drivers/amba/bus.c

   1 /*
   2  *  linux/arch/arm/common/amba.c
   3  *
   4  *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/device.h>
  13 #include <linux/string.h>
  14 #include <linux/slab.h>
  15 #include <linux/io.h>
  16 #include <linux/amba/bus.h>
  17
  18 #include <asm/irq.h>
  19 #include <asm/sizes.h>
  20
  21 #define to_amba_device(d)       container_of(d, struct amba_device, dev)
  22 #define to_amba_driver(d)       container_of(d, struct amba_driver, drv)
  23
  24 static struct amba_id *
  25 amba_lookup(struct amba_id *table, struct amba_device *dev)
  26 {
  27         int ret = 0;
  28
  29         while (table->mask) {
  30                 ret = (dev->periphid & table->mask) == table->id;
  31                 if (ret)
  32                         break;
  33                 table++;
  34         }
  35
  36         return ret ? table : NULL;
  37 }
  38
  39 static int amba_match(struct device *dev, struct device_driver *drv)
  40 {
  41         struct amba_device *pcdev = to_amba_device(dev);
  42         struct amba_driver *pcdrv = to_amba_driver(drv);
  43
  44         return amba_lookup(pcdrv->id_table, pcdev) != NULL;
  45 }
  46
  47 #ifdef CONFIG_HOTPLUG
  48 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
  49 {
  50         struct amba_device *pcdev = to_amba_device(dev);
  51         int retval = 0;
  52
  53         retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
  54         return retval;
  55 }
  56 #else
  57 #define amba_uevent NULL
  58 #endif
  59
  60 static int amba_suspend(struct device *dev, pm_message_t state)
  61 {
  62         struct amba_driver *drv = to_amba_driver(dev->driver);
  63         int ret = 0;
  64
  65         if (dev->driver && drv->suspend)
  66                 ret = drv->suspend(to_amba_device(dev), state);
  67         return ret;
  68 }
  69
  70 static int amba_resume(struct device *dev)
  71 {
  72         struct amba_driver *drv = to_amba_driver(dev->driver);
  73         int ret = 0;
  74
  75         if (dev->driver && drv->resume)
  76                 ret = drv->resume(to_amba_device(dev));
  77         return ret;
  78 }
  79
  80 #define amba_attr_func(name,fmt,arg...)                                 \
  81 static ssize_t name##_show(struct device *_dev,                         \
  82                            struct device_attribute *attr, char *buf)    \
  83 {                                                                       \
  84         struct amba_device *dev = to_amba_device(_dev);                 \
  85         return sprintf(buf, fmt, arg);                                  \
  86 }
  87
  88 #define amba_attr(name,fmt,arg...)      \
  89 amba_attr_func(name,fmt,arg)            \
  90 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  91
  92 amba_attr_func(id, "%08x\n", dev->periphid);
  93 amba_attr(irq0, "%u\n", dev->irq[0]);
  94 amba_attr(irq1, "%u\n", dev->irq[1]);
  95 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  96          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  97          dev->res.flags);
  98
  99 static struct device_attribute amba_dev_attrs[] = {
 100         __ATTR_RO(id),
 101         __ATTR_RO(resource),
 102         __ATTR_NULL,
 103 };
 104
 105 /*
 106  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 107  * so we call the bus "amba".
 108  */
 109 static struct bus_type amba_bustype = {
 110         .name           = "amba",
 111         .dev_attrs      = amba_dev_attrs,
 112         .match          = amba_match,
 113         .uevent         = amba_uevent,
 114         .suspend        = amba_suspend,
 115         .resume         = amba_resume,
 116 };
 117
 118 static int __init amba_init(void)
 119 {
 120         return bus_register(&amba_bustype);
 121 }
 122
 123 postcore_initcall(amba_init);
 124
 125 static int amba_get_enable_pclk(struct amba_device *pcdev)
 126 {
 127         struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
 128         int ret;
 129
 130         pcdev->pclk = pclk;
 131
 132         if (IS_ERR(pclk))
 133                 return PTR_ERR(pclk);
 134
 135         ret = clk_enable(pclk);
 136         if (ret)
 137                 clk_put(pclk);
 138
 139         return ret;
 140 }
 141
 142 static void amba_put_disable_pclk(struct amba_device *pcdev)
 143 {
 144         struct clk *pclk = pcdev->pclk;
 145
 146         clk_disable(pclk);
 147         clk_put(pclk);
 148 }
 149
 150 static int amba_get_enable_vcore(struct amba_device *pcdev)
 151 {
 152         struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
 153         int ret;
 154
 155         pcdev->vcore = vcore;
 156
 157         if (IS_ERR(vcore)) {
 158                 /* It is OK not to supply a vcore regulator */
 159                 if (PTR_ERR(vcore) == -ENODEV)
 160                         return 0;
 161                 return PTR_ERR(vcore);
 162         }
 163
 164         ret = regulator_enable(vcore);
 165         if (ret) {
 166                 regulator_put(vcore);
 167                 pcdev->vcore = ERR_PTR(-ENODEV);
 168         }
 169
 170         return ret;
 171 }
 172
 173 static void amba_put_disable_vcore(struct amba_device *pcdev)
 174 {
 175         struct regulator *vcore = pcdev->vcore;
 176
 177         if (!IS_ERR(vcore)) {
 178                 regulator_disable(vcore);
 179                 regulator_put(vcore);
 180         }
 181 }
 182
 183 /*
 184  * These are the device model conversion veneers; they convert the
 185  * device model structures to our more specific structures.
