uboot/include/dm/device.h
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   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * Copyright (c) 2013 Google, Inc
   4 *
   5 * (C) Copyright 2012
   6 * Pavel Herrmann <morpheus.ibis@gmail.com>
   7 * Marek Vasut <marex@denx.de>
   8 */
   9
  10#ifndef _DM_DEVICE_H
  11#define _DM_DEVICE_H
  12
  13#include <dm/ofnode.h>
  14#include <dm/tag.h>
  15#include <dm/uclass-id.h>
  16#include <fdtdec.h>
  17#include <linker_lists.h>
  18#include <linux/kernel.h>
  19#include <linux/list.h>
  20#include <linux/printk.h>
  21
  22struct driver_info;
  23
  24/* Driver is active (probed). Cleared when it is removed */
  25#define DM_FLAG_ACTIVATED               (1 << 0)
  26
  27/* DM is responsible for allocating and freeing plat */
  28#define DM_FLAG_ALLOC_PDATA             (1 << 1)
  29
  30/* DM should init this device prior to relocation */
  31#define DM_FLAG_PRE_RELOC               (1 << 2)
  32
  33/* DM is responsible for allocating and freeing parent_plat */
  34#define DM_FLAG_ALLOC_PARENT_PDATA      (1 << 3)
  35
  36/* DM is responsible for allocating and freeing uclass_plat */
  37#define DM_FLAG_ALLOC_UCLASS_PDATA      (1 << 4)
  38
  39/* Allocate driver private data on a DMA boundary */
  40#define DM_FLAG_ALLOC_PRIV_DMA          (1 << 5)
  41
  42/* Device is bound */
  43#define DM_FLAG_BOUND                   (1 << 6)
  44
  45/* Device name is allocated and should be freed on unbind() */
  46#define DM_FLAG_NAME_ALLOCED            (1 << 7)
  47
  48/* Device has platform data provided by of-platdata */
  49#define DM_FLAG_OF_PLATDATA             (1 << 8)
  50
  51/*
  52 * Call driver remove function to stop currently active DMA transfers or
  53 * give DMA buffers back to the HW / controller. This may be needed for
  54 * some drivers to do some final stage cleanup before the OS is called
  55 * (U-Boot exit)
  56 */
  57#define DM_FLAG_ACTIVE_DMA              (1 << 9)
  58
  59/*
  60 * Call driver remove function to do some final configuration, before
  61 * U-Boot exits and the OS is started
  62 */
  63#define DM_FLAG_OS_PREPARE              (1 << 10)
  64
  65/* DM does not enable/disable the power domains corresponding to this device */
  66#define DM_FLAG_DEFAULT_PD_CTRL_OFF     (1 << 11)
  67
  68/* Driver plat has been read. Cleared when the device is removed */
  69#define DM_FLAG_PLATDATA_VALID          (1 << 12)
  70
  71/*
  72 * Device is removed without switching off its power domain. This might
  73 * be required, i. e. for serial console (debug) output when booting OS.
  74 */
  75#define DM_FLAG_LEAVE_PD_ON             (1 << 13)
  76
  77/*
  78 * Device is vital to the operation of other devices. It is possible to remove
  79 * removed this device after all regular devices are removed. This is useful
  80 * e.g. for clock, which need to be active during the device-removal phase.
  81 */
  82#define DM_FLAG_VITAL                   (1 << 14)
  83
  84/* Device must be probed after it was bound. This flag is per-device and does
  85 * nothing if set on a U_BOOT_DRIVER() definition. Apply it with
  86 * dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND) in the devices bind function.
  87 */
  88#define DM_FLAG_PROBE_AFTER_BIND        (1 << 15)
  89
  90/*
  91 * One or multiple of these flags are passed to device_remove() so that
  92 * a selective device removal as specified by the remove-stage and the
  93 * driver flags can be done.
  94 *
  95 * DO NOT use these flags in your driver's @flags value...
  96 *      use the above DM_FLAG_... values instead
  97 */
  98enum {
  99        /* Normal remove, remove all devices */
 100        DM_REMOVE_NORMAL        = 1 << 0,
 101
 102        /* Remove devices with active DMA */
 103        DM_REMOVE_ACTIVE_DMA    = DM_FLAG_ACTIVE_DMA,
 104
 105        /* Remove devices which need some final OS preparation steps */
 106        DM_REMOVE_OS_PREPARE    = DM_FLAG_OS_PREPARE,
 107
 108        /* Remove only devices that are not marked vital */
 109        DM_REMOVE_NON_VITAL     = DM_FLAG_VITAL,
 110
 111        /* Remove devices with any active flag */
 112        DM_REMOVE_ACTIVE_ALL    = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
 113
 114        /* Don't power down any attached power domains */
 115        DM_REMOVE_NO_PD         = 1 << 1,
 116};
 117
 118/**
 119 * struct udevice - An instance of a driver
 120 *
 121 * This holds information about a device, which is a driver bound to a
 122 * particular port or peripheral (essentially a driver instance).
