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 /*
 151  * These are the device model conversion veneers; they convert the
 152  * device model structures to our more specific structures.
 153  */
 154 static int amba_probe(struct device *dev)
 155 {
 156         struct amba_device *pcdev = to_amba_device(dev);
 157         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 158         struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
 159         int ret;
 160
 161         do {
 162                 ret = amba_get_enable_pclk(pcdev);
 163                 if (ret)
 164                         break;
 165
 166                 ret = pcdrv->probe(pcdev, id);
 167                 if (ret == 0)
 168                         break;
 169
 170                 amba_put_disable_pclk(pcdev);
 171         } while (0);
 172
 173         return ret;
 174 }
 175
 176 static int amba_remove(struct device *dev)
 177 {
 178         struct amba_device *pcdev = to_amba_device(dev);
 179         struct amba_driver *drv = to_amba_driver(dev->driver);
 180         int ret = drv->remove(pcdev);
 181
 182         amba_put_disable_pclk(pcdev);
 183
 184         return ret;
 185 }
 186
 187 static void amba_shutdown(struct device *dev)
 188 {
 189         struct amba_driver *drv = to_amba_driver(dev->driver);
 190         drv->shutdown(to_amba_device(dev));
 191 }
 192
 193 /**
 194  *      amba_driver_register - register an AMBA device driver
 195  *      @drv: amba device driver structure
 196  *
 197  *      Register an AMBA device driver with the Linux device model
 198  *      core.  If devices pre-exist, the drivers probe function will
 199  *      be called.
 200  */
 201 int amba_driver_register(struct amba_driver *drv)
 202 {
 203         drv->drv.bus = &amba_bustype;
 204
 205 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 206         SETFN(probe);
 207         SETFN(remove);
 208         SETFN(shutdown);
 209
 210         return driver_register(&drv->drv);
 211 }
 212
 213 /**
 214  *      amba_driver_unregister - remove an AMBA device driver
 215  *      @drv: AMBA device driver structure to remove
 216  *
 217  *      Unregister an AMBA device driver from the Linux device
 218  *      model.  The device model will call the drivers remove function
 219  *      for each device the device driver is currently handling.
 220  */
 221 void amba_driver_unregister(struct amba_driver *drv)
 222 {
 223         driver_unregister(&drv->drv);
 224 }
 225
 226
 227 static void amba_device_release(struct device *dev)
 228 {
 229         struct amba_device *d = to_amba_device(dev);
 230
 231         if (d->res.parent)
 232                 release_resource(&d->res);
 233         kfree(d);
 234 }
 235
 236 /**
 237  *      amba_device_register - register an AMBA device
 238  *      @dev: AMBA device to register
 239  *      @parent: parent memory resource
 240  *
 241  *      Setup the AMBA device, reading the cell ID if present.
 242  *      Claim the resource, and register the AMBA device with
 243  *      the Linux device manager.
 244  */
 245 int amba_device_register(struct amba_device *dev, struct resource *parent)
 246 {
 247         u32 size;
 248         void __iomem *tmp;
 249         int i, ret;
 250
 251         device_initialize(&dev->dev);
 252
 253         /*
 254          * Copy from device_add
 255          */
 256         if (dev->dev.init_name) {
 257                 dev_set_name(&dev->dev, "%s", dev->dev.init_name);
 258                 dev->dev.init_name = NULL;
 259         }
 260
 261         dev->dev.release = amba_device_release;
 262         dev->dev.bus = &amba_bustype;
 263         dev->dev.dma_mask = &dev->dma_mask;
 264         dev->res.name = dev_name(&dev->dev);
 265
 266         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 267                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 268
 269         ret = request_resource(parent, &dev->res);
 270         if (ret)
 271                 goto err_out;
 272
 273         /*
 274          * Dynamically calculate the size of the resource
 275          * and use this for iomap
 276          */
 277         size = resource_size(&dev->res);
 278         tmp = ioremap(dev->res.start, size);
 279         if (!tmp) {
 280                 ret = -ENOMEM;
 281                 goto err_release;
 282         }
 283
 284         ret = amba_get_enable_pclk(dev);
 285         if (ret == 0) {
 286                 u32 pid, cid;
 287
 288                 /*
 289                  * Read pid and cid based on size of resource
 290                  * they are located at end of region
 291                  */
 292                 for (pid = 0, i = 0; i < 4; i++)
 293                         pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
 294                                 (i * 8);
 295                 for (cid = 0, i = 0; i < 4; i++)
 296                         cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
 297                                 (i * 8);
 298
 299                 amba_put_disable_pclk(dev);
 300
 301                 if (cid == AMBA_CID)
 302                         dev->periphid = pid;
 303
 304                 if (!dev->periphid)
 305                         ret = -ENODEV;
 306         }
 307
 308         iounmap(tmp);
 309
 310         if (ret)
 311                 goto err_release;
 312
 313         ret = device_add(&dev->dev);
 314         if (ret)
 315                 goto err_release;
 316
 317         if (dev->irq[0] != NO_IRQ)
 318                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 319         if (ret == 0 && dev->irq[1] != NO_IRQ)
 320                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 321         if (ret == 0)
 322                 return ret;
 323
 324         device_unregister(&dev->dev);
 325
 326  err_release:
 327         release_resource(&dev->res);
 328  err_out:
 329         return ret;
 330 }
 331
 332 /**
 333  *      amba_device_unregister - unregister an AMBA device
 334  *      @dev: AMBA device to remove
 335  *
 336  *      Remove the specified AMBA device from the Linux device
 337  *      manager.  All files associated with this object will be
 338  *      destroyed, and device drivers notified that the device has
 339  *      been removed.  The AMBA device's resources including
 340  *      the amba_device structure will be freed once all
 341  *      references to it have been dropped.