 186  */
 187 static int amba_probe(struct device *dev)
 188 {
 189         struct amba_device *pcdev = to_amba_device(dev);
 190         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 191         struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
 192         int ret;
 193
 194         do {
 195                 ret = amba_get_enable_vcore(pcdev);
 196                 if (ret)
 197                         break;
 198
 199                 ret = amba_get_enable_pclk(pcdev);
 200                 if (ret)
 201                         break;
 202
 203                 ret = pcdrv->probe(pcdev, id);
 204                 if (ret == 0)
 205                         break;
 206
 207                 amba_put_disable_pclk(pcdev);
 208                 amba_put_disable_vcore(pcdev);
 209         } while (0);
 210
 211         return ret;
 212 }
 213
 214 static int amba_remove(struct device *dev)
 215 {
 216         struct amba_device *pcdev = to_amba_device(dev);
 217         struct amba_driver *drv = to_amba_driver(dev->driver);
 218         int ret = drv->remove(pcdev);
 219
 220         amba_put_disable_pclk(pcdev);
 221         amba_put_disable_vcore(pcdev);
 222
 223         return ret;
 224 }
 225
 226 static void amba_shutdown(struct device *dev)
 227 {
 228         struct amba_driver *drv = to_amba_driver(dev->driver);
 229         drv->shutdown(to_amba_device(dev));
 230 }
 231
 232 /**
 233  *      amba_driver_register - register an AMBA device driver
 234  *      @drv: amba device driver structure
 235  *
 236  *      Register an AMBA device driver with the Linux device model
 237  *      core.  If devices pre-exist, the drivers probe function will
 238  *      be called.
 239  */
 240 int amba_driver_register(struct amba_driver *drv)
 241 {
 242         drv->drv.bus = &amba_bustype;
 243
 244 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 245         SETFN(probe);
 246         SETFN(remove);
 247         SETFN(shutdown);
 248
 249         return driver_register(&drv->drv);
 250 }
 251
 252 /**
 253  *      amba_driver_unregister - remove an AMBA device driver
 254  *      @drv: AMBA device driver structure to remove
 255  *
 256  *      Unregister an AMBA device driver from the Linux device
 257  *      model.  The device model will call the drivers remove function
 258  *      for each device the device driver is currently handling.
 259  */
 260 void amba_driver_unregister(struct amba_driver *drv)
 261 {
 262         driver_unregister(&drv->drv);
 263 }
 264
 265
 266 static void amba_device_release(struct device *dev)
 267 {
 268         struct amba_device *d = to_amba_device(dev);
 269
 270         if (d->res.parent)
 271                 release_resource(&d->res);
 272         kfree(d);
 273 }
 274
 275 /**
 276  *      amba_device_register - register an AMBA device
 277  *      @dev: AMBA device to register
 278  *      @parent: parent memory resource
 279  *
 280  *      Setup the AMBA device, reading the cell ID if present.
 281  *      Claim the resource, and register the AMBA device with
 282  *      the Linux device manager.
