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 <linker_lists.h>
  16 #include <linux/list.h>
  17
  18 struct driver_info;
  19
  20 /* Driver is active (probed). Cleared when it is removed */
  21 #define DM_FLAG_ACTIVATED       (1 << 0)
  22
  23 /* DM is responsible for allocating and freeing platdata */
  24 #define DM_FLAG_ALLOC_PDATA     (1 << 1)
  25
  26 /* DM should init this device prior to relocation */
  27 #define DM_FLAG_PRE_RELOC       (1 << 2)
  28
  29 /* DM is responsible for allocating and freeing parent_platdata */
  30 #define DM_FLAG_ALLOC_PARENT_PDATA      (1 << 3)
  31
  32 /**
  33  * struct udevice - An instance of a driver
  34  *
  35  * This holds information about a device, which is a driver bound to a
  36  * particular port or peripheral (essentially a driver instance).
  37  *
  38  * A device will come into existence through a 'bind' call, either due to
  39  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  40  * in the device tree (in which case of_offset is >= 0). In the latter case
  41  * we translate the device tree information into platdata in a function
  42  * implemented by the driver ofdata_to_platdata method (called just before the
  43  * probe method if the device has a device tree node.
  44  *
  45  * All three of platdata, priv and uclass_priv can be allocated by the
  46  * driver, or you can use the auto_alloc_size members of struct driver and
  47  * struct uclass_driver to have driver model do this automatically.
  48  *
  49  * @driver: The driver used by this device
  50  * @name: Name of device, typically the FDT node name
  51  * @platdata: Configuration data for this device
  52  * @parent_platdata: The parent bus's configuration data for this device
  53  * @of_offset: Device tree node offset for this device (- for none)
  54  * @of_id: Pointer to the udevice_id structure which created the device
  55  * @parent: Parent of this device, or NULL for the top level device
  56  * @priv: Private data for this device
  57  * @uclass: Pointer to uclass for this device
  58  * @uclass_priv: The uclass's private data for this device
  59  * @parent_priv: The parent's private data for this device
  60  * @uclass_node: Used by uclass to link its devices
  61  * @child_head: List of children of this device
  62  * @sibling_node: Next device in list of all devices
  63  * @flags: Flags for this device DM_FLAG_...
  64  * @req_seq: Requested sequence number for this device (-1 = any)
  65  * @seq: Allocated sequence number for this device (-1 = none). This is set up
  66  * when the device is probed and will be unique within the device's uclass.
  67  */
  68 struct udevice {
  69         struct driver *driver;
  70         const char *name;
  71         void *platdata;
  72         void *parent_platdata;
  73         int of_offset;
  74         const struct udevice_id *of_id;
  75         struct udevice *parent;
  76         void *priv;
  77         struct uclass *uclass;
  78         void *uclass_priv;
  79         void *parent_priv;
  80         struct list_head uclass_node;
  81         struct list_head child_head;
  82         struct list_head sibling_node;
  83         uint32_t flags;
  84         int req_seq;
  85         int seq;
  86 };
  87
  88 /* Maximum sequence number supported */
  89 #define DM_MAX_SEQ      999
  90
  91 /* Returns the operations for a device */
  92 #define device_get_ops(dev)     (dev->driver->ops)
  93
  94 /* Returns non-zero if the device is active (probed and not removed) */
  95 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
  96
  97 /**
  98  * struct udevice_id - Lists the compatible strings supported by a driver
  99  * @compatible: Compatible string
 100  * @data: Data for this compatible string
 101  */
 102 struct udevice_id {
 103         const char *compatible;
 104         ulong data;
 105 };
 106
 107 #ifdef CONFIG_OF_CONTROL
 108 #define of_match_ptr(_ptr)      (_ptr)
 109 #else
 110 #define of_match_ptr(_ptr)      NULL
 111 #endif /* CONFIG_OF_CONTROL */
 112
 113 /**
 114  * struct driver - A driver for a feature or peripheral
 115  *
 116  * This holds methods for setting up a new device, and also removing it.
 117  * The device needs information to set itself up - this is provided either
 118  * by platdata or a device tree node (which we find by looking up
 119  * matching compatible strings with of_match).
 120  *
 121  * Drivers all belong to a uclass, representing a class of devices of the
 122  * same type. Common elements of the drivers can be implemented in the uclass,
 123  * or the uclass can provide a consistent interface to the drivers within
 124  * it.