 342  */
 343 void amba_device_unregister(struct amba_device *dev)
 344 {
 345         device_unregister(&dev->dev);
 346 }
 347
 348
 349 struct find_data {
 350         struct amba_device *dev;
 351         struct device *parent;
 352         const char *busid;
 353         unsigned int id;
 354         unsigned int mask;
 355 };
 356
 357 static int amba_find_match(struct device *dev, void *data)
 358 {
 359         struct find_data *d = data;
 360         struct amba_device *pcdev = to_amba_device(dev);
 361         int r;
 362
 363         r = (pcdev->periphid & d->mask) == d->id;
 364         if (d->parent)
 365                 r &= d->parent == dev->parent;
 366         if (d->busid)
 367                 r &= strcmp(dev_name(dev), d->busid) == 0;
 368
 369         if (r) {
 370                 get_device(dev);
 371                 d->dev = pcdev;
 372         }
 373
 374         return r;
 375 }
 376
 377 /**
 378  *      amba_find_device - locate an AMBA device given a bus id
 379  *      @busid: bus id for device (or NULL)
 380  *      @parent: parent device (or NULL)
 381  *      @id: peripheral ID (or 0)
 382  *      @mask: peripheral ID mask (or 0)
 383  *
 384  *      Return the AMBA device corresponding to the supplied parameters.
 385  *      If no device matches, returns NULL.
 386  *
 387  *      NOTE: When a valid device is found, its refcount is
 388  *      incremented, and must be decremented before the returned
 389  *      reference.
 390  */
 391 struct amba_device *
 392 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 393                  unsigned int mask)
 394 {
 395         struct find_data data;
 396
 397         data.dev = NULL;
 398         data.parent = parent;
 399         data.busid = busid;
 400         data.id = id;
 401         data.mask = mask;
 402
 403         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 404
 405         return data.dev;
 406 }
 407
 408 /**
 409  *      amba_request_regions - request all mem regions associated with device
 410  *      @dev: amba_device structure for device
 411  *      @name: name, or NULL to use driver name
 412  */
 413 int amba_request_regions(struct amba_device *dev, const char *name)
 414 {
 415         int ret = 0;
 416         u32 size;
 417
 418         if (!name)
 419                 name = dev->dev.driver->name;
 420
 421         size = resource_size(&dev->res);
 422
 423         if (!request_mem_region(dev->res.start, size, name))
 424                 ret = -EBUSY;
 425
 426         return ret;
 427 }
 428
 429 /**
 430  *      amba_release_regions - release mem regions assoicated with device
 431  *      @dev: amba_device structure for device
 432  *
 433  *      Release regions claimed by a successful call to amba_request_regions.
 434  */
 435 void amba_release_regions(struct amba_device *dev)
 436 {
 437         u32 size;
 438
 439         size = resource_size(&dev->res);
 440         release_mem_region(dev->res.start, size);
 441 }
 442
 443 EXPORT_SYMBOL(amba_driver_register);
 444 EXPORT_SYMBOL(amba_driver_unregister);
 445 EXPORT_SYMBOL(amba_device_register);
 446 EXPORT_SYMBOL(amba_device_unregister);
 447 EXPORT_SYMBOL(amba_find_device);
 448 EXPORT_SYMBOL(amba_request_regions);
 449 EXPORT_SYMBOL(amba_release_regions);