drivers/base/platform.c

   1 /*
   2  * platform.c - platform 'pseudo' bus for legacy devices
   3  *
   4  * Copyright (c) 2002-3 Patrick Mochel
   5  * Copyright (c) 2002-3 Open Source Development Labs
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  * Please see Documentation/driver-model/platform.txt for more
  10  * information.
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/bootmem.h>
  18 #include <linux/err.h>
  19
  20 struct device platform_bus = {
  21         .bus_id         = "platform",
  22 };
  23
  24 /**
  25  *      platform_get_resource - get a resource for a device
  26  *      @dev: platform device
  27  *      @type: resource type
  28  *      @num: resource index
  29  */
  30 struct resource *
  31 platform_get_resource(struct platform_device *dev, unsigned int type,
  32                       unsigned int num)
  33 {
  34         int i;
  35
  36         for (i = 0; i < dev->num_resources; i++) {
  37                 struct resource *r = &dev->resource[i];
  38
  39                 if ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
  40                                  IORESOURCE_IRQ|IORESOURCE_DMA))
  41                     == type)
  42                         if (num-- == 0)
  43                                 return r;
  44         }
  45         return NULL;
  46 }
  47
  48 /**
  49  *      platform_get_irq - get an IRQ for a device
  50  *      @dev: platform device
  51  *      @num: IRQ number index
  52  */
  53 int platform_get_irq(struct platform_device *dev, unsigned int num)
  54 {
  55         struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
  56
  57         return r ? r->start : 0;
  58 }
  59
  60 /**
  61  *      platform_get_resource_byname - get a resource for a device by name
  62  *      @dev: platform device
  63  *      @type: resource type
  64  *      @name: resource name
  65  */
  66 struct resource *
  67 platform_get_resource_byname(struct platform_device *dev, unsigned int type,
  68                       char *name)
  69 {
  70         int i;
  71
  72         for (i = 0; i < dev->num_resources; i++) {
  73                 struct resource *r = &dev->resource[i];
  74
  75                 if ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
  76                                  IORESOURCE_IRQ|IORESOURCE_DMA)) == type)
  77                         if (!strcmp(r->name, name))
  78                                 return r;
  79         }
  80         return NULL;
  81 }
  82
  83 /**
  84  *      platform_get_irq - get an IRQ for a device
  85  *      @dev: platform device
  86  *      @name: IRQ name
  87  */
  88 int platform_get_irq_byname(struct platform_device *dev, char *name)
  89 {
  90         struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
  91
  92         return r ? r->start : 0;
  93 }
  94
  95 /**
  96  *      platform_add_devices - add a numbers of platform devices
  97  *      @devs: array of platform devices to add
  98  *      @num: number of platform devices in array
  99  */
 100 int platform_add_devices(struct platform_device **devs, int num)
 101 {
 102         int i, ret = 0;
 103
 104         for (i = 0; i < num; i++) {
 105                 ret = platform_device_register(devs[i]);
 106                 if (ret) {
 107                         while (--i >= 0)
 108                                 platform_device_unregister(devs[i]);
 109                         break;
 110                 }
 111         }
 112
 113         return ret;
 114 }
 115
 116 /**
 117  *      platform_device_register - add a platform-level device
 118  *      @pdev:  platform device we're adding
 119  *
 120  */
 121 int platform_device_register(struct platform_device * pdev)
 122 {
 123         int i, ret = 0;
 124
 125         if (!pdev)
 126                 return -EINVAL;
 127
 128         if (!pdev->dev.parent)
 129                 pdev->dev.parent = &platform_bus;
 130
 131         pdev->dev.bus = &platform_bus_type;
 132
 133         if (pdev->id != -1)
 134                 snprintf(pdev->dev.bus_id, BUS_ID_SIZE, "%s.%u", pdev->name, pdev->id);
 135         else
 136                 strlcpy(pdev->dev.bus_id, pdev->name, BUS_ID_SIZE);
 137
 138         for (i = 0; i < pdev->num_resources; i++) {
