include/dm/uclass.h

   1 /*
   2  * Copyright (c) 2013 Google, Inc
   3  *
   4  * (C) Copyright 2012
   5  * Pavel Herrmann <morpheus.ibis@gmail.com>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #ifndef _DM_UCLASS_H
  11 #define _DM_UCLASS_H
  12
  13 #include <dm/ofnode.h>
  14 #include <dm/uclass-id.h>
  15 #include <linker_lists.h>
  16 #include <linux/list.h>
  17
  18 /**
  19  * struct uclass - a U-Boot drive class, collecting together similar drivers
  20  *
  21  * A uclass provides an interface to a particular function, which is
  22  * implemented by one or more drivers. Every driver belongs to a uclass even
  23  * if it is the only driver in that uclass. An example uclass is GPIO, which
  24  * provides the ability to change read inputs, set and clear outputs, etc.
  25  * There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
  26  * PMIC IO lines, all made available in a unified way through the uclass.
  27  *
  28  * @priv: Private data for this uclass
  29  * @uc_drv: The driver for the uclass itself, not to be confused with a
  30  * 'struct driver'
  31  * @dev_head: List of devices in this uclass (devices are attached to their
  32  * uclass when their bind method is called)
  33  * @sibling_node: Next uclass in the linked list of uclasses
  34  */
  35 struct uclass {
  36         void *priv;
  37         struct uclass_driver *uc_drv;
  38         struct list_head dev_head;
  39         struct list_head sibling_node;
  40 };
  41
  42 struct driver;
  43 struct udevice;
  44
  45 /* Members of this uclass sequence themselves with aliases */
  46 #define DM_UC_FLAG_SEQ_ALIAS                    (1 << 0)
  47
  48 /**
  49  * struct uclass_driver - Driver for the uclass
  50  *
  51  * A uclass_driver provides a consistent interface to a set of related
  52  * drivers.
  53  *
  54  * @name: Name of uclass driver
  55  * @id: ID number of this uclass
  56  * @post_bind: Called after a new device is bound to this uclass
  57  * @pre_unbind: Called before a device is unbound from this uclass
  58  * @pre_probe: Called before a new device is probed
  59  * @post_probe: Called after a new device is probed
  60  * @pre_remove: Called before a device is removed
  61  * @child_post_bind: Called after a child is bound to a device in this uclass
  62  * @init: Called to set up the uclass
  63  * @destroy: Called to destroy the uclass
  64  * @priv_auto_alloc_size: If non-zero this is the size of the private data
  65  * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
  66  * driver is responsible for allocating any data required.
  67  * @per_device_auto_alloc_size: Each device can hold private data owned
  68  * by the uclass. If required this will be automatically allocated if this
  69  * value is non-zero.
  70  * @per_device_platdata_auto_alloc_size: Each device can hold platform data
  71  * owned by the uclass as 'dev->uclass_platdata'. If the value is non-zero,
  72  * then this will be automatically allocated.
  73  * @per_child_auto_alloc_size: Each child device (of a parent in this
  74  * uclass) can hold parent data for the device/uclass. This value is only
  75  * used as a falback if this member is 0 in the driver.
  76  * @per_child_platdata_auto_alloc_size: A bus likes to store information about
  77  * its children. If non-zero this is the size of this data, to be allocated
  78  * in the child device's parent_platdata pointer. This value is only used as
  79  * a falback if this member is 0 in the driver.
  80  * @ops: Uclass operations, providing the consistent interface to devices
  81  * within the uclass.
  82  * @flags: Flags for this uclass (DM_UC_...)
  83  */
  84 struct uclass_driver {
  85         const char *name;
  86         enum uclass_id id;
  87         int (*post_bind)(struct udevice *dev);
  88         int (*pre_unbind)(struct udevice *dev);
  89         int (*pre_probe)(struct udevice *dev);
  90         int (*post_probe)(struct udevice *dev);
  91         int (*pre_remove)(struct udevice *dev);
  92         int (*child_post_bind)(struct udevice *dev);
  93         int (*child_pre_probe)(struct udevice *dev);
  94         int (*init)(struct uclass *class);
  95         int (*destroy)(struct uclass *class);
  96         int priv_auto_alloc_size;
  97         int per_device_auto_alloc_size;
  98         int per_device_platdata_auto_alloc_size;
  99         int per_child_auto_alloc_size;
 100         int per_child_platdata_auto_alloc_size;
 101         const void *ops;
 102         uint32_t flags;
 103 };
 104
 105 /* Declare a new uclass_driver */
 106 #define UCLASS_DRIVER(__name)                                           \
 107         ll_entry_declare(struct uclass_driver, __name, uclass)
 108
 109 /**
 110  * uclass_get() - Get a uclass based on an ID, creating it if needed
 111  *
 112  * Every uclass is identified by an ID, a number from 0 to n-1 where n is
 113  * the number of uclasses. This function allows looking up a uclass by its
 114  * ID.
