: Called before a child device is probed. The device has
147 * memory allocated but it has not yet been probed.
148 * @child_post_remove: Called after a child device is removed. The device
149 * has memory allocated but its device_remove() method has been called.
150 * @priv_auto_alloc_size: If non-zero this is the size of the private data
151 * to be allocated in the device's ->priv pointer. If zero, then the driver
152 * is responsible for allocating any data required.
153 * @platdata_auto_alloc_size: If non-zero this is the size of the
154 * platform data to be allocated in the device's ->platdata pointer.
155 * This is typically only useful for device-tree-aware drivers (those with
156 * an of_match), since drivers which use platdata will have the data
157 * provided in the U_BOOT_DEVICE() instantiation.
158 * @per_child_auto_alloc_size: Each device can hold private data owned by
159 * its parent. If required this will be automatically allocated if this
161 * TODO(sjg@chromium.org): I'm considering dropping this, and just having
162 * device_probe_child() pass it in. So far the use case for allocating it
163 * is SPI, but I found that unsatisfactory. Since it is here I will leave it
164 * until things are clearer.
165 * @per_child_platdata_auto_alloc_size: A bus likes to store information about
166 * its children. If non-zero this is the size of this data, to be allocated
167 * in the child's parent_platdata pointer.
168 * @ops: Driver-specific operations. This is typically a list of function
169 * pointers defined by the driver, to implement driver functions required by
171 * @flags: driver flags - see DM_FLAGS_...
176 const struct udevice_id *of_match;
177 int (*bind)(struct udevice *dev);
178 int (*probe)(struct udevice *dev);
179 int (*remove)(struct udevice *dev);
180 int (*unbind)(struct udevice *dev);
181 int (*ofdata_to_platdata)(struct udevice *dev);
182 int (*child_post_bind)(struct udevice *dev);
183 int (*child_pre_probe)(struct udevice *dev);
184 int (*child_post_remove)(struct udevice *dev);
185 int priv_auto_alloc_size;
186 int platdata_auto_alloc_size;
187 int per_child_auto_alloc_size;
188 int per_child_platdata_auto_alloc_size;
189 const void *ops; /* driver-specific operations */
193 /* Declare a new U-Boot driver */
194 #define U_BOOT_DRIVER(__name) \
195 ll_entry_declare(struct driver, __name, driver)
198 * dev_get_platdata() - Get the platform 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 platform data, or NULL if none
205 void *dev_get_platdata(struct udevice *dev);
208 * dev_get_parent_platdata() - Get the parent platform data for a device
210 * This checks that dev is not NULL, but no other checks for now
212 * @dev Device to check
213 * @return parent's platform data, or NULL if none
215 void *dev_get_parent_platdata(struct udevice *dev);
218 * dev_get_uclass_platdata() - Get the uclass platform data for a device
220 * This checks that dev is not NULL, but no other checks for now
222 * @dev Device to check
223 * @return uclass's platform data, or NULL if none
225 void *dev_get_uclass_platdata(struct udevice *dev);
228 * dev_get_parentdata() - Get the parent data for a device
230 * The parent data is data stored in the device but owned by the parent.
231 * For example, a USB device may have parent data which contains information
232 * about how to talk to the device over USB.
234 * This checks that dev is not NULL, but no other checks for now
236 * @dev Device to check
237 * @return parent data, or NULL if none
239 void *dev_get_parentdata(struct udevice *dev);
242 * dev_get_priv() - Get the private data for a device
244 * This checks that dev is not NULL, but no other checks for now
246 * @dev Device to check
247 * @return private data, or NULL if none
249 void *dev_get_priv(struct udevice *dev);
252 * struct dev_get_parent() - Get the parent of a device
254 * @child: Child to check
255 * @return parent of child, or NULL if this is the root device
257 struct udevice *dev_get_parent(struct udevice *child);
260 * dev_get_uclass_priv() - Get the private uclass data for a device
262 * This checks that dev is not NULL, but no other checks for now
264 * @dev Device to check
265 * @return private uclass data for this device, or NULL if none
267 void *dev_get_uclass_priv(struct udevice *dev);
270 * dev_get_driver_data() - get the driver data used to bind a device
272 * When a device is bound using a device tree node, it matches a
273 * particular compatible string as in struct udevice_id. This function
274 * returns the associated data value for that compatible string. This is
275 * the 'data' field in struct udevice_id.
