1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2013 Google, Inc
6 * Pavel Herrmann <morpheus.ibis@gmail.com>
7 * Marek Vasut <marex@denx.de>
13 #include <dm/ofnode.h>
14 #include <dm/uclass-id.h>
16 #include <linker_lists.h>
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/printk.h>
23 /* Driver is active (probed). Cleared when it is removed */
24 #define DM_FLAG_ACTIVATED (1 << 0)
26 /* DM is responsible for allocating and freeing platdata */
27 #define DM_FLAG_ALLOC_PDATA (1 << 1)
29 /* DM should init this device prior to relocation */
30 #define DM_FLAG_PRE_RELOC (1 << 2)
32 /* DM is responsible for allocating and freeing parent_platdata */
33 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
35 /* DM is responsible for allocating and freeing uclass_platdata */
36 #define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
38 /* Allocate driver private data on a DMA boundary */
39 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
42 #define DM_FLAG_BOUND (1 << 6)
44 /* Device name is allocated and should be freed on unbind() */
45 #define DM_FLAG_NAME_ALLOCED (1 << 7)
47 /* Device has platform data provided by of-platdata */
48 #define DM_FLAG_OF_PLATDATA (1 << 8)
51 * Call driver remove function to stop currently active DMA transfers or
52 * give DMA buffers back to the HW / controller. This may be needed for
53 * some drivers to do some final stage cleanup before the OS is called
56 #define DM_FLAG_ACTIVE_DMA (1 << 9)
59 * Call driver remove function to do some final configuration, before
60 * U-Boot exits and the OS is started
62 #define DM_FLAG_OS_PREPARE (1 << 10)
64 /* DM does not enable/disable the power domains corresponding to this device */
65 #define DM_FLAG_DEFAULT_PD_CTRL_OFF (1 << 11)
67 /* Driver platdata has been read. Cleared when the device is removed */
68 #define DM_FLAG_PLATDATA_VALID (1 << 12)
71 * One or multiple of these flags are passed to device_remove() so that
72 * a selective device removal as specified by the remove-stage and the
73 * driver flags can be done.
76 /* Normal remove, remove all devices */
77 DM_REMOVE_NORMAL = 1 << 0,
79 /* Remove devices with active DMA */
80 DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
82 /* Remove devices which need some final OS preparation steps */
83 DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
85 /* Add more use cases here */
87 /* Remove devices with any active flag */
88 DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
92 * struct udevice - An instance of a driver
94 * This holds information about a device, which is a driver bound to a
95 * particular port or peripheral (essentially a driver instance).
97 * A device will come into existence through a 'bind' call, either due to
98 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
99 * in the device tree (in which case of_offset is >= 0). In the latter case
100 * we translate the device tree information into platdata in a function
101 * implemented by the driver ofdata_to_platdata method (called just before the
102 * probe method if the device has a device tree node.
104 * All three of platdata, priv and uclass_priv can be allocated by the
105 * driver, or you can use the auto_alloc_size members of struct driver and
106 * struct uclass_driver to have driver model do this automatically.
108 * @driver: The driver used by this device
109 * @name: Name of device, typically the FDT node name
110 * @platdata: Configuration data for this device
111 * @parent_platdata: The parent bus's configuration data for this device
112 * @uclass_platdata: The uclass's configuration data for this device
113 * @node: Reference to device tree node for this device
114 * @driver_data: Driver data word for the entry that matched this device with
116 * @parent: Parent of this device, or NULL for the top level device
117 * @priv: Private data for this device
118 * @uclass: Pointer to uclass for this device
119 * @uclass_priv: The uclass's private data for this device
120 * @parent_priv: The parent's private data for this device
121 * @uclass_node: Used by uclass to link its devices
122 * @child_head: List of children of this device
123 * @sibling_node: Next device in list of all devices
124 * @flags: Flags for this device DM_FLAG_...
