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 /**
  34  * struct udevice - An instance of a driver
  35  *
  36  * This holds information about a device, which is a driver bound to a
  37  * particular port or peripheral (essentially a driver instance).
  38  *
  39  * A device will come into existence through a 'bind' call, either due to
  40  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  41  * in the device tree (in which case of_offset is >= 0). In the latter case
  42  * we translate the device tree information into platdata in a function
  43  * implemented by the driver ofdata_to_platdata method (called just before the
  44  * probe method if the device has a device tree node.
  45  *
  46  * All three of platdata, priv and uclass_priv can be allocated by the
  47  * driver, or you can use the auto_alloc_size members of struct driver and
  48  * struct uclass_driver to have driver model do this automatically.
  49  *
  50  * @driver: The driver used by this device
  51  * @name: Name of device, typically the FDT node name
  52  * @platdata: Configuration data for this device
  53  * @parent_platdata: The parent bus's configuration data for this device
  54  * @of_offset: Device tree node offset for this device (- for none)
  55  * @of_id: Pointer to the udevice_id structure which created the device
  56  * @parent: Parent of this device, or NULL for the top level device
  57  * @priv: Private data for this device
  58  * @uclass: Pointer to uclass for this device
  59  * @uclass_priv: The uclass's private data for this device
  60  * @parent_priv: The parent's private data for this device
  61  * @uclass_node: Used by uclass to link its devices
  62  * @child_head: List of children of this device
  63  * @sibling_node: Next device in list of all devices
  64  * @flags: Flags for this device DM_FLAG_...
  65  * @req_seq: Requested sequence number for this device (-1 = any)
  66  * @seq: Allocated sequence number for this device (-1 = none). This is set up
  67  * when the device is probed and will be unique within the device's uclass.
  68  */
  69 struct udevice {
  70         struct driver *driver;
  71         const char *name;
  72         void *platdata;
  73         void *parent_platdata;
  74         int of_offset;
  75         const struct udevice_id *of_id;
  76         struct udevice *parent;
  77         void *priv;
  78         struct uclass *uclass;
  79         void *uclass_priv;
  80         void *parent_priv;
  81         struct list_head uclass_node;
  82         struct list_head child_head;
  83         struct list_head sibling_node;
  84         uint32_t flags;
  85         int req_seq;
  86         int seq;
  87 };
  88
  89 /* Maximum sequence number supported */
  90 #define DM_MAX_SEQ      999
  91
  92 /* Returns the operations for a device */
  93 #define device_get_ops(dev)     (dev->driver->ops)
  94
  95 /* Returns non-zero if the device is active (probed and not removed) */
  96 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
  97
  98 /**
  99  * struct udevice_id - Lists the compatible strings supported by a driver
 100  * @compatible: Compatible string
 101  * @data: Data for this compatible string
 102  */
 103 struct udevice_id {
 104         const char *compatible;
 105         ulong data;
 106 };
 107
 108 #ifdef CONFIG_OF_CONTROL
 109 #define of_match_ptr(_ptr)      (_ptr)
 110 #else
 111 #define of_match_ptr(_ptr)      NULL
 112 #endif /* CONFIG_OF_CONTROL */
 113
 114 /**
 115  * struct driver - A driver for a feature or peripheral
 116  *
 117  * This holds methods for setting up a new device, and also removing it.
 118  * The device needs information to set itself up - this is provided either
 119  * by platdata or a device tree node (which we find by looking up
 120  * matching compatible strings with of_match).
 121  *
 122  * Drivers all belong to a uclass, representing a class of devices of the
 123  * same type. Common elements of the drivers can be implemented in the uclass,
 124  * or the uclass can provide a consistent interface to the drivers within
 125  * it.
 126  *
 127  * @name: Device name
 128  * @id: Identiies the uclass we belong to
 129  * @of_match: List of compatible strings to match, and any identifying data
 130  * for each.
 131  * @bind: Called to bind a device to its driver
 132  * @probe: Called to probe a device, i.e. activate it
 133  * @remove: Called to remove a device, i.e. de-activate it
 134  * @unbind: Called to unbind a device from its driver
 135  * @ofdata_to_platdata: Called before probe to decode device tree data
 136  * @child_post_bind: Called after a new child has been bound
 137  * @child_pre_probe: Called before a child device is probed. The device has
 138  * memory allocated but it has not yet been probed.