 123 *
 124 * A device will come into existence through a 'bind' call, either due to
 125 * a U_BOOT_DRVINFO() macro (in which case plat is non-NULL) or a node
 126 * in the device tree (in which case of_offset is >= 0). In the latter case
 127 * we translate the device tree information into plat in a function
 128 * implemented by the driver of_to_plat method (called just before the
 129 * probe method if the device has a device tree node.
 130 *
 131 * All three of plat, priv and uclass_priv can be allocated by the
 132 * driver, or you can use the auto members of struct driver and
 133 * struct uclass_driver to have driver model do this automatically.
 134 *
 135 * @driver: The driver used by this device
 136 * @name: Name of device, typically the FDT node name
 137 * @plat_: Configuration data for this device (do not access outside driver
 138 *      model)
 139 * @parent_plat_: The parent bus's configuration data for this device (do not
 140 *      access outside driver model)
 141 * @uclass_plat_: The uclass's configuration data for this device (do not access
 142 *      outside driver model)
 143 * @driver_data: Driver data word for the entry that matched this device with
 144 *              its driver
 145 * @parent: Parent of this device, or NULL for the top level device
 146 * @priv_: Private data for this device (do not access outside driver model)
 147 * @uclass: Pointer to uclass for this device
 148 * @uclass_priv_: The uclass's private data for this device (do not access
 149 *      outside driver model)
 150 * @parent_priv_: The parent's private data for this device (do not access
 151 *      outside driver model)
 152 * @uclass_node: Used by uclass to link its devices
 153 * @child_head: List of children of this device
 154 * @sibling_node: Next device in list of all devices
 155 * @flags_: Flags for this device `DM_FLAG_...` (do not access outside driver
 156 *      model)
 157 * @seq_: Allocated sequence number for this device (-1 = none). This is set up
 158 * when the device is bound and is unique within the device's uclass. If the
 159 * device has an alias in the devicetree then that is used to set the sequence
 160 * number. Otherwise, the next available number is used. Sequence numbers are
 161 * used by certain commands that need device to be numbered (e.g. 'mmc dev').
 162 * (do not access outside driver model)
 163 * @node_: Reference to device tree node for this device (do not access outside
 164 *      driver model)
 165 * @devres_head: List of memory allocations associated with this device.
 166 *              When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
 167 *              add to this list. Memory so-allocated will be freed
 168 *              automatically when the device is removed / unbound
 169 * @dma_offset: Offset between the physical address space (CPU's) and the
 170 *              device's bus address space
 171 * @iommu: IOMMU device associated with this device
 172 */
 173struct udevice {
 174        const struct driver *driver;
 175        const char *name;
 176        void *plat_;
 177        void *parent_plat_;
 178        void *uclass_plat_;
 179        ulong driver_data;
 180        struct udevice *parent;
 181        void *priv_;
 182        struct uclass *uclass;
 183        void *uclass_priv_;
 184        void *parent_priv_;
 185        struct list_head uclass_node;
 186        struct list_head child_head;
 187        struct list_head sibling_node;
 188#if !CONFIG_IS_ENABLED(OF_PLATDATA_RT)
 189        u32 flags_;
 190#endif
 191        int seq_;
 192#if CONFIG_IS_ENABLED(OF_REAL)
 193        ofnode node_;
 194#endif
 195#if CONFIG_IS_ENABLED(DEVRES)
 196        struct list_head devres_head;
 197#endif
 198#if CONFIG_IS_ENABLED(DM_DMA)
 199        ulong dma_offset;
 200#endif
 201#if CONFIG_IS_ENABLED(IOMMU)
 202        struct udevice *iommu;
 203#endif
 204};
 205
 206static inline int dm_udevice_size(void)
 207{
 208        if (CONFIG_IS_ENABLED(OF_PLATDATA_RT))
 209                return ALIGN(sizeof(struct udevice), CONFIG_LINKER_LIST_ALIGN);
 210
 211        return sizeof(struct udevice);
 212}
 213
 214/**
 215 * struct udevice_rt - runtime information set up by U-Boot
 216 *
 217 * This is only used with OF_PLATDATA_RT
 218 *
 219 * There is one of these for every udevice in the linker list, indexed by
 220 * the udevice_info idx value.
