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