 139                 struct resource *p, *r = &pdev->resource[i];
 140
 141                 if (r->name == NULL)
 142                         r->name = pdev->dev.bus_id;
 143
 144                 p = r->parent;
 145                 if (!p) {
 146                         if (r->flags & IORESOURCE_MEM)
 147                                 p = &iomem_resource;
 148                         else if (r->flags & IORESOURCE_IO)
 149                                 p = &ioport_resource;
 150                 }
 151
 152                 if (p && request_resource(p, r)) {
 153                         printk(KERN_ERR
 154                                "%s: failed to claim resource %d\n",
 155                                pdev->dev.bus_id, i);
 156                         ret = -EBUSY;
 157                         goto failed;
 158                 }
 159         }
 160
 161         pr_debug("Registering platform device '%s'. Parent at %s\n",
 162                  pdev->dev.bus_id, pdev->dev.parent->bus_id);
 163
 164         ret = device_register(&pdev->dev);
 165         if (ret == 0)
 166                 return ret;
 167
 168  failed:
 169         while (--i >= 0)
 170                 if (pdev->resource[i].flags & (IORESOURCE_MEM|IORESOURCE_IO))
 171                         release_resource(&pdev->resource[i]);
 172         return ret;
 173 }
 174
 175 /**
 176  *      platform_device_unregister - remove a platform-level device
 177  *      @pdev:  platform device we're removing
 178  *
 179  *      Note that this function will also release all memory- and port-based
 180  *      resources owned by the device (@dev->resource).
 181  */
 182 void platform_device_unregister(struct platform_device * pdev)
 183 {
 184         int i;
 185
 186         if (pdev) {
 187                 for (i = 0; i < pdev->num_resources; i++) {
 188                         struct resource *r = &pdev->resource[i];
 189                         if (r->flags & (IORESOURCE_MEM|IORESOURCE_IO))
 190                                 release_resource(r);
 191                 }
 192
 193                 device_unregister(&pdev->dev);
 194         }
 195 }
 196
 197 struct platform_object {
 198         struct platform_device pdev;
 199         struct resource resources[0];
 200 };
 201
 202 static void platform_device_release_simple(struct device *dev)
 203 {
 204         struct platform_device *pdev = to_platform_device(dev);
 205
 206         kfree(container_of(pdev, struct platform_object, pdev));
 207 }
 208
 209 /**
 210  *      platform_device_register_simple
 211  *      @name:  base name of the device we're adding
 212  *      @id:    instance id
 213  *      @res:   set of resources that needs to be allocated for the device
 214  *      @num:   number of resources
 215  *
 216  *      This function creates a simple platform device that requires minimal
 217  *      resource and memory management. Canned release function freeing
 218  *      memory allocated for the device allows drivers using such devices
 219  *      to be unloaded iwithout waiting for the last reference to the device
 220  *      to be dropped.
 221  */
 222 struct platform_device *platform_device_register_simple(char *name, unsigned int id,
 223                                                         struct resource *res, unsigned int num)
 224 {
 225         struct platform_object *pobj;
 226         int retval;
 227
 228         pobj = kzalloc(sizeof(*pobj) + sizeof(struct resource) * num, GFP_KERNEL);
 229         if (!pobj) {
 230                 retval = -ENOMEM;
 231                 goto error;
 232         }
 233
 234         pobj->pdev.name = name;
 235         pobj->pdev.id = id;
 236         pobj->pdev.dev.release = platform_device_release_simple;
 237
 238         if (num) {
 239                 memcpy(pobj->resources, res, sizeof(struct resource) * num);
 240                 pobj->pdev.resource = pobj->resources;
 241                 pobj->pdev.num_resources = num;
 242         }
 243
 244         retval = platform_device_register(&pobj->pdev);
 245         if (retval)
 246                 goto error;
 247
 248         return &pobj->pdev;
 249
 250 error:
 251         kfree(pobj);
 252         return ERR_PTR(retval);
 253 }
 254
 255
 256 /**
 257  *      platform_match - bind platform device to platform driver.