 221 *
 222 * @flags_: Flags for this device `DM_FLAG_...` (do not access outside driver
 223 *      model)
 224 */
 225struct udevice_rt {
 226        u32 flags_;
 227};
 228
 229/* Maximum sequence number supported and associated string length */
 230#define DM_MAX_SEQ      999
 231#define DM_MAX_SEQ_STR  3
 232
 233/* Returns the operations for a device */
 234#define device_get_ops(dev)     ((dev)->driver->ops)
 235
 236#if CONFIG_IS_ENABLED(OF_PLATDATA_RT)
 237u32 dev_get_flags(const struct udevice *dev);
 238void dev_or_flags(const struct udevice *dev, u32 or);
 239void dev_bic_flags(const struct udevice *dev, u32 bic);
 240#else
 241static inline u32 dev_get_flags(const struct udevice *dev)
 242{
 243        return dev->flags_;
 244}
 245
 246static inline void dev_or_flags(struct udevice *dev, u32 or)
 247{
 248        dev->flags_ |= or;
 249}
 250
 251static inline void dev_bic_flags(struct udevice *dev, u32 bic)
 252{
 253        dev->flags_ &= ~bic;
 254}
 255#endif /* OF_PLATDATA_RT */
 256
 257/**
 258 * dev_ofnode() - get the DT node reference associated with a udevice
 259 *
 260 * @dev:        device to check
 261 * Return: reference of the device's DT node
 262 */
 263static inline __attribute_const__ ofnode dev_ofnode(const struct udevice *dev)
 264{
 265#if CONFIG_IS_ENABLED(OF_REAL)
 266        return dev->node_;
 267#else
 268        return ofnode_null();
 269#endif
 270}
 271
 272/* Returns non-zero if the device is active (probed and not removed) */
 273#define device_active(dev)      (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
 274
 275#if CONFIG_IS_ENABLED(DM_DMA)
 276#define dev_set_dma_offset(_dev, _offset)       _dev->dma_offset = _offset
 277#define dev_get_dma_offset(_dev)                _dev->dma_offset
 278#else
 279#define dev_set_dma_offset(_dev, _offset)
 280#define dev_get_dma_offset(_dev)                0
 281#endif
 282
 283static inline __attribute_const__ int dev_of_offset(const struct udevice *dev)
 284{
 285#if CONFIG_IS_ENABLED(OF_REAL)
 286        return ofnode_to_offset(dev_ofnode(dev));
 287#else
 288        return -1;
 289#endif
 290}
 291
 292static inline __attribute_const__ bool dev_has_ofnode(const struct udevice *dev)
 293{
 294#if CONFIG_IS_ENABLED(OF_REAL)
 295        return ofnode_valid(dev_ofnode(dev));
 296#else
 297        return false;
 298#endif
 299}
 300
 301static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
 302{
 303#if CONFIG_IS_ENABLED(OF_REAL)
 304        dev->node_ = node;
 305#endif
 306}
 307
 308static inline int dev_seq(const struct udevice *dev)
 309{
 310        return dev->seq_;
 311}
 312
 313/**
 314 * struct udevice_id - Lists the compatible strings supported by a driver
 315 * @compatible: Compatible string
 316 * @data: Data for this compatible string
 317 */
 318struct udevice_id {
 319        const char *compatible;
 320        ulong data;
 321};
 322
 323#if CONFIG_IS_ENABLED(OF_REAL)
 324#define of_match_ptr(_ptr)      (_ptr)
 325#else
 326#define of_match_ptr(_ptr)      NULL
 327#endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
 328
 329/**
 330 * struct driver - A driver for a feature or peripheral
 331 *
 332 * This holds methods for setting up a new device, and also removing it.
 333 * The device needs information to set itself up - this is provided either
 334 * by plat or a device tree node (which we find by looking up
 335 * matching compatible strings with of_match).
 336 *
 337 * Drivers all belong to a uclass, representing a class of devices of the
 338 * same type. Common elements of the drivers can be implemented in the uclass,
 339 * or the uclass can provide a consistent interface to the drivers within
 340 * it.
 341 *
 342 * @name: Device name
 343 * @id: Identifies the uclass we belong to
 344 * @of_match: List of compatible strings to match, and any identifying data
 345 * for each.
 346 * @bind: Called to bind a device to its driver
 347 * @probe: Called to probe a device, i.e. activate it
 348 * @remove: Called to remove a device, i.e. de-activate it
 349 * @unbind: Called to unbind a device from its driver
 350 * @of_to_plat: Called before probe to decode device tree data
 351 * @child_post_bind: Called after a new child has been bound
 352 * @child_pre_probe: Called before a child device is probed. The device has
 353 * memory allocated but it has not yet been probed.
 354 * @child_post_remove: Called after a child device is removed. The device
 355 * has memory allocated but its device_remove() method has been called.
 356 * @priv_auto: If non-zero this is the size of the private data
 357 * to be allocated in the device's ->priv pointer. If zero, then the driver
 358 * is responsible for allocating any data required.
 359 * @plat_auto: If non-zero this is the size of the
 360 * platform data to be allocated in the device's ->plat pointer.
 361 * This is typically only useful for device-tree-aware drivers (those with
 362 * an of_match), since drivers which use plat will have the data
 363 * provided in the U_BOOT_DRVINFO() instantiation.
 364 * @per_child_auto: Each device can hold private data owned by
 365 * its parent. If required this will be automatically allocated if this
 366 * value is non-zero.
 367 * @per_child_plat_auto: A bus likes to store information about
 368 * its children. If non-zero this is the size of this data, to be allocated
 369 * in the child's parent_plat pointer.
 370 * @ops: Driver-specific operations. This is typically a list of function
 371 * pointers defined by the driver, to implement driver functions required by
 372 * the uclass.