 125  *
 126  * @name: Device name
 127  * @id: Identiies the uclass we belong to
 128  * @of_match: List of compatible strings to match, and any identifying data
 129  * for each.
 130  * @bind: Called to bind a device to its driver
 131  * @probe: Called to probe a device, i.e. activate it
 132  * @remove: Called to remove a device, i.e. de-activate it
 133  * @unbind: Called to unbind a device from its driver
 134  * @ofdata_to_platdata: Called before probe to decode device tree data
 135  * @child_pre_probe: Called before a child device is probed. The device has
 136  * memory allocated but it has not yet been probed.
 137  * @child_post_remove: Called after a child device is removed. The device
 138  * has memory allocated but its device_remove() method has been called.
 139  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 140  * to be allocated in the device's ->priv pointer. If zero, then the driver
 141  * is responsible for allocating any data required.
 142  * @platdata_auto_alloc_size: If non-zero this is the size of the
 143  * platform data to be allocated in the device's ->platdata pointer.
 144  * This is typically only useful for device-tree-aware drivers (those with
 145  * an of_match), since drivers which use platdata will have the data
 146  * provided in the U_BOOT_DEVICE() instantiation.
 147  * @per_child_auto_alloc_size: Each device can hold private data owned by
 148  * its parent. If required this will be automatically allocated if this
 149  * value is non-zero.
 150  * TODO(sjg@chromium.org): I'm considering dropping this, and just having
 151  * device_probe_child() pass it in. So far the use case for allocating it
 152  * is SPI, but I found that unsatisfactory. Since it is here I will leave it
 153  * until things are clearer.
 154  * @per_child_platdata_auto_alloc_size: A bus likes to store information about
 155  * its children. If non-zero this is the size of this data, to be allocated
 156  * in the child's parent_platdata pointer.
 157  * @ops: Driver-specific operations. This is typically a list of function
 158  * pointers defined by the driver, to implement driver functions required by
 159  * the uclass.
 160  * @flags: driver flags - see DM_FLAGS_...
 161  */
 162 struct driver {
 163         char *name;
 164         enum uclass_id id;
 165         const struct udevice_id *of_match;
 166         int (*bind)(struct udevice *dev);
 167         int (*probe)(struct udevice *dev);
 168         int (*remove)(struct udevice *dev);
 169         int (*unbind)(struct udevice *dev);
 170         int (*ofdata_to_platdata)(struct udevice *dev);
 171         int (*child_pre_probe)(struct udevice *dev);
 172         int (*child_post_remove)(struct udevice *dev);
 173         int priv_auto_alloc_size;
 174         int platdata_auto_alloc_size;
 175         int per_child_auto_alloc_size;
 176         int per_child_platdata_auto_alloc_size;
 177         const void *ops;        /* driver-specific operations */
 178         uint32_t flags;
 179 };
 180
 181 /* Declare a new U-Boot driver */
 182 #define U_BOOT_DRIVER(__name)                                           \
 183         ll_entry_declare(struct driver, __name, driver)
 184
 185 /**
 186  * dev_get_platdata() - Get the platform data for a device
 187  *
 188  * This checks that dev is not NULL, but no other checks for now
 189  *
 190  * @dev         Device to check
 191  * @return platform data, or NULL if none
 192  */
 193 void *dev_get_platdata(struct udevice *dev);
 194
 195 /**
 196  * dev_get_parent_platdata() - Get the parent platform data for a device
 197  *
 198  * This checks that dev is not NULL, but no other checks for now
 199  *
 200  * @dev         Device to check
 201  * @return parent's platform data, or NULL if none
 202  */
 203 void *dev_get_parent_platdata(struct udevice *dev);
 204
 205 /**
 206  * dev_get_parentdata() - Get the parent data for a device
 207  *
 208  * The parent data is data stored in the device but owned by the parent.
 209  * For example, a USB device may have parent data which contains information
 210  * about how to talk to the device over USB.
