arch/microblaze/kernel/of_platform.c

   1 /*
   2  *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
   3  *                       <benh@kernel.crashing.org>
   4  *    and                Arnd Bergmann, IBM Corp.
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version
   9  *  2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #undef DEBUG
  14
  15 #include <linux/string.h>
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/module.h>
  19 #include <linux/mod_devicetable.h>
  20 #include <linux/pci.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/of_platform.h>
  24
  25 #include <linux/errno.h>
  26 #include <linux/topology.h>
  27 #include <asm/atomic.h>
  28
  29 struct bus_type of_platform_bus_type = {
  30        .uevent  = of_device_uevent,
  31 };
  32 EXPORT_SYMBOL(of_platform_bus_type);
  33
  34 static int __init of_bus_driver_init(void)
  35 {
  36         return of_bus_type_init(&of_platform_bus_type, "of_platform");
  37 }
  38 postcore_initcall(of_bus_driver_init);
  39
  40 struct of_device *of_platform_device_create(struct device_node *np,
  41                                             const char *bus_id,
  42                                             struct device *parent)
  43 {
  44         struct of_device *dev;
  45
  46         dev = of_device_alloc(np, bus_id, parent);
  47         if (!dev)
  48                 return NULL;
  49
  50         dev->dma_mask = 0xffffffffUL;
  51         dev->dev.bus = &of_platform_bus_type;
  52
  53         /* We do not fill the DMA ops for platform devices by default.
  54          * This is currently the responsibility of the platform code
  55          * to do such, possibly using a device notifier
  56          */
  57
  58         if (of_device_register(dev) != 0) {
  59                 of_device_free(dev);
  60                 return NULL;
  61         }
  62
  63         return dev;
  64 }
  65 EXPORT_SYMBOL(of_platform_device_create);
  66
  67 /**
  68  * of_platform_bus_create - Create an OF device for a bus node and all its
  69  * children. Optionally recursively instanciate matching busses.
  70  * @bus: device node of the bus to instanciate
  71  * @matches: match table, NULL to use the default, OF_NO_DEEP_PROBE to
  72  * disallow recursive creation of child busses
  73  */
  74 static int of_platform_bus_create(const struct device_node *bus,
  75                                   const struct of_device_id *matches,
  76                                   struct device *parent)
  77 {
  78         struct device_node *child;
  79         struct of_device *dev;
  80         int rc = 0;
  81
  82         for_each_child_of_node(bus, child) {
  83                 pr_debug("   create child: %s\n", child->full_name);
  84                 dev = of_platform_device_create(child, NULL, parent);
  85                 if (dev == NULL)
  86                         rc = -ENOMEM;
  87                 else if (!of_match_node(matches, child))
  88                         continue;
  89                 if (rc == 0) {
  90                         pr_debug("   and sub busses\n");
  91                         rc = of_platform_bus_create(child, matches, &dev->dev);
  92                 }
  93                 if (rc) {
  94                         of_node_put(child);
  95                         break;
  96                 }
  97         }
  98         return rc;
  99 }
 100
 101
 102 /**
 103  * of_platform_bus_probe - Probe the device-tree for platform busses
 104  * @root: parent of the first level to probe or NULL for the root of the tree
 105  * @matches: match table, NULL to use the default
 106  * @parent: parent to hook devices from, NULL for toplevel
 107  *
 108  * Note that children of the provided root are not instanciated as devices
 109  * unless the specified root itself matches the bus list and is not NULL.
 110  */
 111
 112 int of_platform_bus_probe(struct device_node *root,
 113                           const struct of_device_id *matches,
 114                           struct device *parent)
 115 {
 116         struct device_node *child;
 117         struct of_device *dev;
 118         int rc = 0;
 119
 120         if (matches == NULL)
 121                 matches = of_default_bus_ids;
 122         if (matches == OF_NO_DEEP_PROBE)
 123                 return -EINVAL;
 124         if (root == NULL)
 125                 root = of_find_node_by_path("/");
 126         else
 127                 of_node_get(root);
 128
 129         pr_debug("of_platform_bus_probe()\n");
 130         pr_debug(" starting at: %s\n", root->full_name);
 131
 132         /* Do a self check of bus type, if there's a match, create
 133          * children
 134          */
 135         if (of_match_node(matches, root)) {
 136                 pr_debug(" root match, create all sub devices\n");
 137                 dev = of_platform_device_create(root, NULL, parent);
 138                 if (dev == NULL) {
 139                         rc = -ENOMEM;
 140                         goto bail;
 141                 }
 142                 pr_debug(" create all sub busses\n");
 143                 rc = of_platform_bus_create(root, matches, &dev->dev);
 144                 goto bail;
 145         }
 146         for_each_child_of_node(root, child) {
 147                 if (!of_match_node(matches, child))
 148                         continue;
 149
 150                 pr_debug("  match: %s\n", child->full_name);
 151                 dev = of_platform_device_create(child, NULL, parent);
 152                 if (dev == NULL)
 153                         rc = -ENOMEM;
 154                 else
 155                         rc = of_platform_bus_create(child, matches, &dev->dev);
 156                 if (rc) {
 157                         of_node_put(child);
 158                         break;
 159                 }
 160         }
 161  bail:
 162         of_node_put(root);
 163         return rc;
 164 }
 165 EXPORT_SYMBOL(of_platform_bus_probe);
 166
 167 static int of_dev_node_match(struct device *dev, void *data)
 168 {
 169         return to_of_device(dev)->node == data;
 170 }
 171
 172 struct of_device *of_find_device_by_node(struct device_node *np)
 173 {
 174         struct device *dev;
 175
 176         dev = bus_find_device(&of_platform_bus_type,
 177                               NULL, np, of_dev_node_match);
 178         if (dev)
 179                 return to_of_device(dev);
 180         return NULL;
 181 }
 182 EXPORT_SYMBOL(of_find_device_by_node);
 183
 184 static int of_dev_phandle_match(struct device *dev, void *data)
 185 {
 186         phandle *ph = data;
 187         return to_of_device(dev)->node->phandle == *ph;
 188 }
 189
 190 struct of_device *of_find_device_by_phandle(phandle ph)
 191 {
 192         struct device *dev;
 193
 194         dev = bus_find_device(&of_platform_bus_type,
 195                               NULL, &ph, of_dev_phandle_match);
 196         if (dev)
 197                 return to_of_device(dev);
 198         return NULL;
 199 }
 200 EXPORT_SYMBOL(of_find_device_by_phandle);