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/amba/bus.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/sizes.h>
  19
  20 #define to_amba_device(d)       container_of(d, struct amba_device, dev)
  21 #define to_amba_driver(d)       container_of(d, struct amba_driver, drv)
  22
  23 static struct amba_id *
  24 amba_lookup(struct amba_id *table, struct amba_device *dev)
  25 {
  26         int ret = 0;
  27
  28         while (table->mask) {
  29                 ret = (dev->periphid & table->mask) == table->id;
  30                 if (ret)
  31                         break;
  32                 table++;
  33         }
  34
  35         return ret ? table : NULL;
  36 }
  37
  38 static int amba_match(struct device *dev, struct device_driver *drv)
  39 {
  40         struct amba_device *pcdev = to_amba_device(dev);
  41         struct amba_driver *pcdrv = to_amba_driver(drv);
  42
  43         return amba_lookup(pcdrv->id_table, pcdev) != NULL;
  44 }
  45
  46 #ifdef CONFIG_HOTPLUG
  47 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
  48 {
  49         struct amba_device *pcdev = to_amba_device(dev);
  50         int retval = 0;
  51
  52         retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
  53         return retval;
  54 }
  55 #else
  56 #define amba_uevent NULL
  57 #endif
  58
  59 static int amba_suspend(struct device *dev, pm_message_t state)
  60 {
  61         struct amba_driver *drv = to_amba_driver(dev->driver);
  62         int ret = 0;
  63
  64         if (dev->driver && drv->suspend)
  65                 ret = drv->suspend(to_amba_device(dev), state);
  66         return ret;
  67 }
  68
  69 static int amba_resume(struct device *dev)
  70 {
  71         struct amba_driver *drv = to_amba_driver(dev->driver);
  72         int ret = 0;
  73
  74         if (dev->driver && drv->resume)
  75                 ret = drv->resume(to_amba_device(dev));
  76         return ret;
  77 }
  78
  79 #define amba_attr_func(name,fmt,arg...)                                 \
  80 static ssize_t name##_show(struct device *_dev,                         \
  81                            struct device_attribute *attr, char *buf)    \
  82 {                                                                       \
  83         struct amba_device *dev = to_amba_device(_dev);                 \
  84         return sprintf(buf, fmt, arg);                                  \
  85 }
  86
  87 #define amba_attr(name,fmt,arg...)      \
  88 amba_attr_func(name,fmt,arg)            \
  89 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  90
  91 amba_attr_func(id, "%08x\n", dev->periphid);
  92 amba_attr(irq0, "%u\n", dev->irq[0]);
  93 amba_attr(irq1, "%u\n", dev->irq[1]);
  94 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  95          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  96          dev->res.flags);
  97
  98 static struct device_attribute amba_dev_attrs[] = {
  99         __ATTR_RO(id),
 100         __ATTR_RO(resource),
 101         __ATTR_NULL,
 102 };
 103
 104 /*
 105  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 106  * so we call the bus "amba".
 107  */
 108 static struct bus_type amba_bustype = {
 109         .name           = "amba",
 110         .dev_attrs      = amba_dev_attrs,
 111         .match          = amba_match,
 112         .uevent         = amba_uevent,
 113         .suspend        = amba_suspend,
 114         .resume         = amba_resume,
 115 };
 116
 117 static int __init amba_init(void)
 118 {
 119         return bus_register(&amba_bustype);
 120 }
 121
 122 postcore_initcall(amba_init);
 123
 124 /*
 125  * These are the device model conversion veneers; they convert the
 126  * device model structures to our more specific structures.
 127  */
 128 static int amba_probe(struct device *dev)
 129 {
 130         struct amba_device *pcdev = to_amba_device(dev);
 131         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 132         struct amba_id *id;
 133
 134         id = amba_lookup(pcdrv->id_table, pcdev);
 135
 136         return pcdrv->probe(pcdev, id);
 137 }
 138
 139 static int amba_remove(struct device *dev)
 140 {
 141         struct amba_driver *drv = to_amba_driver(dev->driver);
 142         return drv->remove(to_amba_device(dev));
 143 }
 144
 145 static void amba_shutdown(struct device *dev)
 146 {
 147         struct amba_driver *drv = to_amba_driver(dev->driver);
 148         drv->shutdown(to_amba_device(dev));
 149 }
 150
 151 /**
 152  *      amba_driver_register - register an AMBA device driver
 153  *      @drv: amba device driver structure
 154  *
 155  *      Register an AMBA device driver with the Linux device model
 156  *      core.  If devices pre-exist, the drivers probe function will
 157  *      be called.
 158  */
 159 int amba_driver_register(struct amba_driver *drv)
 160 {
 161         drv->drv.bus = &amba_bustype;
 162
 163 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 164         SETFN(probe);
 165         SETFN(remove);
 166         SETFN(shutdown);
 167
 168         return driver_register(&drv->drv);
 169 }
 170
 171 /**
 172  *      amba_driver_unregister - remove an AMBA device driver
 173  *      @drv: AMBA device driver structure to remove
 174  *
 175  *      Unregister an AMBA device driver from the Linux device
 176  *      model.  The device model will call the drivers remove function
 177  *      for each device the device driver is currently handling.
 178  */
 179 void amba_driver_unregister(struct amba_driver *drv)
 180 {
 181         driver_unregister(&drv->drv);
 182 }
 183
 184
 185 static void amba_device_release(struct device *dev)
 186 {
 187         struct amba_device *d = to_amba_device(dev);
 188
 189         if (d->res.parent)
 190                 release_resource(&d->res);
 191         kfree(d);
 192 }
 193
 194 /**
 195  *      amba_device_register - register an AMBA device
 196  *      @dev: AMBA device to register
 197  *      @parent: parent memory resource
 198  *
 199  *      Setup the AMBA device, reading the cell ID if present.