125 * @req_seq: Requested sequence number for this device (-1 = any)
126 * @seq: Allocated sequence number for this device (-1 = none). This is set up
127 * when the device is probed and will be unique within the device's uclass.
128 * @devres_head: List of memory allocations associated with this device.
129 * When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
130 * add to this list. Memory so-allocated will be freed
131 * automatically when the device is removed / unbound
134 const struct driver *driver;
137 void *parent_platdata;
138 void *uclass_platdata;
141 struct udevice *parent;
143 struct uclass *uclass;
146 struct list_head uclass_node;
147 struct list_head child_head;
148 struct list_head sibling_node;
153 struct list_head devres_head;
157 /* Maximum sequence number supported */
158 #define DM_MAX_SEQ 999
160 /* Returns the operations for a device */
161 #define device_get_ops(dev) (dev->driver->ops)
163 /* Returns non-zero if the device is active (probed and not removed) */
164 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
166 static inline int dev_of_offset(const struct udevice *dev)
168 return ofnode_to_offset(dev->node);
171 static inline void dev_set_of_offset(struct udevice *dev, int of_offset)
173 dev->node = offset_to_ofnode(of_offset);
176 static inline bool dev_has_of_node(struct udevice *dev)
178 return ofnode_valid(dev->node);
182 * struct udevice_id - Lists the compatible strings supported by a driver
183 * @compatible: Compatible string
184 * @data: Data for this compatible string
187 const char *compatible;
191 #if CONFIG_IS_ENABLED(OF_CONTROL)
192 #define of_match_ptr(_ptr) (_ptr)
194 #define of_match_ptr(_ptr) NULL
195 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
198 * struct driver - A driver for a feature or peripheral
200 * This holds methods for setting up a new device, and also removing it.
201 * The device needs information to set itself up - this is provided either
202 * by platdata or a device tree node (which we find by looking up
203 * matching compatible strings with of_match).
205 * Drivers all belong to a uclass, representing a class of devices of the
206 * same type. Common elements of the drivers can be implemented in the uclass,
207 * or the uclass can provide a consistent interface to the drivers within
211 * @id: Identifies the uclass we belong to
212 * @of_match: List of compatible strings to match, and any identifying data
214 * @bind: Called to bind a device to its driver
215 * @probe: Called to probe a device, i.e. activate it
216 * @remove: Called to remove a device, i.e. de-activate it
217 * @unbind: Called to unbind a device from its driver
218 * @ofdata_to_platdata: Called before probe to decode device tree data
219 * @child_post_bind: Called after a new child has been bound
220 * @child_pre_probe: Called before a child device is probed. The device has
221 * memory allocated but it has not yet been probed.
222 * @child_post_remove: Called after a child device is removed. The device
223 * has memory allocated but its device_remove() method has been called.
224 * @priv_auto_alloc_size: If non-zero this is the size of the private data
225 * to be allocated in the device's ->priv pointer. If zero, then the driver
226 * is responsible for allocating any data required.
227 * @platdata_auto_alloc_size: If non-zero this is the size of the
228 * platform data to be allocated in the device's ->platdata pointer.
229 * This is typically only useful for device-tree-aware drivers (those with
230 * an of_match), since drivers which use platdata will have the data
231 * provided in the U_BOOT_DEVICE() instantiation.
232 * @per_child_auto_alloc_size: Each device can hold private data owned by
233 * its parent. If required this will be automatically allocated if this
235 * @per_child_platdata_auto_alloc_size: A bus likes to store information about
236 * its children. If non-zero this is the size of this data, to be allocated
237 * in the child's parent_platdata pointer.
238 * @ops: Driver-specific operations. This is typically a list of function
239 * pointers defined by the driver, to implement driver functions required by
241 * @flags: driver flags - see DM_FLAGS_...
