device.h 28 KB

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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. #ifndef _DM_DEVICE_H
  10. #define _DM_DEVICE_H
  11. #include <dm/ofnode.h>
  12. #include <dm/uclass-id.h>
  13. #include <fdtdec.h>
  14. #include <linker_lists.h>
  15. #include <linux/kernel.h>
  16. #include <linux/list.h>
  17. #include <linux/printk.h>
  18. struct driver_info;
  19. /* Driver is active (probed). Cleared when it is removed */
  20. #define DM_FLAG_ACTIVATED (1 << 0)
  21. /* DM is responsible for allocating and freeing platdata */
  22. #define DM_FLAG_ALLOC_PDATA (1 << 1)
  23. /* DM should init this device prior to relocation */
  24. #define DM_FLAG_PRE_RELOC (1 << 2)
  25. /* DM is responsible for allocating and freeing parent_platdata */
  26. #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
  27. /* DM is responsible for allocating and freeing uclass_platdata */
  28. #define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
  29. /* Allocate driver private data on a DMA boundary */
  30. #define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
  31. /* Device is bound */
  32. #define DM_FLAG_BOUND (1 << 6)
  33. /* Device name is allocated and should be freed on unbind() */
  34. #define DM_FLAG_NAME_ALLOCED (1 << 7)
  35. /* Device has platform data provided by of-platdata */
  36. #define DM_FLAG_OF_PLATDATA (1 << 8)
  37. /*
  38. * Call driver remove function to stop currently active DMA transfers or
  39. * give DMA buffers back to the HW / controller. This may be needed for
  40. * some drivers to do some final stage cleanup before the OS is called
  41. * (U-Boot exit)
  42. */
  43. #define DM_FLAG_ACTIVE_DMA (1 << 9)
  44. /*
  45. * Call driver remove function to do some final configuration, before
  46. * U-Boot exits and the OS is started
  47. */
  48. #define DM_FLAG_OS_PREPARE (1 << 10)
  49. /* DM does not enable/disable the power domains corresponding to this device */
  50. #define DM_FLAG_DEFAULT_PD_CTRL_OFF (1 << 11)
  51. /* Driver platdata has been read. Cleared when the device is removed */
  52. #define DM_FLAG_PLATDATA_VALID (1 << 12)
  53. /*
  54. * Device is removed without switching off its power domain. This might
  55. * be required, i. e. for serial console (debug) output when booting OS.
  56. */
  57. #define DM_FLAG_REMOVE_WITH_PD_ON (1 << 13)
  58. /*
  59. * One or multiple of these flags are passed to device_remove() so that
  60. * a selective device removal as specified by the remove-stage and the
  61. * driver flags can be done.
  62. */
  63. enum {
  64. /* Normal remove, remove all devices */
  65. DM_REMOVE_NORMAL = 1 << 0,
  66. /* Remove devices with active DMA */
  67. DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
  68. /* Remove devices which need some final OS preparation steps */
  69. DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
  70. /* Add more use cases here */
  71. /* Remove devices with any active flag */
  72. DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
  73. /* Don't power down any attached power domains */
  74. DM_REMOVE_NO_PD = 1 << 1,
  75. };
  76. /**
  77. * struct udevice - An instance of a driver
  78. *
  79. * This holds information about a device, which is a driver bound to a
  80. * particular port or peripheral (essentially a driver instance).
  81. *
  82. * A device will come into existence through a 'bind' call, either due to
  83. * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  84. * in the device tree (in which case of_offset is >= 0). In the latter case
  85. * we translate the device tree information into platdata in a function
  86. * implemented by the driver ofdata_to_platdata method (called just before the
  87. * probe method if the device has a device tree node.
  88. *
  89. * All three of platdata, priv and uclass_priv can be allocated by the
  90. * driver, or you can use the auto_alloc_size members of struct driver and
  91. * struct uclass_driver to have driver model do this automatically.
