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