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). This is set up
  61  * when the device is probed and will be unique within the device's uclass.
  62  */
  63 struct udevice {
  64         struct driver *driver;
  65         const char *name;
  66         void *platdata;
  67         int of_offset;
  68         struct udevice *parent;
  69         void *priv;
  70         struct uclass *uclass;
  71         void *uclass_priv;
  72         void *parent_priv;
  73         struct list_head uclass_node;
  74         struct list_head child_head;
  75         struct list_head sibling_node;
  76         uint32_t flags;
  77         int req_seq;
  78         int seq;
  79 };
  80
  81 /* Maximum sequence number supported */
  82 #define DM_MAX_SEQ      999
  83
  84 /* Returns the operations for a device */
  85 #define device_get_ops(dev)     (dev->driver->ops)
  86
  87 /* Returns non-zero if the device is active (probed and not removed) */
  88 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
  89
  90 /**
  91  * struct udevice_id - Lists the compatible strings supported by a driver
  92  * @compatible: Compatible string
  93  * @data: Data for this compatible string
  94  */
  95 struct udevice_id {
  96         const char *compatible;
  97         ulong data;
  98 };
  99
 100 #ifdef CONFIG_OF_CONTROL
 101 #define of_match_ptr(_ptr)      (_ptr)
 102 #else
 103 #define of_match_ptr(_ptr)      NULL
 104 #endif /* CONFIG_OF_CONTROL */
 105
 106 /**
 107  * struct driver - A driver for a feature or peripheral
 108  *
 109  * This holds methods for setting up a new device, and also removing it.
 110  * The device needs information to set itself up - this is provided either
 111  * by platdata or a device tree node (which we find by looking up
 112  * matching compatible strings with of_match).
 113  *
 114  * Drivers all belong to a uclass, representing a class of devices of the
 115  * same type. Common elements of the drivers can be implemented in the uclass,
 116  * or the uclass can provide a consistent interface to the drivers within
 117  * it.
 118  *
 119  * @name: Device name
 120  * @id: Identiies the uclass we belong to
 121  * @of_match: List of compatible strings to match, and any identifying data
 122  * for each.
 123  * @bind: Called to bind a device to its driver
 124  * @probe: Called to probe a device, i.e. activate it
 125  * @remove: Called to remove a device, i.e. de-activate it
 126  * @unbind: Called to unbind a device from its driver
 127  * @ofdata_to_platdata: Called before probe to decode device tree data
 128  * @child_pre_probe: Called before a child device is probed. The device has
 129  * memory allocated but it has not yet been probed.
 130  * @child_post_remove: Called after a child device is removed. The device
 131  * has memory allocated but its device_remove() method has been called.
 132  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 133  * to be allocated in the device's ->priv pointer. If zero, then the driver
 134  * is responsible for allocating any data required.
 135  * @platdata_auto_alloc_size: If non-zero this is the size of the
 136  * platform data to be allocated in the device's ->platdata pointer.
 137  * This is typically only useful for device-tree-aware drivers (those with
 138  * an of_match), since drivers which use platdata will have the data
 139  * provided in the U_BOOT_DEVICE() instantiation.
 140  * @per_child_auto_alloc_size: Each device can hold private data owned by
 141  * its parent. If required this will be automatically allocated if this
 142  * value is non-zero.
 143  * TODO(sjg@chromium.org): I'm considering dropping this, and just having
 144  * device_probe_child() pass it in. So far the use case for allocating it
 145  * is SPI, but I found that unsatisfactory. Since it is here I will leave it
 146  * until things are clearer.
 147  * @ops: Driver-specific operations. This is typically a list of function
 148  * pointers defined by the driver, to implement driver functions required by
 149  * the uclass.
 150  * @flags: driver flags - see DM_FLAGS_...
 151  */
 152 struct driver {
 153         char *name;
 154         enum uclass_id id;
 155         const struct udevice_id *of_match;
 156         int (*bind)(struct udevice *dev);
 157         int (*probe)(struct udevice *dev);
 158         int (*remove)(struct udevice *dev);
 159         int (*unbind)(struct udevice *dev);
 160         int (*ofdata_to_platdata)(struct udevice *dev);
 161         int (*child_pre_probe)(struct udevice *dev);
 162         int (*child_post_remove)(struct udevice *dev);
 163         int priv_auto_alloc_size;
 164         int platdata_auto_alloc_size;
 165         int per_child_auto_alloc_size;
 166         const void *ops;        /* driver-specific operations */
 167         uint32_t flags;
 168 };
 169
 170 /* Declare a new U-Boot driver */
 171 #define U_BOOT_DRIVER(__name)                                           \
 172         ll_entry_declare(struct driver, __name, driver)
 173
 174 /**
 175  * dev_get_platdata() - Get the platform data for a device
 176  *
 177  * This checks that dev is not NULL, but no other checks for now
 178  *
 179  * @dev         Device to check
 180  * @return platform data, or NULL if none
 181  */
 182 void *dev_get_platdata(struct udevice *dev);
 183
 184 /**
 185  * dev_get_parentdata() - Get the parent data for a device
 186  *
 187  * The parent data is data stored in the device but owned by the parent.