 115  *
 116  * @key: ID to look up
 117  * @ucp: Returns pointer to uclass (there is only one per ID)
 118  * @return 0 if OK, -ve on error
 119  */
 120 int uclass_get(enum uclass_id key, struct uclass **ucp);
 121
 122 /**
 123  * uclass_get_name() - Get the name of a uclass driver
 124  *
 125  * @id: ID to look up
 126  * @returns the name of the uclass driver for that ID, or NULL if none
 127  */
 128 const char *uclass_get_name(enum uclass_id id);
 129
 130 /**
 131  * uclass_get_device() - Get a uclass device based on an ID and index
 132  *
 133  * The device is probed to activate it ready for use.
 134  *
 135  * @id: ID to look up
 136  * @index: Device number within that uclass (0=first)
 137  * @devp: Returns pointer to device (there is only one per for each ID)
 138  * @return 0 if OK, -ve on error
 139  */
 140 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
 141
 142 /**
 143  * uclass_get_device_by_name() - Get a uclass device by its name
 144  *
 145  * This searches the devices in the uclass for one with the exactly given name.
 146  *
 147  * The device is probed to activate it ready for use.
 148  *
 149  * @id: ID to look up
 150  * @name: name of a device to get
 151  * @devp: Returns pointer to device (the first one with the name)
 152  * @return 0 if OK, -ve on error
 153  */
 154 int uclass_get_device_by_name(enum uclass_id id, const char *name,
 155                               struct udevice **devp);
 156
 157 /**
 158  * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
 159  *
 160  * If an active device has this sequence it will be returned. If there is no
 161  * such device then this will check for a device that is requesting this
 162  * sequence.
 163  *
 164  * The device is probed to activate it ready for use.
 165  *
 166  * @id: ID to look up
 167  * @seq: Sequence number to find (0=first)
 168  * @devp: Returns pointer to device (there is only one for each seq)
 169  * @return 0 if OK, -ve on error
 170  */
 171 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
 172
 173 /**
 174  * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
 175  *
 176  * This searches the devices in the uclass for one attached to the given
 177  * device tree node.
 178  *
 179  * The device is probed to activate it ready for use.
 180  *
 181  * @id: ID to look up
 182  * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
 183  * @devp: Returns pointer to device (there is only one for each node)
 184  * @return 0 if OK, -ve on error
 185  */
 186 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
 187                                    struct udevice **devp);
 188
 189 /**
 190  * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
 191  *
 192  * This searches the devices in the uclass for one attached to the given
 193  * device tree node.
 194  *
 195  * The device is probed to activate it ready for use.
 196  *
 197  * @id: ID to look up
 198  * @np: Device tree node to search for (if NULL then -ENODEV is returned)
 199  * @devp: Returns pointer to device (there is only one for each node)
 200  * @return 0 if OK, -ve on error
 201  */
 202 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
 203                                 struct udevice **devp);
 204
 205 /**
 206  * uclass_get_device_by_phandle() - Get a uclass device by phandle
 207  *
 208  * This searches the devices in the uclass for one with the given phandle.
 209  *
 210  * The device is probed to activate it ready for use.
 211  *
 212  * @id: uclass ID to look up
 213  * @parent: Parent device containing the phandle pointer
 214  * @name: Name of property in the parent device node
 215  * @devp: Returns pointer to device (there is only one for each node)
 216  * @return 0 if OK, -ENOENT if there is no @name present in the node, other
 217  *      -ve on error
 218  */
 219 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
 220                                  const char *name, struct udevice **devp);
 221
 222 /**
 223  * uclass_get_device_by_driver() - Get a uclass device for a driver
 224  *
 225  * This searches the devices in the uclass for one that uses the given
 226  * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is
 227  * the driver name - as used in U_BOOT_DRIVER(name).
 228  *
 229  * The device is probed to activate it ready for use.
