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, char **envp, int nr_env, char *buf, int bufsz)
  48 {
  49         struct amba_device *pcdev = to_amba_device(dev);
  50
  51         if (nr_env < 2)
  52                 return -ENOMEM;
  53
  54         snprintf(buf, bufsz, "AMBA_ID=%08x", pcdev->periphid);
  55         *envp++ = buf;
  56         *envp++ = NULL;
  57         return 0;
  58 }
  59 #else
  60 #define amba_uevent NULL
  61 #endif
  62
  63 static int amba_suspend(struct device *dev, pm_message_t state)
  64 {
  65         struct amba_driver *drv = to_amba_driver(dev->driver);
  66         int ret = 0;
  67
  68         if (dev->driver && drv->suspend)
  69                 ret = drv->suspend(to_amba_device(dev), state);
  70         return ret;
  71 }
  72
  73 static int amba_resume(struct device *dev)
  74 {
  75         struct amba_driver *drv = to_amba_driver(dev->driver);
  76         int ret = 0;
  77
  78         if (dev->driver && drv->resume)
  79                 ret = drv->resume(to_amba_device(dev));
  80         return ret;
  81 }
  82
  83 /*
  84  * Primecells are part of the Advanced Microcontroller Bus Architecture,
  85  * so we call the bus "amba".
  86  */
  87 static struct bus_type amba_bustype = {
  88         .name           = "amba",
  89         .match          = amba_match,
  90         .uevent         = amba_uevent,
  91         .suspend        = amba_suspend,
  92         .resume         = amba_resume,
  93 };
  94
  95 static int __init amba_init(void)
  96 {
  97         return bus_register(&amba_bustype);
  98 }
  99
 100 postcore_initcall(amba_init);
 101
 102 /*
 103  * These are the device model conversion veneers; they convert the
 104  * device model structures to our more specific structures.
 105  */
 106 static int amba_probe(struct device *dev)
 107 {
 108         struct amba_device *pcdev = to_amba_device(dev);
 109         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 110         struct amba_id *id;
 111
 112         id = amba_lookup(pcdrv->id_table, pcdev);
 113
 114         return pcdrv->probe(pcdev, id);
 115 }
 116
 117 static int amba_remove(struct device *dev)
 118 {
 119         struct amba_driver *drv = to_amba_driver(dev->driver);
 120         return drv->remove(to_amba_device(dev));
 121 }
 122
 123 static void amba_shutdown(struct device *dev)
 124 {
 125         struct amba_driver *drv = to_amba_driver(dev->driver);
 126         drv->shutdown(to_amba_device(dev));
 127 }
 128
 129 /**
 130  *      amba_driver_register - register an AMBA device driver
 131  *      @drv: amba device driver structure
 132  *
 133  *      Register an AMBA device driver with the Linux device model
 134  *      core.  If devices pre-exist, the drivers probe function will
 135  *      be called.
 136  */
 137 int amba_driver_register(struct amba_driver *drv)
 138 {
 139         drv->drv.bus = &amba_bustype;
 140
 141 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 142         SETFN(probe);
 143         SETFN(remove);
 144         SETFN(shutdown);
 145
 146         return driver_register(&drv->drv);
 147 }
 148
 149 /**
 150  *      amba_driver_unregister - remove an AMBA device driver
 151  *      @drv: AMBA device driver structure to remove
 152  *
 153  *      Unregister an AMBA device driver from the Linux device
 154  *      model.  The device model will call the drivers remove function
 155  *      for each device the device driver is currently handling.
 156  */
 157 void amba_driver_unregister(struct amba_driver *drv)
 158 {
 159         driver_unregister(&drv->drv);
 160 }
 161
 162
 163 static void amba_device_release(struct device *dev)
 164 {
 165         struct amba_device *d = to_amba_device(dev);
 166
 167         if (d->res.parent)
 168                 release_resource(&d->res);
 169         kfree(d);
 170 }
 171
 172 #define amba_attr(name,fmt,arg...)                              \
 173 static ssize_t show_##name(struct device *_dev, struct device_attribute *attr, char *buf)       \
 174 {                                                               \
 175         struct amba_device *dev = to_amba_device(_dev);         \
 176         return sprintf(buf, fmt, arg);                          \
 177 }                                                               \
 178 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 179
 180 amba_attr(id, "%08x\n", dev->periphid);
 181 amba_attr(irq0, "%u\n", dev->irq[0]);
 182 amba_attr(irq1, "%u\n", dev->irq[1]);
 183 amba_attr(resource, "\t%08lx\t%08lx\t%08lx\n",
 184           dev->res.start, dev->res.end, dev->res.flags);
 185
 186 /**
 187  *      amba_device_register - register an AMBA device
 188  *      @dev: AMBA device to register
 189  *      @parent: parent memory resource
 190  *
 191  *      Setup the AMBA device, reading the cell ID if present.
 192  *      Claim the resource, and register the AMBA device with
 193  *      the Linux device manager.