 258  *      @dev:   device.
 259  *      @drv:   driver.
 260  *
 261  *      Platform device IDs are assumed to be encoded like this:
 262  *      "<name><instance>", where <name> is a short description of the
 263  *      type of device, like "pci" or "floppy", and <instance> is the
 264  *      enumerated instance of the device, like '0' or '42'.
 265  *      Driver IDs are simply "<name>".
 266  *      So, extract the <name> from the platform_device structure,
 267  *      and compare it against the name of the driver. Return whether
 268  *      they match or not.
 269  */
 270
 271 static int platform_match(struct device * dev, struct device_driver * drv)
 272 {
 273         struct platform_device *pdev = container_of(dev, struct platform_device, dev);
 274
 275         return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0);
 276 }
 277
 278 static int platform_suspend(struct device * dev, pm_message_t state)
 279 {
 280         int ret = 0;
 281
 282         if (dev->driver && dev->driver->suspend) {
 283                 ret = dev->driver->suspend(dev, state, SUSPEND_DISABLE);
 284                 if (ret == 0)
 285                         ret = dev->driver->suspend(dev, state, SUSPEND_SAVE_STATE);
 286                 if (ret == 0)
 287                         ret = dev->driver->suspend(dev, state, SUSPEND_POWER_DOWN);
 288         }
 289         return ret;
 290 }
 291
 292 static int platform_resume(struct device * dev)
 293 {
 294         int ret = 0;
 295
 296         if (dev->driver && dev->driver->resume) {
 297                 ret = dev->driver->resume(dev, RESUME_POWER_ON);
 298                 if (ret == 0)
 299                         ret = dev->driver->resume(dev, RESUME_RESTORE_STATE);
 300                 if (ret == 0)
 301                         ret = dev->driver->resume(dev, RESUME_ENABLE);
 302         }
 303         return ret;
 304 }
 305
 306 struct bus_type platform_bus_type = {
 307         .name           = "platform",
 308         .match          = platform_match,
 309         .suspend        = platform_suspend,
 310         .resume         = platform_resume,
 311 };
 312
 313 int __init platform_bus_init(void)
 314 {
 315         device_register(&platform_bus);
 316         return bus_register(&platform_bus_type);
 317 }
 318
 319 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
 320 u64 dma_get_required_mask(struct device *dev)
 321 {
 322         u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
 323         u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
 324         u64 mask;
 325
 326         if (!high_totalram) {
 327                 /* convert to mask just covering totalram */
 328                 low_totalram = (1 << (fls(low_totalram) - 1));
 329                 low_totalram += low_totalram - 1;
 330                 mask = low_totalram;
 331         } else {
 332                 high_totalram = (1 << (fls(high_totalram) - 1));
 333                 high_totalram += high_totalram - 1;
 334                 mask = (((u64)high_totalram) << 32) + 0xffffffff;
 335         }
 336         return mask & *dev->dma_mask;
 337 }
 338 EXPORT_SYMBOL_GPL(dma_get_required_mask);
 339 #endif
 340
 341 EXPORT_SYMBOL_GPL(platform_bus);
 342 EXPORT_SYMBOL_GPL(platform_bus_type);
 343 EXPORT_SYMBOL_GPL(platform_add_devices);
 344 EXPORT_SYMBOL_GPL(platform_device_register);
 345 EXPORT_SYMBOL_GPL(platform_device_register_simple);
 346 EXPORT_SYMBOL_GPL(platform_device_unregister);
 347 EXPORT_SYMBOL_GPL(platform_get_irq);
 348 EXPORT_SYMBOL_GPL(platform_get_resource);
 349 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
 350 EXPORT_SYMBOL_GPL(platform_get_resource_byname);