  92. *
  93. * @driver: The driver used by this device
  94. * @name: Name of device, typically the FDT node name
  95. * @platdata: Configuration data for this device
  96. * @parent_platdata: The parent bus's configuration data for this device
  97. * @uclass_platdata: The uclass's configuration data for this device
  98. * @node: Reference to device tree node for this device
  99. * @driver_data: Driver data word for the entry that matched this device with
  100. * its driver
  101. * @parent: Parent of this device, or NULL for the top level device
  102. * @priv: Private data for this device
  103. * @uclass: Pointer to uclass for this device
  104. * @uclass_priv: The uclass's private data for this device
  105. * @parent_priv: The parent's private data for this device
  106. * @uclass_node: Used by uclass to link its devices
  107. * @child_head: List of children of this device
  108. * @sibling_node: Next device in list of all devices
  109. * @flags: Flags for this device DM_FLAG_...
  110. * @req_seq: Requested sequence number for this device (-1 = any)
  111. * @seq: Allocated sequence number for this device (-1 = none). This is set up
  112. * when the device is probed and will be unique within the device's uclass.
  113. * @devres_head: List of memory allocations associated with this device.
  114. * When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
  115. * add to this list. Memory so-allocated will be freed
  116. * automatically when the device is removed / unbound
  117. */
  118. struct udevice {
  119. const struct driver *driver;
  120. const char *name;
  121. void *platdata;
  122. void *parent_platdata;
  123. void *uclass_platdata;
  124. ofnode node;
  125. ulong driver_data;
  126. struct udevice *parent;
  127. void *priv;
  128. struct uclass *uclass;
  129. void *uclass_priv;
  130. void *parent_priv;
  131. struct list_head uclass_node;
  132. struct list_head child_head;
  133. struct list_head sibling_node;
  134. uint32_t flags;
  135. int req_seq;
  136. int seq;
  137. #ifdef CONFIG_DEVRES
  138. struct list_head devres_head;
  139. #endif
  140. };
  141. /* Maximum sequence number supported */
  142. #define DM_MAX_SEQ 999
  143. /* Returns the operations for a device */
  144. #define device_get_ops(dev) (dev->driver->ops)
  145. /* Returns non-zero if the device is active (probed and not removed) */
  146. #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
  147. static inline int dev_of_offset(const struct udevice *dev)
  148. {
  149. return ofnode_to_offset(dev->node);
  150. }
  151. static inline void dev_set_of_offset(struct udevice *dev, int of_offset)
  152. {
  153. dev->node = offset_to_ofnode(of_offset);
  154. }
  155. static inline bool dev_has_of_node(struct udevice *dev)
  156. {
  157. return ofnode_valid(dev->node);
  158. }
  159. /**
  160. * struct udevice_id - Lists the compatible strings supported by a driver
  161. * @compatible: Compatible string
  162. * @data: Data for this compatible string
  163. */
  164. struct udevice_id {
  165. const char *compatible;
  166. ulong data;
  167. };
  168. #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
  169. #define of_match_ptr(_ptr) (_ptr)
  170. #else
  171. #define of_match_ptr(_ptr) NULL
  172. #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
  173. /**
  174. * struct driver - A driver for a feature or peripheral
  175. *
  176. * This holds methods for setting up a new device, and also removing it.
  177. * The device needs information to set itself up - this is provided either
  178. * by platdata or a device tree node (which we find by looking up
  179. * matching compatible strings with of_match).
  180. *
  181. * Drivers all belong to a uclass, representing a class of devices of the
  182. * same type. Common elements of the drivers can be implemented in the uclass,
  183. * or the uclass can provide a consistent interface to the drivers within
  184. * it.
  185. *
  186. * @name: Device name
  187. * @id: Identifies the uclass we belong to
  188. * @of_match: List of compatible strings to match, and any identifying data
  189. * for each.
  190. * @bind: Called to bind a device to its driver
  191. * @probe: Called to probe a device, i.e. activate it
  192. * @remove: Called to remove a device, i.e. de-activate it
  193. * @unbind: Called to unbind a device from its driver
  194. * @ofdata_to_platdata: Called before probe to decode device tree data
  195. * @child_post_bind: Called after a new child has been bound
  196. * @child_pre_probe: Called before a child device is probed. The device has
  197. * memory allocated but it has not yet been probed.
  198. * @child_post_remove: Called after a child device is removed. The device
  199. * has memory allocated but its device_remove() method has been called.
  200. * @priv_auto_alloc_size: If non-zero this is the size of the private data
  201. * to be allocated in the device's ->priv pointer. If zero, then the driver
  202. * is responsible for allocating any data required.
