include/dm/device.h

   1 /*
   2  * Copyright (c) 2013 Google, Inc
   3  *
   4  * (C) Copyright 2012
   5  * Pavel Herrmann <morpheus.ibis@gmail.com>
   6  * Marek Vasut <marex@denx.de>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #ifndef _DM_DEVICE_H
  12 #define _DM_DEVICE_H
  13
  14 #include <dm/uclass-id.h>
  15 #include <fdtdec.h>
  16 #include <linker_lists.h>
  17 #include <linux/list.h>
  18
  19 struct driver_info;
  20
  21 /* Driver is active (probed). Cleared when it is removed */
  22 #define DM_FLAG_ACTIVATED       (1 << 0)
  23
  24 /* DM is responsible for allocating and freeing platdata */
  25 #define DM_FLAG_ALLOC_PDATA     (1 << 1)
  26
  27 /* DM should init this device prior to relocation */
  28 #define DM_FLAG_PRE_RELOC       (1 << 2)
  29
  30 /* DM is responsible for allocating and freeing parent_platdata */
  31 #define DM_FLAG_ALLOC_PARENT_PDATA      (1 << 3)
  32
  33 /* DM is responsible for allocating and freeing uclass_platdata */
  34 #define DM_FLAG_ALLOC_UCLASS_PDATA      (1 << 4)
  35
  36 /* Allocate driver private data on a DMA boundary */
  37 #define DM_FLAG_ALLOC_PRIV_DMA  (1 << 5)
  38
  39 /**
  40  * struct udevice - An instance of a driver
  41  *
  42  * This holds information about a device, which is a driver bound to a
  43  * particular port or peripheral (essentially a driver instance).
  44  *
  45  * A device will come into existence through a 'bind' call, either due to
  46  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  47  * in the device tree (in which case of_offset is >= 0). In the latter case
  48  * we translate the device tree information into platdata in a function
  49  * implemented by the driver ofdata_to_platdata method (called just before the
  50  * probe method if the device has a device tree node.
  51  *
  52  * All three of platdata, priv and uclass_priv can be allocated by the
  53  * driver, or you can use the auto_alloc_size members of struct driver and
  54  * struct uclass_driver to have driver model do this automatically.
  55  *
  56  * @driver: The driver used by this device
  57  * @name: Name of device, typically the FDT node name
  58  * @platdata: Configuration data for this device
  59  * @parent_platdata: The parent bus's configuration data for this device
  60  * @uclass_platdata: The uclass's configuration data for this device
  61  * @of_offset: Device tree node offset for this device (- for none)
  62  * @driver_data: Driver data word for the entry that matched this device with
  63  *              its driver
  64  * @parent: Parent of this device, or NULL for the top level device
  65  * @priv: Private data for this device
  66  * @uclass: Pointer to uclass for this device
  67  * @uclass_priv: The uclass's private data for this device
  68  * @parent_priv: The parent's private data for this device
  69  * @uclass_node: Used by uclass to link its devices
  70  * @child_head: List of children of this device
  71  * @sibling_node: Next device in list of all devices
  72  * @flags: Flags for this device DM_FLAG_...
  73  * @req_seq: Requested sequence number for this device (-1 = any)
  74  * @seq: Allocated sequence number for this device (-1 = none). This is set up
  75  * when the device is probed and will be unique within the device's uclass.
  76  */
  77 struct udevice {
  78         const struct driver *driver;
  79         const char *name;
  80         void *platdata;
  81         void *parent_platdata;
  82         void *uclass_platdata;
  83         int of_offset;
  84         ulong driver_data;
  85         struct udevice *parent;
  86         void *priv;
  87         struct uclass *uclass;
  88         void *uclass_priv;
  89         void *parent_priv;
  90         struct list_head uclass_node;
  91         struct list_head child_head;
  92         struct list_head sibling_node;
  93         uint32_t flags;
  94         int req_seq;
  95         int seq;
  96 };
  97
  98 /* Maximum sequence number supported */
  99 #define DM_MAX_SEQ      999
 100
 101 /* Returns the operations for a device */
 102 #define device_get_ops(dev)     (dev->driver->ops)
 103
 104 /* Returns non-zero if the device is active (probed and not removed) */
 105 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
 106
 107 /**
 108  * struct udevice_id - Lists the compatible strings supported by a driver
 109  * @compatible: Compatible string
 110  * @data: Data for this compatible string
 111  */
 112 struct udevice_id {
 113         const char *compatible;
 114         ulong data;
 115 };
 116
 117 #ifdef CONFIG_OF_CONTROL
 118 #define of_match_ptr(_ptr)      (_ptr)
 119 #else
 120 #define of_match_ptr(_ptr)      NULL
 121 #endif /* CONFIG_OF_CONTROL */
 122
 123 /**
 124  * struct driver - A driver for a feature or peripheral
 125  *
 126  * This holds methods for setting up a new device, and also removing it.