 188  * For example, a USB device may have parent data which contains information
 189  * about how to talk to the device over USB.
 190  *
 191  * This checks that dev is not NULL, but no other checks for now
 192  *
 193  * @dev         Device to check
 194  * @return parent data, or NULL if none
 195  */
 196 void *dev_get_parentdata(struct udevice *dev);
 197
 198 /**
 199  * dev_get_priv() - Get the private 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 private data, or NULL if none
 205  */
 206 void *dev_get_priv(struct udevice *dev);
 207
 208 /**
 209  * device_get_child() - Get the child of a device by index
 210  *
 211  * Returns the numbered child, 0 being the first. This does not use
 212  * sequence numbers, only the natural order.
 213  *
 214  * @dev:        Parent device to check
 215  * @index:      Child index
 216  * @devp:       Returns pointer to device
 217  */
 218 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
 219
 220 /**
 221  * device_find_child_by_seq() - Find a child device based on a sequence
 222  *
 223  * This searches for a device with the given seq or req_seq.
 224  *
 225  * For seq, if an active device has this sequence it will be returned.
 226  * If there is no such device then this will return -ENODEV.
 227  *
 228  * For req_seq, if a device (whether activated or not) has this req_seq
 229  * value, that device will be returned. This is a strong indication that
 230  * the device will receive that sequence when activated.
 231  *
 232  * @parent: Parent device
 233  * @seq_or_req_seq: Sequence number to find (0=first)
 234  * @find_req_seq: true to find req_seq, false to find seq
 235  * @devp: Returns pointer to device (there is only one per for each seq).
 236  * Set to NULL if none is found
 237  * @return 0 if OK, -ve on error
 238  */
 239 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
 240                              bool find_req_seq, struct udevice **devp);
 241
 242 /**
 243  * device_get_child_by_seq() - Get a child device based on a sequence
 244  *
 245  * If an active device has this sequence it will be returned. If there is no
 246  * such device then this will check for a device that is requesting this
 247  * sequence.
 248  *
 249  * The device is probed to activate it ready for use.
 250  *
 251  * @parent: Parent device
 252  * @seq: Sequence number to find (0=first)
 253  * @devp: Returns pointer to device (there is only one per for each seq)
 254  * Set to NULL if none is found
 255  * @return 0 if OK, -ve on error
 256  */
 257 int device_get_child_by_seq(struct udevice *parent, int seq,
 258                             struct udevice **devp);
 259
 260 /**
 261  * device_find_child_by_of_offset() - Find a child device based on FDT offset
 262  *
 263  * Locates a child device by its device tree offset.
 264  *
 265  * @parent: Parent device
 266  * @of_offset: Device tree offset to find
 267  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 268  * @return 0 if OK, -ve on error
 269  */
 270 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
 271                                    struct udevice **devp);
 272
 273 /**
 274  * device_get_child_by_of_offset() - Get a child device based on FDT offset
 275  *
 276  * Locates a child device by its device tree offset.
 277  *
 278  * The device is probed to activate it ready for use.
 279  *
 280  * @parent: Parent device
 281  * @of_offset: Device tree offset to find
 282  * @devp: Returns pointer to device if found, otherwise this is set to NULL
 283  * @return 0 if OK, -ve on error
 284  */
 285 int device_get_child_by_of_offset(struct udevice *parent, int seq,
 286                                   struct udevice **devp);
 287
 288 /**
 289  * device_find_first_child() - Find the first child of a device
 290  *
 291  * @parent: Parent device to search
 292  * @devp: Returns first child device, or NULL if none
 293  * @return 0
 294  */
 295 int device_find_first_child(struct udevice *parent, struct udevice **devp);
 296
 297 /**
 298  * device_find_first_child() - Find the first child of a device
 299  *
 300  * @devp: Pointer to previous child device on entry. Returns pointer to next
 301  *              child device, or NULL if none
 302  * @return 0
 303  */
 304 int device_find_next_child(struct udevice **devp);
 305
 306 #endif