  203. * @platdata_auto_alloc_size: If non-zero this is the size of the
  204. * platform data to be allocated in the device's ->platdata pointer.
  205. * This is typically only useful for device-tree-aware drivers (those with
  206. * an of_match), since drivers which use platdata will have the data
  207. * provided in the U_BOOT_DEVICE() instantiation.
  208. * @per_child_auto_alloc_size: Each device can hold private data owned by
  209. * its parent. If required this will be automatically allocated if this
  210. * value is non-zero.
  211. * @per_child_platdata_auto_alloc_size: A bus likes to store information about
  212. * its children. If non-zero this is the size of this data, to be allocated
  213. * in the child's parent_platdata pointer.
  214. * @ops: Driver-specific operations. This is typically a list of function
  215. * pointers defined by the driver, to implement driver functions required by
  216. * the uclass.
  217. * @flags: driver flags - see DM_FLAGS_...
  218. * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
  219. * allowing the device to add things to the ACPI tables passed to Linux
  220. */
  221. struct driver {
  222. char *name;
  223. enum uclass_id id;
  224. const struct udevice_id *of_match;
  225. int (*bind)(struct udevice *dev);
  226. int (*probe)(struct udevice *dev);
  227. int (*remove)(struct udevice *dev);
  228. int (*unbind)(struct udevice *dev);
  229. int (*ofdata_to_platdata)(struct udevice *dev);
  230. int (*child_post_bind)(struct udevice *dev);
  231. int (*child_pre_probe)(struct udevice *dev);
  232. int (*child_post_remove)(struct udevice *dev);
  233. int priv_auto_alloc_size;
  234. int platdata_auto_alloc_size;
  235. int per_child_auto_alloc_size;
  236. int per_child_platdata_auto_alloc_size;
  237. const void *ops; /* driver-specific operations */
  238. uint32_t flags;
  239. #if CONFIG_IS_ENABLED(ACPIGEN)
  240. struct acpi_ops *acpi_ops;
  241. #endif
  242. };
  243. /* Declare a new U-Boot driver */
  244. #define U_BOOT_DRIVER(__name) \
  245. ll_entry_declare(struct driver, __name, driver)
  246. /* Get a pointer to a given driver */
  247. #define DM_GET_DRIVER(__name) \
  248. ll_entry_get(struct driver, __name, driver)
  249. /**
  250. * Declare a macro to state a alias for a driver name. This macro will
  251. * produce no code but its information will be parsed by tools like
  252. * dtoc
  253. */
  254. #define U_BOOT_DRIVER_ALIAS(__name, __alias)
  255. /**
  256. * dev_get_platdata() - Get the platform data for a device
  257. *
  258. * This checks that dev is not NULL, but no other checks for now
  259. *
  260. * @dev Device to check
  261. * @return platform data, or NULL if none
  262. */
  263. void *dev_get_platdata(const struct udevice *dev);
  264. /**
  265. * dev_get_parent_platdata() - Get the parent platform data for a device
  266. *
  267. * This checks that dev is not NULL, but no other checks for now
  268. *
  269. * @dev Device to check
  270. * @return parent's platform data, or NULL if none
  271. */
  272. void *dev_get_parent_platdata(const struct udevice *dev);
  273. /**
  274. * dev_get_uclass_platdata() - Get the uclass platform data for a device
  275. *
  276. * This checks that dev is not NULL, but no other checks for now
  277. *
  278. * @dev Device to check
  279. * @return uclass's platform data, or NULL if none
  280. */
  281. void *dev_get_uclass_platdata(const struct udevice *dev);
  282. /**
  283. * dev_get_priv() - Get the private data for a device
  284. *
  285. * This checks that dev is not NULL, but no other checks for now
  286. *
  287. * @dev Device to check
  288. * @return private data, or NULL if none
  289. */
  290. void *dev_get_priv(const struct udevice *dev);
  291. /**
  292. * dev_get_parent_priv() - Get the parent private data for a device
  293. *
  294. * The parent private data is data stored in the device but owned by the
  295. * parent. For example, a USB device may have parent data which contains
  296. * information about how to talk to the device over USB.
