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 /**
  30  * struct udevice - An instance of a driver
  31  *
  32  * This holds information about a device, which is a driver bound to a
  33  * particular port or peripheral (essentially a driver instance).
  34  *
  35  * A device will come into existence through a 'bind' call, either due to
  36  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  37  * in the device tree (in which case of_offset is >= 0). In the latter case
  38  * we translate the device tree information into platdata in a function
  39  * implemented by the driver ofdata_to_platdata method (called just before the
  40  * probe method if the device has a device tree node.
  41  *
  42  * All three of platdata, priv and uclass_priv can be allocated by the
  43  * driver, or you can use the auto_alloc_size members of struct driver and
  44  * struct uclass_driver to have driver model do this automatically.
  45  *
  46  * @driver: The driver used by this device
  47  * @name: Name of device, typically the FDT node name
  48  * @platdata: Configuration data for this device
  49  * @of_offset: Device tree node offset for this device (- for none)
  50  * @parent: Parent of this device, or NULL for the top level device
  51  * @priv: Private data for this device
  52  * @uclass: Pointer to uclass for this device
  53  * @uclass_priv: The uclass's private data for this device
  54  * @parent_priv: The parent's private data for this device
  55  * @uclass_node: Used by uclass to link its devices
  56  * @child_head: List of children of this device
  57  * @sibling_node: Next device in list of all devices
  58  * @flags: Flags for this device DM_FLAG_...
  59  * @req_seq: Requested sequence number for this device (-1 = any)
  60  * @seq: Allocated sequence number for this device (-1 = none)
  61  */
  62 struct udevice {
  63         struct driver *driver;
  64         const char *name;
  65         void *platdata;
  66         int of_offset;
  67         struct udevice *parent;
  68         void *priv;
  69         struct uclass *uclass;
  70         void *uclass_priv;
  71         void *parent_priv;
  72         struct list_head uclass_node;
  73         struct list_head child_head;
  74         struct list_head sibling_node;
  75         uint32_t flags;
  76         int req_seq;
  77         int seq;
  78 };
  79
  80 /* Maximum sequence number supported */
  81 #define DM_MAX_SEQ      999
  82
  83 /* Returns the operations for a device */
  84 #define device_get_ops(dev)     (dev->driver->ops)
  85
  86 /* Returns non-zero if the device is active (probed and not removed) */
  87 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
  88
  89 /**
  90  * struct udevice_id - Lists the compatible strings supported by a driver
  91  * @compatible: Compatible string
  92  * @data: Data for this compatible string
  93  */
  94 struct udevice_id {
  95         const char *compatible;
  96         ulong data;
  97 };
  98
  99 /**
 100  * struct driver - A driver for a feature or peripheral
 101  *
 102  * This holds methods for setting up a new device, and also removing it.
 103  * The device needs information to set itself up - this is provided either
 104  * by platdata or a device tree node (which we find by looking up
 105  * matching compatible strings with of_match).
 106  *
 107  * Drivers all belong to a uclass, representing a class of devices of the
 108  * same type. Common elements of the drivers can be implemented in the uclass,
 109  * or the uclass can provide a consistent interface to the drivers within
 110  * it.
 111  *
 112  * @name: Device name
 113  * @id: Identiies the uclass we belong to
 114  * @of_match: List of compatible strings to match, and any identifying data
 115  * for each.
 116  * @bind: Called to bind a device to its driver
 117  * @probe: Called to probe a device, i.e. activate it
 118  * @remove: Called to remove a device, i.e. de-activate it
 119  * @unbind: Called to unbind a device from its driver
 120  * @ofdata_to_platdata: Called before probe to decode device tree data
 121  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 122  * to be allocated in the device's ->priv pointer. If zero, then the driver
 123  * is responsible for allocating any data required.
 124  * @platdata_auto_alloc_size: If non-zero this is the size of the
 125  * platform data to be allocated in the device's ->platdata pointer.
 126  * This is typically only useful for device-tree-aware drivers (those with
 127  * an of_match), since drivers which use platdata will have the data
 128  * provided in the U_BOOT_DEVICE() instantiation.
 129  * @per_child_auto_alloc_size: Each device can hold private data owned by
 130  * its parent. If required this will be automatically allocated if this
 131  * value is non-zero.
 132  * @ops: Driver-specific operations. This is typically a list of function
 133  * pointers defined by the driver, to implement driver functions required by
 134  * the uclass.
 135  * @flags: driver flags - see DM_FLAGS_...