 194  */
 195 int amba_device_register(struct amba_device *dev, struct resource *parent)
 196 {
 197         u32 pid, cid;
 198         void __iomem *tmp;
 199         int i, ret;
 200
 201         dev->dev.release = amba_device_release;
 202         dev->dev.bus = &amba_bustype;
 203         dev->dev.dma_mask = &dev->dma_mask;
 204         dev->res.name = dev->dev.bus_id;
 205
 206         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 207                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 208
 209         ret = request_resource(parent, &dev->res);
 210         if (ret == 0) {
 211                 tmp = ioremap(dev->res.start, SZ_4K);
 212                 if (!tmp) {
 213                         ret = -ENOMEM;
 214                         goto out;
 215                 }
 216
 217                 for (pid = 0, i = 0; i < 4; i++)
 218                         pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
 219                 for (cid = 0, i = 0; i < 4; i++)
 220                         cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
 221
 222                 iounmap(tmp);
 223
 224                 if (cid == 0xb105f00d)
 225                         dev->periphid = pid;
 226
 227                 if (dev->periphid)
 228                         ret = device_register(&dev->dev);
 229                 else
 230                         ret = -ENODEV;
 231
 232                 if (ret == 0) {
 233                         device_create_file(&dev->dev, &dev_attr_id);
 234                         if (dev->irq[0] != NO_IRQ)
 235                                 device_create_file(&dev->dev, &dev_attr_irq0);
 236                         if (dev->irq[1] != NO_IRQ)
 237                                 device_create_file(&dev->dev, &dev_attr_irq1);
 238                         device_create_file(&dev->dev, &dev_attr_resource);
 239                 } else {
 240  out:
 241                         release_resource(&dev->res);
 242                 }
 243         }
 244         return ret;
 245 }
 246
 247 /**
 248  *      amba_device_unregister - unregister an AMBA device
 249  *      @dev: AMBA device to remove
 250  *
 251  *      Remove the specified AMBA device from the Linux device
 252  *      manager.  All files associated with this object will be
 253  *      destroyed, and device drivers notified that the device has
 254  *      been removed.  The AMBA device's resources including
 255  *      the amba_device structure will be freed once all
 256  *      references to it have been dropped.
 257  */
 258 void amba_device_unregister(struct amba_device *dev)
 259 {
 260         device_unregister(&dev->dev);
 261 }
 262
 263
 264 struct find_data {
 265         struct amba_device *dev;
 266         struct device *parent;
 267         const char *busid;
 268         unsigned int id;
 269         unsigned int mask;
 270 };
 271
 272 static int amba_find_match(struct device *dev, void *data)
 273 {
 274         struct find_data *d = data;
 275         struct amba_device *pcdev = to_amba_device(dev);
 276         int r;
 277
 278         r = (pcdev->periphid & d->mask) == d->id;
 279         if (d->parent)
 280                 r &= d->parent == dev->parent;
 281         if (d->busid)
 282                 r &= strcmp(dev->bus_id, d->busid) == 0;
 283
 284         if (r) {
 285                 get_device(dev);
 286                 d->dev = pcdev;
 287         }
 288
 289         return r;
 290 }
 291
 292 /**
 293  *      amba_find_device - locate an AMBA device given a bus id
 294  *      @busid: bus id for device (or NULL)
 295  *      @parent: parent device (or NULL)
 296  *      @id: peripheral ID (or 0)
 297  *      @mask: peripheral ID mask (or 0)
 298  *
 299  *      Return the AMBA device corresponding to the supplied parameters.
 300  *      If no device matches, returns NULL.
 301  *
 302  *      NOTE: When a valid device is found, its refcount is
 303  *      incremented, and must be decremented before the returned
 304  *      reference.
 305  */
 306 struct amba_device *
 307 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 308                  unsigned int mask)
 309 {
 310         struct find_data data;
 311
 312         data.dev = NULL;
 313         data.parent = parent;
 314         data.busid = busid;
 315         data.id = id;
 316         data.mask = mask;
 317
 318         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 319
 320         return data.dev;
 321 }
 322
 323 /**
 324  *      amba_request_regions - request all mem regions associated with device
 325  *      @dev: amba_device structure for device
 326  *      @name: name, or NULL to use driver name
 327  */
 328 int amba_request_regions(struct amba_device *dev, const char *name)
 329 {
 330         int ret = 0;
 331
 332         if (!name)
 333                 name = dev->dev.driver->name;
 334
 335         if (!request_mem_region(dev->res.start, SZ_4K, name))
 336                 ret = -EBUSY;
 337
 338         return ret;
 339 }
 340
 341 /**
 342  *      amba_release_regions - release mem regions assoicated with device
 343  *      @dev: amba_device structure for device
 344  *
 345  *      Release regions claimed by a successful call to amba_request_regions.
 346  */
 347 void amba_release_regions(struct amba_device *dev)
 348 {
 349         release_mem_region(dev->res.start, SZ_4K);
 350 }
 351
 352 EXPORT_SYMBOL(amba_driver_register);
 353 EXPORT_SYMBOL(amba_driver_unregister);
 354 EXPORT_SYMBOL(amba_device_register);
 355 EXPORT_SYMBOL(amba_device_unregister);
 356 EXPORT_SYMBOL(amba_find_device);
 357 EXPORT_SYMBOL(amba_request_regions);
 358 EXPORT_SYMBOL(amba_release_regions);