  297. *
  298. * This checks that dev is not NULL, but no other checks for now
  299. *
  300. * @dev Device to check
  301. * @return parent data, or NULL if none
  302. */
  303. void *dev_get_parent_priv(const struct udevice *dev);
  304. /**
  305. * dev_get_uclass_priv() - Get the private uclass data for a device
  306. *
  307. * This checks that dev is not NULL, but no other checks for now
  308. *
  309. * @dev Device to check
  310. * @return private uclass data for this device, or NULL if none
  311. */
  312. void *dev_get_uclass_priv(const struct udevice *dev);
  313. /**
  314. * struct dev_get_parent() - Get the parent of a device
  315. *
  316. * @child: Child to check
  317. * @return parent of child, or NULL if this is the root device
  318. */
  319. struct udevice *dev_get_parent(const struct udevice *child);
  320. /**
  321. * dev_get_driver_data() - get the driver data used to bind a device
  322. *
  323. * When a device is bound using a device tree node, it matches a
  324. * particular compatible string in struct udevice_id. This function
  325. * returns the associated data value for that compatible string. This is
  326. * the 'data' field in struct udevice_id.
  327. *
  328. * As an example, consider this structure:
  329. * static const struct udevice_id tegra_i2c_ids[] = {
  330. * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
  331. * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
  332. * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
  333. * { }
  334. * };
  335. *
  336. * When driver model finds a driver for this it will store the 'data' value
  337. * corresponding to the compatible string it matches. This function returns
  338. * that value. This allows the driver to handle several variants of a device.
  339. *
  340. * For USB devices, this is the driver_info field in struct usb_device_id.
  341. *
  342. * @dev: Device to check
  343. * @return driver data (0 if none is provided)
  344. */
  345. ulong dev_get_driver_data(const struct udevice *dev);
  346. /**
  347. * dev_get_driver_ops() - get the device's driver's operations
  348. *
  349. * This checks that dev is not NULL, and returns the pointer to device's
  350. * driver's operations.
  351. *
  352. * @dev: Device to check
  353. * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
  354. */
  355. const void *dev_get_driver_ops(const struct udevice *dev);
  356. /**
  357. * device_get_uclass_id() - return the uclass ID of a device
  358. *
  359. * @dev: Device to check
  360. * @return uclass ID for the device
  361. */
  362. enum uclass_id device_get_uclass_id(const struct udevice *dev);
  363. /**
  364. * dev_get_uclass_name() - return the uclass name of a device
  365. *
  366. * This checks that dev is not NULL.
  367. *
  368. * @dev: Device to check
  369. * @return pointer to the uclass name for the device
  370. */
  371. const char *dev_get_uclass_name(const struct udevice *dev);
  372. /**
  373. * device_get_child() - Get the child of a device by index
  374. *
  375. * Returns the numbered child, 0 being the first. This does not use
  376. * sequence numbers, only the natural order.
  377. *
  378. * @dev: Parent device to check
  379. * @index: Child index
  380. * @devp: Returns pointer to device
  381. * @return 0 if OK, -ENODEV if no such device, other error if the device fails
  382. * to probe
  383. */
  384. int device_get_child(const struct udevice *parent, int index,
  385. struct udevice **devp);
  386. /**
  387. * device_get_child_count() - Get the available child count of a device
  388. *
  389. * Returns the number of children to a device.
  390. *
  391. * @parent: Parent device to check
  392. */
  393. int device_get_child_count(const struct udevice *parent);
  394. /**
  395. * device_find_child_by_seq() - Find a child device based on a sequence
  396. *
  397. * This searches for a device with the given seq or req_seq.
  398. *
  399. * For seq, if an active device has this sequence it will be returned.
  400. * If there is no such device then this will return -ENODEV.
  401. *
  402. * For req_seq, if a device (whether activated or not) has this req_seq
  403. * value, that device will be returned. This is a strong indication that
  404. * the device will receive that sequence when activated.
  405. *
  406. * @parent: Parent device
  407. * @seq_or_req_seq: Sequence number to find (0=first)
  408. * @find_req_seq: true to find req_seq, false to find seq
  409. * @devp: Returns pointer to device (there is only one per for each seq).
  410. * Set to NULL if none is found
  411. * @return 0 if OK, -ve on error
  412. */
  413. int device_find_child_by_seq(const struct udevice *parent, int seq_or_req_seq,
  414. bool find_req_seq, struct udevice **devp);
  415. /**
  416. * device_get_child_by_seq() - Get a child device based on a sequence
  417. *
  418. * If an active device has this sequence it will be returned. If there is no
  419. * such device then this will check for a device that is requesting this
  420. * sequence.