 136  */
 137 struct driver {
 138         char *name;
 139         enum uclass_id id;
 140         const struct udevice_id *of_match;
 141         int (*bind)(struct udevice *dev);
 142         int (*probe)(struct udevice *dev);
 143         int (*remove)(struct udevice *dev);
 144         int (*unbind)(struct udevice *dev);
 145         int (*ofdata_to_platdata)(struct udevice *dev);
 146         int priv_auto_alloc_size;
 147         int platdata_auto_alloc_size;
 148         int per_child_auto_alloc_size;
 149         const void *ops;        /* driver-specific operations */
 150         uint32_t flags;
 151 };
 152
 153 /* Declare a new U-Boot driver */
 154 #define U_BOOT_DRIVER(__name)                                           \
 155         ll_entry_declare(struct driver, __name, driver)
 156
 157 /**
 158  * dev_get_platdata() - Get the platform data for a device
 159  *
 160  * This checks that dev is not NULL, but no other checks for now
 161  *
 162  * @dev         Device to check
 163  * @return platform data, or NULL if none
 164  */
 165 void *dev_get_platdata(struct udevice *dev);
 166
 167 /**
 168  * dev_get_parentdata() - Get the parent data for a device
 169  *
 170  * The parent data is data stored in the device but owned by the parent.
 171  * For example, a USB device may have parent data which contains information
 172  * about how to talk to the device over USB.
 173  *
 174  * This checks that dev is not NULL, but no other checks for now
 175  *
 176  * @dev         Device to check
 177  * @return parent data, or NULL if none
 178  */
 179 void *dev_get_parentdata(struct udevice *dev);
 180
 181 /**
 182  * dev_get_priv() - Get the private data for a device
 183  *
 184  * This checks that dev is not NULL, but no other checks for now
 185  *
 186  * @dev         Device to check
 187  * @return private data, or NULL if none
 188  */
 189 void *dev_get_priv(struct udevice *dev);
 190
 191 /**
 192  * device_get_child() - Get the child of a device by index
 193  *
 194  * Returns the numbered child, 0 being the first. This does not use
 195  * sequence numbers, only the natural order.
 196  *
 197  * @dev:        Parent device to check
 198  * @index:      Child index
 199  * @devp:       Returns pointer to device
 200  */
 201 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
 202
 203 /**
 204  * device_find_child_by_seq() - Find a child device based on a sequence
 205  *
 206  * This searches for a device with the given seq or req_seq.
 207  *
 208  * For seq, if an active device has this sequence it will be returned.
 209  * If there is no such device then this will return -ENODEV.
 210  *
 211  * For req_seq, if a device (whether activated or not) has this req_seq
 212  * value, that device will be returned. This is a strong indication that
 213  * the device will receive that sequence when activated.
 214  *
 215  * @parent: Parent device
 216  * @seq_or_req_seq: Sequence number to find (0=first)
 217  * @find_req_seq: true to find req_seq, false to find seq
 218  * @devp: Returns pointer to device (there is only one per for each seq).
 219  * Set to NULL if none is found
 220  * @return 0 if OK, -ve on error
 221  */
 222 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
 223                              bool find_req_seq, struct udevice **devp);
 224
 225 /**
 226  * device_get_child_by_seq() - Get a child device based on a sequence
 227  *
 228  * If an active device has this sequence it will be returned. If there is no
 229  * such device then this will check for a device that is requesting this
 230  * sequence.
 231  *
 232  * The device is probed to activate it ready for use.
 233  *
 234  * @parent: Parent device
 235  * @seq: Sequence number to find (0=first)
 236  * @devp: Returns pointer to device (there is only one per for each seq)
 237  * Set to NULL if none is found
 238  * @return 0 if OK, -ve on error
 239  */
 240 int device_get_child_by_seq(struct udevice *parent, int seq,
 241                             struct udevice **devp);
 242
 243 /**
 244  * device_find_child_by_of_offset() - Find a child device based on FDT offset
 245  *
 246  * Locates a child device by its device tree offset.
 247  *
 248  * @parent: Parent device
 249  * @of_offset: Device tree offset to find
 250  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 251  * @return 0 if OK, -ve on error
 252  */
 253 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
 254                                    struct udevice **devp);
 255
 256 /**
 257  * device_get_child_by_of_offset() - Get a child device based on FDT offset
 258  *
 259  * Locates a child device by its device tree offset.
 260  *
 261  * The device is probed to activate it ready for use.
 262  *
 263  * @parent: Parent device
 264  * @of_offset: Device tree offset to find
 265  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 266  * @return 0 if OK, -ve on error
 267  */
 268 int device_get_child_by_of_offset(struct udevice *parent, int seq,
 269                                   struct udevice **devp);
 270
 271 #endif