drivers/of/platform.c

   1 /*
   2  *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
   3  *                       <benh@kernel.crashing.org>
   4  *    and                Arnd Bergmann, IBM Corp.
   5  *    Merged from powerpc/kernel/of_platform.c and
   6  *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
   7  *
   8  *  This program is free software; you can redistribute it and/or
   9  *  modify it under the terms of the GNU General Public License
  10  *  as published by the Free Software Foundation; either version
  11  *  2 of the License, or (at your option) any later version.
  12  *
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/slab.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_device.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/platform_device.h>
  24
  25 static int of_dev_node_match(struct device *dev, void *data)
  26 {
  27         return dev->of_node == data;
  28 }
  29
  30 /**
  31  * of_find_device_by_node - Find the platform_device associated with a node
  32  * @np: Pointer to device tree node
  33  *
  34  * Returns platform_device pointer, or NULL if not found
  35  */
  36 struct platform_device *of_find_device_by_node(struct device_node *np)
  37 {
  38         struct device *dev;
  39
  40         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  41         return dev ? to_platform_device(dev) : NULL;
  42 }
  43 EXPORT_SYMBOL(of_find_device_by_node);
  44
  45 #if defined(CONFIG_PPC_DCR)
  46 #include <asm/dcr.h>
  47 #endif
  48
  49 #if !defined(CONFIG_SPARC)
  50 /*
  51  * The following routines scan a subtree and registers a device for
  52  * each applicable node.
  53  *
  54  * Note: sparc doesn't use these routines because it has a different
  55  * mechanism for creating devices from device tree nodes.
  56  */
  57
  58 /**
  59  * of_device_make_bus_id - Use the device node data to assign a unique name
  60  * @dev: pointer to device structure that is linked to a device tree node
  61  *
  62  * This routine will first try using either the dcr-reg or the reg property
  63  * value to derive a unique name.  As a last resort it will use the node
  64  * name followed by a unique number.
  65  */
  66 void of_device_make_bus_id(struct device *dev)
  67 {
  68         static atomic_t bus_no_reg_magic;
  69         struct device_node *node = dev->of_node;
  70         const u32 *reg;
  71         u64 addr;
  72         int magic;
  73
  74 #ifdef CONFIG_PPC_DCR
  75         /*
  76          * If it's a DCR based device, use 'd' for native DCRs
  77          * and 'D' for MMIO DCRs.
  78          */
  79         reg = of_get_property(node, "dcr-reg", NULL);
  80         if (reg) {
  81 #ifdef CONFIG_PPC_DCR_NATIVE
  82                 dev_set_name(dev, "d%x.%s", *reg, node->name);
  83 #else /* CONFIG_PPC_DCR_NATIVE */
  84                 u64 addr = of_translate_dcr_address(node, *reg, NULL);
  85                 if (addr != OF_BAD_ADDR) {
  86                         dev_set_name(dev, "D%llx.%s",
  87                                      (unsigned long long)addr, node->name);
  88                         return;
  89                 }
  90 #endif /* !CONFIG_PPC_DCR_NATIVE */
  91         }
  92 #endif /* CONFIG_PPC_DCR */
  93
  94         /*
  95          * For MMIO, get the physical address
  96          */
  97         reg = of_get_property(node, "reg", NULL);
  98         if (reg) {
  99                 addr = of_translate_address(node, reg);
 100                 if (addr != OF_BAD_ADDR) {
 101                         dev_set_name(dev, "%llx.%s",
 102                                      (unsigned long long)addr, node->name);
 103                         return;
 104                 }
 105         }
 106
 107         /*
 108          * No BusID, use the node name and add a globally incremented
 109          * counter (and pray...)
 110          */
 111         magic = atomic_add_return(1, &bus_no_reg_magic);
 112         dev_set_name(dev, "%s.%d", node->name, magic - 1);
 113 }
 114
 115 /**
 116  * of_device_alloc - Allocate and initialize an of_device
 117  * @np: device node to assign to device
 118  * @bus_id: Name to assign to the device.  May be null to use default name.
 119  * @parent: Parent device.