246 const struct udevice_id *of_match;
247 int (*bind)(struct udevice *dev);
248 int (*probe)(struct udevice *dev);
249 int (*remove)(struct udevice *dev);
250 int (*unbind)(struct udevice *dev);
251 int (*ofdata_to_platdata)(struct udevice *dev);
252 int (*child_post_bind)(struct udevice *dev);
253 int (*child_pre_probe)(struct udevice *dev);
254 int (*child_post_remove)(struct udevice *dev);
255 int priv_auto_alloc_size;
256 int platdata_auto_alloc_size;
257 int per_child_auto_alloc_size;
258 int per_child_platdata_auto_alloc_size;
259 const void *ops; /* driver-specific operations */
263 /* Declare a new U-Boot driver */
264 #define U_BOOT_DRIVER(__name) \
265 ll_entry_declare(struct driver, __name, driver)
267 /* Get a pointer to a given driver */
268 #define DM_GET_DRIVER(__name) \
269 ll_entry_get(struct driver, __name, driver)
272 * dev_get_platdata() - Get the platform data for a device
274 * This checks that dev is not NULL, but no other checks for now
276 * @dev Device to check
277 * @return platform data, or NULL if none
279 void *dev_get_platdata(const struct udevice *dev);
282 * dev_get_parent_platdata() - Get the parent platform data for a device
284 * This checks that dev is not NULL, but no other checks for now
286 * @dev Device to check
287 * @return parent's platform data, or NULL if none
289 void *dev_get_parent_platdata(const struct udevice *dev);
292 * dev_get_uclass_platdata() - Get the uclass platform data for a device
294 * This checks that dev is not NULL, but no other checks for now
296 * @dev Device to check
297 * @return uclass's platform data, or NULL if none
299 void *dev_get_uclass_platdata(const struct udevice *dev);
302 * dev_get_priv() - Get the private data for a device
304 * This checks that dev is not NULL, but no other checks for now
306 * @dev Device to check
307 * @return private data, or NULL if none
309 void *dev_get_priv(const struct udevice *dev);
312 * dev_get_parent_priv() - Get the parent private data for a device
314 * The parent private data is data stored in the device but owned by the
315 * parent. For example, a USB device may have parent data which contains
316 * information about how to talk to the device over USB.
318 * This checks that dev is not NULL, but no other checks for now
320 * @dev Device to check
321 * @return parent data, or NULL if none
323 void *dev_get_parent_priv(const struct udevice *dev);
326 * dev_get_uclass_priv() - Get the private uclass data for a device
328 * This checks that dev is not NULL, but no other checks for now
330 * @dev Device to check
331 * @return private uclass data for this device, or NULL if none
333 void *dev_get_uclass_priv(const struct udevice *dev);
336 * struct dev_get_parent() - Get the parent of a device
338 * @child: Child to check
339 * @return parent of child, or NULL if this is the root device
341 struct udevice *dev_get_parent(const struct udevice *child);
344 * dev_get_driver_data() - get the driver data used to bind a device
346 * When a device is bound using a device tree node, it matches a
347 * particular compatible string in struct udevice_id. This function
348 * returns the associated data value for that compatible string. This is
349 * the 'data' field in struct udevice_id.
351 * As an example, consider this structure:
352 * static const struct udevice_id tegra_i2c_ids[] = {
353 * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
354 * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
355 * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
359 * When driver model finds a driver for this it will store the 'data' value
360 * corresponding to the compatible string it matches. This function returns
361 * that value. This allows the driver to handle several variants of a device.
363 * For USB devices, this is the driver_info field in struct usb_device_id.
365 * @dev: Device to check
366 * @return driver data (0 if none is provided)
368 ulong dev_get_driver_data(const struct udevice *dev);
371 * dev_get_driver_ops() - get the device's driver's operations
373 * This checks that dev is not NULL, and returns the pointer to device's
374 * driver's operations.