277 * For USB devices, this is the driver_info field in struct usb_device_id.
279 * @dev: Device to check
281 ulong dev_get_driver_data(struct udevice *dev);
284 * dev_get_driver_ops() - get the device's driver's operations
286 * This checks that dev is not NULL, and returns the pointer to device's
287 * driver's operations.
289 * @dev: Device to check
290 * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
292 const void *dev_get_driver_ops(struct udevice *dev);
295 * device_get_uclass_id() - return the uclass ID of a device
297 * @dev: Device to check
298 * @return uclass ID for the device
300 enum uclass_id device_get_uclass_id(struct udevice *dev);
303 * device_get_child() - Get the child of a device by index
305 * Returns the numbered child, 0 being the first. This does not use
306 * sequence numbers, only the natural order.
308 * @dev: Parent device to check
309 * @index: Child index
310 * @devp: Returns pointer to device
312 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
315 * device_find_child_by_seq() - Find a child device based on a sequence
317 * This searches for a device with the given seq or req_seq.
319 * For seq, if an active device has this sequence it will be returned.
320 * If there is no such device then this will return -ENODEV.
322 * For req_seq, if a device (whether activated or not) has this req_seq
323 * value, that device will be returned. This is a strong indication that
324 * the device will receive that sequence when activated.
326 * @parent: Parent device
327 * @seq_or_req_seq: Sequence number to find (0=first)
328 * @find_req_seq: true to find req_seq, false to find seq
329 * @devp: Returns pointer to device (there is only one per for each seq).
330 * Set to NULL if none is found
331 * @return 0 if OK, -ve on error
333 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
334 bool find_req_seq, struct udevice **devp);
337 * device_get_child_by_seq() - Get a child device based on a sequence
339 * If an active device has this sequence it will be returned. If there is no
340 * such device then this will check for a device that is requesting this
343 * The device is probed to activate it ready for use.
345 * @parent: Parent device
346 * @seq: Sequence number to find (0=first)
347 * @devp: Returns pointer to device (there is only one per for each seq)
348 * Set to NULL if none is found
349 * @return 0 if OK, -ve on error
351 int device_get_child_by_seq(struct udevice *parent, int seq,
352 struct udevice **devp);
355 * device_find_child_by_of_offset() - Find a child device based on FDT offset
357 * Locates a child device by its device tree offset.
359 * @parent: Parent device
360 * @of_offset: Device tree offset to find
361 * @devp: Returns pointer to device if found, otherwise this is set to NULL
362 * @return 0 if OK, -ve on error
364 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
365 struct udevice **devp);
368 * device_get_child_by_of_offset() - Get a child device based on FDT offset
370 * Locates a child device by its device tree offset.
372 * The device is probed to activate it ready for use.
374 * @parent: Parent device
375 * @of_offset: Device tree offset to find
376 * @devp: Returns pointer to device if found, otherwise this is set to NULL
377 * @return 0 if OK, -ve on error
379 int device_get_child_by_of_offset(struct udevice *parent, int seq,
380 struct udevice **devp);
383 * device_find_first_child() - Find the first child of a device
385 * @parent: Parent device to search
386 * @devp: Returns first child device, or NULL if none
389 int device_find_first_child(struct udevice *parent, struct udevice **devp);
392 * device_find_first_child() - Find the first child of a device
394 * @devp: Pointer to previous child device on entry. Returns pointer to next
395 * child device, or NULL if none
398 int device_find_next_child(struct udevice **devp);
401 * dev_get_addr() - Get the reg property of a device
403 * @dev: Pointer to a device
407 fdt_addr_t dev_get_addr(struct udevice *dev);
410 * device_has_children() - check if a device has any children
412 * @dev: Device to check
413 * @return true if the device has one or more children
415 bool device_has_children(struct udevice *dev);
418 * device_has_active_children() - check if a device has any active children
420 * @dev: Device to check
421 * @return true if the device has one or more children and at least one of
422 * them is active (probed).
424 bool device_has_active_children(struct udevice *dev);
427 * device_is_last_sibling() - check if a device is the last sibling
429 * This function can be useful for display purposes, when special action needs
430 * to be taken when displaying the last sibling. This can happen when a tree
431 * view of devices is being displayed.
433 * @dev: Device to check
434 * @return true if there are no more siblings after this one - i.e. is it
437 bool device_is_last_sibling(struct udevice *dev);