 283  */
 284 int amba_device_register(struct amba_device *dev, struct resource *parent)
 285 {
 286         u32 size;
 287         void __iomem *tmp;
 288         int i, ret;
 289
 290         device_initialize(&dev->dev);
 291
 292         /*
 293          * Copy from device_add
 294          */
 295         if (dev->dev.init_name) {
 296                 dev_set_name(&dev->dev, "%s", dev->dev.init_name);
 297                 dev->dev.init_name = NULL;
 298         }
 299
 300         dev->dev.release = amba_device_release;
 301         dev->dev.bus = &amba_bustype;
 302         dev->dev.dma_mask = &dev->dma_mask;
 303         dev->res.name = dev_name(&dev->dev);
 304
 305         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 306                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 307
 308         ret = request_resource(parent, &dev->res);
 309         if (ret)
 310                 goto err_out;
 311
 312         /*
 313          * Dynamically calculate the size of the resource
 314          * and use this for iomap
 315          */
 316         size = resource_size(&dev->res);
 317         tmp = ioremap(dev->res.start, size);
 318         if (!tmp) {
 319                 ret = -ENOMEM;
 320                 goto err_release;
 321         }
 322
 323         ret = amba_get_enable_pclk(dev);
 324         if (ret == 0) {
 325                 u32 pid, cid;
 326
 327                 /*
 328                  * Read pid and cid based on size of resource
 329                  * they are located at end of region
 330                  */
 331                 for (pid = 0, i = 0; i < 4; i++)
 332                         pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
 333                                 (i * 8);
 334                 for (cid = 0, i = 0; i < 4; i++)
 335                         cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
 336                                 (i * 8);
 337
 338                 amba_put_disable_pclk(dev);
 339
 340                 if (cid == AMBA_CID)
 341                         dev->periphid = pid;
 342
 343                 if (!dev->periphid)
 344                         ret = -ENODEV;
 345         }
 346
 347         iounmap(tmp);
 348
 349         if (ret)
 350                 goto err_release;
 351
 352         ret = device_add(&dev->dev);
 353         if (ret)
 354                 goto err_release;
 355
 356         if (dev->irq[0] != NO_IRQ)
 357                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 358         if (ret == 0 && dev->irq[1] != NO_IRQ)
 359                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 360         if (ret == 0)
 361                 return ret;
 362
 363         device_unregister(&dev->dev);
 364
 365  err_release:
 366         release_resource(&dev->res);
 367  err_out:
 368         return ret;
 369 }
 370
 371 /**
 372  *      amba_device_unregister - unregister an AMBA device
 373  *      @dev: AMBA device to remove
 374  *
 375  *      Remove the specified AMBA device from the Linux device
 376  *      manager.  All files associated with this object will be
 377  *      destroyed, and device drivers notified that the device has
 378  *      been removed.  The AMBA device's resources including
 379  *      the amba_device structure will be freed once all
 380  *      references to it have been dropped.
 381  */
 382 void amba_device_unregister(struct amba_device *dev)
 383 {
 384         device_unregister(&dev->dev);
 385 }
 386
 387
 388 struct find_data {
 389         struct amba_device *dev;
 390         struct device *parent;
 391         const char *busid;
 392         unsigned int id;
 393         unsigned int mask;
 394 };
 395
 396 static int amba_find_match(struct device *dev, void *data)
 397 {
 398         struct find_data *d = data;
 399         struct amba_device *pcdev = to_amba_device(dev);
 400         int r;
 401
 402         r = (pcdev->periphid & d->mask) == d->id;
 403         if (d->parent)
 404                 r &= d->parent == dev->parent;
 405         if (d->busid)
 406                 r &= strcmp(dev_name(dev), d->busid) == 0;
 407
 408         if (r) {
 409                 get_device(dev);
 410                 d->dev = pcdev;
 411         }
 412
 413         return r;
 414 }
 415
 416 /**
 417  *      amba_find_device - locate an AMBA device given a bus id
 418  *      @busid: bus id for device (or NULL)
 419  *      @parent: parent device (or NULL)
 420  *      @id: peripheral ID (or 0)
 421  *      @mask: peripheral ID mask (or 0)
 422  *
 423  *      Return the AMBA device corresponding to the supplied parameters.
 424  *      If no device matches, returns NULL.
 425  *
 426  *      NOTE: When a valid device is found, its refcount is
 427  *      incremented, and must be decremented before the returned
 428  *      reference.
 429  */
 430 struct amba_device *
 431 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 432                  unsigned int mask)
 433 {
 434         struct find_data data;
 435
 436         data.dev = NULL;
 437         data.parent = parent;
 438         data.busid = busid;
 439         data.id = id;
 440         data.mask = mask;
 441
 442         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 443
 444         return data.dev;
 445 }
 446
 447 /**
 448  *      amba_request_regions - request all mem regions associated with device
 449  *      @dev: amba_device structure for device
 450  *      @name: name, or NULL to use driver name
 451  */
 452 int amba_request_regions(struct amba_device *dev, const char *name)
 453 {
 454         int ret = 0;
 455         u32 size;
 456
 457         if (!name)
 458                 name = dev->dev.driver->name;
 459
 460         size = resource_size(&dev->res);
 461
 462         if (!request_mem_region(dev->res.start, size, name))
 463                 ret = -EBUSY;
 464
 465         return ret;
 466 }
 467
 468 /**
 469  *      amba_release_regions - release mem regions assoicated with device
 470  *      @dev: amba_device structure for device
 471  *
 472  *      Release regions claimed by a successful call to amba_request_regions.
 473  */
 474 void amba_release_regions(struct amba_device *dev)
 475 {
 476         u32 size;
 477
 478         size = resource_size(&dev->res);
 479         release_mem_region(dev->res.start, size);
 480 }
 481
 482 EXPORT_SYMBOL(amba_driver_register);
 483 EXPORT_SYMBOL(amba_driver_unregister);
 484 EXPORT_SYMBOL(amba_device_register);
 485 EXPORT_SYMBOL(amba_device_unregister);
 486 EXPORT_SYMBOL(amba_find_device);
 487 EXPORT_SYMBOL(amba_request_regions);
 488 EXPORT_SYMBOL(amba_release_regions);