376 * @dev: Device to check
377 * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
379 const void *dev_get_driver_ops(const struct udevice *dev);
382 * device_get_uclass_id() - return the uclass ID of a device
384 * @dev: Device to check
385 * @return uclass ID for the device
387 enum uclass_id device_get_uclass_id(const struct udevice *dev);
390 * dev_get_uclass_name() - return the uclass name of a device
392 * This checks that dev is not NULL.
394 * @dev: Device to check
395 * @return pointer to the uclass name for the device
397 const char *dev_get_uclass_name(const struct udevice *dev);
400 * device_get_child() - Get the child of a device by index
402 * Returns the numbered child, 0 being the first. This does not use
403 * sequence numbers, only the natural order.
405 * @dev: Parent device to check
406 * @index: Child index
407 * @devp: Returns pointer to device
408 * @return 0 if OK, -ENODEV if no such device, other error if the device fails
411 int device_get_child(const struct udevice *parent, int index,
412 struct udevice **devp);
415 * device_get_child_count() - Get the available child count of a device
417 * Returns the number of children to a device.
419 * @parent: Parent device to check
421 int device_get_child_count(const struct udevice *parent);
424 * device_find_child_by_seq() - Find a child device based on a sequence
426 * This searches for a device with the given seq or req_seq.
428 * For seq, if an active device has this sequence it will be returned.
429 * If there is no such device then this will return -ENODEV.
431 * For req_seq, if a device (whether activated or not) has this req_seq
432 * value, that device will be returned. This is a strong indication that
433 * the device will receive that sequence when activated.
435 * @parent: Parent device
436 * @seq_or_req_seq: Sequence number to find (0=first)
437 * @find_req_seq: true to find req_seq, false to find seq
438 * @devp: Returns pointer to device (there is only one per for each seq).
439 * Set to NULL if none is found
440 * @return 0 if OK, -ve on error
442 int device_find_child_by_seq(const struct udevice *parent, int seq_or_req_seq,
443 bool find_req_seq, struct udevice **devp);
446 * device_get_child_by_seq() - Get a child device based on a sequence
448 * If an active device has this sequence it will be returned. If there is no
449 * such device then this will check for a device that is requesting this
452 * The device is probed to activate it ready for use.
454 * @parent: Parent device
455 * @seq: Sequence number to find (0=first)
456 * @devp: Returns pointer to device (there is only one per for each seq)
457 * Set to NULL if none is found
458 * @return 0 if OK, -ve on error
460 int device_get_child_by_seq(const struct udevice *parent, int seq,
461 struct udevice **devp);
464 * device_find_child_by_of_offset() - Find a child device based on FDT offset
466 * Locates a child device by its device tree offset.
468 * @parent: Parent device
469 * @of_offset: Device tree offset to find
470 * @devp: Returns pointer to device if found, otherwise this is set to NULL
471 * @return 0 if OK, -ve on error
473 int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
474 struct udevice **devp);
477 * device_get_child_by_of_offset() - Get a child device based on FDT offset
479 * Locates a child device by its device tree offset.
481 * The device is probed to activate it ready for use.
483 * @parent: Parent device
484 * @of_offset: Device tree offset to find
485 * @devp: Returns pointer to device if found, otherwise this is set to NULL
486 * @return 0 if OK, -ve on error
488 int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
489 struct udevice **devp);
492 * device_find_global_by_ofnode() - Get a device based on ofnode
494 * Locates a device by its device tree ofnode, searching globally throughout
495 * the all driver model devices.
497 * The device is NOT probed
499 * @node: Device tree ofnode to find
500 * @devp: Returns pointer to device if found, otherwise this is set to NULL
501 * @return 0 if OK, -ve on error
504 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
507 * device_get_global_by_ofnode() - Get a device based on ofnode
509 * Locates a device by its device tree ofnode, searching globally throughout
510 * the all driver model devices.
512 * The device is probed to activate it ready for use.