 211  *
 212  * This checks that dev is not NULL, but no other checks for now
 213  *
 214  * @dev         Device to check
 215  * @return parent data, or NULL if none
 216  */
 217 void *dev_get_parentdata(struct udevice *dev);
 218
 219 /**
 220  * dev_get_priv() - Get the private data for a device
 221  *
 222  * This checks that dev is not NULL, but no other checks for now
 223  *
 224  * @dev         Device to check
 225  * @return private data, or NULL if none
 226  */
 227 void *dev_get_priv(struct udevice *dev);
 228
 229 /**
 230  * struct dev_get_parent() - Get the parent of a device
 231  *
 232  * @child:      Child to check
 233  * @return parent of child, or NULL if this is the root device
 234  */
 235 struct udevice *dev_get_parent(struct udevice *child);
 236
 237 /**
 238  * dev_get_of_data() - get the device tree data used to bind a device
 239  *
 240  * When a device is bound using a device tree node, it matches a
 241  * particular compatible string as in struct udevice_id. This function
 242  * returns the associated data value for that compatible string
 243  */
 244 ulong dev_get_of_data(struct udevice *dev);
 245
 246 /**
 247  * device_get_child() - Get the child of a device by index
 248  *
 249  * Returns the numbered child, 0 being the first. This does not use
 250  * sequence numbers, only the natural order.
 251  *
 252  * @dev:        Parent device to check
 253  * @index:      Child index
 254  * @devp:       Returns pointer to device
 255  */
 256 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
 257
 258 /**
 259  * device_find_child_by_seq() - Find a child device based on a sequence
 260  *
 261  * This searches for a device with the given seq or req_seq.
 262  *
 263  * For seq, if an active device has this sequence it will be returned.
 264  * If there is no such device then this will return -ENODEV.
 265  *
 266  * For req_seq, if a device (whether activated or not) has this req_seq
 267  * value, that device will be returned. This is a strong indication that
 268  * the device will receive that sequence when activated.
 269  *
 270  * @parent: Parent device
 271  * @seq_or_req_seq: Sequence number to find (0=first)
 272  * @find_req_seq: true to find req_seq, false to find seq
 273  * @devp: Returns pointer to device (there is only one per for each seq).
 274  * Set to NULL if none is found
 275  * @return 0 if OK, -ve on error
 276  */
 277 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
 278                              bool find_req_seq, struct udevice **devp);
 279
 280 /**
 281  * device_get_child_by_seq() - Get a child device based on a sequence
 282  *
 283  * If an active device has this sequence it will be returned. If there is no
 284  * such device then this will check for a device that is requesting this
 285  * sequence.
 286  *
 287  * The device is probed to activate it ready for use.
 288  *
 289  * @parent: Parent device
 290  * @seq: Sequence number to find (0=first)
 291  * @devp: Returns pointer to device (there is only one per for each seq)
 292  * Set to NULL if none is found
 293  * @return 0 if OK, -ve on error
 294  */
 295 int device_get_child_by_seq(struct udevice *parent, int seq,
 296                             struct udevice **devp);
 297
 298 /**
 299  * device_find_child_by_of_offset() - Find a child device based on FDT offset
 300  *
 301  * Locates a child device by its device tree offset.
 302  *
 303  * @parent: Parent device
 304  * @of_offset: Device tree offset to find
 305  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 306  * @return 0 if OK, -ve on error
 307  */
 308 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
 309                                    struct udevice **devp);
 310
 311 /**
 312  * device_get_child_by_of_offset() - Get a child device based on FDT offset
 313  *
 314  * Locates a child device by its device tree offset.
 315  *
 316  * The device is probed to activate it ready for use.
 317  *
 318  * @parent: Parent device
 319  * @of_offset: Device tree offset to find
 320  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 321  * @return 0 if OK, -ve on error
 322  */
 323 int device_get_child_by_of_offset(struct udevice *parent, int seq,
 324                                   struct udevice **devp);
 325
 326 /**
 327  * device_find_first_child() - Find the first child of a device
 328  *
 329  * @parent: Parent device to search
 330  * @devp: Returns first child device, or NULL if none
 331  * @return 0
 332  */
 333 int device_find_first_child(struct udevice *parent, struct udevice **devp);
 334
 335 /**
 336  * device_find_first_child() - Find the first child of a device
 337  *
 338  * @devp: Pointer to previous child device on entry. Returns pointer to next
 339  *              child device, or NULL if none
 340  * @return 0
 341  */
 342 int device_find_next_child(struct udevice **devp);
 343
 344 #endif