 127  * The device needs information to set itself up - this is provided either
 128  * by platdata or a device tree node (which we find by looking up
 129  * matching compatible strings with of_match).
 130  *
 131  * Drivers all belong to a uclass, representing a class of devices of the
 132  * same type. Common elements of the drivers can be implemented in the uclass,
 133  * or the uclass can provide a consistent interface to the drivers within
 134  * it.
 135  *
 136  * @name: Device name
 137  * @id: Identiies the uclass we belong to
 138  * @of_match: List of compatible strings to match, and any identifying data
 139  * for each.
 140  * @bind: Called to bind a device to its driver
 141  * @probe: Called to probe a device, i.e. activate it
 142  * @remove: Called to remove a device, i.e. de-activate it
 143  * @unbind: Called to unbind a device from its driver
 144  * @ofdata_to_platdata: Called before probe to decode device tree data
 145  * @child_post_bind: Called after a new child has been bound
 146  * @child_pre_probe: Called before a child device is probed. The device has
 147  * memory allocated but it has not yet been probed.
 148  * @child_post_remove: Called after a child device is removed. The device
 149  * has memory allocated but its device_remove() method has been called.
 150  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 151  * to be allocated in the device's ->priv pointer. If zero, then the driver
 152  * is responsible for allocating any data required.
 153  * @platdata_auto_alloc_size: If non-zero this is the size of the
 154  * platform data to be allocated in the device's ->platdata pointer.
 155  * This is typically only useful for device-tree-aware drivers (those with
 156  * an of_match), since drivers which use platdata will have the data
 157  * provided in the U_BOOT_DEVICE() instantiation.
 158  * @per_child_auto_alloc_size: Each device can hold private data owned by
 159  * its parent. If required this will be automatically allocated if this
 160  * value is non-zero.
 161  * TODO(sjg@chromium.org): I'm considering dropping this, and just having
 162  * device_probe_child() pass it in. So far the use case for allocating it
 163  * is SPI, but I found that unsatisfactory. Since it is here I will leave it
 164  * until things are clearer.
 165  * @per_child_platdata_auto_alloc_size: A bus likes to store information about
 166  * its children. If non-zero this is the size of this data, to be allocated
 167  * in the child's parent_platdata pointer.
 168  * @ops: Driver-specific operations. This is typically a list of function
 169  * pointers defined by the driver, to implement driver functions required by
 170  * the uclass.
 171  * @flags: driver flags - see DM_FLAGS_...
 172  */
 173 struct driver {
 174         char *name;
 175         enum uclass_id id;
 176         const struct udevice_id *of_match;
 177         int (*bind)(struct udevice *dev);
 178         int (*probe)(struct udevice *dev);
 179         int (*remove)(struct udevice *dev);
 180         int (*unbind)(struct udevice *dev);
 181         int (*ofdata_to_platdata)(struct udevice *dev);
 182         int (*child_post_bind)(struct udevice *dev);
 183         int (*child_pre_probe)(struct udevice *dev);
 184         int (*child_post_remove)(struct udevice *dev);
 185         int priv_auto_alloc_size;
 186         int platdata_auto_alloc_size;
 187         int per_child_auto_alloc_size;
 188         int per_child_platdata_auto_alloc_size;
 189         const void *ops;        /* driver-specific operations */
 190         uint32_t flags;
 191 };
 192
 193 /* Declare a new U-Boot driver */
 194 #define U_BOOT_DRIVER(__name)                                           \
 195         ll_entry_declare(struct driver, __name, driver)
 196
 197 /**
 198  * dev_get_platdata() - Get the platform data for a device
 199  *
 200  * This checks that dev is not NULL, but no other checks for now
 201  *
 202  * @dev         Device to check
 203  * @return platform data, or NULL if none
 204  */
 205 void *dev_get_platdata(struct udevice *dev);
 206
 207 /**
 208  * dev_get_parent_platdata() - Get the parent platform data for a device
 209  *
 210  * This checks that dev is not NULL, but no other checks for now
 211  *
 212  * @dev         Device to check
 213  * @return parent's platform data, or NULL if none
 214  */
 215 void *dev_get_parent_platdata(struct udevice *dev);
 216
 217 /**
 218  * dev_get_uclass_platdata() - Get the uclass platform data for a device
 219  *
 220  * This checks that dev is not NULL, but no other checks for now
 221  *
 222  * @dev         Device to check
 223  * @return uclass's platform data, or NULL if none
 224  */
 225 void *dev_get_uclass_platdata(struct udevice *dev);
 226
 227 /**
 228  * dev_get_parentdata() - Get the parent data for a device
 229  *
 230  * The parent data is data stored in the device but owned by the parent.