  421. *
  422. * The device is probed to activate it ready for use.
  423. *
  424. * @parent: Parent device
  425. * @seq: Sequence number to find (0=first)
  426. * @devp: Returns pointer to device (there is only one per for each seq)
  427. * Set to NULL if none is found
  428. * @return 0 if OK, -ve on error
  429. */
  430. int device_get_child_by_seq(const struct udevice *parent, int seq,
  431. struct udevice **devp);
  432. /**
  433. * device_find_child_by_of_offset() - Find a child device based on FDT offset
  434. *
  435. * Locates a child device by its device tree offset.
  436. *
  437. * @parent: Parent device
  438. * @of_offset: Device tree offset to find
  439. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  440. * @return 0 if OK, -ve on error
  441. */
  442. int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
  443. struct udevice **devp);
  444. /**
  445. * device_get_child_by_of_offset() - Get a child device based on FDT offset
  446. *
  447. * Locates a child device by its device tree offset.
  448. *
  449. * The device is probed to activate it ready for use.
  450. *
  451. * @parent: Parent device
  452. * @of_offset: Device tree offset to find
  453. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  454. * @return 0 if OK, -ve on error
  455. */
  456. int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
  457. struct udevice **devp);
  458. /**
  459. * device_find_global_by_ofnode() - Get a device based on ofnode
  460. *
  461. * Locates a device by its device tree ofnode, searching globally throughout
  462. * the all driver model devices.
  463. *
  464. * The device is NOT probed
  465. *
  466. * @node: Device tree ofnode to find
  467. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  468. * @return 0 if OK, -ve on error
  469. */
  470. int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
  471. /**
  472. * device_get_global_by_ofnode() - Get a device based on ofnode
  473. *
  474. * Locates a device by its device tree ofnode, searching globally throughout
  475. * the all driver model devices.
  476. *
  477. * The device is probed to activate it ready for use.
  478. *
  479. * @node: Device tree ofnode to find
  480. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  481. * @return 0 if OK, -ve on error
  482. */
  483. int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
  484. /**
  485. * device_get_by_driver_info() - Get a device based on driver_info
  486. *
  487. * Locates a device by its struct driver_info, by using its reference which
  488. * is updated during the bind process.
  489. *
  490. * The device is probed to activate it ready for use.
  491. *
  492. * @info: Struct driver_info
  493. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  494. * @return 0 if OK, -ve on error
  495. */
  496. int device_get_by_driver_info(const struct driver_info *info,
  497. struct udevice **devp);
  498. /**
  499. * device_get_by_driver_info_idx() - Get a device based on driver_info index
  500. *
  501. * Locates a device by its struct driver_info, by using its index number which
  502. * is written into the idx field of struct phandle_1_arg, etc.
  503. *
  504. * The device is probed to activate it ready for use.
  505. *
  506. * @idx: Index number of the driver_info structure (0=first)
  507. * @devp: Returns pointer to device if found, otherwise this is set to NULL
  508. * @return 0 if OK, -ve on error
  509. */
  510. int device_get_by_driver_info_idx(uint idx, struct udevice **devp);
  511. /**
  512. * device_find_first_child() - Find the first child of a device
  513. *
  514. * @parent: Parent device to search
  515. * @devp: Returns first child device, or NULL if none
  516. * @return 0
  517. */
  518. int device_find_first_child(const struct udevice *parent,
  519. struct udevice **devp);
  520. /**
  521. * device_find_next_child() - Find the next child of a device
  522. *
  523. * @devp: Pointer to previous child device on entry. Returns pointer to next
  524. * child device, or NULL if none
  525. * @return 0
  526. */
  527. int device_find_next_child(struct udevice **devp);
  528. /**
  529. * device_find_first_inactive_child() - Find the first inactive child
  530. *
  531. * This is used to locate an existing child of a device which is of a given
  532. * uclass.