514 * @node: Device tree ofnode to find
515 * @devp: Returns pointer to device if found, otherwise this is set to NULL
516 * @return 0 if OK, -ve on error
518 int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
521 * device_find_first_child() - Find the first child of a device
523 * @parent: Parent device to search
524 * @devp: Returns first child device, or NULL if none
527 int device_find_first_child(const struct udevice *parent,
528 struct udevice **devp);
531 * device_find_next_child() - Find the next child of a device
533 * @devp: Pointer to previous child device on entry. Returns pointer to next
534 * child device, or NULL if none
537 int device_find_next_child(struct udevice **devp);
540 * device_find_first_inactive_child() - Find the first inactive child
542 * This is used to locate an existing child of a device which is of a given
545 * The device is NOT probed
547 * @parent: Parent device to search
548 * @uclass_id: Uclass to look for
549 * @devp: Returns device found, if any
550 * @return 0 if found, else -ENODEV
552 int device_find_first_inactive_child(const struct udevice *parent,
553 enum uclass_id uclass_id,
554 struct udevice **devp);
557 * device_find_first_child_by_uclass() - Find the first child of a device in uc
559 * @parent: Parent device to search
560 * @uclass_id: Uclass to look for
561 * @devp: Returns first child device in that uclass, if any
562 * @return 0 if found, else -ENODEV
564 int device_find_first_child_by_uclass(const struct udevice *parent,
565 enum uclass_id uclass_id,
566 struct udevice **devp);
569 * device_find_child_by_name() - Find a child by device name
571 * @parent: Parent device to search
572 * @name: Name to look for
573 * @devp: Returns device found, if any
574 * @return 0 if found, else -ENODEV
576 int device_find_child_by_name(const struct udevice *parent, const char *name,
577 struct udevice **devp);
580 * device_first_child_ofdata_err() - Find the first child and reads its platdata
582 * The ofdata_to_platdata() method is called on the child before it is returned,
583 * but the child is not probed.
585 * @parent: Parent to check
586 * @devp: Returns child that was found, if any
587 * @return 0 on success, -ENODEV if no children, other -ve on error
589 int device_first_child_ofdata_err(struct udevice *parent,
590 struct udevice **devp);
593 * device_next_child_ofdata_err() - Find the next child and read its platdata
595 * The ofdata_to_platdata() method is called on the child before it is returned,
596 * but the child is not probed.
598 * @devp: On entry, points to the previous child; on exit returns the child that
600 * @return 0 on success, -ENODEV if no children, other -ve on error
602 int device_next_child_ofdata_err(struct udevice **devp);
605 * device_first_child_err() - Get the first child of a device
607 * The device returned is probed if necessary, and ready for use
609 * @parent: Parent device to search
610 * @devp: Returns device found, if any
611 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
613 int device_first_child_err(struct udevice *parent, struct udevice **devp);
616 * device_next_child_err() - Get the next child of a parent device
618 * The device returned is probed if necessary, and ready for use
620 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
621 * to the next sibling if no error occurred
622 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
624 int device_next_child_err(struct udevice **devp);
627 * device_has_children() - check if a device has any children
629 * @dev: Device to check
630 * @return true if the device has one or more children
632 bool device_has_children(const struct udevice *dev);
635 * device_has_active_children() - check if a device has any active children
637 * @dev: Device to check
638 * @return true if the device has one or more children and at least one of
639 * them is active (probed).
641 bool device_has_active_children(const struct udevice *dev);
644 * device_is_last_sibling() - check if a device is the last sibling
646 * This function can be useful for display purposes, when special action needs
647 * to be taken when displaying the last sibling. This can happen when a tree
648 * view of devices is being displayed.
650 * @dev: Device to check
651 * @return true if there are no more siblings after this one - i.e. is it
654 bool device_is_last_sibling(const struct udevice *dev);
657 * device_set_name() - set the name of a device
659 * This must be called in the device's bind() method and no later. Normally
660 * this is unnecessary but for probed devices which don't get a useful name
661 * this function can be helpful.