 373 * @flags: driver flags - see `DM_FLAG_...`
 374 * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
 375 * allowing the device to add things to the ACPI tables passed to Linux
 376 */
 377struct driver {
 378        char *name;
 379        enum uclass_id id;
 380        const struct udevice_id *of_match;
 381        int (*bind)(struct udevice *dev);
 382        int (*probe)(struct udevice *dev);
 383        int (*remove)(struct udevice *dev);
 384        int (*unbind)(struct udevice *dev);
 385        int (*of_to_plat)(struct udevice *dev);
 386        int (*child_post_bind)(struct udevice *dev);
 387        int (*child_pre_probe)(struct udevice *dev);
 388        int (*child_post_remove)(struct udevice *dev);
 389        int priv_auto;
 390        int plat_auto;
 391        int per_child_auto;
 392        int per_child_plat_auto;
 393        const void *ops;        /* driver-specific operations */
 394        uint32_t flags;
 395#if CONFIG_IS_ENABLED(ACPIGEN)
 396        struct acpi_ops *acpi_ops;
 397#endif
 398};
 399
 400/**
 401 * U_BOOT_DRIVER() - Declare a new U-Boot driver
 402 * @__name: name of the driver
 403 */
 404#define U_BOOT_DRIVER(__name)                                           \
 405        ll_entry_declare(struct driver, __name, driver)
 406
 407/**
 408 * DM_DRIVER_GET() - Get a pointer to a given driver
 409 *
 410 * This is useful in code for referencing a driver at build time.
 411 * Before this is used, an extern U_BOOT_DRIVER() must have been
 412 * declared.
 413 *
 414 * @__name:     Name of the driver. This must be a valid C identifier,
 415 * used by the linker_list
 416 * Return: struct driver * for the driver
 417 */
 418#define DM_DRIVER_GET(__name)                                           \
 419        ll_entry_get(struct driver, __name, driver)
 420
 421/**
 422 * DM_DRIVER_REF() - Get a reference to a driver
 423 *
 424 * This is useful in data structures and code for referencing a driver at
 425 * build time. Before this is used, an extern U_BOOT_DRIVER() must have been
 426 * declared.
 427 * This is like DM_DRIVER_GET, but without the extra code, so it is suitable
 428 * for putting into data structures.
 429 *
 430 * For example::
 431 *
 432 *   extern U_BOOT_DRIVER(sandbox_fixed_clock);
 433 *   struct driver *drvs[] = {
 434 *       DM_DRIVER_REF(sandbox_fixed_clock),
 435 *   };
 436 *
 437 * @_name:      Name of the driver. This must be a valid C identifier,
 438 * used by the linker_list
 439 * Return: struct driver * for the driver
 440 */
 441#define DM_DRIVER_REF(_name)                                    \
 442        ll_entry_ref(struct driver, _name, driver)
 443
 444/**
 445 * DM_DRIVER_ALIAS() - Declare a macro to state an alias for a driver name
 446 *
 447 * This macro will produce no code but its information will be parsed by tools
 448 * like dtoc
 449 *
 450 * @__name:     name of driver
 451 * @__alias:    alias for the driver name
 452 */
 453#define DM_DRIVER_ALIAS(__name, __alias)
 454
 455/**
 456 * DM_PHASE() - Declare a macro to indicate which phase of U-Boot this driver is for.
 457 *
 458 * This macro produces no code but its information will be parsed by dtoc. The
 459 * macro can be only be used once in a driver. Put it within the U_BOOT_DRIVER()
 460 * declaration, e.g.::
 461 *
 462 *   U_BOOT_DRIVER(cpu) = {
 463 *       .name = ...
 464 *       ...
 465 *       DM_PHASE(tpl)
 466 *   };
 467 *
 468 * @_phase:     Associated phase of U-Boot ("spl", "tpl")
 469 */
 470#define DM_PHASE(_phase)
 471
 472/**
 473 * DM_HEADER() - Declare a macro to declare a header needed for a driver.
 474 *
 475 * Often the correct header can be found automatically, but only for struct
 476 * declarations. For enums and #defines used in the driver declaration and
 477 * declared in a different header from the structs, this macro must be used.
 478 *
 479 * This macro produces no code but its information will be parsed by dtoc. The
 480 * macro can be used multiple times with different headers, for the same driver.
 481 * Put it within the U_BOOT_DRIVER() declaration, e.g.::
 482 *
 483 *   U_BOOT_DRIVER(cpu) = {
 484 *       .name = ...
 485 *       ...
 486 *       DM_HEADER(<asm/cpu.h>)
 487 *   };
 488 *
 489 * @_hdr:       header needed for a driver
 490 */
 491#define DM_HEADER(_hdr)
 492
 493/**
 494 * dev_get_plat() - Get the platform data for a device
 495 *
 496 * This checks that dev is not NULL, but no other checks for now
 497 *
 498 * @dev:        Device to check
 499 * Return: platform data, or NULL if none
 500 */
 501void *dev_get_plat(const struct udevice *dev);
 502
 503/**
 504 * dev_get_parent_plat() - Get the parent platform data for a device
 505 *
 506 * This checks that dev is not NULL, but no other checks for now
 507 *
 508 * @dev:        Device to check
 509 * Return: parent's platform data, or NULL if none
 510 */
 511void *dev_get_parent_plat(const struct udevice *dev);
 512
 513/**
 514 * dev_get_uclass_plat() - Get the uclass platform data for a device
 515 *
 516 * This checks that dev is not NULL, but no other checks for now
 517 *
 518 * @dev:        Device to check
 519 * Return: uclass's platform data, or NULL if none
 520 */
 521void *dev_get_uclass_plat(const struct udevice *dev);
 522
 523/**
 524 * dev_get_priv() - Get the private data for a device
 525 *
 526 * This checks that dev is not NULL, but no other checks for now
 527 *
 528 * @dev:        Device to check
 529 * Return: private data, or NULL if none
 530 */
 531void *dev_get_priv(const struct udevice *dev);
 532
 533/**
 534 * dev_get_parent_priv() - Get the parent private data for a device
 535 *
 536 * The parent private data is data stored in the device but owned by the
 537 * parent. For example, a USB device may have parent data which contains
 538 * information about how to talk to the device over USB.