 231  * For example, a USB device may have parent data which contains information
 232  * about how to talk to the device over USB.
 233  *
 234  * This checks that dev is not NULL, but no other checks for now
 235  *
 236  * @dev         Device to check
 237  * @return parent data, or NULL if none
 238  */
 239 void *dev_get_parentdata(struct udevice *dev);
 240
 241 /**
 242  * dev_get_priv() - Get the private data for a device
 243  *
 244  * This checks that dev is not NULL, but no other checks for now
 245  *
 246  * @dev         Device to check
 247  * @return private data, or NULL if none
 248  */
 249 void *dev_get_priv(struct udevice *dev);
 250
 251 /**
 252  * struct dev_get_parent() - Get the parent of a device
 253  *
 254  * @child:      Child to check
 255  * @return parent of child, or NULL if this is the root device
 256  */
 257 struct udevice *dev_get_parent(struct udevice *child);
 258
 259 /**
 260  * dev_get_uclass_priv() - Get the private uclass data for a device
 261  *
 262  * This checks that dev is not NULL, but no other checks for now
 263  *
 264  * @dev         Device to check
 265  * @return private uclass data for this device, or NULL if none
 266  */
 267 void *dev_get_uclass_priv(struct udevice *dev);
 268
 269 /**
 270  * dev_get_driver_data() - get the driver data used to bind a device
 271  *
 272  * When a device is bound using a device tree node, it matches a
 273  * particular compatible string as in struct udevice_id. This function
 274  * returns the associated data value for that compatible string. This is
 275  * the 'data' field in struct udevice_id.
 276  *
 277  * For USB devices, this is the driver_info field in struct usb_device_id.
 278  *
 279  * @dev:        Device to check
 280  */
 281 ulong dev_get_driver_data(struct udevice *dev);
 282
 283 /**
 284  * dev_get_driver_ops() - get the device's driver's operations
 285  *
 286  * This checks that dev is not NULL, and returns the pointer to device's
 287  * driver's operations.
 288  *
 289  * @dev:        Device to check
 290  * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
 291  */
 292 const void *dev_get_driver_ops(struct udevice *dev);
 293
 294 /*
 295  * device_get_uclass_id() - return the uclass ID of a device
 296  *
 297  * @dev:        Device to check
 298  * @return uclass ID for the device
 299  */
 300 enum uclass_id device_get_uclass_id(struct udevice *dev);
 301
 302 /*
 303  * dev_get_uclass_name() - return the uclass name of a device
 304  *
 305  * This checks that dev is not NULL.
 306  *
 307  * @dev:        Device to check
 308  * @return  pointer to the uclass name for the device
 309  */
 310 const char *dev_get_uclass_name(struct udevice *dev);
 311
 312 /**
 313  * device_get_child() - Get the child of a device by index
 314  *
 315  * Returns the numbered child, 0 being the first. This does not use
 316  * sequence numbers, only the natural order.
 317  *
 318  * @dev:        Parent device to check
 319  * @index:      Child index
 320  * @devp:       Returns pointer to device
 321  */
 322 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
 323
 324 /**
 325  * device_find_child_by_seq() - Find a child device based on a sequence
 326  *
 327  * This searches for a device with the given seq or req_seq.
 328  *
 329  * For seq, if an active device has this sequence it will be returned.
 330  * If there is no such device then this will return -ENODEV.
 331  *
 332  * For req_seq, if a device (whether activated or not) has this req_seq
 333  * value, that device will be returned. This is a strong indication that
 334  * the device will receive that sequence when activated.