 230  *
 231  * @id: ID to look up
 232  * @drv: Driver to look for
 233  * @devp: Returns pointer to the first device with that driver
 234  * @return 0 if OK, -ve on error
 235  */
 236 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
 237                                 struct udevice **devp);
 238
 239 /**
 240  * uclass_first_device() - Get the first device in a uclass
 241  *
 242  * The device returned is probed if necessary, and ready for use
 243  *
 244  * This function is useful to start iterating through a list of devices which
 245  * are functioning correctly and can be probed.
 246  *
 247  * @id: Uclass ID to look up
 248  * @devp: Returns pointer to the first device in that uclass if no error
 249  * occurred, or NULL if there is no first device, or an error occurred with
 250  * that device.
 251  * @return 0 if OK (found or not found), other -ve on error
 252  */
 253 int uclass_first_device(enum uclass_id id, struct udevice **devp);
 254
 255 /**
 256  * uclass_first_device_err() - Get the first device in a uclass
 257  *
 258  * The device returned is probed if necessary, and ready for use
 259  *
 260  * @id: Uclass ID to look up
 261  * @devp: Returns pointer to the first device in that uclass, or NULL if none
 262  * @return 0 if found, -ENODEV if not found, other -ve on error
 263  */
 264 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
 265
 266 /**
 267  * uclass_next_device() - Get the next device in a uclass
 268  *
 269  * The device returned is probed if necessary, and ready for use
 270  *
 271  * This function is useful to start iterating through a list of devices which
 272  * are functioning correctly and can be probed.
 273  *
 274  * @devp: On entry, pointer to device to lookup. On exit, returns pointer
 275  * to the next device in the uclass if no error occurred, or NULL if there is
 276  * no next device, or an error occurred with that next device.
 277  * @return 0 if OK (found or not found), other -ve on error
 278  */
 279 int uclass_next_device(struct udevice **devp);
 280
 281 /**
 282  * uclass_first_device() - Get the first device in a uclass
 283  *
 284  * The device returned is probed if necessary, and ready for use
 285  *
 286  * This function is useful to start iterating through a list of devices which
 287  * are functioning correctly and can be probed.
 288  *
 289  * @id: Uclass ID to look up
 290  * @devp: Returns pointer to the first device in that uclass, or NULL if there
 291  * is no first device
 292  * @return 0 if OK (found or not found), other -ve on error. If an error occurs
 293  * it is still possible to move to the next device.
 294  */
 295 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
 296
 297 /**
 298  * uclass_next_device() - Get the next device in a uclass
 299  *
 300  * The device returned is probed if necessary, and ready for use
 301  *
 302  * This function is useful to start iterating through a list of devices which
 303  * are functioning correctly and can be probed.
 304  *
 305  * @devp: On entry, pointer to device to lookup. On exit, returns pointer
 306  * to the next device in the uclass if any
 307  * @return 0 if OK (found or not found), other -ve on error. If an error occurs
 308  * it is still possible to move to the next device.
 309  */
 310 int uclass_next_device_check(struct udevice **devp);
 311
 312 /**
 313  * uclass_resolve_seq() - Resolve a device's sequence number
 314  *
 315  * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
 316  * sequence number automatically, or >= 0 to select a particular number.
 317  * If the requested sequence number is in use, then this device will
 318  * be allocated another one.
 319  *
 320  * Note that the device's seq value is not changed by this function.
 321  *
 322  * @dev: Device for which to allocate sequence number
 323  * @return sequence number allocated, or -ve on error
 324  */
 325 int uclass_resolve_seq(struct udevice *dev);
 326
 327 /**
 328  * uclass_foreach_dev() - Helper function to iteration through devices
 329  *
 330  * This creates a for() loop which works through the available devices in
 331  * a uclass in order from start to end.
 332  *
 333  * @pos: struct udevice * to hold the current device. Set to NULL when there
 334  * are no more devices.
 335  * @uc: uclass to scan
 336  */
 337 #define uclass_foreach_dev(pos, uc)     \
 338         list_for_each_entry(pos, &uc->dev_head, uclass_node)
 339
 340 /**
 341  * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
 342  *
 343  * This creates a for() loop which works through the available devices in
 344  * a uclass in order from start to end. Inside the loop, it is safe to remove
 345  * @pos if required.
 346  *
 347  * @pos: struct udevice * to hold the current device. Set to NULL when there
 348  * are no more devices.
 349  * @next: struct udevice * to hold the next next
 350  * @uc: uclass to scan
 351  */
 352 #define uclass_foreach_dev_safe(pos, next, uc)  \
 353         list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
 354
 355 #endif