663 * The name is allocated and will be freed automatically when the device is
666 * @dev: Device to update
667 * @name: New name (this string is allocated new memory and attached to
669 * @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
672 int device_set_name(struct udevice *dev, const char *name);
675 * device_set_name_alloced() - note that a device name is allocated
677 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
678 * unbound the name will be freed. This avoids memory leaks.
680 * @dev: Device to update
682 void device_set_name_alloced(struct udevice *dev);
685 * device_is_compatible() - check if the device is compatible with the compat
687 * This allows to check whether the device is comaptible with the compat.
689 * @dev: udevice pointer for which compatible needs to be verified.
690 * @compat: Compatible string which needs to verified in the given
692 * @return true if OK, false if the compatible is not found
694 bool device_is_compatible(const struct udevice *dev, const char *compat);
697 * of_machine_is_compatible() - check if the machine is compatible with
700 * This allows to check whether the machine is comaptible with the compat.
702 * @compat: Compatible string which needs to verified
703 * @return true if OK, false if the compatible is not found
705 bool of_machine_is_compatible(const char *compat);
708 * dev_disable_by_path() - Disable a device given its device tree path
710 * @path: The device tree path identifying the device to be disabled
711 * @return 0 on success, -ve on error
713 int dev_disable_by_path(const char *path);
716 * dev_enable_by_path() - Enable a device given its device tree path
718 * @path: The device tree path identifying the device to be enabled
719 * @return 0 on success, -ve on error
721 int dev_enable_by_path(const char *path);
724 * device_is_on_pci_bus - Test if a device is on a PCI bus
726 * @dev: device to test
727 * @return: true if it is on a PCI bus, false otherwise
729 static inline bool device_is_on_pci_bus(const struct udevice *dev)
731 return device_get_uclass_id(dev->parent) == UCLASS_PCI;
735 * device_foreach_child_safe() - iterate through child devices safely
737 * This allows the @pos child to be removed in the loop if required.
739 * @pos: struct udevice * for the current device
740 * @next: struct udevice * for the next device
741 * @parent: parent device to scan
743 #define device_foreach_child_safe(pos, next, parent) \
744 list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
747 * device_foreach_child() - iterate through child devices
749 * @pos: struct udevice * for the current device
750 * @parent: parent device to scan
752 #define device_foreach_child(pos, parent) \
753 list_for_each_entry(pos, &parent->child_head, sibling_node)
756 * device_foreach_child_ofdata_to_platdata() - iterate through children
758 * This stops when it gets an error, with @pos set to the device that failed to
761 * This creates a for() loop which works through the available children of
762 * a device in order from start to end. Device ofdata is read by calling
763 * device_ofdata_to_platdata() on each one. The devices are not probed.
765 * @pos: struct udevice * for the current device
766 * @parent: parent device to scan
768 #define device_foreach_child_ofdata_to_platdata(pos, parent) \
769 for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
770 _ret = device_next_child_ofdata_err(&dev))
773 * device_foreach_child_probe() - iterate through children, probing them
775 * This creates a for() loop which works through the available children of
776 * a device in order from start to end. Devices are probed if necessary,
779 * This stops when it gets an error, with @pos set to the device that failed to
782 * @pos: struct udevice * for the current device
783 * @parent: parent device to scan
785 #define device_foreach_child_probe(pos, parent) \
786 for (int _ret = device_first_child_err(parent, &dev); !_ret; \
787 _ret = device_next_child_err(&dev))
790 * dm_scan_fdt_dev() - Bind child device in a the device tree
792 * This handles device which have sub-nodes in the device tree. It scans all
793 * sub-nodes and binds drivers for each node where a driver can be found.
795 * If this is called prior to relocation, only pre-relocation devices will be
796 * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
797 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
800 * @dev: Device to scan
801 * @return 0 if OK, -ve on error
803 int dm_scan_fdt_dev(struct udevice *dev);