 200  *      Claim the resource, and register the AMBA device with
 201  *      the Linux device manager.
 202  */
 203 int amba_device_register(struct amba_device *dev, struct resource *parent)
 204 {
 205         u32 pid, cid;
 206         void __iomem *tmp;
 207         int i, ret;
 208
 209         dev->dev.release = amba_device_release;
 210         dev->dev.bus = &amba_bustype;
 211         dev->dev.dma_mask = &dev->dma_mask;
 212         dev->res.name = dev->dev.bus_id;
 213
 214         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 215                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 216
 217         ret = request_resource(parent, &dev->res);
 218         if (ret)
 219                 goto err_out;
 220
 221         tmp = ioremap(dev->res.start, SZ_4K);
 222         if (!tmp) {
 223                 ret = -ENOMEM;
 224                 goto err_release;
 225         }
 226
 227         for (pid = 0, i = 0; i < 4; i++)
 228                 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
 229         for (cid = 0, i = 0; i < 4; i++)
 230                 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
 231
 232         iounmap(tmp);
 233
 234         if (cid == 0xb105f00d)
 235                 dev->periphid = pid;
 236
 237         if (!dev->periphid) {
 238                 ret = -ENODEV;
 239                 goto err_release;
 240         }
 241
 242         ret = device_register(&dev->dev);
 243         if (ret)
 244                 goto err_release;
 245
 246         if (dev->irq[0] != NO_IRQ)
 247                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 248         if (ret == 0 && dev->irq[1] != NO_IRQ)
 249                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 250         if (ret == 0)
 251                 return ret;
 252
 253         device_unregister(&dev->dev);
 254
 255  err_release:
 256         release_resource(&dev->res);
 257  err_out:
 258         return ret;
 259 }
 260
 261 /**
 262  *      amba_device_unregister - unregister an AMBA device
 263  *      @dev: AMBA device to remove
 264  *
 265  *      Remove the specified AMBA device from the Linux device
 266  *      manager.  All files associated with this object will be
 267  *      destroyed, and device drivers notified that the device has
 268  *      been removed.  The AMBA device's resources including
 269  *      the amba_device structure will be freed once all
 270  *      references to it have been dropped.
 271  */
 272 void amba_device_unregister(struct amba_device *dev)
 273 {
 274         device_unregister(&dev->dev);
 275 }
 276
 277
 278 struct find_data {
 279         struct amba_device *dev;
 280         struct device *parent;
 281         const char *busid;
 282         unsigned int id;
 283         unsigned int mask;
 284 };
 285
 286 static int amba_find_match(struct device *dev, void *data)
 287 {
 288         struct find_data *d = data;
 289         struct amba_device *pcdev = to_amba_device(dev);
 290         int r;
 291
 292         r = (pcdev->periphid & d->mask) == d->id;
 293         if (d->parent)
 294                 r &= d->parent == dev->parent;
 295         if (d->busid)
 296                 r &= strcmp(dev->bus_id, d->busid) == 0;
 297
 298         if (r) {
 299                 get_device(dev);
 300                 d->dev = pcdev;
 301         }
 302
 303         return r;
 304 }
 305
 306 /**
 307  *      amba_find_device - locate an AMBA device given a bus id
 308  *      @busid: bus id for device (or NULL)
 309  *      @parent: parent device (or NULL)
 310  *      @id: peripheral ID (or 0)
 311  *      @mask: peripheral ID mask (or 0)
 312  *
 313  *      Return the AMBA device corresponding to the supplied parameters.
 314  *      If no device matches, returns NULL.
 315  *
 316  *      NOTE: When a valid device is found, its refcount is
 317  *      incremented, and must be decremented before the returned
 318  *      reference.
 319  */
 320 struct amba_device *
 321 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 322                  unsigned int mask)
 323 {
 324         struct find_data data;
 325
 326         data.dev = NULL;
 327         data.parent = parent;
 328         data.busid = busid;
 329         data.id = id;
 330         data.mask = mask;
 331
 332         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 333
 334         return data.dev;
 335 }
 336
 337 /**
 338  *      amba_request_regions - request all mem regions associated with device
 339  *      @dev: amba_device structure for device
 340  *      @name: name, or NULL to use driver name
 341  */
 342 int amba_request_regions(struct amba_device *dev, const char *name)
 343 {
 344         int ret = 0;
 345
 346         if (!name)
 347                 name = dev->dev.driver->name;
 348
 349         if (!request_mem_region(dev->res.start, SZ_4K, name))
 350                 ret = -EBUSY;
 351
 352         return ret;
 353 }
 354
 355 /**
 356  *      amba_release_regions - release mem regions assoicated with device
 357  *      @dev: amba_device structure for device
 358  *
 359  *      Release regions claimed by a successful call to amba_request_regions.
 360  */
 361 void amba_release_regions(struct amba_device *dev)
 362 {
 363         release_mem_region(dev->res.start, SZ_4K);
 364 }
 365
 366 EXPORT_SYMBOL(amba_driver_register);
 367 EXPORT_SYMBOL(amba_driver_unregister);
 368 EXPORT_SYMBOL(amba_device_register);
 369 EXPORT_SYMBOL(amba_device_unregister);
 370 EXPORT_SYMBOL(amba_find_device);
 371 EXPORT_SYMBOL(amba_request_regions);
 372 EXPORT_SYMBOL(amba_release_regions);