  533. *
  534. * The device is NOT probed
  535. *
  536. * @parent: Parent device to search
  537. * @uclass_id: Uclass to look for
  538. * @devp: Returns device found, if any
  539. * @return 0 if found, else -ENODEV
  540. */
  541. int device_find_first_inactive_child(const struct udevice *parent,
  542. enum uclass_id uclass_id,
  543. struct udevice **devp);
  544. /**
  545. * device_find_first_child_by_uclass() - Find the first child of a device in uc
  546. *
  547. * @parent: Parent device to search
  548. * @uclass_id: Uclass to look for
  549. * @devp: Returns first child device in that uclass, if any
  550. * @return 0 if found, else -ENODEV
  551. */
  552. int device_find_first_child_by_uclass(const struct udevice *parent,
  553. enum uclass_id uclass_id,
  554. struct udevice **devp);
  555. /**
  556. * device_find_child_by_name() - Find a child by device name
  557. *
  558. * @parent: Parent device to search
  559. * @name: Name to look for
  560. * @devp: Returns device found, if any
  561. * @return 0 if found, else -ENODEV
  562. */
  563. int device_find_child_by_name(const struct udevice *parent, const char *name,
  564. struct udevice **devp);
  565. /**
  566. * device_first_child_ofdata_err() - Find the first child and reads its platdata
  567. *
  568. * The ofdata_to_platdata() method is called on the child before it is returned,
  569. * but the child is not probed.
  570. *
  571. * @parent: Parent to check
  572. * @devp: Returns child that was found, if any
  573. * @return 0 on success, -ENODEV if no children, other -ve on error
  574. */
  575. int device_first_child_ofdata_err(struct udevice *parent,
  576. struct udevice **devp);
  577. /*
  578. * device_next_child_ofdata_err() - Find the next child and read its platdata
  579. *
  580. * The ofdata_to_platdata() method is called on the child before it is returned,
  581. * but the child is not probed.
  582. *
  583. * @devp: On entry, points to the previous child; on exit returns the child that
  584. * was found, if any
  585. * @return 0 on success, -ENODEV if no children, other -ve on error
  586. */
  587. int device_next_child_ofdata_err(struct udevice **devp);
  588. /**
  589. * device_first_child_err() - Get the first child of a device
  590. *
  591. * The device returned is probed if necessary, and ready for use
  592. *
  593. * @parent: Parent device to search
  594. * @devp: Returns device found, if any
  595. * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
  596. */
  597. int device_first_child_err(struct udevice *parent, struct udevice **devp);
  598. /**
  599. * device_next_child_err() - Get the next child of a parent device
  600. *
  601. * The device returned is probed if necessary, and ready for use
  602. *
  603. * @devp: On entry, pointer to device to lookup. On exit, returns pointer
  604. * to the next sibling if no error occurred
  605. * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
  606. */
  607. int device_next_child_err(struct udevice **devp);
  608. /**
  609. * device_has_children() - check if a device has any children
  610. *
  611. * @dev: Device to check
  612. * @return true if the device has one or more children
  613. */
  614. bool device_has_children(const struct udevice *dev);
  615. /**
  616. * device_has_active_children() - check if a device has any active children
  617. *
  618. * @dev: Device to check
  619. * @return true if the device has one or more children and at least one of
  620. * them is active (probed).
  621. */
  622. bool device_has_active_children(const struct udevice *dev);
  623. /**
  624. * device_is_last_sibling() - check if a device is the last sibling
  625. *
  626. * This function can be useful for display purposes, when special action needs
  627. * to be taken when displaying the last sibling. This can happen when a tree
  628. * view of devices is being displayed.
  629. *
  630. * @dev: Device to check
  631. * @return true if there are no more siblings after this one - i.e. is it
  632. * last in the list.
  633. */
  634. bool device_is_last_sibling(const struct udevice *dev);
  635. /**
  636. * device_set_name() - set the name of a device
  637. *
  638. * This must be called in the device's bind() method and no later. Normally
  639. * this is unnecessary but for probed devices which don't get a useful name
  640. * this function can be helpful.
  641. *
  642. * The name is allocated and will be freed automatically when the device is
  643. * unbound.
  644. *
  645. * @dev: Device to update
  646. * @name: New name (this string is allocated new memory and attached to
  647. * the device)
  648. * @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
  649. * string
  650. */
  651. int device_set_name(struct udevice *dev, const char *name);
  652. /**
  653. * device_set_name_alloced() - note that a device name is allocated
  654. *
  655. * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
  656. * unbound the name will be freed. This avoids memory leaks.