 539 *
 540 * This checks that dev is not NULL, but no other checks for now
 541 *
 542 * @dev:        Device to check
 543 * Return: parent data, or NULL if none
 544 */
 545void *dev_get_parent_priv(const struct udevice *dev);
 546
 547/**
 548 * dev_get_uclass_priv() - Get the private uclass data for a device
 549 *
 550 * This checks that dev is not NULL, but no other checks for now
 551 *
 552 * @dev:        Device to check
 553 * Return: private uclass data for this device, or NULL if none
 554 */
 555void *dev_get_uclass_priv(const struct udevice *dev);
 556
 557/**
 558 * dev_get_attach_ptr() - Get the value of an attached pointed tag
 559 *
 560 * The tag is assumed to hold a pointer, if it exists
 561 *
 562 * @dev: Device to look at
 563 * @tag: Tag to access
 564 * @return value of tag, or NULL if there is no tag of this type
 565 */
 566void *dev_get_attach_ptr(const struct udevice *dev, enum dm_tag_t tag);
 567
 568/**
 569 * dev_get_attach_size() - Get the size of an attached tag
 570 *
 571 * Core tags have an automatic-allocation mechanism where the allocated size is
 572 * defined by the device, parent or uclass. This returns the size associated
 573 * with a particular tag
 574 *
 575 * @dev: Device to look at
 576 * @tag: Tag to access
 577 * @return size of auto-allocated data, 0 if none
 578 */
 579int dev_get_attach_size(const struct udevice *dev, enum dm_tag_t tag);
 580
 581/**
 582 * dev_get_parent() - Get the parent of a device
 583 *
 584 * @child:      Child to check
 585 * Return: parent of child, or NULL if this is the root device
 586 */
 587struct udevice *dev_get_parent(const struct udevice *child);
 588
 589/**
 590 * dev_get_driver_data() - get the driver data used to bind a device
 591 *
 592 * When a device is bound using a device tree node, it matches a
 593 * particular compatible string in struct udevice_id. This function
 594 * returns the associated data value for that compatible string. This is
 595 * the 'data' field in struct udevice_id.
 596 *
 597 * As an example, consider this structure::
 598 *
 599 *  static const struct udevice_id tegra_i2c_ids[] = {
 600 *      { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
 601 *      { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
 602 *      { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
 603 *      { }
 604 *  };
 605 *
 606 * When driver model finds a driver for this it will store the 'data' value
 607 * corresponding to the compatible string it matches. This function returns
 608 * that value. This allows the driver to handle several variants of a device.
 609 *
 610 * For USB devices, this is the driver_info field in struct usb_device_id.
 611 *
 612 * @dev:        Device to check
 613 * Return: driver data (0 if none is provided)
 614 */
 615ulong dev_get_driver_data(const struct udevice *dev);
 616
 617/**
 618 * dev_get_driver_ops() - get the device's driver's operations
 619 *
 620 * This checks that dev is not NULL, and returns the pointer to device's
 621 * driver's operations.
 622 *
 623 * @dev:        Device to check
 624 * Return: void pointer to driver's operations or NULL for NULL-dev or NULL-ops
 625 */
 626const void *dev_get_driver_ops(const struct udevice *dev);
 627
 628/**
 629 * device_get_uclass_id() - return the uclass ID of a device
 630 *
 631 * @dev:        Device to check
 632 * Return: uclass ID for the device
 633 */
 634enum uclass_id device_get_uclass_id(const struct udevice *dev);
 635
 636/**
 637 * dev_get_uclass_name() - return the uclass name of a device
 638 *
 639 * This checks that dev is not NULL.
 640 *
 641 * @dev:        Device to check
 642 * Return:  pointer to the uclass name for the device
 643 */
 644const char *dev_get_uclass_name(const struct udevice *dev);
 645
 646/**
 647 * device_get_child() - Get the child of a device by index
 648 *
 649 * Returns the numbered child, 0 being the first. This does not use
 650 * sequence numbers, only the natural order.
 651 *
 652 * @parent:     Parent device to check
 653 * @index:      Child index
 654 * @devp:       Returns pointer to device
 655 * Return:
 656 * 0 if OK, -ENODEV if no such device, other error if the device fails to probe
 657 */
 658int device_get_child(const struct udevice *parent, int index,
 659                     struct udevice **devp);
 660
 661/**
 662 * device_get_child_count() - Get the child count of a device
 663 *
 664 * Returns the number of children to a device.