 120  */
 121 struct platform_device *of_device_alloc(struct device_node *np,
 122                                   const char *bus_id,
 123                                   struct device *parent)
 124 {
 125         struct platform_device *dev;
 126         int rc, i, num_reg = 0, num_irq;
 127         struct resource *res, temp_res;
 128
 129         dev = platform_device_alloc("", -1);
 130         if (!dev)
 131                 return NULL;
 132
 133         /* count the io and irq resources */
 134         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 135                 num_reg++;
 136         num_irq = of_irq_count(np);
 137
 138         /* Populate the resource table */
 139         if (num_irq || num_reg) {
 140                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 141                 if (!res) {
 142                         platform_device_put(dev);
 143                         return NULL;
 144                 }
 145
 146                 dev->num_resources = num_reg + num_irq;
 147                 dev->resource = res;
 148                 for (i = 0; i < num_reg; i++, res++) {
 149                         rc = of_address_to_resource(np, i, res);
 150                         WARN_ON(rc);
 151                 }
 152                 WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
 153         }
 154
 155         dev->dev.of_node = of_node_get(np);
 156 #if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
 157         dev->dev.dma_mask = &dev->archdata.dma_mask;
 158 #endif
 159         dev->dev.parent = parent;
 160
 161         if (bus_id)
 162                 dev_set_name(&dev->dev, "%s", bus_id);
 163         else
 164                 of_device_make_bus_id(&dev->dev);
 165
 166         return dev;
 167 }
 168 EXPORT_SYMBOL(of_device_alloc);
 169
 170 /**
 171  * of_platform_device_create - Alloc, initialize and register an of_device
 172  * @np: pointer to node to create device for
 173  * @bus_id: name to assign device
 174  * @parent: Linux device model parent device.
 175  *
 176  * Returns pointer to created platform device, or NULL if a device was not
 177  * registered.  Unavailable devices will not get registered.
 178  */
 179 struct platform_device *of_platform_device_create(struct device_node *np,
 180                                             const char *bus_id,
 181                                             struct device *parent)
 182 {
 183         struct platform_device *dev;
 184
 185         if (!of_device_is_available(np))
 186                 return NULL;
 187
 188         dev = of_device_alloc(np, bus_id, parent);
 189         if (!dev)
 190                 return NULL;
 191
 192 #if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
 193         dev->archdata.dma_mask = 0xffffffffUL;
 194 #endif
 195         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 196         dev->dev.bus = &platform_bus_type;
 197
 198         /* We do not fill the DMA ops for platform devices by default.
 199          * This is currently the responsibility of the platform code
 200          * to do such, possibly using a device notifier
 201          */
 202
 203         if (of_device_add(dev) != 0) {
 204                 platform_device_put(dev);
 205                 return NULL;
 206         }
 207
 208         return dev;
 209 }
 210 EXPORT_SYMBOL(of_platform_device_create);
 211
 212 /**
 213  * of_platform_bus_create() - Create a device for a node and its children.
 214  * @bus: device node of the bus to instantiate
 215  * @matches: match table for bus nodes
 216  * disallow recursive creation of child buses
 217  * @parent: parent for new device, or NULL for top level.
 218  *
 219  * Creates a platform_device for the provided device_node, and optionally
 220  * recursively create devices for all the child nodes.
 221  */
 222 static int of_platform_bus_create(struct device_node *bus,
 223                                   const struct of_device_id *matches,
 224                                   struct device *parent)
 225 {
 226         struct device_node *child;
 227         struct platform_device *dev;
 228         int rc = 0;
 229
 230         dev = of_platform_device_create(bus, NULL, parent);
 231         if (!dev || !of_match_node(matches, bus))
 232                 return 0;
 233
 234         for_each_child_of_node(bus, child) {
 235                 pr_debug("   create child: %s\n", child->full_name);
 236                 rc = of_platform_bus_create(child, matches, &dev->dev);
 237                 if (rc) {
 238                         of_node_put(child);
 239                         break;
 240                 }
 241         }
 242         return rc;
 243 }
 244
 245 /**
 246  * of_platform_bus_probe() - Probe the device-tree for platform buses
 247  * @root: parent of the first level to probe or NULL for the root of the tree
 248  * @matches: match table for bus nodes
 249  * @parent: parent to hook devices from, NULL for toplevel
 250  *
 251  * Note that children of the provided root are not instantiated as devices
 252  * unless the specified root itself matches the bus list and is not NULL.
 253  */
 254 int of_platform_bus_probe(struct device_node *root,
 255                           const struct of_device_id *matches,
 256                           struct device *parent)
 257 {
 258         struct device_node *child;
 259         int rc = 0;
 260
 261         root = root ? of_node_get(root) : of_find_node_by_path("/");
 262         if (!root)
 263                 return -EINVAL;
 264
 265         pr_debug("of_platform_bus_probe()\n");
 266         pr_debug(" starting at: %s\n", root->full_name);
 267
 268         /* Do a self check of bus type, if there's a match, create children */
 269         if (of_match_node(matches, root)) {
 270                 rc = of_platform_bus_create(root, matches, parent);
 271         } else for_each_child_of_node(root, child) {
 272                 if (!of_match_node(matches, child))
 273                         continue;
 274                 rc = of_platform_bus_create(child, matches, parent);
 275                 if (rc)
 276                         break;
 277         }
 278
 279         of_node_put(root);
 280         return rc;
 281 }
 282 EXPORT_SYMBOL(of_platform_bus_probe);
 283 #endif /* !CONFIG_SPARC */