 139  * @child_post_remove: Called after a child device is removed. The device
 140  * has memory allocated but its device_remove() method has been called.
 141  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 142  * to be allocated in the device's ->priv pointer. If zero, then the driver
 143  * is responsible for allocating any data required.
 144  * @platdata_auto_alloc_size: If non-zero this is the size of the
 145  * platform data to be allocated in the device's ->platdata pointer.
 146  * This is typically only useful for device-tree-aware drivers (those with
 147  * an of_match), since drivers which use platdata will have the data
 148  * provided in the U_BOOT_DEVICE() instantiation.
 149  * @per_child_auto_alloc_size: Each device can hold private data owned by
 150  * its parent. If required this will be automatically allocated if this
 151  * value is non-zero.
 152  * TODO(sjg@chromium.org): I'm considering dropping this, and just having
 153  * device_probe_child() pass it in. So far the use case for allocating it
 154  * is SPI, but I found that unsatisfactory. Since it is here I will leave it
 155  * until things are clearer.
 156  * @per_child_platdata_auto_alloc_size: A bus likes to store information about
 157  * its children. If non-zero this is the size of this data, to be allocated
 158  * in the child's parent_platdata pointer.
 159  * @ops: Driver-specific operations. This is typically a list of function
 160  * pointers defined by the driver, to implement driver functions required by
 161  * the uclass.
 162  * @flags: driver flags - see DM_FLAGS_...
 163  */
 164 struct driver {
 165         char *name;
 166         enum uclass_id id;
 167         const struct udevice_id *of_match;
 168         int (*bind)(struct udevice *dev);
 169         int (*probe)(struct udevice *dev);
 170         int (*remove)(struct udevice *dev);
 171         int (*unbind)(struct udevice *dev);
 172         int (*ofdata_to_platdata)(struct udevice *dev);
 173         int (*child_post_bind)(struct udevice *dev);
 174         int (*child_pre_probe)(struct udevice *dev);
 175         int (*child_post_remove)(struct udevice *dev);
 176         int priv_auto_alloc_size;
 177         int platdata_auto_alloc_size;
 178         int per_child_auto_alloc_size;
 179         int per_child_platdata_auto_alloc_size;
 180         const void *ops;        /* driver-specific operations */
 181         uint32_t flags;
 182 };
 183
 184 /* Declare a new U-Boot driver */
 185 #define U_BOOT_DRIVER(__name)                                           \
 186         ll_entry_declare(struct driver, __name, driver)
 187
 188 /**
 189  * dev_get_platdata() - Get the platform data for a device
 190  *
 191  * This checks that dev is not NULL, but no other checks for now
 192  *
 193  * @dev         Device to check
 194  * @return platform data, or NULL if none
 195  */
 196 void *dev_get_platdata(struct udevice *dev);
 197
 198 /**
 199  * dev_get_parent_platdata() - Get the parent platform data for a device
 200  *
 201  * This checks that dev is not NULL, but no other checks for now
 202  *
 203  * @dev         Device to check
 204  * @return parent's platform data, or NULL if none
 205  */
 206 void *dev_get_parent_platdata(struct udevice *dev);
 207
 208 /**
 209  * dev_get_parentdata() - Get the parent data for a device
 210  *
 211  * The parent data is data stored in the device but owned by the parent.
 212  * For example, a USB device may have parent data which contains information
 213  * about how to talk to the device over USB.