 665 *
 666 * @parent:     Parent device to check
 667 */
 668int device_get_child_count(const struct udevice *parent);
 669
 670/**
 671 * device_get_decendent_count() - Get the total number of decendents of a device
 672 *
 673 * Returns the total number of decendents, including all children
 674 *
 675 * @parent:     Parent device to check
 676 */
 677int device_get_decendent_count(const struct udevice *parent);
 678
 679/**
 680 * device_find_child_by_seq() - Find a child device based on a sequence
 681 *
 682 * This searches for a device with the given seq.
 683 *
 684 * @parent: Parent device
 685 * @seq: Sequence number to find (0=first)
 686 * @devp: Returns pointer to device (there is only one per for each seq).
 687 * Set to NULL if none is found
 688 * Return: 0 if OK, -ENODEV if not found
 689 */
 690int device_find_child_by_seq(const struct udevice *parent, int seq,
 691                             struct udevice **devp);
 692
 693/**
 694 * device_get_child_by_seq() - Get a child device based on a sequence
 695 *
 696 * If an active device has this sequence it will be returned. If there is no
 697 * such device then this will check for a device that is requesting this
 698 * sequence.
 699 *
 700 * The device is probed to activate it ready for use.
 701 *
 702 * @parent: Parent device
 703 * @seq: Sequence number to find (0=first)
 704 * @devp: Returns pointer to device (there is only one per for each seq)
 705 * Set to NULL if none is found
 706 * Return: 0 if OK, -ve on error
 707 */
 708int device_get_child_by_seq(const struct udevice *parent, int seq,
 709                            struct udevice **devp);
 710
 711/**
 712 * device_find_child_by_of_offset() - Find a child device based on FDT offset
 713 *
 714 * Locates a child device by its device tree offset.
 715 *
 716 * @parent: Parent device
 717 * @of_offset: Device tree offset to find
 718 * @devp: Returns pointer to device if found, otherwise this is set to NULL
 719 * Return: 0 if OK, -ve on error
 720 */
 721int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
 722                                   struct udevice **devp);
 723
 724/**
 725 * device_get_child_by_of_offset() - Get a child device based on FDT offset
 726 *
 727 * Locates a child device by its device tree offset.
 728 *
 729 * The device is probed to activate it ready for use.
 730 *
 731 * @parent: Parent device
 732 * @of_offset: Device tree offset to find
 733 * @devp: Returns pointer to device if found, otherwise this is set to NULL
 734 * Return: 0 if OK, -ve on error
 735 */
 736int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
 737                                  struct udevice **devp);
 738
 739/**
 740 * device_find_global_by_ofnode() - Get a device based on ofnode
 741 *
 742 * Locates a device by its device tree ofnode, searching globally throughout
 743 * the all driver model devices.
 744 *
 745 * The device is NOT probed
 746 *
 747 * @node: Device tree ofnode to find
 748 * @devp: Returns pointer to device if found, otherwise this is set to NULL
 749 * Return: 0 if OK, -ve on error
 750 */
 751
 752int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
 753
 754/**
 755 * device_get_global_by_ofnode() - Get a device based on ofnode
 756 *
 757 * Locates a device by its device tree ofnode, searching globally throughout
 758 * the all driver model devices.
 759 *
 760 * The device is probed to activate it ready for use.
 761 *
 762 * @node: Device tree ofnode to find
 763 * @devp: Returns pointer to device if found, otherwise this is set to NULL
 764 * Return: 0 if OK, -ve on error
 765 */
 766int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
 767
 768/**
 769 * device_get_by_ofplat_idx() - Get a device based on of-platdata index
 770 *
 771 * Locates a device by either its struct driver_info index, or its
 772 * struct udevice index. The latter is used with OF_PLATDATA_INST, since we have
 773 * a list of build-time instantiated struct udevice records, The former is used
 774 * with !OF_PLATDATA_INST since in that case we have a list of
 775 * struct driver_info records.
 776 *
 777 * The index number is written into the idx field of struct phandle_1_arg, etc.
 778 * It is the position of this driver_info/udevice in its linker list.
 779 *
 780 * The device is probed to activate it ready for use.
 781 *
 782 * @idx: Index number of the driver_info/udevice structure (0=first)
 783 * @devp: Returns pointer to device if found, otherwise this is set to NULL
 784 * Return: 0 if OK, -ve on error
 785 */
 786int device_get_by_ofplat_idx(uint idx, struct udevice **devp);
 787
 788/**
 789 * device_find_first_child() - Find the first child of a device
 790 *
 791 * @parent: Parent device to search
 792 * @devp: Returns first child device, or NULL if none
 793 * Return: 0
 794 */
 795int device_find_first_child(const struct udevice *parent,
 796                            struct udevice **devp);
 797
 798/**
 799 * device_find_next_child() - Find the next child of a device
 800 *
 801 * @devp: Pointer to previous child device on entry. Returns pointer to next
 802 *              child device, or NULL if none
 803 * Return: 0
 804 */
 805int device_find_next_child(struct udevice **devp);
 806
 807/**
 808 * device_find_first_inactive_child() - Find the first inactive child
 809 *
 810 * This is used to locate an existing child of a device which is of a given
 811 * uclass.