 335  *
 336  * @parent: Parent device
 337  * @seq_or_req_seq: Sequence number to find (0=first)
 338  * @find_req_seq: true to find req_seq, false to find seq
 339  * @devp: Returns pointer to device (there is only one per for each seq).
 340  * Set to NULL if none is found
 341  * @return 0 if OK, -ve on error
 342  */
 343 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
 344                              bool find_req_seq, struct udevice **devp);
 345
 346 /**
 347  * device_get_child_by_seq() - Get a child device based on a sequence
 348  *
 349  * If an active device has this sequence it will be returned. If there is no
 350  * such device then this will check for a device that is requesting this
 351  * sequence.
 352  *
 353  * The device is probed to activate it ready for use.
 354  *
 355  * @parent: Parent device
 356  * @seq: Sequence number to find (0=first)
 357  * @devp: Returns pointer to device (there is only one per for each seq)
 358  * Set to NULL if none is found
 359  * @return 0 if OK, -ve on error
 360  */
 361 int device_get_child_by_seq(struct udevice *parent, int seq,
 362                             struct udevice **devp);
 363
 364 /**
 365  * device_find_child_by_of_offset() - Find a child device based on FDT offset
 366  *
 367  * Locates a child device by its device tree offset.
 368  *
 369  * @parent: Parent device
 370  * @of_offset: Device tree offset to find
 371  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 372  * @return 0 if OK, -ve on error
 373  */
 374 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
 375                                    struct udevice **devp);
 376
 377 /**
 378  * device_get_child_by_of_offset() - Get a child device based on FDT offset
 379  *
 380  * Locates a child device by its device tree offset.
 381  *
 382  * The device is probed to activate it ready for use.
 383  *
 384  * @parent: Parent device
 385  * @of_offset: Device tree offset to find
 386  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 387  * @return 0 if OK, -ve on error
 388  */
 389 int device_get_child_by_of_offset(struct udevice *parent, int of_offset,
 390                                   struct udevice **devp);
 391
 392 /**
 393  * device_get_global_by_of_offset() - Get a device based on FDT offset
 394  *
 395  * Locates a device by its device tree offset, searching globally throughout
 396  * the all driver model devices.
 397  *
 398  * The device is probed to activate it ready for use.
 399  *
 400  * @of_offset: Device tree offset to find
 401  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 402  * @return 0 if OK, -ve on error
 403  */
 404 int device_get_global_by_of_offset(int of_offset, struct udevice **devp);
 405
 406 /**
 407  * device_find_first_child() - Find the first child of a device
 408  *
 409  * @parent: Parent device to search
 410  * @devp: Returns first child device, or NULL if none
 411  * @return 0
 412  */
 413 int device_find_first_child(struct udevice *parent, struct udevice **devp);
 414
 415 /**
 416  * device_find_first_child() - Find the first child of a device
 417  *
 418  * @devp: Pointer to previous child device on entry. Returns pointer to next
 419  *              child device, or NULL if none
 420  * @return 0
 421  */
 422 int device_find_next_child(struct udevice **devp);
 423
 424 /**
 425  * dev_get_addr() - Get the reg property of a device
 426  *
 427  * @dev: Pointer to a device
 428  *
 429  * @return addr
 430  */
 431 fdt_addr_t dev_get_addr(struct udevice *dev);
 432
 433 /**
 434  * device_has_children() - check if a device has any children
 435  *
 436  * @dev:        Device to check
 437  * @return true if the device has one or more children
 438  */
 439 bool device_has_children(struct udevice *dev);
 440
 441 /**
 442  * device_has_active_children() - check if a device has any active children
 443  *
 444  * @dev:        Device to check
 445  * @return true if the device has one or more children and at least one of
 446  * them is active (probed).
 447  */
 448 bool device_has_active_children(struct udevice *dev);
 449
 450 /**
 451  * device_is_last_sibling() - check if a device is the last sibling
 452  *
 453  * This function can be useful for display purposes, when special action needs
 454  * to be taken when displaying the last sibling. This can happen when a tree
 455  * view of devices is being displayed.
 456  *
 457  * @dev:        Device to check
 458  * @return true if there are no more siblings after this one - i.e. is it
 459  * last in the list.
 460  */
 461 bool device_is_last_sibling(struct udevice *dev);
 462
 463 #endif