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     (2 << 0)
  25
  26 /**
  27  * struct device - An instance of a driver
  28  *
  29  * This holds information about a device, which is a driver bound to a
  30  * particular port or peripheral (essentially a driver instance).
  31  *
  32  * A device will come into existence through a 'bind' call, either due to
  33  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
  34  * in the device tree (in which case of_offset is >= 0). In the latter case
  35  * we translate the device tree information into platdata in a function
  36  * implemented by the driver ofdata_to_platdata method (called just before the
  37  * probe method if the device has a device tree node.
  38  *
  39  * All three of platdata, priv and uclass_priv can be allocated by the
  40  * driver, or you can use the auto_alloc_size members of struct driver and
  41  * struct uclass_driver to have driver model do this automatically.
  42  *
  43  * @driver: The driver used by this device
  44  * @name: Name of device, typically the FDT node name
  45  * @platdata: Configuration data for this device
  46  * @of_offset: Device tree node offset for this device (- for none)
  47  * @parent: Parent of this device, or NULL for the top level device
  48  * @priv: Private data for this device
  49  * @uclass: Pointer to uclass for this device
  50  * @uclass_priv: The uclass's private data for this device
  51  * @uclass_node: Used by uclass to link its devices
  52  * @child_head: List of children of this device
  53  * @sibling_node: Next device in list of all devices
  54  * @flags: Flags for this device DM_FLAG_...
  55  */
  56 struct device {
  57         struct driver *driver;
  58         const char *name;
  59         void *platdata;
  60         int of_offset;
  61         struct device *parent;
  62         void *priv;
  63         struct uclass *uclass;
  64         void *uclass_priv;
  65         struct list_head uclass_node;
  66         struct list_head child_head;
  67         struct list_head sibling_node;
  68         uint32_t flags;
  69 };
  70
  71 /* Returns the operations for a device */
  72 #define device_get_ops(dev)     (dev->driver->ops)
  73
  74 /* Returns non-zero if the device is active (probed and not removed) */
  75 #define device_active(dev)      ((dev)->flags & DM_FLAG_ACTIVATED)
  76
  77 /**
  78  * struct device_id - Lists the compatible strings supported by a driver
  79  * @compatible: Compatible string
  80  * @data: Data for this compatible string
  81  */
  82 struct device_id {
  83         const char *compatible;
  84         ulong data;
  85 };
  86
  87 /**
  88  * struct driver - A driver for a feature or peripheral
  89  *
  90  * This holds methods for setting up a new device, and also removing it.
  91  * The device needs information to set itself up - this is provided either
  92  * by platdata or a device tree node (which we find by looking up
  93  * matching compatible strings with of_match).
  94  *
  95  * Drivers all belong to a uclass, representing a class of devices of the
  96  * same type. Common elements of the drivers can be implemented in the uclass,
  97  * or the uclass can provide a consistent interface to the drivers within
  98  * it.
  99  *
 100  * @name: Device name
 101  * @id: Identiies the uclass we belong to
 102  * @of_match: List of compatible strings to match, and any identifying data
 103  * for each.
 104  * @bind: Called to bind a device to its driver
 105  * @probe: Called to probe a device, i.e. activate it
 106  * @remove: Called to remove a device, i.e. de-activate it
 107  * @unbind: Called to unbind a device from its driver
 108  * @ofdata_to_platdata: Called before probe to decode device tree data
 109  * @priv_auto_alloc_size: If non-zero this is the size of the private data
 110  * to be allocated in the device's ->priv pointer. If zero, then the driver
 111  * is responsible for allocating any data required.
 112  * @platdata_auto_alloc_size: If non-zero this is the size of the
 113  * platform data to be allocated in the device's ->platdata pointer.
 114  * This is typically only useful for device-tree-aware drivers (those with
 115  * an of_match), since drivers which use platdata will have the data
 116  * provided in the U_BOOT_DEVICE() instantiation.
 117  * ops: Driver-specific operations. This is typically a list of function
 118  * pointers defined by the driver, to implement driver functions required by
 119  * the uclass.
 120  */
 121 struct driver {
 122         char *name;
 123         enum uclass_id id;
 124         const struct device_id *of_match;
 125         int (*bind)(struct device *dev);
 126         int (*probe)(struct device *dev);
 127         int (*remove)(struct device *dev);
 128         int (*unbind)(struct device *dev);
 129         int (*ofdata_to_platdata)(struct device *dev);
 130         int priv_auto_alloc_size;
 131         int platdata_auto_alloc_size;
 132         const void *ops;        /* driver-specific operations */
 133 };
 134
 135 /* Declare a new U-Boot driver */
 136 #define U_BOOT_DRIVER(__name)                                           \
 137         ll_entry_declare(struct driver, __name, driver)
 138
 139 /**
 140  * dev_get_platdata() - Get the platform data for a device
 141  *
 142  * This checks that dev is not NULL, but no other checks for now
 143  *
 144  * @dev         Device to check
 145  * @return platform data, or NULL if none
 146  */
 147 void *dev_get_platdata(struct device *dev);
 148
 149 /**
 150  * dev_get_priv() - Get the private data for a device
 151  *
 152  * This checks that dev is not NULL, but no other checks for now
 153  *
 154  * @dev         Device to check
 155  * @return private data, or NULL if none
 156  */
 157 void *dev_get_priv(struct device *dev);
 158
 159 #endif