 812 *
 813 * The device is NOT probed
 814 *
 815 * @parent:     Parent device to search
 816 * @uclass_id:  Uclass to look for
 817 * @devp:       Returns device found, if any, else NULL
 818 * Return: 0 if found, else -ENODEV
 819 */
 820int device_find_first_inactive_child(const struct udevice *parent,
 821                                     enum uclass_id uclass_id,
 822                                     struct udevice **devp);
 823
 824/**
 825 * device_find_first_child_by_uclass() - Find the first child of a device in uc
 826 *
 827 * @parent: Parent device to search
 828 * @uclass_id:  Uclass to look for
 829 * @devp: Returns first child device in that uclass, if any, else NULL
 830 * Return: 0 if found, else -ENODEV
 831 */
 832int device_find_first_child_by_uclass(const struct udevice *parent,
 833                                      enum uclass_id uclass_id,
 834                                      struct udevice **devp);
 835
 836/**
 837 * device_find_child_by_namelen() - Find a child by device name
 838 *
 839 * @parent:     Parent device to search
 840 * @name:       Name to look for
 841 * @len:        Length of the name
 842 * @devp:       Returns device found, if any
 843 * Return: 0 if found, else -ENODEV
 844 */
 845int device_find_child_by_namelen(const struct udevice *parent, const char *name,
 846                                 int len, struct udevice **devp);
 847
 848/**
 849 * device_find_child_by_name() - Find a child by device name
 850 *
 851 * @parent:     Parent device to search
 852 * @name:       Name to look for
 853 * @devp:       Returns device found, if any
 854 * Return: 0 if found, else -ENODEV
 855 */
 856int device_find_child_by_name(const struct udevice *parent, const char *name,
 857                              struct udevice **devp);
 858
 859/**
 860 * device_first_child_ofdata_err() - Find the first child and reads its plat
 861 *
 862 * The of_to_plat() method is called on the child before it is returned,
 863 * but the child is not probed.
 864 *
 865 * @parent: Parent to check
 866 * @devp: Returns child that was found, if any
 867 * Return: 0 on success, -ENODEV if no children, other -ve on error
 868 */
 869int device_first_child_ofdata_err(struct udevice *parent,
 870                                  struct udevice **devp);
 871
 872/*
 873 * device_next_child_ofdata_err() - Find the next child and read its plat
 874 *
 875 * The of_to_plat() method is called on the child before it is returned,
 876 * but the child is not probed.
 877 *
 878 * @devp: On entry, points to the previous child; on exit returns the child that
 879 *      was found, if any
 880 * Return: 0 on success, -ENODEV if no children, other -ve on error
 881 */
 882int device_next_child_ofdata_err(struct udevice **devp);
 883
 884/**
 885 * device_first_child_err() - Get the first child of a device
 886 *
 887 * The device returned is probed if necessary, and ready for use
 888 *
 889 * @parent:     Parent device to search
 890 * @devp:       Returns device found, if any
 891 * Return: 0 if found, -ENODEV if not, -ve error if device failed to probe
 892 */
 893int device_first_child_err(struct udevice *parent, struct udevice **devp);
 894
 895/**
 896 * device_next_child_err() - Get the next child of a parent device
 897 *
 898 * The device returned is probed if necessary, and ready for use
 899 *
 900 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
 901 * to the next sibling if no error occurred
 902 * Return: 0 if found, -ENODEV if not, -ve error if device failed to probe
 903 */
 904int device_next_child_err(struct udevice **devp);
 905
 906/**
 907 * device_has_children() - check if a device has any children
 908 *
 909 * @dev:        Device to check
 910 * Return: true if the device has one or more children
 911 */
 912bool device_has_children(const struct udevice *dev);
 913
 914/**
 915 * device_has_active_children() - check if a device has any active children
 916 *
 917 * @dev:        Device to check
 918 * Return: true if the device has one or more children and at least one of
 919 * them is active (probed).
 920 */
 921bool device_has_active_children(const struct udevice *dev);
 922
 923/**
 924 * device_is_last_sibling() - check if a device is the last sibling
 925 *
 926 * This function can be useful for display purposes, when special action needs
 927 * to be taken when displaying the last sibling. This can happen when a tree
 928 * view of devices is being displayed.
 929 *
 930 * @dev:        Device to check
 931 * Return: true if there are no more siblings after this one - i.e. is it
 932 * last in the list.
 933 */
 934bool device_is_last_sibling(const struct udevice *dev);
 935
 936/**
 937 * device_set_name() - set the name of a device
 938 *
 939 * This must be called in the device's bind() method and no later. Normally
 940 * this is unnecessary but for probed devices which don't get a useful name
 941 * this function can be helpful.
 942 *
 943 * The name is allocated and will be freed automatically when the device is
 944 * unbound.