 214  *
 215  * This checks that dev is not NULL, but no other checks for now
 216  *
 217  * @dev         Device to check
 218  * @return parent data, or NULL if none
 219  */
 220 void *dev_get_parentdata(struct udevice *dev);
 221
 222 /**
 223  * dev_get_priv() - Get the private data for a device
 224  *
 225  * This checks that dev is not NULL, but no other checks for now
 226  *
 227  * @dev         Device to check
 228  * @return private data, or NULL if none
 229  */
 230 void *dev_get_priv(struct udevice *dev);
 231
 232 /**
 233  * struct dev_get_parent() - Get the parent of a device
 234  *
 235  * @child:      Child to check
 236  * @return parent of child, or NULL if this is the root device
 237  */
 238 struct udevice *dev_get_parent(struct udevice *child);
 239
 240 /**
 241  * dev_get_of_data() - get the device tree data used to bind a device
 242  *
 243  * When a device is bound using a device tree node, it matches a
 244  * particular compatible string as in struct udevice_id. This function
 245  * returns the associated data value for that compatible string
 246  */
 247 ulong dev_get_of_data(struct udevice *dev);
 248
 249 /*
 250  * device_get_uclass_id() - return the uclass ID of a device
 251  *
 252  * @dev:        Device to check
 253  * @return uclass ID for the device
 254  */
 255 enum uclass_id device_get_uclass_id(struct udevice *dev);
 256
 257 /**
 258  * device_get_child() - Get the child of a device by index
 259  *
 260  * Returns the numbered child, 0 being the first. This does not use
 261  * sequence numbers, only the natural order.
 262  *
 263  * @dev:        Parent device to check
 264  * @index:      Child index
 265  * @devp:       Returns pointer to device
 266  */
 267 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
 268
 269 /**
 270  * device_find_child_by_seq() - Find a child device based on a sequence
 271  *
 272  * This searches for a device with the given seq or req_seq.
 273  *
 274  * For seq, if an active device has this sequence it will be returned.
 275  * If there is no such device then this will return -ENODEV.
 276  *
 277  * For req_seq, if a device (whether activated or not) has this req_seq
 278  * value, that device will be returned. This is a strong indication that
 279  * the device will receive that sequence when activated.
 280  *
 281  * @parent: Parent device
 282  * @seq_or_req_seq: Sequence number to find (0=first)
 283  * @find_req_seq: true to find req_seq, false to find seq
 284  * @devp: Returns pointer to device (there is only one per for each seq).
 285  * Set to NULL if none is found
 286  * @return 0 if OK, -ve on error
 287  */
 288 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
 289                              bool find_req_seq, struct udevice **devp);
 290
 291 /**
 292  * device_get_child_by_seq() - Get a child device based on a sequence
 293  *
 294  * If an active device has this sequence it will be returned. If there is no
 295  * such device then this will check for a device that is requesting this
 296  * sequence.
 297  *
 298  * The device is probed to activate it ready for use.
 299  *
 300  * @parent: Parent device
 301  * @seq: Sequence number to find (0=first)
 302  * @devp: Returns pointer to device (there is only one per for each seq)
 303  * Set to NULL if none is found
 304  * @return 0 if OK, -ve on error
 305  */
 306 int device_get_child_by_seq(struct udevice *parent, int seq,
 307                             struct udevice **devp);
 308
 309 /**
 310  * device_find_child_by_of_offset() - Find a child device based on FDT offset
 311  *
 312  * Locates a child device by its device tree offset.
 313  *
 314  * @parent: Parent device
 315  * @of_offset: Device tree offset to find
 316  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 317  * @return 0 if OK, -ve on error
 318  */
 319 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
 320                                    struct udevice **devp);
 321
 322 /**
 323  * device_get_child_by_of_offset() - Get a child device based on FDT offset
 324  *
 325  * Locates a child device by its device tree offset.
 326  *
 327  * The device is probed to activate it ready for use.
 328  *
 329  * @parent: Parent device
 330  * @of_offset: Device tree offset to find
 331  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 332  * @return 0 if OK, -ve on error
 333  */
 334 int device_get_child_by_of_offset(struct udevice *parent, int seq,
 335                                   struct udevice **devp);
 336
 337 /**
 338  * device_find_first_child() - Find the first child of a device
 339  *
 340  * @parent: Parent device to search
 341  * @devp: Returns first child device, or NULL if none
 342  * @return 0
 343  */
 344 int device_find_first_child(struct udevice *parent, struct udevice **devp);
 345
 346 /**
 347  * device_find_first_child() - Find the first child of a device
 348  *
 349  * @devp: Pointer to previous child device on entry. Returns pointer to next
 350  *              child device, or NULL if none
 351  * @return 0
 352  */
 353 int device_find_next_child(struct udevice **devp);
 354
 355 /**
 356  * dev_get_addr() - Get the reg property of a device
 357  *
 358  * @dev: Pointer to a device
 359  *
 360  * @return addr
 361  */
 362 fdt_addr_t dev_get_addr(struct udevice *dev);
 363
 364 #endif