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