 945 *
 946 * @dev:        Device to update
 947 * @name:       New name (this string is allocated new memory and attached to
 948 *              the device)
 949 * Return: 0 if OK, -ENOMEM if there is not enough memory to allocate the
 950 * string
 951 */
 952int device_set_name(struct udevice *dev, const char *name);
 953
 954/**
 955 * device_set_name_alloced() - note that a device name is allocated
 956 *
 957 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
 958 * unbound the name will be freed. This avoids memory leaks.
 959 *
 960 * @dev:        Device to update
 961 */
 962void device_set_name_alloced(struct udevice *dev);
 963
 964/**
 965 * device_is_compatible() - check if the device is compatible with the compat
 966 *
 967 * This allows to check whether the device is comaptible with the compat.
 968 *
 969 * @dev:        udevice pointer for which compatible needs to be verified.
 970 * @compat:     Compatible string which needs to verified in the given
 971 *              device
 972 * Return: true if OK, false if the compatible is not found
 973 */
 974bool device_is_compatible(const struct udevice *dev, const char *compat);
 975
 976/**
 977 * of_machine_is_compatible() - check if the machine is compatible with
 978 *                              the compat
 979 *
 980 * This allows to check whether the machine is comaptible with the compat.
 981 *
 982 * @compat:     Compatible string which needs to verified
 983 * Return: true if OK, false if the compatible is not found
 984 */
 985bool of_machine_is_compatible(const char *compat);
 986
 987/**
 988 * dev_disable_by_path() - Disable a device given its device tree path
 989 *
 990 * @path:       The device tree path identifying the device to be disabled
 991 * Return: 0 on success, -ve on error
 992 */
 993int dev_disable_by_path(const char *path);
 994
 995/**
 996 * dev_enable_by_path() - Enable a device given its device tree path
 997 *
 998 * @path:       The device tree path identifying the device to be enabled
 999 * Return: 0 on success, -ve on error
1000 */
1001int dev_enable_by_path(const char *path);
1002
1003/**
1004 * device_is_on_pci_bus - Test if a device is on a PCI bus
1005 *
1006 * @dev:        device to test
1007 * Return:      true if it is on a PCI bus, false otherwise
1008 */
1009static inline bool device_is_on_pci_bus(const struct udevice *dev)
1010{
1011        return CONFIG_IS_ENABLED(PCI) && dev->parent &&
1012                device_get_uclass_id(dev->parent) == UCLASS_PCI;
1013}
1014
1015/**
1016 * device_foreach_child_safe() - iterate through child devices safely
1017 *
1018 * This allows the @pos child to be removed in the loop if required.
1019 *
1020 * @pos: struct udevice * for the current device
1021 * @next: struct udevice * for the next device
1022 * @parent: parent device to scan
1023 */
1024#define device_foreach_child_safe(pos, next, parent)    \
1025        list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
1026
1027/**
1028 * device_foreach_child() - iterate through child devices
1029 *
1030 * @pos: struct udevice * for the current device
1031 * @parent: parent device to scan
1032 */
1033#define device_foreach_child(pos, parent)       \
1034        list_for_each_entry(pos, &parent->child_head, sibling_node)
1035
1036/**
1037 * device_foreach_child_of_to_plat() - iterate through children
1038 *
1039 * This stops when it gets an error, with @pos set to the device that failed to
1040 * read ofdata.
1041 *
1042 * This creates a for() loop which works through the available children of
1043 * a device in order from start to end. Device ofdata is read by calling
1044 * device_of_to_plat() on each one. The devices are not probed.
1045 *
1046 * @pos: struct udevice * for the current device
1047 * @parent: parent device to scan
1048 */
1049#define device_foreach_child_of_to_plat(pos, parent)    \
1050        for (int _ret = device_first_child_ofdata_err(parent, &pos); !_ret; \
1051             _ret = device_next_child_ofdata_err(&pos))
1052
1053/**
1054 * device_foreach_child_probe() - iterate through children, probing them
1055 *
1056 * This creates a for() loop which works through the available children of
1057 * a device in order from start to end. Devices are probed if necessary,
1058 * and ready for use.
1059 *
1060 * This stops when it gets an error, with @pos set to the device that failed to
1061 * probe
1062 *
1063 * @pos: struct udevice * for the current device
1064 * @parent: parent device to scan
1065 */
1066#define device_foreach_child_probe(pos, parent) \
1067        for (int _ret = device_first_child_err(parent, &pos); !_ret; \
1068             _ret = device_next_child_err(&pos))
1069
1070/**
1071 * dm_scan_fdt_dev() - Bind child device in the device tree
1072 *
1073 * This handles device which have sub-nodes in the device tree. It scans all
1074 * sub-nodes and binds drivers for each node where a driver can be found.
1075 *
1076 * If this is called prior to relocation, only pre-relocation devices will be
1077 * bound (those marked with bootph-all in the device tree, or where
1078 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
1079 * be bound.
1080 *
1081 * @dev:        Device to scan
1082 * Return: 0 if OK, -ve on error
1083 */
1084int dm_scan_fdt_dev(struct udevice *dev);
1085
1086#endif
1087