  657. *
  658. * @dev: Device to update
  659. */
  660. void device_set_name_alloced(struct udevice *dev);
  661. /**
  662. * device_is_compatible() - check if the device is compatible with the compat
  663. *
  664. * This allows to check whether the device is comaptible with the compat.
  665. *
  666. * @dev: udevice pointer for which compatible needs to be verified.
  667. * @compat: Compatible string which needs to verified in the given
  668. * device
  669. * @return true if OK, false if the compatible is not found
  670. */
  671. bool device_is_compatible(const struct udevice *dev, const char *compat);
  672. /**
  673. * of_machine_is_compatible() - check if the machine is compatible with
  674. * the compat
  675. *
  676. * This allows to check whether the machine is comaptible with the compat.
  677. *
  678. * @compat: Compatible string which needs to verified
  679. * @return true if OK, false if the compatible is not found
  680. */
  681. bool of_machine_is_compatible(const char *compat);
  682. /**
  683. * dev_disable_by_path() - Disable a device given its device tree path
  684. *
  685. * @path: The device tree path identifying the device to be disabled
  686. * @return 0 on success, -ve on error
  687. */
  688. int dev_disable_by_path(const char *path);
  689. /**
  690. * dev_enable_by_path() - Enable a device given its device tree path
  691. *
  692. * @path: The device tree path identifying the device to be enabled
  693. * @return 0 on success, -ve on error
  694. */
  695. int dev_enable_by_path(const char *path);
  696. /**
  697. * device_is_on_pci_bus - Test if a device is on a PCI bus
  698. *
  699. * @dev: device to test
  700. * @return: true if it is on a PCI bus, false otherwise
  701. */
  702. static inline bool device_is_on_pci_bus(const struct udevice *dev)
  703. {
  704. return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
  705. }
  706. /**
  707. * device_foreach_child_safe() - iterate through child devices safely
  708. *
  709. * This allows the @pos child to be removed in the loop if required.
  710. *
  711. * @pos: struct udevice * for the current device
  712. * @next: struct udevice * for the next device
  713. * @parent: parent device to scan
  714. */
  715. #define device_foreach_child_safe(pos, next, parent) \
  716. list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
  717. /**
  718. * device_foreach_child() - iterate through child devices
  719. *
  720. * @pos: struct udevice * for the current device
  721. * @parent: parent device to scan
  722. */
  723. #define device_foreach_child(pos, parent) \
  724. list_for_each_entry(pos, &parent->child_head, sibling_node)
  725. /**
  726. * device_foreach_child_ofdata_to_platdata() - iterate through children
  727. *
  728. * This stops when it gets an error, with @pos set to the device that failed to
  729. * read ofdata.
  730. * This creates a for() loop which works through the available children of
  731. * a device in order from start to end. Device ofdata is read by calling
  732. * device_ofdata_to_platdata() on each one. The devices are not probed.
  733. *
  734. * @pos: struct udevice * for the current device
  735. * @parent: parent device to scan
  736. */
  737. #define device_foreach_child_ofdata_to_platdata(pos, parent) \
  738. for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
  739. _ret = device_next_child_ofdata_err(&dev))
  740. /**
  741. * device_foreach_child_probe() - iterate through children, probing them
  742. *
  743. * This creates a for() loop which works through the available children of
  744. * a device in order from start to end. Devices are probed if necessary,
  745. * and ready for use.
  746. *
  747. * This stops when it gets an error, with @pos set to the device that failed to
  748. * probe
  749. *
  750. * @pos: struct udevice * for the current device
  751. * @parent: parent device to scan
  752. */
  753. #define device_foreach_child_probe(pos, parent) \
  754. for (int _ret = device_first_child_err(parent, &dev); !_ret; \
  755. _ret = device_next_child_err(&dev))
  756. /**
  757. * dm_scan_fdt_dev() - Bind child device in the device tree
  758. *
  759. * This handles device which have sub-nodes in the device tree. It scans all
  760. * sub-nodes and binds drivers for each node where a driver can be found.
  761. *
  762. * If this is called prior to relocation, only pre-relocation devices will be
  763. * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
  764. * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
  765. * be bound.
  766. *
  767. * @dev: Device to scan
  768. * @return 0 if OK, -ve on error
  769. */
  770. int dm_scan_fdt_dev(struct udevice *dev);
  771. #endif